The Utility of Radiopharmaceutical Uptake in the Bladder Neck and Prostate on Preoperative FDG PET/CT in Determining Urethral Surgical Margin Positivity in Patients Undergoing Radical Cystoprostatectomy for Bladder Cancer

The Utility of Radiopharmaceutical Uptake in the Bladder Neck and Prostate on Preoperative FDG PET/CT in Determining Urethral Surgical Margin Positivity in Patients Undergoing Radical Cystoprostatectomy for Bladder Cancer | 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 The Utility of Radiopharmaceutical Uptake in the Bladder Neck and Prostate on Preoperative FDG PET/CT in Determining Urethral Surgical Margin Positivity in Patients Undergoing Radical Cystoprostatectomy for Bladder Cancer Resat Aydın, Rifat Burak Ergül, Anıl Tantekin, Yasemin Şanlı, and 3 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6580219/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 28 Oct, 2025 Read the published version in BMC Urology → Version 1 posted 12 You are reading this latest preprint version Abstract Background Bladder cancer is the most common malignancy of the urinary system. It is a heterogeneous type of cancer with a high potential for metastasis, approximately 25% of which occurs as muscle invasive. As with other malignancies, accurate and precise staging of bladder cancer is one of the mainstays for choosing the most appropriate treatment for the patient. Detection of metastasis is extremely important in choosing the treatment strategy. FDG PET/CT is widely used in the clinical management of various malignancies and is increasingly used in the primary staging of muscle-invasive bladder cancer and detection of recurrence after radical cystectomy. We aimed to determine the role of radiopharmaceutical uptake in the bladder neck and prostate region in preoperative FDG PET/CT in patients with muscle-invasive bladder tumors in determining the positivity of prostatic urethra surgical margins in the final pathology after cystectomy and its effect in determining the type of diversion to be chosen. Methods The data of male patients who underwent FDG PET/CT before radical cystectomy due to MIBC between January 2009 and January 2023 in the Department of Urology at Istanbul Faculty of Medicine were retrospectively analyzed. The correlations between the presence of radiopharmaceutical uptake in the bladder neck or prostate in FDG PET CT and the positivity of the prostatic urethra surgical margin in the postoperative final pathology of these patients and the invasion of urothelial carcinoma in the prostate were analyzed. Results Prostatic urethra surgical margin positivity was detected in 8 of 50 male patients who had FDG PET CT in the preoperative period. Prostatic urethra surgical margin positivity was detected in 5 of 19 patients with bladder neck and prostate region involvement on FDG (p = 0.2554). Prostate involvement was seen on FDG in 6 of 9 patients with urothelial carcinoma invasion into the prostate (p = 0.1492). Prostate adenocarcinoma was observed in the final pathology of 12 patients, and 8 of these patients had FDG uptake (p = 0.106). While no statistically significant relationship was found between the presence of bladder neck and prostate region involvement on FDG and prostatic urethra surgical margin, urothelial carcinoma invasion into the prostate and prostate adenocarcinoma, a statistically significant relationship was observed between the presence of malignancy in the prostate (urothelial carcinoma and/or adenocarcinoma) (p = 0.0189). Conclusions While no statistically significant relationship was found between radiopharmaceutical uptake in the bladder neck and prostate region on preoperative FDG PET CT in CIBC and prostatic urethra surgical margin positivity, urothelial carcinoma invasion into the prostate and the presence of prostate adenocarcinoma; It was found valuable in detecting the presence of malignancy in the prostate (adenocarcinoma/urothelial carcinoma). Background Bladder cancer is the most common malignancy of the urinary system. It is a heterogeneous type of cancer with a high potential for metastasis, with approximately 25% of cases occurring as muscle invasive. As with other malignancies, accurate and precise staging of bladder cancer is one of the fundamental bases for selecting the most appropriate treatment for the patient. Detection of metastasis is extremely important in determining the treatment strategy. It is known that bladder tumors can involve the prostatic urethra and ducts in men. Primary transitional cell carcinoma (TCC) of the prostate is rare, while the incidence of secondary transitional cell carcinoma of the prostate and prostate is higher, with a reported incidence of 12%-48% [ 1 ]. Bladder tumors can spread to the prostatic urethra, prostatic ducts, and prostate stroma in two different ways: extravesical and intraurethral. Preoperative transurethral loop biopsies from the prostatic urethra have been used to detect urothelial carcinoma in the prostatic urethra. However, the diagnostic value of such biopsies is controversial; one study reported only a 53% sensitivity for prostatic stromal invasion [ 2 ]. Since transurethral loop biopsies sample only the prostatic urethral mucosa and/or prostate tissue close to the urethral lumen, they may lead to the possibility of missing urothelial carcinoma invasion in deeper prostate tissue. F-18 fluoro-2-deoxy-glucose positron emission tomography (FDG PET/CT) is widely used in the clinical management of various malignancies and is increasingly being used in the primary staging of muscle-invasive bladder cancer and in the detection of recurrence after radical cystectomy. It is thought that if the preoperative FDG-PET CT detects involvement in these regions of the prostate, it will contribute to the clinical and surgical management. Diagnosis of urethral tumor before cystectomy may lead to urethrectomy, which may be a contraindication for orthotopic diversion. It is recommended that orthotopic diversion should not be abandoned based on positive preoperative biopsy findings alone in this patient group and that frozen section examination should be a part of radical cystectomy operation, especially in male patients [ 3 , 4 ]. A significant portion of male patients with MIBC have a request for orthotopic diversion when making the decision for surgery. Positive urethral surgical margins may be a contraindication for orthotopic urinary diversion, and the fact that this decision can only be determined with intraoperative frozen section may be confusing for patients before surgery. If the positive predictive value of involvement in the bladder neck and prostate region in preoperative FDG PET/CT is found to be high in showing positive urethral surgical margins, it will make preoperative planning easier. In this study, we aimed to determine the role of radiopharmaceutical uptake in the bladder neck and prostate region in FDG PET/CT performed preoperatively in patients with muscle-invasive bladder tumors in determining the positive prostatic urethral surgical margins in the final pathology after cystectomy and its effect in determining the type of diversion to be selected. Methods Following the approval of the local ethics committee, the data of patients who underwent radical cystectomy due to bladder cancer between January 2009 and January 2023 at Istanbul University School of Medicine Department of Urology were retrospectively reviewed. Patient demographics’, FDG uptake patterns in the prostate gland, mean SUVmax value of uptake in the bladder neck and prostate, status of preoperative BCG treatment and neoadjuvant chemotherapy, whether frozen section was sent from the urethra during the operation, and the selected diversion types, prostatic urethra surgical margin positivity, prostate pathologies, bladder tumor stage, location of the tumor in the bladder, lymph node positivity rate, presence of variant histology in the postoperative final pathology and status of recurrence in the urethra during the follow-up were recorded. FDG PET/CT images of these patients were re-evaluated by an experienced nuclear medicine specialist in our hospital in order to prevent possible reporting errors. All patients who underwent radical cystectomy having FDG PET/CT for preoperative staging purposes were included the study. Patients who received radiotherapy to the pelvic region, and who had previously diagnosed with prostate cancer were excluded. The study was approved by Istanbul University Clinical Research Ethics Committee protocol code E-29624016–050.99-1810738. All procedures performed in our study were in accordance with the ethical standards of the local research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. The need for consent to participate was deemed unnecessary according to national regulations. Statistical analysis Statistical analysis was performed using IBM SPSS statistical package programme v.21 for Mac IL, USA. Quantitative variables were given as mean ± standard deviation and qualitative values ​​are shown in numbers and percentages. Distribution of data was tested using Kolmogorov-Smirnov test. Comparison of variables between two groups was made by using Chi-Square and Mann-Whitney U tests. The one-way analysis of variance (ANOVA) was used to determine the difference between three or more independent groups. P < .05 was considered statistically significant. Results A total of 50 patients were included the study. The mean age of the patients was 65 years. The selected urinary diversion type was orthotopic ileal neobladder in 12 patients, ileal loop in 35 patients and ureterocutaneostomy in one patient. Also, ureters were occluded and nephrostomy tubes were inserted into the kidneys in two patients. Patient characteristics are given in Table 1 . Radiopharmaceutical uptake was detected in the bladder neck and prostate region in 19 (38%) of 50 patients. At the final pathologic examination prostatic urethra surgical margin positivity was detected in 8 (16%) patients. Among 8 patients, 7 (87.5%) patients had urothelial carcinoma invasion. Radiopharmaceutical uptake in the bladder neck and prostate region was detected in 5 (62.5%) of 8 patients with positive prostatic urethra surgical margins in preoperative FDG-PET. In other words, while 5 out of 19 patients with bladder neck and prostate involvement detected on FDG-PET CT had positive prostatic urethra surgical margins, 3 out of 31 patients without involvement detected on FDG-PET CT had positive prostatic urethra surgical margins. No statistically significant relationship was found between bladder neck and prostate involvement on FDG PET CT and positive prostatic urethra surgical margins (p = 0.2554). The sensitivity, specificity, positive predictive value and negative predictive value of FDG PET/CT in determining prostatic urethra surgical margin positivity were 62.50%, 56.25%, 26.32% and 85.71%, respectively. Among 8 patients with positive prostatic urethral surgical margins: two received Neoadjuvant chemotherapy (NAC), three received intravesical BCG treatment, and 5 patients were found to have variant histology in their final pathology. No statistically significant relationship was found between prostatic urethral surgical margin positivity and history of neoadjuvant chemotherapy, intravesical BCG application, and presence of variant histology. (p = 1, p = 0.4, p = 0.7547, respectively). Urothelial carcinoma invasion of the prostate was detected in 9 (18%) patients in the final pathology, involvement in the bladder neck and prostate region was detected in 6 (66.6%) of these patients at FDG-PET, while 3 patients had no involvement. In other words, urothelial carcinoma invasion of the prostate was detected via FDG PET CT in 6 of 19 patients with involvement in the bladder neck and prostate region. On the other hand, urothelial carcinoma invasion of the prostate was detected in 3 of 31 patients who had involvement in FDG PET CT. The relationship between involvement in the bladder neck and prostate region in FDG PET CT and urothelial carcinoma invasion of the prostate was not found to be statistically significant (p = 0.1492). The sensitivity, specificity, positive predictive value and negative predictive value of FDG PET/CT in determining urothelial carcinoma invasion in the prostate were 66.67%, 68.29%, 31.58% and 90.32%, respectively. Concomitant prostate adenocarcinoma was detected in 12 (24%) of 50 patients. Six (50%) patients had Gleason score 6 (3 + 3); five (42%) patients had Gleason score 7 [4 patients had G (3 + 4), 1 patient had G (4 + 3)] and one patient had Gleason score 8 (4 + 4) adenocarcinoma. One patient had urothelial carcinoma and adenocarcinoma infiltration of the prostate. Prostate involvement was detected in 8 (66.6%) of 12 patients with prostate adenocarcinoma on FDG-PET CT, while no prostate involvement was detected in four patients. In other words, prostate adenocarcinoma was detected in 8 of 19 patients with prostate involvement on FDG PET CT; while prostate adenocarcinoma was detected in 4 of 31 patients without prostate involvement on FDG PET CT. No statistically significant relationship was found between prostate involvement and the presence of prostate adenocarcinoma in FDG PET CT (p = 0.106). (Table 2 ) The sensitivity, specificity, positive predictive value and negative predictive value of FDG PET/CT for prostate adenocarcinoma were determined as 66.6%, 71.05%, 42.11% and 87.10%, respectively. No statistically significant relationship was found between bladder neck and prostate region involvement in FDG PET/CT and prostatic urethra surgical margin positivity, urothelial carcinoma invasion in the prostate and the presence of prostate adenocarcinoma. Bladder neck and prostate involvement was detected on FDG PET CT in 6 out of 9 patients with urothelial carcinoma invasion in the prostate and in 8 out of 12 patients with prostate adenocarcinoma. A statistically significant relationship was found between the presence of any malignancy in the prostate (urothelial carcinoma invasion and/or prostate adenocarcinoma) and bladder neck and prostate involvement on FDG PET/CT (p = 0.0189). The sensitivity, specificity, positive predictive value and negative predictive value of FDG PET/CT in showing the presence of a malignancy in the prostate gland (urothelial carcinoma invasion or prostate adenocarcinoma) were determined as 68.42%, 80.65%, 68.42% and 80.65%, respectively. Discussion Urothelial carcinoma is a frequent disease with 549,393 new cases worldwide in 2018. About one of four patients present with muscle invasive bladder cancer (MIBC) which treatment is usually radical cystectomy with pelvic lymph node dissection. In case of metastatic disease, the first line therapy is usually chemotherapy. To decide appropriate treatment accurate staging is crucial. Either contrast enhanced computed tomography or magnetic resonance imaging is recommended for staging in current guidelines. However, radical cystectomy reveals up-stating in 40% of patients and downstaging in 20% [ 5 ]. This phenomenon highlights the limitations of the current staging of MIBC. In men undergoing radical cystoprostatectomy (RCP) for urothelial carcinoma (UC), prostatic involvement is detected on final pathology in 15–48% of cases. The American Joint Committee on Cancer Staging (AJCC) categorized prostatic involvement as T4 disease, regardless of the degree of prostatic involvement. However, researchers have found differences in outcomes based on the depth of prostatic invasion (superficial ductal or stromal) and in some cases the site of origin (bladder or prostatic urethra) [ 6 ]. In a study, prostatic involvement was found to be an independent predictor of urethral recurrence in men following radical cystectomy for urothelial carcinoma. Surprisingly the incidence of urethral recurrence was lower in patient with orthotopic diversion which might be a consequence of patient selection [ 7 ]. In our study, the sensitivity of FDG PET/CT in determining urothelial carcinoma invasion in the prostate were 66.67%; however no statistically significant relationship was found between bladder neck and prostate region involvement in FDG PET/CT and prostatic urethra surgical margin positivity. In a study by Barocas et al. [ 6 ] both bladder tumor stage and prostatic stromal involvement found to lead unfavorable outcomes. The authors concluded that although prostatic involvement originating from the bladder appears to be locally aggressive in nature and is associated with higher rates of positive LNs, patients have similar survival outcomes compared to those with stromal involvement originating from the prostatic urethra. In another study by Bruins et al. [ 8 ] authors reported that more than 51% of the 1476 patients who underwent radical cystoprostatectomy had cancer involving the prostate and those who had prostatic urothelial carcinoma, especially with prostatic stromal involvement, had worse prognosis. The researchers concluded that there are no reliable preoperative clinical and histopathological risk factors to predict clinically significant prostatic adenocarcinoma/urothelial carcinoma. 18 F-FDG PET/CT has a limited role in evaluating the local extension of bladder cancer due to interference of radioactive urine. Some researchers requested to take images after 18 F-FDG washout, urination, bladder catheterization or bladder irrigation. To take very early images might also be useful [ 9 ]. Based on the results of another study authors concluded that diuretic 18 F-FDG PET/CT has a higher diagnostic value compared to contrast-enhanced CT in detecting primary urinary bladder cancer and evaluating locoregional staging, (sensitivity 96% vs. 92% and sensitivity 78% vs. 44%, respectively) [ 10 ]. In our study, no statistically significant relationship was found between radiopharmaceutical uptake in the bladder neck and prostate region in FDG PET CT and prostate invasion of urothelial carcinoma, prostatic urethra surgical margin positivity and prostate adenocarcinoma; however, a statistically significant relationship was found with the presence of any malignancy in the prostate (urothelial carcinoma and/or adenocarcinoma) (p = 0.0189). Especially in patients requesting orthotopic urinary diversion, predicting the possible presence of malignancy in the prostate (urothelial carcinoma and adenocarcinoma) without performing a prostate biopsy before the operation may be useful in determining the surgical strategy. In order to reduce surgical margin positivity in the presence of both urothelial carcinoma invasion and adenocarcinoma in the bladder neck and prostate, more distant control of the bladder and prostate pedicles; more careful apical dissection during prostate dorsal vein control are important in reducing surgical margin positivity in these regions. In patients undergoing surgery for prostate adenocarcinoma, the most common positive surgical margins and recurrence are detected in the apex region. Conclusion In our study, although no significant relationship was found between radiopharmaceutical uptake in the bladder neck/prostate region and prostatic urethra surgical margin positivity, prostate urothelial carcinoma invasion and prostate adenocarcinoma, a significant result was obtained in showing the presence of any malignancy in the prostate (adenocarcinoma and/or urothelial carcinoma invasion). In the presence of uptake in this region in FDG, surgical techniques aimed at reducing and preventing surgical margin positivity should be emphasized. Abbreviations FDG PET/CT: Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography MIBC: Muscle-Invasive Bladder Cancer RCP: Radical Cystoprostatectomy UC: Urothelial Carcinoma SUVmax: Maximum Standardized Uptake Value BCG: Bacillus Calmette–Guérin NAC: Neoadjuvant Chemotherapy Declarations Ethics approval and consent to participate This study was approved by the Clinical Research Ethics Committee of Istanbul University (Protocol code: E-29624016–050.99-1810738). All procedures were conducted in accordance with the ethical standards of the institutional research committee and with the 1964 Helsinki Declaration and its later amendments. The need for informed consent was waived due to the retrospective nature of the study and in accordance with national regulations. Consent for publication Not applicable. Availability of data and materials The datasets generated and/or analysed during the current study are available in the Zenodo repository at: https://doi.org/10.5281/zenodo.15425614. Competing Interests The authors declare that they have no competing interests. Funding This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors. Authors' contributions R.B.E. and R.A. conceived and designed the study. R.B.E. and A.T. collected the data. R.B.E., R.A., Y.Ş., and S.E. performed the data analysis. R.A., and Y.Ş. drafted the initial manuscript. M.Ö.S. and F.Ö. critically revised the manuscript for important intellectual content. All authors reviewed and approved the final version of the manuscript. Acknowledgements The authors would like to thank the staff of the Department of Urology and Nuclear Medicine at Istanbul University for their support during data collection and evaluation. Funding This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. References Liedberg F, Chebil G, Månsson W: Urothelial carcinoma in the prostatic urethra and prostate: current controversies . Expert Review of Anticancer Therapy 2014, 7 (3):383-390. Kassouf W, Spiess PE, Brown GA, Liu P, Grossman HB, Dinney CP, Kamat AM: Prostatic urethral biopsy has limited usefulness in counseling patients regarding final urethral margin status during orthotopic neobladder reconstruction . The Journal of urology 2008, 180 (1):164-167. von Rundstedt F-C, Mata DA, Shen S, Li Y, Godoy G, Lerner SP: Transurethral biopsy of the prostatic urethra is associated with final apical margin status at radical cystoprostatectomy . Journal of clinical urology 2016, 9 (6):404-408. Kates M, Ball MW, Chappidi MR, Baras AS, Gordetsky J, Sopko NA, Brant A, Pierorazio PM, Epstein JI, Schoenberg MP: Accuracy of urethral frozen section during radical cystectomy for bladder cancer . In: Urologic Oncology: Seminars and Original Investigations: 2016 : Elsevier; 2016: 532. e531-532. e536. Einerhand SMH, van Gennep EJ, Mertens LS, Hendricksen K, Donswijk ML, van der Poel HG, van Rhijn BWG: 18F-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography in muscle-invasive bladder cancer . Current Opinion in Urology 2020, 30 (5):654-664. Barocas DA, Patel SG, Chang SS, Clark PE, Smith Jr JA, Cookson MS: Outcomes of patients undergoing radical cystoprostatectomy for bladder cancer with prostatic involvement on final pathology . BJU international 2009, 104 (8):1091-1097. Huguet J, Monllau V, Sabaté S, Rodriguez-Faba O, Algaba F, Palou J, Villavicencio H: Diagnosis, risk factors, and outcome of urethral recurrences following radical cystectomy for bladder cancer in 729 male patients . European urology 2008, 53 (4):785-793. Bruins HM, Djaladat H, Ahmadi H, Sherrod A, Cai J, Miranda G, Skinner EC, Daneshmand S: Incidental prostate cancer in patients with bladder urothelial carcinoma: comprehensive analysis of 1,476 radical cystoprostatectomy specimens . The Journal of urology 2013, 190 (5):1704-1709. Chondrogiannis S, Marzola MC, Colletti PM, Rubello D: Proposal of a new acquisition protocol for bladder cancer visualization with 18F-FDG PET/CT . Clinical Nuclear Medicine 2015, 40 (1):e78-e80. Nayak B, Dogra PN, Naswa N, Kumar R: Diuretic 18 F-FDG PET/CT imaging for detection and locoregional staging of urinary bladder cancer: prospective evaluation of a novel technique . European journal of nuclear medicine and molecular imaging 2013, 40 :386-393. Tables Tables are available in the Supplementary Files section. Additional Declarations No competing interests reported. Supplementary Files Tables.docx Cite Share Download PDF Status: Published Journal Publication published 28 Oct, 2025 Read the published version in BMC Urology → Version 1 posted Editorial decision: Revision requested 29 Jul, 2025 Reviews received at journal 08 Jun, 2025 Reviews received at journal 06 Jun, 2025 Reviewers agreed at journal 06 Jun, 2025 Reviews received at journal 01 Jun, 2025 Reviewers agreed at journal 01 Jun, 2025 Reviewers agreed at journal 30 May, 2025 Reviewers invited by journal 30 May, 2025 Editor assigned by journal 28 May, 2025 Editor invited by journal 15 May, 2025 Submission checks completed at journal 15 May, 2025 First submitted to journal 15 May, 2025 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. 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It is a heterogeneous type of cancer with a high potential for metastasis, with approximately 25% of cases occurring as muscle invasive. As with other malignancies, accurate and precise staging of bladder cancer is one of the fundamental bases for selecting the most appropriate treatment for the patient. Detection of metastasis is extremely important in determining the treatment strategy.\u003c/p\u003e \u003cp\u003eIt is known that bladder tumors can involve the prostatic urethra and ducts in men. Primary transitional cell carcinoma (TCC) of the prostate is rare, while the incidence of secondary transitional cell carcinoma of the prostate and prostate is higher, with a reported incidence of 12%-48% [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. Bladder tumors can spread to the prostatic urethra, prostatic ducts, and prostate stroma in two different ways: extravesical and intraurethral. Preoperative transurethral loop biopsies from the prostatic urethra have been used to detect urothelial carcinoma in the prostatic urethra. However, the diagnostic value of such biopsies is controversial; one study reported only a 53% sensitivity for prostatic stromal invasion [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. Since transurethral loop biopsies sample only the prostatic urethral mucosa and/or prostate tissue close to the urethral lumen, they may lead to the possibility of missing urothelial carcinoma invasion in deeper prostate tissue.\u003c/p\u003e \u003cp\u003eF-18 fluoro-2-deoxy-glucose positron emission tomography (FDG PET/CT) is widely used in the clinical management of various malignancies and is increasingly being used in the primary staging of muscle-invasive bladder cancer and in the detection of recurrence after radical cystectomy.\u003c/p\u003e \u003cp\u003eIt is thought that if the preoperative FDG-PET CT detects involvement in these regions of the prostate, it will contribute to the clinical and surgical management. Diagnosis of urethral tumor before cystectomy may lead to urethrectomy, which may be a contraindication for orthotopic diversion. It is recommended that orthotopic diversion should not be abandoned based on positive preoperative biopsy findings alone in this patient group and that frozen section examination should be a part of radical cystectomy operation, especially in male patients [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. A significant portion of male patients with MIBC have a request for orthotopic diversion when making the decision for surgery. Positive urethral surgical margins may be a contraindication for orthotopic urinary diversion, and the fact that this decision can only be determined with intraoperative frozen section may be confusing for patients before surgery. If the positive predictive value of involvement in the bladder neck and prostate region in preoperative FDG PET/CT is found to be high in showing positive urethral surgical margins, it will make preoperative planning easier.\u003c/p\u003e \u003cp\u003eIn this study, we aimed to determine the role of radiopharmaceutical uptake in the bladder neck and prostate region in FDG PET/CT performed preoperatively in patients with muscle-invasive bladder tumors in determining the positive prostatic urethral surgical margins in the final pathology after cystectomy and its effect in determining the type of diversion to be selected.\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003e Following the approval of the local ethics committee, the data of patients who underwent radical cystectomy due to bladder cancer between January 2009 and January 2023 at Istanbul University School of Medicine Department of Urology were retrospectively reviewed. Patient demographics\u0026rsquo;, FDG uptake patterns in the prostate gland, mean SUVmax value of uptake in the bladder neck and prostate, status of preoperative BCG treatment and neoadjuvant chemotherapy, whether frozen section was sent from the urethra during the operation, and the selected diversion types, prostatic urethra surgical margin positivity, prostate pathologies, bladder tumor stage, location of the tumor in the bladder, lymph node positivity rate, presence of variant histology in the postoperative final pathology and status of recurrence in the urethra during the follow-up were recorded. FDG PET/CT images of these patients were re-evaluated by an experienced nuclear medicine specialist in our hospital in order to prevent possible reporting errors. All patients who underwent radical cystectomy having FDG PET/CT for preoperative staging purposes were included the study. Patients who received radiotherapy to the pelvic region, and who had previously diagnosed with prostate cancer were excluded.\u003c/p\u003e \u003cp\u003e The study was approved by Istanbul University Clinical Research Ethics Committee protocol code E-29624016\u0026ndash;050.99-1810738. All procedures performed in our study were in accordance with the ethical standards of the local research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. The need for consent to participate was deemed unnecessary according to national regulations.\u003c/p\u003e \u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eStatistical analysis\u003c/h2\u003e \u003cp\u003eStatistical analysis was performed using IBM SPSS statistical package programme v.21 for Mac IL, USA. Quantitative variables were given as mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation and qualitative values ​​are shown in numbers and percentages. Distribution of data was tested using Kolmogorov-Smirnov test. Comparison of variables between two groups was made by using Chi-Square and Mann-Whitney U tests. The one-way analysis of variance (ANOVA) was used to determine the difference between three or more independent groups. P\u0026thinsp;\u0026lt;\u0026thinsp;.05 was considered statistically significant.\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003eA total of 50 patients were included the study. The mean age of the patients was 65 years. The selected urinary diversion type was orthotopic ileal neobladder in 12 patients, ileal loop in 35 patients and ureterocutaneostomy in one patient. Also, ureters were occluded and nephrostomy tubes were inserted into the kidneys in two patients. Patient characteristics are given in Table \u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e\n\u003cdiv\u003eRadiopharmaceutical uptake was detected in the bladder neck and prostate region in 19 (38%) of 50 patients. At the final pathologic examination prostatic urethra surgical margin positivity was detected in 8 (16%) patients. Among 8 patients, 7 (87.5%) patients had urothelial carcinoma invasion. Radiopharmaceutical uptake in the bladder neck and prostate region was detected in 5 (62.5%) of 8 patients with positive prostatic urethra surgical margins in preoperative FDG-PET.\u003c/div\u003e\n\u003cp\u003eIn other words, while 5 out of 19 patients with bladder neck and prostate involvement detected on FDG-PET CT had positive prostatic urethra surgical margins, 3 out of 31 patients without involvement detected on FDG-PET CT had positive prostatic urethra surgical margins. No statistically significant relationship was found between bladder neck and prostate involvement on FDG PET CT and positive prostatic urethra surgical margins (p\u0026thinsp;=\u0026thinsp;0.2554).\u003c/p\u003e\n\u003cp\u003eThe sensitivity, specificity, positive predictive value and negative predictive value of FDG PET/CT in determining prostatic urethra surgical margin positivity were 62.50%, 56.25%, 26.32% and 85.71%, respectively.\u003c/p\u003e\n\u003cp\u003eAmong 8 patients with positive prostatic urethral surgical margins: two received Neoadjuvant chemotherapy (NAC), three received intravesical BCG treatment, and 5 patients were found to have variant histology in their final pathology. No statistically significant relationship was found between prostatic urethral surgical margin positivity and history of neoadjuvant chemotherapy, intravesical BCG application, and presence of variant histology. (p\u0026thinsp;=\u0026thinsp;1, p\u0026thinsp;=\u0026thinsp;0.4, p\u0026thinsp;=\u0026thinsp;0.7547, respectively).\u003c/p\u003e\n\u003cp\u003eUrothelial carcinoma invasion of the prostate was detected in 9 (18%) patients in the final pathology, involvement in the bladder neck and prostate region was detected in 6 (66.6%) of these patients at FDG-PET, while 3 patients had no involvement. In other words, urothelial carcinoma invasion of the prostate was detected via FDG PET CT in 6 of 19 patients with involvement in the bladder neck and prostate region. On the other hand, urothelial carcinoma invasion of the prostate was detected in 3 of 31 patients who had involvement in FDG PET CT. The relationship between involvement in the bladder neck and prostate region in FDG PET CT and urothelial carcinoma invasion of the prostate was not found to be statistically significant (p\u0026thinsp;=\u0026thinsp;0.1492).\u003c/p\u003e\n\u003cp\u003eThe sensitivity, specificity, positive predictive value and negative predictive value of FDG PET/CT in determining urothelial carcinoma invasion in the prostate were 66.67%, 68.29%, 31.58% and 90.32%, respectively.\u003c/p\u003e\n\u003cp\u003eConcomitant prostate adenocarcinoma was detected in 12 (24%) of 50 patients. Six (50%) patients had Gleason score 6 (3\u0026thinsp;+\u0026thinsp;3); five (42%) patients had Gleason score 7 [4 patients had G (3\u0026thinsp;+\u0026thinsp;4), 1 patient had G (4\u0026thinsp;+\u0026thinsp;3)] and one patient had Gleason score 8 (4\u0026thinsp;+\u0026thinsp;4) adenocarcinoma. One patient had urothelial carcinoma and adenocarcinoma infiltration of the prostate. Prostate involvement was detected in 8 (66.6%) of 12 patients with prostate adenocarcinoma on FDG-PET CT, while no prostate involvement was detected in four patients. In other words, prostate adenocarcinoma was detected in 8 of 19 patients with prostate involvement on FDG PET CT; while prostate adenocarcinoma was detected in 4 of 31 patients without prostate involvement on FDG PET CT. No statistically significant relationship was found between prostate involvement and the presence of prostate adenocarcinoma in FDG PET CT (p\u0026thinsp;=\u0026thinsp;0.106). (Table \u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e)\u003c/p\u003e\n\u003cdiv\u003eThe sensitivity, specificity, positive predictive value and negative predictive value of FDG PET/CT for prostate adenocarcinoma were determined as 66.6%, 71.05%, 42.11% and 87.10%, respectively. No statistically significant relationship was found between bladder neck and prostate region involvement in FDG PET/CT and prostatic urethra surgical margin positivity, urothelial carcinoma invasion in the prostate and the presence of prostate adenocarcinoma.\u003c/div\u003e\n\u003cp\u003eBladder neck and prostate involvement was detected on FDG PET CT in 6 out of 9 patients with urothelial carcinoma invasion in the prostate and in 8 out of 12 patients with prostate adenocarcinoma. A statistically significant relationship was found between the presence of any malignancy in the prostate (urothelial carcinoma invasion and/or prostate adenocarcinoma) and bladder neck and prostate involvement on FDG PET/CT (p\u0026thinsp;=\u0026thinsp;0.0189).\u003c/p\u003e\n\u003cp\u003eThe sensitivity, specificity, positive predictive value and negative predictive value of FDG PET/CT in showing the presence of a malignancy in the prostate gland (urothelial carcinoma invasion or prostate adenocarcinoma) were determined as 68.42%, 80.65%, 68.42% and 80.65%, respectively.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eUrothelial carcinoma is a frequent disease with 549,393 new cases worldwide in 2018. About one of four patients present with muscle invasive bladder cancer (MIBC) which treatment is usually radical cystectomy with pelvic lymph node dissection. In case of metastatic disease, the first line therapy is usually chemotherapy. To decide appropriate treatment accurate staging is crucial. Either contrast enhanced computed tomography or magnetic resonance imaging is recommended for staging in current guidelines. However, radical cystectomy reveals up-stating in 40% of patients and downstaging in 20% [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. This phenomenon highlights the limitations of the current staging of MIBC.\u003c/p\u003e \u003cp\u003eIn men undergoing radical cystoprostatectomy (RCP) for urothelial carcinoma (UC), prostatic\u003c/p\u003e \u003cp\u003einvolvement is detected on final pathology in 15\u0026ndash;48% of cases. The American Joint Committee\u003c/p\u003e \u003cp\u003eon Cancer Staging (AJCC) categorized prostatic involvement as T4 disease, regardless of the degree of prostatic involvement. However, researchers have found differences in outcomes based on the depth of prostatic invasion (superficial ductal or stromal) and in some cases the site of origin (bladder or prostatic urethra) [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eIn a study, prostatic involvement was found to be an independent predictor of urethral recurrence in men following radical cystectomy for urothelial carcinoma. Surprisingly the incidence of urethral recurrence was lower in patient with orthotopic diversion which might be a consequence of patient selection [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. In our study, the sensitivity of FDG PET/CT in determining urothelial carcinoma invasion in the prostate were 66.67%; however no statistically significant relationship was found between bladder neck and prostate region involvement in FDG PET/CT and prostatic urethra surgical margin positivity.\u003c/p\u003e \u003cp\u003eIn a study by Barocas et al. [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e] both bladder tumor stage and prostatic stromal involvement found to lead unfavorable outcomes. The authors concluded that although prostatic involvement originating from the bladder appears to be locally aggressive in nature and is associated with higher rates of positive LNs, patients have similar survival outcomes compared to those with stromal involvement originating from the prostatic urethra.\u003c/p\u003e \u003cp\u003eIn another study by Bruins et al. [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e] authors reported that more than 51% of the 1476 patients who underwent radical cystoprostatectomy had cancer involving the prostate and those who had prostatic urothelial carcinoma, especially with prostatic stromal involvement, had worse prognosis. The researchers concluded that there are no reliable preoperative clinical and histopathological risk factors to predict clinically significant prostatic adenocarcinoma/urothelial carcinoma.\u003c/p\u003e \u003cp\u003e \u003csup\u003e18\u003c/sup\u003eF-FDG PET/CT has a limited role in evaluating the local extension of bladder cancer due to interference of radioactive urine. Some researchers requested to take images after \u003csup\u003e18\u003c/sup\u003eF-FDG washout, urination, bladder catheterization or bladder irrigation. To take very early images might also be useful [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. Based on the results of another study authors concluded that diuretic \u003csup\u003e18\u003c/sup\u003eF-FDG PET/CT has a higher diagnostic value compared to contrast-enhanced CT in detecting primary urinary bladder cancer and evaluating locoregional staging, (sensitivity 96% vs. 92% and sensitivity 78% vs. 44%, respectively) [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eIn our study, no statistically significant relationship was found between radiopharmaceutical uptake in the bladder neck and prostate region in FDG PET CT and prostate invasion of urothelial carcinoma, prostatic urethra surgical margin positivity and prostate adenocarcinoma; however, a statistically significant relationship was found with the presence of any malignancy in the prostate (urothelial carcinoma and/or adenocarcinoma) (p\u0026thinsp;=\u0026thinsp;0.0189). Especially in patients requesting orthotopic urinary diversion, predicting the possible presence of malignancy in the prostate (urothelial carcinoma and adenocarcinoma) without performing a prostate biopsy before the operation may be useful in determining the surgical strategy. In order to reduce surgical margin positivity in the presence of both urothelial carcinoma invasion and adenocarcinoma in the bladder neck and prostate, more distant control of the bladder and prostate pedicles; more careful apical dissection during prostate dorsal vein control are important in reducing surgical margin positivity in these regions. In patients undergoing surgery for prostate adenocarcinoma, the most common positive surgical margins and recurrence are detected in the apex region.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eIn our study, although no significant relationship was found between radiopharmaceutical uptake in the bladder neck/prostate region and prostatic urethra surgical margin positivity, prostate urothelial carcinoma invasion and prostate adenocarcinoma, a significant result was obtained in showing the presence of any malignancy in the prostate (adenocarcinoma and/or urothelial carcinoma invasion). In the presence of uptake in this region in FDG, surgical techniques aimed at reducing and preventing surgical margin positivity should be emphasized.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003eFDG PET/CT: Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography\u003c/p\u003e\n\u003cp\u003eMIBC: Muscle-Invasive Bladder Cancer\u003c/p\u003e\n\u003cp\u003eRCP: Radical Cystoprostatectomy\u003c/p\u003e\n\u003cp\u003eUC: Urothelial Carcinoma\u003c/p\u003e\n\u003cp\u003eSUVmax: Maximum Standardized Uptake Value\u003c/p\u003e\n\u003cp\u003eBCG: Bacillus Calmette\u0026ndash;Gu\u0026eacute;rin\u003c/p\u003e\n\u003cp\u003eNAC: Neoadjuvant Chemotherapy\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003eEthics approval and consent to participate\u003c/p\u003e\n\u003cp\u003eThis study was approved by the Clinical Research Ethics Committee of Istanbul University (Protocol code: E-29624016\u0026ndash;050.99-1810738). All procedures were conducted in accordance with the ethical standards of the institutional research committee and with the 1964 Helsinki Declaration and its later amendments. The need for informed consent was waived due to the retrospective nature of the study and in accordance with national regulations.\u003c/p\u003e\n\u003cp\u003eConsent for publication\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003eAvailability of data and materials\u003c/p\u003e\n\u003cp\u003eThe datasets generated and/or analysed during the current study are available in the Zenodo repository at:\u0026nbsp;https://doi.org/10.5281/zenodo.15425614.\u003c/p\u003e\n\u003cp\u003eCompeting Interests\u003c/p\u003e\n\u003cp\u003eThe authors declare that they have no competing interests.\u003c/p\u003e\n\u003cp\u003eFunding\u003c/p\u003e\n\u003cp\u003eThis research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.\u003c/p\u003e\n\u003cp\u003eAuthors\u0026apos; contributions\u003c/p\u003e\n\u003cp\u003eR.B.E. and R.A. conceived and designed the study. R.B.E. and A.T. collected the data. R.B.E., R.A., Y.Ş., and S.E. performed the data analysis. R.A., and Y.Ş. drafted the initial manuscript. M.\u0026Ouml;.S. and F.\u0026Ouml;. critically revised the manuscript for important intellectual content. All authors reviewed and approved the final version of the manuscript.\u003c/p\u003e\n\u003cp\u003eAcknowledgements\u003c/p\u003e\n\u003cp\u003eThe authors would like to thank the staff of the Department of Urology and Nuclear Medicine at Istanbul University for their support during data collection and evaluation.\u003c/p\u003e\n\u003cp\u003eFunding This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.\u003c/p\u003e"},{"header":"References ","content":"\u003col\u003e\n\u003cli\u003eLiedberg F, Chebil G, M\u0026aring;nsson W: \u003cstrong\u003eUrothelial carcinoma in the prostatic urethra and prostate: current controversies\u003c/strong\u003e. \u003cem\u003eExpert Review of Anticancer Therapy \u003c/em\u003e2014, \u003cstrong\u003e7\u003c/strong\u003e(3):383-390.\u003c/li\u003e\n\u003cli\u003eKassouf W, Spiess PE, Brown GA, Liu P, Grossman HB, Dinney CP, Kamat AM: \u003cstrong\u003eProstatic urethral biopsy has limited usefulness in counseling patients regarding final urethral margin status during orthotopic neobladder reconstruction\u003c/strong\u003e. \u003cem\u003eThe Journal of urology \u003c/em\u003e2008, \u003cstrong\u003e180\u003c/strong\u003e(1):164-167.\u003c/li\u003e\n\u003cli\u003evon Rundstedt F-C, Mata DA, Shen S, Li Y, Godoy G, Lerner SP: \u003cstrong\u003eTransurethral biopsy of the prostatic urethra is associated with final apical margin status at radical cystoprostatectomy\u003c/strong\u003e. \u003cem\u003eJournal of clinical urology \u003c/em\u003e2016, \u003cstrong\u003e9\u003c/strong\u003e(6):404-408.\u003c/li\u003e\n\u003cli\u003eKates M, Ball MW, Chappidi MR, Baras AS, Gordetsky J, Sopko NA, Brant A, Pierorazio PM, Epstein JI, Schoenberg MP: \u003cstrong\u003eAccuracy of urethral frozen section during radical cystectomy for bladder cancer\u003c/strong\u003e. In: \u003cem\u003eUrologic Oncology: Seminars and Original Investigations: 2016\u003c/em\u003e: Elsevier; 2016: 532. e531-532. e536.\u003c/li\u003e\n\u003cli\u003eEinerhand SMH, van Gennep EJ, Mertens LS, Hendricksen K, Donswijk ML, van der Poel HG, van Rhijn BWG: \u003cstrong\u003e18F-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography in muscle-invasive bladder cancer\u003c/strong\u003e. \u003cem\u003eCurrent Opinion in Urology \u003c/em\u003e2020, \u003cstrong\u003e30\u003c/strong\u003e(5):654-664.\u003c/li\u003e\n\u003cli\u003eBarocas DA, Patel SG, Chang SS, Clark PE, Smith Jr JA, Cookson MS: \u003cstrong\u003eOutcomes of patients undergoing radical cystoprostatectomy for bladder cancer with prostatic involvement on final pathology\u003c/strong\u003e. \u003cem\u003eBJU international \u003c/em\u003e2009, \u003cstrong\u003e104\u003c/strong\u003e(8):1091-1097.\u003c/li\u003e\n\u003cli\u003eHuguet J, Monllau V, Sabat\u0026eacute; S, Rodriguez-Faba O, Algaba F, Palou J, Villavicencio H: \u003cstrong\u003eDiagnosis, risk factors, and outcome of urethral recurrences following radical cystectomy for bladder cancer in 729 male patients\u003c/strong\u003e. \u003cem\u003eEuropean urology \u003c/em\u003e2008, \u003cstrong\u003e53\u003c/strong\u003e(4):785-793.\u003c/li\u003e\n\u003cli\u003eBruins HM, Djaladat H, Ahmadi H, Sherrod A, Cai J, Miranda G, Skinner EC, Daneshmand S: \u003cstrong\u003eIncidental prostate cancer in patients with bladder urothelial carcinoma: comprehensive analysis of 1,476 radical cystoprostatectomy specimens\u003c/strong\u003e. \u003cem\u003eThe Journal of urology \u003c/em\u003e2013, \u003cstrong\u003e190\u003c/strong\u003e(5):1704-1709.\u003c/li\u003e\n\u003cli\u003eChondrogiannis S, Marzola MC, Colletti PM, Rubello D: \u003cstrong\u003eProposal of a new acquisition protocol for bladder cancer visualization with 18F-FDG PET/CT\u003c/strong\u003e. \u003cem\u003eClinical Nuclear Medicine \u003c/em\u003e2015, \u003cstrong\u003e40\u003c/strong\u003e(1):e78-e80.\u003c/li\u003e\n\u003cli\u003eNayak B, Dogra PN, Naswa N, Kumar R: \u003cstrong\u003eDiuretic 18 F-FDG PET/CT imaging for detection and locoregional staging of urinary bladder cancer: prospective evaluation of a novel technique\u003c/strong\u003e. \u003cem\u003eEuropean journal of nuclear medicine and molecular imaging \u003c/em\u003e2013, \u003cstrong\u003e40\u003c/strong\u003e:386-393. \u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Tables","content":"\u003cp\u003eTables are available in the Supplementary Files section.\u003c/p\u003e\n"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"bmc-urology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"buro","sideBox":"Learn more about [BMC Urology](http://bmcurol.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/buro/default.aspx","title":"BMC Urology","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"","lastPublishedDoi":"10.21203/rs.3.rs-6580219/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6580219/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eBladder cancer is the most common malignancy of the urinary system. It is a heterogeneous type of cancer with a high potential for metastasis, approximately 25% of which occurs as muscle invasive. As with other malignancies, accurate and precise staging of bladder cancer is one of the mainstays for choosing the most appropriate treatment for the patient. Detection of metastasis is extremely important in choosing the treatment strategy. FDG PET/CT is widely used in the clinical management of various malignancies and is increasingly used in the primary staging of muscle-invasive bladder cancer and detection of recurrence after radical cystectomy. We aimed to determine the role of radiopharmaceutical uptake in the bladder neck and prostate region in preoperative FDG PET/CT in patients with muscle-invasive bladder tumors in determining the positivity of prostatic urethra surgical margins in the final pathology after cystectomy and its effect in determining the type of diversion to be chosen.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eThe data of male patients who underwent FDG PET/CT before radical cystectomy due to MIBC between January 2009 and January 2023 in the Department of Urology at Istanbul Faculty of Medicine were retrospectively analyzed. The correlations between the presence of radiopharmaceutical uptake in the bladder neck or prostate in FDG PET CT and the positivity of the prostatic urethra surgical margin in the postoperative final pathology of these patients and the invasion of urothelial carcinoma in the prostate were analyzed.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eProstatic urethra surgical margin positivity was detected in 8 of 50 male patients who had FDG PET CT in the preoperative period. Prostatic urethra surgical margin positivity was detected in 5 of 19 patients with bladder neck and prostate region involvement on FDG (p\u0026thinsp;=\u0026thinsp;0.2554). Prostate involvement was seen on FDG in 6 of 9 patients with urothelial carcinoma invasion into the prostate (p\u0026thinsp;=\u0026thinsp;0.1492). Prostate adenocarcinoma was observed in the final pathology of 12 patients, and 8 of these patients had FDG uptake (p\u0026thinsp;=\u0026thinsp;0.106). While no statistically significant relationship was found between the presence of bladder neck and prostate region involvement on FDG and prostatic urethra surgical margin, urothelial carcinoma invasion into the prostate and prostate adenocarcinoma, a statistically significant relationship was observed between the presence of malignancy in the prostate (urothelial carcinoma and/or adenocarcinoma) (p\u0026thinsp;=\u0026thinsp;0.0189).\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e \u003cp\u003eWhile no statistically significant relationship was found between radiopharmaceutical uptake in the bladder neck and prostate region on preoperative FDG PET CT in CIBC and prostatic urethra surgical margin positivity, urothelial carcinoma invasion into the prostate and the presence of prostate adenocarcinoma; It was found valuable in detecting the presence of malignancy in the prostate (adenocarcinoma/urothelial carcinoma).\u003c/p\u003e","manuscriptTitle":"The Utility of Radiopharmaceutical Uptake in the Bladder Neck and Prostate on Preoperative FDG PET/CT in Determining Urethral Surgical Margin Positivity in Patients Undergoing Radical Cystoprostatectomy for Bladder Cancer","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-06-02 15:28:38","doi":"10.21203/rs.3.rs-6580219/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-07-29T13:14:55+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-06-08T17:16:47+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-06-06T20:33:42+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"308564191748333659040119325042411167913","date":"2025-06-06T08:10:17+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-06-01T21:54:50+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"318991963212758033029004788644090431272","date":"2025-06-01T21:51:36+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"339199944223183871196220176672898505577","date":"2025-05-30T20:17:28+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-05-30T11:34:06+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-05-29T03:52:52+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2025-05-15T16:28:19+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-05-15T14:54:13+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Urology","date":"2025-05-15T14:53:06+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-urology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"buro","sideBox":"Learn more about [BMC Urology](http://bmcurol.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/buro/default.aspx","title":"BMC Urology","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"f1192bca-ca77-44f8-961a-8b8ace98a1e8","owner":[],"postedDate":"June 2nd, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2025-11-03T16:00:20+00:00","versionOfRecord":{"articleIdentity":"rs-6580219","link":"https://doi.org/10.1186/s12894-025-01962-w","journal":{"identity":"bmc-urology","isVorOnly":false,"title":"BMC Urology"},"publishedOn":"2025-10-28 15:57:15","publishedOnDateReadable":"October 28th, 2025"},"versionCreatedAt":"2025-06-02 15:28:38","video":"","vorDoi":"10.1186/s12894-025-01962-w","vorDoiUrl":"https://doi.org/10.1186/s12894-025-01962-w","workflowStages":[]},"version":"v1","identity":"rs-6580219","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6580219","identity":"rs-6580219","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}