Comparison of adverse events between intensity-modulated radiation therapy and Tomotherapy for early-stage breast cancer: a retrospective cohort study

Comparison of adverse events between intensity-modulated radiation therapy and Tomotherapy for early-stage breast cancer: a retrospective cohort study | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Comparison of adverse events between intensity-modulated radiation therapy and Tomotherapy for early-stage breast cancer: a retrospective cohort study Yan Xia, Yan-Cheng Yang, Hang-Qi Ren, Yan-Zun Wang, Qing-Feng Li, and 8 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-5967595/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Introduction : Early-stage breast cancer treated with adjuvant radiotherapy with two different techniques, Tomotherapy (TOMO) and intensity-modulated radiation therapy (IMRT) and their acute adverse events in terms of skin toxicity, localized edema, sore throat, tracheal mucositis, nausea, mucositis oral, esophagitis and pneumonitis outcomes are compared. Material/methods : A retrospective cohort study was conducted on adverse events comparing IMRT and TOMO in early-stage breast cancer, we reviewed the data of female patients who received lumpectomy or mastectomy for breast cancer in the Oncology Department of the First Affiliated Hospital, Army Medical University from September 2021 to February 2024. A total of 315 female patients were enrolled in this study, including 130 in the TOMO group and 185 in the IMRT group. In this study, the adverse events of the two groups of patients were compared and analyzed. Results : The median age of this retrospective cohort was 47 years (range, 20–74 years). The length of follow-up was 3 months. 185 patients (59%) received IMRT and 130 patients (41%) underwent TOMO. No significant difference was observed in terms of menopausal status, laterality, pathology, estrogen receptor status, progesterone receptor status, triple negative, clinical T stage, clinical N stage or Surgical methods. Negative HER-2 over-expression was found in 38% and 51% of TOMO and IMRT group respectively (P = 0.053).With regard to the the degree of tumor differentiation,the Poor-Moderate differentiation was 69% in TOMO group while 81% in IMRT group(P = 0.052).There was 66% and 55% of TOMO and IMRT group respectively receiving Hormone therapy(p = 0.5). But there is no statistical differences in demographic and tumor characteristics between TOMO group and IMRT group. The comparison adverse events between TOMO and IMRT shown that there were no significant differences in localized edema, sore throat, tracheal mucositis, nausea, mucositis oral, esophagitis between the TOMO and the IMRT groups. Compared these two groups, the TOMO group had a higher proportion of 3–4 grade skin toxicity [16.2% (TOMO) versus 7.6% (IMRT), P = 0.017]. The pneumonitis in the TOMO group was lower than the IMRT group [0.0% (TOMO) versus 4.3% (IMRT), P = 0.016]. Conclusions : Compared to IMRT, TOMO decreases the incidence of radiation Pneumonitis but fail to improve acute skin toxicity. Base on our research, TOMO may contribute to higher odds for acute skin toxicity, which should be payed more attention by clinicians. Breast cancer Toxicity Adverse Event Intensity-modulated radiation therapy Tomotherapy Figures Figure 1 Introduction Breast cancer is a major disease seriously threatening women's health 1 , according to the public data of global cancer statistics from CA: A Cancer Journal for Clinicians , female breast cancer is the second leading cause in the incidence of global cancer in 2022, almost 2.3 million new cases were diagnosed and 666,000 deaths every single year 2 . As the fourth leading cause of cancer mortality worldwide, breast cancer is the leading cause of cancer deaths among women 2 , 3 . Radiotherapy has become one of the main methods used for the adjuvant treatment of breast cancer 4 , 5 . Female patients with early-stage breast cancer (stage 0- II) commonly received adjuvant radiation after lumpectomy with or without (stage 0) sentinel node biopsy 6 , 7 . Adjuvant radiation showed a significant improvement in the local recurrence rate as well as overall survival rate for female patients with early-stage breast cancer 8 . However, those female patients who received radiotherapy for breast cancer suffered different degree of acute toxicity such as tenderness or swelling of chest wall, radiation dermatitis, radiation pneumonitis and fatigue 9 , 10 . In the past few years, toxicity acute adverse events after radiotherapy for early-stage breast cancer has been reported as an important issue 11 , 12 . Tomotherapy (TOMO) has the many advantages of precision radiotherapy, which contributes to the development and improvement of clinical treatment for breast cancer and minimize the toxicity during radiotherapy. By controlling the blades quickly turn on and off in the rotating collimator, TOMO can maintain sufficient radiation dose focus on the complex-shaped breast tumour area while decrease the incidence of toxicity events by reducing the radiation exposure dose to organs and tissues surrounding target area 13 . Precision radiotherapy strategies including traditional intensity-modulated radiotherapy (IMRT) and TOMO are two main treatments for those female patients with early-stage breast cancer after lumpectomy 14 , 15 . Recently, lots of literature revealed the toxicity of IMRT or TOMO radiotherapy for breast cancer 16 , 17 , but few researches focused on the comparison of toxicity side effects between IMRT and TOMO for early-stage breast cancer. In this study, we aimed to evaluate the incidence of adverse events in a TOMO schedule compared with the IMRT schedule for early-stage, node-negative breast cancer. Moreover, we present our clinical experience using TOMO as a adjuvant radiation strategy for the early-stage breast cancer, and hope that would help improving the treatment strategies based on the results of this retrospective study. This study is also expected to provide a more optimized radiation strategy to decrease adverse events in female patients with early-stage breast cancer after lumpectomy or mastectomy. Material/methods A retrospective cohort study was conducted on adverse events comparing TOMO and IMRT in early-stage breast cancer, we reviewed the data of female patients who received lumpectomy or mastectomy of breast cancer in the Oncology Department of the First Affiliated Hospital, Army Medical University (Chongqing, China) from September 2021 to February 2024. A total of 315 female patients were enrolled in this study, including 130 in the TOMO group and 185 in the IMRT group. In this study, the adverse events of the two groups of patients were compared and analyzed. The study was approved by the internal ethical committee and patient consent was obtained. Patient selection In our clinic, patients who received adjuvant radiotherapy with TOMO or IMRT device after performed operation for early stage breast cancer in the Oncology Department of the First Affiliated Hospital, Army Medical University were evaluated retrospectively. The patient characteristics, treatment details and acute adverse events data were obtained from electronic system of medical records, patient interview notes, and patient follow up records. The acute adverse events occurred to patients were evaluated by medical oncologists, radiation oncologists and surgeons. Eligibility criteria were as follow: age >18 years, invasive cancer, American Joint Committee on Cancer AJCC Stage I to II, lumpectomy or mastectomy, TOMO or IMRT radiotherapy. Extensive intraductal carcinoma, multiple foci cancer, and final surgical margins < 5 mm, lack of clinical data, vital organ failure and failed to finish radiotherapy represented the main exclusion criteria.The inclusion and exclusion criteria are listed in table 1. Table 1. Inclusion and exclusion criteria inclusion criteria exclusion criteria age >18 years Extensive intraductal carcinoma female multiple foci cancer invasive cancer final surgical margins < 5 mm Stage I to II triple-negative breast cancer Lumpectomy or mastectomy lack of clinical data TOMO or IMRT radiotherapy failed to finish radiotherapy Abbreviations: TOMO,tomographic intensity-modulated radiation therapy; IMRT, intensity-modulated radiation therapy. Treatment planning Radiation therapy treatments were systematically prescribed following our institution internal policy. Radiotherapy treatment was started after 30 days and within 60 days from the surgery; if adjuvant chemotherapy was performed, radiotherapy was postponed till 4 weeks after the last chemotherapy cycle. Patients in different group received radiation of the whole breast and\or surgical bed at two different devices,TOMO or IMRT, respectively. The treatment procedure was obeyed to the institutional rules, which has been described in detail elsewhere 18, 19 . TOMO planning Treatment planning for TOMO was made by using the Accuray® Planing Station System (TomoHDTM version 2.1.9, Inc., Sunnyvale CA, USA). The Monte Carlo algorithm is used in dose calculation, treatment planning, and quality assurance. The grid size is 3 mm. In line with internal irradiation regimes, the dose prescribed to the planning target volume (PTV) varied from 40 to 60 Gy, with a median dose of 50 Gy for the PTV. Before radiation treatment, the patient's positioning in each automatic registration was executed by experienced staff members. IMRT planning We utilized the Eclipse, version 16.1 (Varian medical Systems Inc, Palo Alto, USA) to make IMRT treatment plans. Patients undergoing IMRT were administered a cumulative dose of 50 Gy over 25 fractions. Subsequently, a radiation therapy boost of 10 Gy was given in 5 weekly fractions to the surgical bed. The dose was delivered through wedged photon tangential fields, while the boost was treated using an electron direct field. Organs at risk (OARs) were contoured in accordance with internal guidelines. The constraints specified that 5% of the heart and 20% of the lung should receive a dose of less than 20 Gy. Follow-Up The length of follow-up was 3 months. After completion of TOMO or IMRT radiotherapy, according to the research plan, the follow-up schedule was as follow: we followed up all patients weekly for 3 months. The start date of following up for each patient is the radiation therapy start date; The end date is 3 months after the last radiation therapy date. Follow-up mainly depended on outpatient department, telephone contact was reserved as an auxiliary way. Clinical examinations were performed by clinicians at each follow-up visit, and others like hematologic or endoscope examinations were performed depending on patients’ suspect symptoms. Adverse events was diagnosed by clinician according to objective clinical and physical examination after radiotherapy during treatment and follow-up. This study was ended in February 2024. Outcomes The clinical endpoint of this study was acute adverse events immediately following completion of radiation therapy treatment. Patients’ acute adverse events were prospectively recorded for a period of 3 months and were evaluated by medical oncologists, radiation oncologists and clinicians in accordance with the Common Terminology Criteria for Adverse Events (CTCAE) (Version 5.0) 20 . Acute adverse events in this study were defined as those first observed and diagnosed within 90 days of the latest radiotherapy session. We recorded: acute skin toxicity (erythema,epilation, desquamation, decreased sweating,edema,ulceration, hemorrhage and necrosis), localized edema, sore throat, tracheal mucositis, nausea, mucositis oral, esophagitis, pneumonitis. Adverse events were recorded weekly during TOMO or IMRT treatment and then repeated till 3 months after last radiotherapy. Statistical Methods The study was designed to compare the toxicity rate between IMRT and TOMO for patients with early-stage breast cancer after lumpectomy or mastectomy. Statistical analyses were performed using SPSS Statistics software (version 26; SPSS Statistics, IBM Corporation, Armonk, NY, USA). Independent t tests, the chi-square test and Fisher’s exact test were used to compare the statistical differences between the two groups. And econometric data that conform to normal distribution with homogeneous variances were expressed as mean ± standard deviation （ ）and subjected to t-test; The count data is expressed as the number of cases (percentage) N (%), and intergroup comparisons are performed using a X 2 -test or Fisher's exact test. All 2-sided P values <0 .05 were considered significant. Results Between September 2021 and February 2024, a total of 394 patients with early stage breast cancer underwent lumpectomy or mastectomy were included in the primary analyses. After patients screened with the exclusion criteria, 79 patients were excluded, 315 patients enrolled in this study eventually. The TOMO group consisted of 130 patients, and the IMRT group consisted of 185 patients (Figure 1). Clinical characteristics The median age of this retrospective cohort was 47 years (range, 20–74 years). Table 2 summarizes the clinical characteristics of the 315 patients, divided by planning method into IMRT and TOMO. The length of follow-up was 3 months. 185 patients (59%) received IMRT and 130 patients (41%) underwent TOMO. Negative HER-2 over-expression was found in 38% and 51% of TOMO and IMRT group respectively (P = 0.053).With regard to the the degree of tumor differentiation,the poor-moderate differentiation was 69% in TOMO group while 81% in IMRT group(P=0.052).There was 66% and 55% of TOMO and IMRT group respectively receiving hormone therapy(p=0.5). But there is no statistical differences in demographic and tumor characteristics between TOMO group and IMRT group. Between the TOMO and IMRT groups, the baseline clinical characteristics were well-balanced (Table 2 ), no significant difference was observed in terms of age, menopausal status, laterality, pathology, estrogen receptor status, progesterone receptor status, triple negative, clinical T stage, clinical N stage or surgical methods . Table 2. Comparison of clinical characteristics of patients between the TOMO and IMRT group IMRT TOMO p-Value (n=185) (n=130) Age Mean (years) 47.48±10.21 47.41±10.20 0.45 Range 20-74 24-72 Menopausal status Premenopausal 95 74 0.329 Postmenopausal 90 56 Laterality Right 88 61 0.91 Left 97 69 Pathology Ductal carcinoma 95 63 0.867 Lobular carcinoma 6 4 Others(Intraductal) 84 63 Estrogen receptor status Negative 51 34 0.781 Positive 134 96 Progesterone receptor status Negative 103 65 0.320 Positive 82 64 Uncertain 0 1 HER2 overexpression Negative 94 50 0.053 Positive 91 79 Uncertain 0 1 Triple negative Yes 23 8 0.066 No 162 122 Differentiation Poor-Moderate 150 90 0.052 Well 9 8 Uncertain 26 32 Clinical T stage 0-1 113 77 0.543 2-4 61 41 Uncertain 11 12 Clinical N stage 0-1 159 107 0.672 2-3 23 20 Uncertain 3 3 Hormone therapy Yes 102 86 0.5 No 83 44 Surgery Breast conservative surgery 105 82 0.261 Modified radical mastectomy 80 48 Abbreviations: TOMO,tomographic intensity-modulated radiation therapy; IMRT, intensity-modulated radiation therapy. Acute adverse events evaluation Clinical results about the adverse response and the comparison between TOMO and IMRT are summarized in Table 3. There was no significant relationship between observed Localized edema(p =0.092);Sore throat(p =0.918); Tracheal mucositis(p =0.369); Nausea(p =0.145); Mucositis oral(p =0.216); Esophagitis(p =0.168). Patients who underwent TOMO were more likely to suffer more severe breast or chest pain in this study. [grade2: 29.2% (TOMO) versus 1.1% (IMRT), P=0.000]. Compared these two groups, the TOMO group had a higher proportion of 3-4 grade skin toxicity [16.2% (TOMO) versus 7.6% (IMRT), P=0.017]. The pneumonitis in the TOMO group was lower than the IMRT group [0.0% (TOMO) versus 4.3% (IMRT), P=0.016]. No fair/poor judgment was recorded in the 315 patients during follow-up. No other adverse events or toxicities were recorded during follow-up. Clinical results are summarized in Table 3. Table 3. Description of acute adverse events Related to Radiotherapy IMRT TOMO p-Value (n=185) (n=130) Skin toxicity 0-2 171 109 0.017 3-4 14 21 Localized edema 0 4 0 0.092 1 181 130 Sore throat 0 176 124 0.918 1-2 9 6 Tracheal mucositis 0 184 128 0.369 1-2 1 2 Pneumonitis 0 177 130 0.016 1-2 8 0 Nausea 0 182 130 0.145 1-2 3 0 Mucositis oral 0 180 129 0.216 1-2 5 1 Esophagitis 0 184 127 0.168 1--2 1 3 Abbreviations: TOMO,tomographic intensity-modulated radiation therapy; IMRT, intensity-modulated radiation therapy. Discussion In the present retrospect, single-center study of 315 patients treated for breast cancer with IMRT or TOMO, we found that adverse events occurred very commonly (observed in 98.7% of the patients), a considerable number of patients in this study suffered at least one (mainly mild) toxicity adverse event. Our study shows that there was a notable improvement in reducing the radiation pneumonitis incidence in TOMO group. 4.3% of all patients developed radiation related pneumonitis but not severe (with only 8 events grade 2 or lower) in IMRT group, while the incidence in TOMO group was 0%. Similarly, researches 21, 22 had revealed that TOMO could decrease unnecessary breast overdose in breast conserving treatment of breast cancer, as a result, TOMO decreased adverse events in some critical organs like lungs by optimizing ipsilateral lung dosimetry 22, 23 . Again, in a single - center retrospective study, Felix et al. 24 discovered that TOMO presented low rates of acute toxicity in critical organs. Pneumonitis was observed in 1.8% of the patients who received treatment 24 . During their follow - up period, none of the patients experienced toxicities higher than grade 3. A recent retrospective study that intended to investigate the clinical outcomes and adverse events associated with adjuvant radiotherapy using TOMO after breast - conserving surgery disclosed that the adverse events were mild, and there was no occurrence of pneumonitis in the observed patients 25 . Similar result was obtained in our study, we also found no pneumonitis in observed patients after TOMO. As mentioned above, TOMO actually improved the critical organs risk especially for lungs during radiotherapy by optimizing its treatment planing. However, that study showed no improvement in other acute adverse events related to radiotherapy like localized edema, sore throat, tracheal mucositis, nausea, mucositis oral, esophagitis. Notably, acute skin toxicity seem to be more severe in TOMO group. Although there was no statistic difference between two groups in the incidence of skin toxicity (grade 0-4), unfortunately, skin toxicity grade 3-4 significantly raised in TOMO group. 16.2% of all patients had acute skin toxicity grade 3-4 in TOMO group, while in IMRT group was 7.6%. Simon et al. 26 explained that if the skin surface is set as a radiation therapy optimization target, tangential beam segments would concentrate on the skin surface as result of inverse planning, which would increase acute skin toxicity. The flexibility of TOMO in delivering dose to tumor bed makes it easier to accumulate high dose to superficial targets like the skin, resulting in significant acute skin toxicity 27, 28 . Theoretically, if the “hot-spot” (>10% of prescribed dose) of TOMO deliver overdose on the skin surface, an abnormal high incidence of acute skin toxicity follows 27 . Actually, according to those results previously reported in literature, factors like TOMO planning system 28-30 , patient positioning 28, 31 , breast size variation 32 , treatment delivery time 28 , edema or breath variation 33 et al. contribute to the incidence of skin toxicity. Clinically, it’s difficult to diminish the impact from those risk factors. For example, patient positioning shift 5mm during TOMO may induce extra dose vary from 3% to 9% 31 . Besides, different system of Tomotherapy planning software may contribute 3–13% of overdose to skin tissue 30 . Although these risk factors involved in acute skin toxicity were difficult to conquer, the additional care must be taken for patient safety and skin toxicity prevention. According to those literature as reported above, when treating breast cancer patients with TOMO, clinician should pay more attention to ensure that patient in accurate positioning 28 . Meanwhile, optimized measurements or dose recalculation technique should be applied to TOMO planning software to reassure adequate dosing for superficial organs including skin during radiation therapy 28, 33 . Furthermore, more robust new technique including artificial intelligence should be applied using TOMO so as to reduce skin dose and avoid toxicity 26, 34-36 . Few experiences have been published with adverse events associated with TOMO in early-stage breast cancer. In our experience, due to the TOMO technique, although we were not able to optimize the radiation dose on the skin tissue and reduce the incidence of acute skin toxicity, TOMO could still decreased radiation pneumonitis in early-stage breast cancer after surgery. Furthermore, other clinical results also showed that the acute adverse events related to radiotherapy in TOMO was not inferior to IMRT, which suggested that as compared to IMRT, TOMO may achieve similar or superior target coverage and a better critical organs sparing. Limitation Given that this is a single - center retrospect cohort study, a more extensive study with a larger sample size and longer follow - up is required to gain a better understanding of survival and long - term toxicity outcomes. Conclusion Compared to IMRT, TOMO decreases the incidence of radiation pneumonitis but fail to improve acute skin toxicity. The presented experience of applying TOMO on the radiotherapy of early stage breast cancer suggests that, with the exception of pneumonitis, it maybe not conducive to decrease acute toxicity adverse events in early-stage breast cancer after lumpectomy or mastectomy. Base on our research, TOMO may contribute to higher odds for acute skin toxicity, which should be payed more attention by clinicians. The balance between benefit and risk of TOMO should be taken into account by clinicians. However, long-term follow-up are needed to perform in order to assess chronic toxicity as well as survival outcomes after TOMO in early-stage breast cancer. Declarations Author contributions: Yan Xia had the original idea of the study, collected and evaluated clinical data. Yan-Cheng Yang and Hang-Qi Ren designed the study and did the measurements, Zhi-Heng Bian and Tian Zeng computed all treatment plans together with Yan-Zun Wang and Qing-Feng Li. Qi-Fa Luo, Guang-Ran Yang and Yang-ke Li proceeded the clinical data and performed statistical analysis. Kai-Cheng Jin and Ya-Yuan Yu participated in drawing figures and tables. Jun-Qing Li provided mentorship and edited the manuscript. All authors read and approved the final manuscript. Declaration of conflict of interest: All authors declare that there is no conflict of interest. Financial support: There was no financial support in this study. Ethical approval: The study was approved by the appropriate institutional and/or national research ethics committee (Ethics Committee of the First Affiliated Hospital of Army Medical University, PLA + BIIT2024135KX) , and all procedures performed in study involving human participants were in accordance with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. Informed consent was obtained from all participants and was written in this study. Our study adheres to CONSORT guidelines for reporting retrospective research. Informed consent: All clinical data related to patients obtained in this study was performed in line with the principles of the Declaration of Helsinki. Written informed consent or waiver of consent was provided by all the patients. Consent for publication: Not applicable. Availability of data: All the data generated from the research are safely stored in an institutional repository designed for preserving scientific information. If researchers or other interested parties make a reasonable request, the corresponding author can release these data for legitimate use. Acknowledgments:The authors acknowledged the support of the Army Medical University Library. References Bray F, Laversanne M, Weiderpass E, Soerjomataram I. The ever-increasing importance of cancer as a leading cause of premature death worldwide. CANCER-AM CANCER SOC . 2021; 127 : 3029-30. Bray F, Laversanne M, Sung H , et al. . Global cancer statistics 2022: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries. CA-CANCER J CLIN . 2024; 74 : 229-63. Guida F, Kidman R, Ferlay J , et al. . Global and regional estimates of orphans attributed to maternal cancer mortality in 2020. NAT MED . 2022; 28 : 2563-72. Meattini I, Becherini C, Caini S , et al. . 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Artificial intelligence (AI) applications in improvement of IMRT and VMAT radiotherapy treatment planning processes: A systematic review. RADIOGRAPHY . 2024; 30 : 1530-5. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-5967595","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":412414517,"identity":"41271a2c-40db-43ad-9c02-60ff40d80f76","order_by":0,"name":"Yan Xia","email":"","orcid":"","institution":"Army Medical University","correspondingAuthor":false,"prefix":"","firstName":"Yan","middleName":"","lastName":"Xia","suffix":""},{"id":412414519,"identity":"485f35fd-da14-49ad-b6c3-d8eca0ec7c3c","order_by":1,"name":"Yan-Cheng Yang","email":"","orcid":"","institution":"The 990 Hospital of the Joint Logistics Support Force of the Chinese People's Liberation Army","correspondingAuthor":false,"prefix":"","firstName":"Yan-Cheng","middleName":"","lastName":"Yang","suffix":""},{"id":412414520,"identity":"0f8157c5-6a91-40c6-8fd5-f0eba7d24798","order_by":2,"name":"Hang-Qi Ren","email":"","orcid":"","institution":"The 942 Hospital of the Joint Logistics Support Force of the Chinese People's Liberation Army, Ningxia Hui Autonomous Region","correspondingAuthor":false,"prefix":"","firstName":"Hang-Qi","middleName":"","lastName":"Ren","suffix":""},{"id":412414521,"identity":"20cc593f-dbf5-4984-8838-2bfe0aaaef99","order_by":3,"name":"Yan-Zun Wang","email":"","orcid":"","institution":"Army Medical University","correspondingAuthor":false,"prefix":"","firstName":"Yan-Zun","middleName":"","lastName":"Wang","suffix":""},{"id":412414524,"identity":"9771cd89-3b64-4833-8ab0-7c64496e6516","order_by":4,"name":"Qing-Feng Li","email":"","orcid":"","institution":"Army Medical University","correspondingAuthor":false,"prefix":"","firstName":"Qing-Feng","middleName":"","lastName":"Li","suffix":""},{"id":412414526,"identity":"15d72bc1-7800-43f4-a307-0b2883087319","order_by":5,"name":"Ya-Yuan Yu","email":"","orcid":"","institution":"Army Medical University","correspondingAuthor":false,"prefix":"","firstName":"Ya-Yuan","middleName":"","lastName":"Yu","suffix":""},{"id":412414528,"identity":"35090551-1c9d-428d-9acb-8c444237b822","order_by":6,"name":"Guang-Ran Yang","email":"","orcid":"","institution":"Army Medical University","correspondingAuthor":false,"prefix":"","firstName":"Guang-Ran","middleName":"","lastName":"Yang","suffix":""},{"id":412414529,"identity":"0eb7889d-344b-43e5-865e-45bc3b7c95ec","order_by":7,"name":"Yang-ke Li","email":"","orcid":"","institution":"Army Medical University","correspondingAuthor":false,"prefix":"","firstName":"Yang-ke","middleName":"","lastName":"Li","suffix":""},{"id":412414535,"identity":"9b5f671c-7e77-4b5c-b386-7fe7723d02e5","order_by":8,"name":"Kai-Cheng Jin","email":"","orcid":"","institution":"Army Medical University","correspondingAuthor":false,"prefix":"","firstName":"Kai-Cheng","middleName":"","lastName":"Jin","suffix":""},{"id":412414539,"identity":"7e071577-ea0f-4391-bfb2-e73110b3f1ae","order_by":9,"name":"Qi-Fa Luo","email":"","orcid":"","institution":"Army Medical University","correspondingAuthor":false,"prefix":"","firstName":"Qi-Fa","middleName":"","lastName":"Luo","suffix":""},{"id":412414542,"identity":"66cdac76-a72a-4645-a609-c73113a27f0d","order_by":10,"name":"Zhi-Heng Bian","email":"","orcid":"","institution":"Army Medical University","correspondingAuthor":false,"prefix":"","firstName":"Zhi-Heng","middleName":"","lastName":"Bian","suffix":""},{"id":412414545,"identity":"5158ffd3-6b90-488c-991f-6c50f5d16e48","order_by":11,"name":"Tian Zeng","email":"","orcid":"","institution":"Army Medical University","correspondingAuthor":false,"prefix":"","firstName":"Tian","middleName":"","lastName":"Zeng","suffix":""},{"id":412414549,"identity":"a4e5eed9-6cbc-46a7-94e9-e512b3e26845","order_by":12,"name":"Jun-Qing Li","email":"data:image/png;base64,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","orcid":"","institution":"Army Medical University","correspondingAuthor":true,"prefix":"","firstName":"Jun-Qing","middleName":"","lastName":"Li","suffix":""}],"badges":[],"createdAt":"2025-02-05 16:53:29","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-5967595/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-5967595/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":76113794,"identity":"8d962346-dd87-4d83-a0a1-31d17862e591","added_by":"auto","created_at":"2025-02-12 12:24:16","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":16946,"visible":true,"origin":"","legend":"\u003cp\u003eScreening and Patient Flow in the study of adverse events comparision between TOMO and IMRT for early-stage breast cancer.\u003c/p\u003e\n\u003cp\u003eAbbreviations: TOMO,tomographic intensity-modulated radiation therapy; IMRT, intensity-modulated radiation therapy.\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-5967595/v1/588b8d013b89f6927f4c9fed.png"},{"id":76878258,"identity":"dc04138b-e158-4f51-886f-ee1def76c96b","added_by":"auto","created_at":"2025-02-21 16:31:57","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":748678,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5967595/v1/5ddae99e-8e13-4f6d-a0a2-b104a23b8ec5.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Comparison of adverse events between intensity-modulated radiation therapy and Tomotherapy for early-stage breast cancer: a retrospective cohort study","fulltext":[{"header":"Introduction","content":"\u003cp\u003eBreast cancer is a major disease seriously threatening women's health\u003csup\u003e\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u003c/sup\u003e, according to the public data of global cancer statistics from \u003cem\u003eCA: A Cancer Journal for Clinicians\u003c/em\u003e, female breast cancer is the second leading cause in the incidence of global cancer in 2022, almost 2.3\u0026nbsp;million new cases were diagnosed and 666,000 deaths every single year\u003csup\u003e\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u003c/sup\u003e. As the fourth leading cause of cancer mortality worldwide, breast cancer is the leading cause of cancer deaths among women\u003csup\u003e\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eRadiotherapy has become one of the main methods used for the adjuvant treatment of breast cancer\u003csup\u003e\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e\u003c/sup\u003e. Female patients with early-stage breast cancer (stage 0- II) commonly received adjuvant radiation after lumpectomy with or without (stage 0) sentinel node biopsy\u003csup\u003e\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e\u003c/sup\u003e. Adjuvant radiation showed a significant improvement in the local recurrence rate as well as overall survival rate for female patients with early-stage breast cancer\u003csup\u003e\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e\u003c/sup\u003e. However, those female patients who received radiotherapy for breast cancer suffered different degree of acute toxicity such as tenderness or swelling of chest wall, radiation dermatitis, radiation pneumonitis and fatigue\u003csup\u003e\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eIn the past few years, toxicity acute adverse events after radiotherapy for early-stage breast cancer has been reported as an important issue\u003csup\u003e\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e\u003c/sup\u003e. Tomotherapy (TOMO) has the many advantages of precision radiotherapy, which contributes to the development and improvement of clinical treatment for breast cancer and minimize the toxicity during radiotherapy. By controlling the blades quickly turn on and off in the rotating collimator, TOMO can maintain sufficient radiation dose focus on the complex-shaped breast tumour area while decrease the incidence of toxicity events by reducing the radiation exposure dose to organs and tissues surrounding target area\u003csup\u003e\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003ePrecision radiotherapy strategies including traditional intensity-modulated radiotherapy (IMRT) and TOMO are two main treatments for those female patients with early-stage breast cancer after lumpectomy\u003csup\u003e\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e, \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e\u003c/sup\u003e. Recently, lots of literature revealed the toxicity of IMRT or TOMO radiotherapy for breast cancer\u003csup\u003e\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e, \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e\u003c/sup\u003e, but few researches focused on the comparison of toxicity side effects between IMRT and TOMO for early-stage breast cancer. In this study, we aimed to evaluate the incidence of adverse events in a TOMO schedule compared with the IMRT schedule for early-stage, node-negative breast cancer.\u003c/p\u003e \u003cp\u003eMoreover, we present our clinical experience using TOMO as a adjuvant radiation strategy for the early-stage breast cancer, and hope that would help improving the treatment strategies based on the results of this retrospective study. This study is also expected to provide a more optimized radiation strategy to decrease adverse events in female patients with early-stage breast cancer after lumpectomy or mastectomy.\u003c/p\u003e"},{"header":"Material/methods","content":"\u003cp\u003eA retrospective cohort study was conducted on adverse events comparing TOMO and IMRT in early-stage breast cancer, we reviewed the data of female patients who received lumpectomy or mastectomy of breast cancer in the Oncology Department of the First Affiliated Hospital, Army Medical University (Chongqing, China) from September 2021 to February 2024. A total of 315 female patients were enrolled in this study, including 130 in the TOMO group and 185 in the IMRT group. In this study, the adverse events of the two groups of patients were compared and analyzed. The study was approved by the internal ethical committee and patient consent was obtained.\u0026nbsp;\u003c/p\u003e\n\u003ch3\u003ePatient selection\u003c/h3\u003e\n\u003cp\u003eIn our clinic,\u0026nbsp;patients who received adjuvant radiotherapy with TOMO or IMRT device after performed operation for early stage breast cancer in the Oncology Department of the First Affiliated Hospital, Army Medical University were evaluated retrospectively. The patient characteristics, treatment details and acute adverse events data were obtained from electronic system of medical records, patient interview notes, and patient follow up records. The acute adverse events occurred to patients were evaluated by medical oncologists, radiation oncologists and surgeons.\u003c/p\u003e\n\u003cp\u003eEligibility criteria were as follow: age \u0026gt;18\u0026thinsp;years, invasive cancer, American Joint Committee on Cancer AJCC Stage I to II, lumpectomy or mastectomy, TOMO or IMRT radiotherapy. Extensive intraductal carcinoma, multiple foci cancer, and final surgical margins \u0026lt; 5 mm, lack of clinical data, vital organ failure and failed to finish radiotherapy represented the main exclusion criteria.The inclusion and exclusion criteria are listed in table 1.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 1. Inclusion and exclusion criteria\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 50%;\"\u003e\n \u003cp\u003einclusion criteria\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 50%;\"\u003e\n \u003cp\u003eexclusion criteria\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 50%;\"\u003e\n \u003cp\u003eage \u0026gt;18\u0026thinsp;years\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 50%;\"\u003e\n \u003cp\u003eExtensive intraductal carcinoma\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 50%;\"\u003e\n \u003cp\u003efemale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 50%;\"\u003e\n \u003cp\u003emultiple foci cancer\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 50%;\"\u003e\n \u003cp\u003einvasive cancer\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 50%;\"\u003e\n \u003cp\u003efinal surgical margins \u0026lt; 5 mm\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 50%;\"\u003e\n \u003cp\u003eStage I to II\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 50%;\"\u003e\n \u003cp\u003etriple-negative breast cancer\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 50%;\"\u003e\n \u003cp\u003eLumpectomy or mastectomy\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 50%;\"\u003e\n \u003cp\u003elack of clinical data\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 50%;\"\u003e\n \u003cp\u003eTOMO or IMRT radiotherapy\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 50%;\"\u003e\n \u003cp\u003efailed to finish radiotherapy\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eAbbreviations: TOMO,tomographic intensity-modulated radiation therapy; \u0026nbsp; IMRT, intensity-modulated radiation therapy.\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eTreatment planning\u003c/p\u003e\n\u003cp\u003eRadiation therapy treatments were systematically prescribed following our institution internal policy. Radiotherapy treatment was started after 30 days and within 60\u0026thinsp;days from the surgery; if adjuvant chemotherapy was performed, radiotherapy was postponed till 4\u0026thinsp;weeks after the last chemotherapy cycle. Patients in different group received radiation of the whole breast and\\or surgical bed at two different devices,TOMO or IMRT, respectively. The treatment procedure was obeyed to the institutional rules, which has been described in detail elsewhere\u003csup\u003e18, 19\u003c/sup\u003e.\u003c/p\u003e\n\u003cp\u003eTOMO planning\u003c/p\u003e\n\u003cp\u003eTreatment planning for TOMO was made by using the Accuray\u0026reg; Planing Station System (TomoHDTM version 2.1.9, Inc., Sunnyvale CA, USA). The Monte Carlo algorithm is used in dose calculation, treatment planning, and quality assurance. The grid size is 3 mm. In line with internal irradiation regimes, the dose prescribed to the planning target volume (PTV) varied from 40 to 60 Gy, with a median dose of 50 Gy for the PTV. Before radiation treatment, the patient\u0026apos;s positioning in each automatic registration was executed by experienced staff members.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eIMRT planning\u003c/p\u003e\n\u003cp\u003eWe utilized the Eclipse, version 16.1 (Varian medical Systems Inc, Palo Alto, USA) to make IMRT treatment plans. Patients undergoing IMRT were administered a cumulative dose of 50 Gy over 25 fractions. Subsequently, a radiation therapy boost of 10 Gy was given in 5 weekly fractions to the surgical bed. The dose was delivered through wedged photon tangential fields, while the boost was treated using an electron direct field. Organs at risk (OARs) were contoured in accordance with internal guidelines. The constraints specified that 5% of the heart and 20% of the lung should receive a dose of less than 20 Gy.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFollow-Up\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe length of follow-up was 3\u0026thinsp;months. After completion of TOMO or IMRT radiotherapy, according to the research plan, the follow-up schedule was as follow: we followed up all patients weekly for 3 months. The start date of following up for each patient is the radiation therapy start date; The end date is 3 months after the last radiation therapy date. Follow-up mainly depended on outpatient department, telephone contact was reserved as an auxiliary way. Clinical examinations were performed by clinicians at each follow-up visit, and others like hematologic or endoscope examinations were performed depending on patients\u0026rsquo; suspect symptoms. Adverse events\u0026nbsp;was diagnosed by clinician according to objective clinical and physical examination after radiotherapy during treatment and follow-up. This study was ended in February 2024.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eOutcomes\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe clinical endpoint of this study was acute adverse events immediately following completion of radiation therapy treatment. Patients\u0026rsquo; acute adverse events were prospectively recorded for a period of 3 months and\u0026nbsp;were evaluated by medical oncologists, radiation oncologists and clinicians in accordance with\u0026nbsp;the Common Terminology Criteria for Adverse Events (CTCAE) (Version\u0026nbsp;5.0)\u003csup\u003e20\u003c/sup\u003e. Acute adverse events in this study were defined as those first observed and diagnosed within 90 days\u0026nbsp;of the latest radiotherapy session. We recorded: acute skin toxicity (erythema,epilation, desquamation, decreased sweating,edema,ulceration, hemorrhage and necrosis), localized edema, sore throat, tracheal mucositis, nausea, mucositis oral, esophagitis, pneumonitis. Adverse events were recorded weekly during TOMO or IMRT treatment and then repeated till 3 months after last radiotherapy.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStatistical Methods\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;The study was designed to compare the toxicity rate between IMRT and TOMO for patients with early-stage breast cancer after lumpectomy or mastectomy. Statistical analyses were performed using SPSS Statistics software (version 26; SPSS Statistics, IBM Corporation, Armonk, NY, USA). Independent t tests, the chi-square test and Fisher\u0026rsquo;s exact test were used to compare the statistical differences between the two groups. And econometric data that conform to normal distribution with homogeneous variances were expressed as mean \u0026plusmn; standard deviation\u0026nbsp;（\u003cimg src=\"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAACAAAAAVCAYAAAAnzezqAAAACXBIWXMAAA7EAAAOxAGVKw4bAAAKoElEQVRIDQGVCmr1AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAQAAAAAAAAAAAAAA/wAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAEAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAP8AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAgAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAABAAAAAAAAAAAAAAAAAAAAAAAAAD/AAAAAAAAAAAAAAABAAAA/wAAAAAAAAABAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAP8AAAAAAAAAAAAAAAAAAAABAAAAAAAAAAAAAAAAAQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAP8AAAAAAAAAAQAAAAAAAAAAAAAAAAAAAP8AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAABAAAAAAAAAAAAAAAAAAAAAAAAAP8AAAABAAAAAAAAAP8AAAABAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAP8AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAP8AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAP8AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAgAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAEAAAD/AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA/wAAAAAAAAD/AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAP8AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA/wAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAD/AAAAAAAAAAAAAAD/AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA/wAAAAAAAAAAAAAA/wAAAAAAAAAAAAAAAAAAAAAAAAAABAAAAAAAAAAAAAAAAAAAAP8AAAAAAAAAAAAAAAAAAAAAAAAA/wAAAAEAAAAAAAAAAAAAAP8AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAABAAAAAAAAAAAAAAAAAAAAAAAAAP8AAAAAAAAAAQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAEfcZArZ2q58AAAAASUVORK5CYII=\" alt=\"image\" width=\"32\" height=\"21\"\u003e）and subjected to t-test; The count data is expressed as the number of cases (percentage) N (%), and intergroup comparisons are performed using a X\u003csup\u003e2\u003c/sup\u003e-test or Fisher\u0026apos;s exact test. All 2-sided P values \u0026lt;0 .05 were considered significant.\u0026nbsp;\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003eBetween September 2021 and February 2024, a total of 394 patients with early stage breast cancer underwent lumpectomy or mastectomy were included in the primary analyses. After patients screened with the exclusion criteria, 79 patients were excluded, 315 patients enrolled in this study eventually. The TOMO group consisted of 130 patients, and the IMRT group consisted of 185 patients (Figure 1).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eClinical characteristics\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe median age of this retrospective cohort was 47 years (range, 20\u0026ndash;74 years). Table 2 summarizes the clinical characteristics of the 315 patients, divided by planning method into IMRT and TOMO. The length of follow-up was 3 months. 185 patients (59%) received IMRT and 130 patients (41%) underwent TOMO. Negative HER-2 over-expression was found in 38% and 51% of TOMO and IMRT group respectively (P\u0026thinsp;=\u0026thinsp;0.053).With regard to the the degree of tumor differentiation,the poor-moderate differentiation was 69% in TOMO group while 81% in IMRT group(P=0.052).There was 66% and 55% of TOMO and IMRT group respectively receiving hormone therapy(p=0.5). But there is no statistical differences in demographic and tumor characteristics between TOMO group and IMRT group.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eBetween the TOMO and IMRT groups, the baseline clinical characteristics were well-balanced (Table 2 ), no significant difference was observed in terms of age, menopausal status, laterality, pathology, estrogen receptor status, progesterone receptor status, triple negative, clinical T stage, clinical N stage or surgical methods\u0026nbsp;.\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 2.\u0026nbsp;\u003c/strong\u003eComparison of clinical characteristics of patients between the TOMO and IMRT group\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\" width=\"608\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 200px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 156px;\"\u003e\n \u003cp\u003eIMRT\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 138px;\"\u003e\n \u003cp\u003eTOMO\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 114px;\"\u003e\n \u003cp\u003ep-Value\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 200px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 156px;\"\u003e\n \u003cp\u003e(n=185)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 138px;\"\u003e\n \u003cp\u003e(n=130)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 114px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 200px;\"\u003e\n \u003cp\u003eAge\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 156px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 138px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 114px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 200px;\"\u003e\n \u003cp\u003eMean (years)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 156px;\"\u003e\n \u003cp\u003e47.48\u0026plusmn;10.21\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 138px;\"\u003e\n \u003cp\u003e47.41\u0026plusmn;10.20\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 114px;\"\u003e\n \u003cp\u003e0.45\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 200px;\"\u003e\n \u003cp\u003eRange\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 156px;\"\u003e\n \u003cp\u003e20-74\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 138px;\"\u003e\n \u003cp\u003e24-72\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 200px;\"\u003e\n \u003cp\u003eMenopausal status\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 156px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 138px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 114px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 200px;\"\u003e\n \u003cp\u003ePremenopausal\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 156px;\"\u003e\n \u003cp\u003e95\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 138px;\"\u003e\n \u003cp\u003e74\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 114px;\"\u003e\n \u003cp\u003e0.329\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 200px;\"\u003e\n \u003cp\u003ePostmenopausal\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 156px;\"\u003e\n \u003cp\u003e90\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 138px;\"\u003e\n \u003cp\u003e56\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 200px;\"\u003e\n \u003cp\u003eLaterality\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 156px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 138px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 114px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 200px;\"\u003e\n \u003cp\u003eRight\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 156px;\"\u003e\n \u003cp\u003e88\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 138px;\"\u003e\n \u003cp\u003e61\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 114px;\"\u003e\n \u003cp\u003e0.91\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 200px;\"\u003e\n \u003cp\u003eLeft\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 156px;\"\u003e\n \u003cp\u003e97\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 138px;\"\u003e\n \u003cp\u003e69\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 200px;\"\u003e\n \u003cp\u003ePathology\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 156px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 138px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 114px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 200px;\"\u003e\n \u003cp\u003eDuctal carcinoma\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 156px;\"\u003e\n \u003cp\u003e95\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 138px;\"\u003e\n \u003cp\u003e63\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"3\" style=\"width: 114px;\"\u003e\n \u003cp\u003e0.867\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 200px;\"\u003e\n \u003cp\u003eLobular carcinoma\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 156px;\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 138px;\"\u003e\n \u003cp\u003e4\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 200px;\"\u003e\n \u003cp\u003eOthers(Intraductal)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 156px;\"\u003e\n \u003cp\u003e84\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 138px;\"\u003e\n \u003cp\u003e63\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 200px;\"\u003e\n \u003cp\u003eEstrogen receptor status\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 156px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 138px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 114px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 200px;\"\u003e\n \u003cp\u003eNegative\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 156px;\"\u003e\n \u003cp\u003e51\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 138px;\"\u003e\n \u003cp\u003e34\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 114px;\"\u003e\n \u003cp\u003e0.781\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 200px;\"\u003e\n \u003cp\u003ePositive\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 156px;\"\u003e\n \u003cp\u003e134\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 138px;\"\u003e\n \u003cp\u003e96\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 200px;\"\u003e\n \u003cp\u003eProgesterone receptor status\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 156px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 138px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 114px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 200px;\"\u003e\n \u003cp\u003eNegative\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 156px;\"\u003e\n \u003cp\u003e103\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 138px;\"\u003e\n \u003cp\u003e65\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"3\" style=\"width: 114px;\"\u003e\n \u003cp\u003e0.320\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 200px;\"\u003e\n \u003cp\u003ePositive\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 156px;\"\u003e\n \u003cp\u003e82\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 138px;\"\u003e\n \u003cp\u003e64\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 200px;\"\u003e\n \u003cp\u003eUncertain\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 156px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 138px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 200px;\"\u003e\n \u003cp\u003eHER2 overexpression\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 156px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 138px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 114px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 200px;\"\u003e\n \u003cp\u003eNegative\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 156px;\"\u003e\n \u003cp\u003e94\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 138px;\"\u003e\n \u003cp\u003e50\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"3\" style=\"width: 114px;\"\u003e\n \u003cp\u003e0.053\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 200px;\"\u003e\n \u003cp\u003ePositive\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 156px;\"\u003e\n \u003cp\u003e91\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 138px;\"\u003e\n \u003cp\u003e79\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 200px;\"\u003e\n \u003cp\u003eUncertain\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 156px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 138px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 200px;\"\u003e\n \u003cp\u003eTriple negative\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 156px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 138px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 114px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 200px;\"\u003e\n \u003cp\u003eYes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 156px;\"\u003e\n \u003cp\u003e23\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 138px;\"\u003e\n \u003cp\u003e8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 114px;\"\u003e\n \u003cp\u003e0.066\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 200px;\"\u003e\n \u003cp\u003eNo\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 156px;\"\u003e\n \u003cp\u003e162\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 138px;\"\u003e\n \u003cp\u003e122\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 200px;\"\u003e\n \u003cp\u003eDifferentiation\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 156px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 138px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 114px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 200px;\"\u003e\n \u003cp\u003ePoor-Moderate\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 156px;\"\u003e\n \u003cp\u003e150\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 138px;\"\u003e\n \u003cp\u003e90\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"3\" style=\"width: 114px;\"\u003e\n \u003cp\u003e0.052\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 200px;\"\u003e\n \u003cp\u003eWell\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 156px;\"\u003e\n \u003cp\u003e9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 138px;\"\u003e\n \u003cp\u003e8\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 200px;\"\u003e\n \u003cp\u003eUncertain\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 156px;\"\u003e\n \u003cp\u003e26\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 138px;\"\u003e\n \u003cp\u003e32\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 200px;\"\u003e\n \u003cp\u003eClinical T stage\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 156px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 138px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 114px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 200px;\"\u003e\n \u003cp\u003e0-1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 156px;\"\u003e\n \u003cp\u003e113\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 138px;\"\u003e\n \u003cp\u003e77\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"3\" style=\"width: 114px;\"\u003e\n \u003cp\u003e0.543\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 200px;\"\u003e\n \u003cp\u003e2-4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 156px;\"\u003e\n \u003cp\u003e61\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 138px;\"\u003e\n \u003cp\u003e41\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 200px;\"\u003e\n \u003cp\u003eUncertain\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 156px;\"\u003e\n \u003cp\u003e11\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 138px;\"\u003e\n \u003cp\u003e12\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 200px;\"\u003e\n \u003cp\u003eClinical N stage\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 156px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 138px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 114px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 200px;\"\u003e\n \u003cp\u003e0-1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 156px;\"\u003e\n \u003cp\u003e159\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 138px;\"\u003e\n \u003cp\u003e107\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"3\" style=\"width: 114px;\"\u003e\n \u003cp\u003e0.672\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 200px;\"\u003e\n \u003cp\u003e2-3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 156px;\"\u003e\n \u003cp\u003e23\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 138px;\"\u003e\n \u003cp\u003e20\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 200px;\"\u003e\n \u003cp\u003eUncertain\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 156px;\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 138px;\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 200px;\"\u003e\n \u003cp\u003eHormone therapy\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 156px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 138px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 114px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 200px;\"\u003e\n \u003cp\u003eYes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 156px;\"\u003e\n \u003cp\u003e102\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 138px;\"\u003e\n \u003cp\u003e86\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 114px;\"\u003e\n \u003cp\u003e0.5\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 200px;\"\u003e\n \u003cp\u003eNo\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 156px;\"\u003e\n \u003cp\u003e83\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 138px;\"\u003e\n \u003cp\u003e44\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 200px;\"\u003e\n \u003cp\u003eSurgery\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 156px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 138px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 114px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 200px;\"\u003e\n \u003cp\u003eBreast conservative surgery\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 156px;\"\u003e\n \u003cp\u003e105\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 138px;\"\u003e\n \u003cp\u003e82\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 114px;\"\u003e\n \u003cp\u003e0.261\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 200px;\"\u003e\n \u003cp\u003eModified radical mastectomy\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 156px;\"\u003e\n \u003cp\u003e80\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 138px;\"\u003e\n \u003cp\u003e48\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eAbbreviations: TOMO,tomographic intensity-modulated radiation therapy; \u0026nbsp; IMRT, intensity-modulated radiation therapy.\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003ch3\u003eAcute adverse events evaluation\u003c/h3\u003e\n\u003cp\u003eClinical results about the adverse response and the comparison between TOMO and IMRT are summarized in Table 3. There was no significant relationship between observed Localized edema(p =0.092);Sore throat(p =0.918); Tracheal mucositis(p =0.369); Nausea(p =0.145); Mucositis oral(p =0.216); Esophagitis(p =0.168). Patients who underwent TOMO were more likely to suffer more severe breast or chest pain in this study. [grade2: 29.2% (TOMO) versus 1.1% (IMRT), P=0.000]. Compared these two groups, the TOMO group had a higher proportion of 3-4 grade skin toxicity [16.2% (TOMO) versus 7.6% (IMRT), P=0.017]. The pneumonitis in the TOMO group was lower than the IMRT group [0.0% (TOMO) versus 4.3% (IMRT), P=0.016]. No fair/poor judgment was recorded in the 315 patients during follow-up. No other adverse events or toxicities were recorded during follow-up. Clinical results are summarized in Table 3.\u003cstrong\u003e\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 3.\u0026nbsp;\u003c/strong\u003eDescription of acute adverse events Related to Radiotherapy\u003c/p\u003e\n \u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\" align=\"\" width=\"524\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003eIMRT\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 163px;\"\u003e\n \u003cp\u003eTOMO\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 103px;\"\u003e\n \u003cp\u003ep-Value\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e(n=185)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 163px;\"\u003e\n \u003cp\u003e(n=130)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 103px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003eSkin toxicity\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 163px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 103px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e0-2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e171\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 163px;\"\u003e\n \u003cp\u003e109\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 103px;\"\u003e\n \u003cp\u003e0.017\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e3-4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e14\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 163px;\"\u003e\n \u003cp\u003e21\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003eLocalized edema\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 163px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 103px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 163px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 103px;\"\u003e\n \u003cp\u003e0.092\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e181\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 163px;\"\u003e\n \u003cp\u003e130\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003eSore throat\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 163px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 103px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e176\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 163px;\"\u003e\n \u003cp\u003e124\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 103px;\"\u003e\n \u003cp\u003e0.918\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e1-2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 163px;\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003eTracheal mucositis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 163px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 103px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e184\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 163px;\"\u003e\n \u003cp\u003e128\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 103px;\"\u003e\n \u003cp\u003e0.369\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e1-2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 163px;\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003ePneumonitis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 163px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 103px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e177\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 163px;\"\u003e\n \u003cp\u003e130\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 103px;\"\u003e\n \u003cp\u003e0.016\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e1-2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 163px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003eNausea\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 163px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 103px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e182\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 163px;\"\u003e\n \u003cp\u003e130\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 103px;\"\u003e\n \u003cp\u003e0.145\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e1-2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 163px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003eMucositis oral\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 163px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 103px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e180\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 163px;\"\u003e\n \u003cp\u003e129\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 103px;\"\u003e\n \u003cp\u003e0.216\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e1-2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 163px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003eEsophagitis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 163px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 103px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e184\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 163px;\"\u003e\n \u003cp\u003e127\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 103px;\"\u003e\n \u003cp\u003e0.168\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e1--2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 163px;\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e\n\u003cp\u003eAbbreviations: TOMO,tomographic intensity-modulated radiation therapy; \u0026nbsp; IMRT, intensity-modulated radiation therapy.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003e\u0026nbsp; In the present retrospect, single-center study of 315 patients treated for breast cancer with IMRT or TOMO, we found that adverse events occurred very commonly (observed in 98.7% of the patients), a considerable number of patients in this study suffered at least one (mainly mild) toxicity adverse event. Our study shows that there was a notable improvement in reducing the radiation pneumonitis incidence in TOMO group. 4.3% of all patients developed radiation related pneumonitis but not severe (with only 8 events grade 2 or lower) in IMRT group, while the incidence in TOMO group was 0%. Similarly, researches\u003csup\u003e21, 22\u003c/sup\u003e had revealed that TOMO could decrease unnecessary breast overdose in breast conserving treatment of breast cancer, as a result, TOMO decreased adverse events in some critical organs like lungs by optimizing ipsilateral lung dosimetry\u003csup\u003e22, 23\u003c/sup\u003e.\u003c/p\u003e\n\u003cp\u003eAgain, in a single - center retrospective study, Felix et al.\u003csup\u003e24\u003c/sup\u003e discovered that TOMO presented low rates of acute toxicity in critical organs. Pneumonitis was observed in 1.8% of the patients who received treatment\u003csup\u003e24\u003c/sup\u003e. During their follow - up period, none of the patients experienced toxicities higher than grade 3. A recent retrospective study that intended to investigate the clinical outcomes and adverse events associated with adjuvant radiotherapy using TOMO after breast - conserving surgery disclosed that the adverse events were mild, and there was no occurrence of pneumonitis in the observed patients\u003csup\u003e25\u003c/sup\u003e. \u0026nbsp;\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eSimilar\u0026nbsp;result\u0026nbsp;was\u0026nbsp;obtained in our study, we also found no pneumonitis in observed patients after TOMO. As mentioned above, TOMO actually improved the critical organs risk especially for lungs during radiotherapy by optimizing its treatment planing.\u003c/p\u003e\n\u003cp\u003eHowever, that study showed no improvement in other acute adverse events related to radiotherapy like localized edema, sore throat, tracheal mucositis, nausea, mucositis oral, esophagitis. Notably, acute skin toxicity seem to be more severe in TOMO group. Although there was no statistic difference between two groups in the incidence of skin toxicity (grade 0-4), unfortunately, skin toxicity grade 3-4 significantly raised in TOMO group. 16.2% of all patients had acute skin toxicity grade 3-4 in TOMO group, while in IMRT group was 7.6%. Simon et al.\u003csup\u003e26\u003c/sup\u003e explained that if the skin surface is set as a radiation therapy optimization target, tangential beam segments would concentrate on the skin surface as result of inverse planning, which would increase acute skin toxicity. The flexibility of TOMO in delivering dose to tumor bed makes it easier to accumulate high dose to superficial targets like the skin, resulting in significant acute skin toxicity\u003csup\u003e27, 28\u003c/sup\u003e. Theoretically, if the \u0026ldquo;hot-spot\u0026rdquo; (\u0026gt;10% of prescribed dose) of TOMO deliver overdose on the skin surface, an abnormal high incidence of acute skin toxicity follows\u003csup\u003e27\u003c/sup\u003e.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;Actually, according to those results previously reported in literature, factors like TOMO planning system\u003csup\u003e28-30\u003c/sup\u003e, patient positioning\u003csup\u003e28, 31\u003c/sup\u003e, breast size variation\u003csup\u003e32\u003c/sup\u003e, treatment delivery time\u003csup\u003e28\u003c/sup\u003e, edema or breath variation\u003csup\u003e33\u003c/sup\u003e et al. contribute to the incidence of skin toxicity. Clinically, it\u0026rsquo;s difficult to diminish the impact from those risk factors. For example, \u0026nbsp;patient positioning shift 5mm during TOMO may induce extra dose vary from 3% to 9%\u003csup\u003e31\u003c/sup\u003e. \u0026nbsp;Besides, different system of Tomotherapy planning software may contribute 3\u0026ndash;13% of overdose to skin tissue\u003csup\u003e30\u003c/sup\u003e. Although these risk factors involved in acute skin toxicity were difficult to conquer, the additional care must be taken for patient safety and skin toxicity prevention. According to those literature as reported above, when treating breast cancer patients with TOMO, clinician should pay more attention to ensure that patient in accurate positioning\u003csup\u003e28\u003c/sup\u003e. Meanwhile, optimized measurements or dose recalculation technique should be applied to TOMO planning software to reassure adequate dosing for superficial organs including skin during radiation therapy\u003csup\u003e28, 33\u003c/sup\u003e. Furthermore, more robust\u0026nbsp;new technique including artificial intelligence should be applied using TOMO so as to reduce skin dose and avoid toxicity\u003csup\u003e26, 34-36\u003c/sup\u003e.\u003c/p\u003e\n\u003cp\u003eFew experiences have been published with adverse events associated with TOMO in early-stage breast cancer. In our experience, due to the TOMO technique, although we were not able to optimize the radiation dose on the skin tissue and reduce the incidence of acute skin toxicity, TOMO could still decreased radiation pneumonitis in early-stage breast cancer after surgery. Furthermore, other clinical results also showed that the acute adverse events related to radiotherapy in TOMO was not inferior to IMRT, which suggested that as compared to IMRT, TOMO may achieve similar or superior target coverage and a better critical organs sparing. \u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eLimitation\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eGiven that this is a single - center retrospect cohort study, a more extensive study with a larger sample size and longer follow - up is required to gain a better understanding of survival and long - term toxicity outcomes.\u0026nbsp;\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eCompared to IMRT, TOMO decreases the incidence of radiation pneumonitis but fail to improve acute skin toxicity. The presented experience of applying TOMO on the radiotherapy of early stage breast cancer suggests that, with the exception of pneumonitis, it maybe not conducive to decrease acute toxicity adverse events in early-stage breast cancer after lumpectomy or mastectomy. Base on our research, TOMO may contribute to higher odds for acute skin toxicity, which should be payed more attention by clinicians. The balance between benefit and risk of TOMO should be taken into account by clinicians. However, long-term follow-up are needed to perform in order to assess chronic toxicity as well as survival outcomes after TOMO in early-stage breast cancer. \u0026nbsp;\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003eAuthor contributions: Yan Xia had the original idea of the study, collected and evaluated clinical data. Yan-Cheng Yang and Hang-Qi Ren designed the study and did the measurements, Zhi-Heng Bian and Tian Zeng computed all treatment plans together with Yan-Zun Wang and Qing-Feng Li. Qi-Fa Luo, Guang-Ran Yang and Yang-ke Li proceeded the clinical data and performed statistical analysis. Kai-Cheng Jin and Ya-Yuan Yu participated in drawing figures and tables. Jun-Qing Li provided mentorship and edited the manuscript. All authors read and approved the final manuscript.\u003c/p\u003e\n\u003cp\u003eDeclaration of conflict of interest: All authors declare that there is no conflict of interest.\u003c/p\u003e\n\u003cp\u003eFinancial support: There was no financial support in this study.\u003c/p\u003e\n\u003cp\u003eEthical approval: The study was approved by the appropriate institutional and/or national research ethics committee (Ethics Committee of the First Affiliated Hospital of Army Medical University, PLA\u0026thinsp; +\u0026thinsp;BIIT2024135KX) , and all procedures performed in study involving human participants were in accordance with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. Informed consent was obtained from all participants and was written in this study.\u003c/p\u003e\n\u003cp\u003eOur study adheres to CONSORT guidelines for reporting retrospective research.\u003c/p\u003e\n\u003cp\u003eInformed consent: All clinical data related to patients obtained in this study was performed in line with the principles of the Declaration of Helsinki. Written informed consent or waiver of consent was provided by all the patients.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eConsent for publication: Not applicable.\u003c/p\u003e\n\u003cp\u003eAvailability of data: All the data generated from the research are safely stored in an institutional repository designed for preserving scientific information. If researchers or other interested parties make a reasonable request, the corresponding author can release these data for legitimate use.\u003c/p\u003e\n\u003cp\u003eAcknowledgments:The authors acknowledged the support of the Army Medical University Library.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eBray F, Laversanne M, Weiderpass E, Soerjomataram I. The ever-increasing importance of cancer as a leading cause of premature death worldwide. \u003cem\u003eCANCER-AM CANCER SOC\u003c/em\u003e. 2021; \u003cstrong\u003e127\u003c/strong\u003e: 3029-30.\u003c/li\u003e\n\u003cli\u003eBray F, Laversanne M, Sung H\u003cem\u003e, et al.\u003c/em\u003e. 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Artificial intelligence (AI) applications in improvement of IMRT and VMAT radiotherapy treatment planning processes: A systematic review. \u003cem\u003eRADIOGRAPHY\u003c/em\u003e. 2024; \u003cstrong\u003e30\u003c/strong\u003e: 1530-5.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Breast cancer, Toxicity, Adverse Event, Intensity-modulated radiation therapy, Tomotherapy","lastPublishedDoi":"10.21203/rs.3.rs-5967595/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-5967595/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e \u003cb\u003eIntroduction\u003c/b\u003e: Early-stage breast cancer treated with adjuvant radiotherapy with two different techniques, Tomotherapy (TOMO) and intensity-modulated radiation therapy (IMRT) and their acute adverse events in terms of skin toxicity, localized edema, sore throat, tracheal mucositis, nausea, mucositis oral, esophagitis and pneumonitis outcomes are compared.\u003c/p\u003e \u003cp\u003e\u003cb\u003eMaterial/methods\u003c/b\u003e: A retrospective cohort study was conducted on adverse events comparing IMRT and TOMO in early-stage breast cancer, we reviewed the data of female patients who received lumpectomy or mastectomy for breast cancer in the Oncology Department of the First Affiliated Hospital, Army Medical University from September 2021 to February 2024. A total of 315 female patients were enrolled in this study, including 130 in the TOMO group and 185 in the IMRT group. In this study, the adverse events of the two groups of patients were compared and analyzed.\u003c/p\u003e \u003cp\u003e\u003cb\u003eResults\u003c/b\u003e: The median age of this retrospective cohort was 47 years (range, 20\u0026ndash;74 years). The length of follow-up was 3 months. 185 patients (59%) received IMRT and 130 patients (41%) underwent TOMO. No significant difference was observed in terms of menopausal status, laterality, pathology, estrogen receptor status, progesterone receptor status, triple negative, clinical T stage, clinical N stage or Surgical methods. Negative HER-2 over-expression was found in 38% and 51% of TOMO and IMRT group respectively (P\u0026thinsp;=\u0026thinsp;0.053).With regard to the the degree of tumor differentiation,the Poor-Moderate differentiation was 69% in TOMO group while 81% in IMRT group(P\u0026thinsp;=\u0026thinsp;0.052).There was 66% and 55% of TOMO and IMRT group respectively receiving Hormone therapy(p\u0026thinsp;=\u0026thinsp;0.5). But there is no statistical differences in demographic and tumor characteristics between TOMO group and IMRT group. The comparison adverse events between TOMO and IMRT shown that there were no significant differences in localized edema, sore throat, tracheal mucositis, nausea, mucositis oral, esophagitis between the TOMO and the IMRT groups. Compared these two groups, the TOMO group had a higher proportion of 3\u0026ndash;4 grade skin toxicity [16.2% (TOMO) versus 7.6% (IMRT), P\u0026thinsp;=\u0026thinsp;0.017]. The pneumonitis in the TOMO group was lower than the IMRT group [0.0% (TOMO) versus 4.3% (IMRT), P\u0026thinsp;=\u0026thinsp;0.016].\u003c/p\u003e \u003cp\u003e \u003cb\u003eConclusions\u003c/b\u003e: Compared to IMRT, TOMO decreases the incidence of radiation Pneumonitis but fail to improve acute skin toxicity. Base on our research, TOMO may contribute to higher odds for acute skin toxicity, which should be payed more attention by clinicians.\u003c/p\u003e","manuscriptTitle":"Comparison of adverse events between intensity-modulated radiation therapy and Tomotherapy for early-stage breast cancer: a retrospective cohort study","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-02-12 12:23:21","doi":"10.21203/rs.3.rs-5967595/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"860e5ba1-d9c5-4910-aecd-8fb9b59d0542","owner":[],"postedDate":"February 12th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-02-27T10:53:22+00:00","versionOfRecord":[],"versionCreatedAt":"2025-02-12 12:23:21","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-5967595","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-5967595","identity":"rs-5967595","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}