Dental Management of Hyperthyroid Patients Undergoing Radioiodine Therapy: A Radiation Safety Perspective

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Tuna Akdoğan, Mustafa Demir This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7410574/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 Background: Hyperthyroidism is an endocrine disorder characterized by the excessive production of thyroid hormones (T3 and T4) by the thyroid gland. The treatment of this disease in Nuclear Medicine clinics is performed by the outpatient oral administration of radioactive iodine (RAI or I-131). The gamma radiation emitted from the patient’s body after I-131 administration may lead to radiation exposure for individuals in close proximity. Objectives: The aim of this study was to determine the safe distance and duration for a dentist to provide services to a patient who has undergone hyperthyroidism treatment, in order to ensure radiation protection. Materials and Methods: A total of 50 randomly selected patients who presented for hyperthyroidism treatment were included in this study. Of these, 31 patients were diagnosed with Graves’ disease and 19 with toxic nodular goiter. Patients were divided into two groups according to the administered therapeutic I-131 activity. Group I: ≤444 MBq (n=26), Group II: >444 MBq (n=24). External radiation exposure (dose rate) measurements were performed using a radiation detector at distances of 5 cm, 15 cm, 30 cm, 60 cm, and 100 cm from the thyroid region of each patient. Results: The administered radioiodine activities ranged from 222 MBq to 925 MBq. The most frequently used I-131 therapeutic regimen was 370 MBq, followed by 555 MBq. Dose rate measurements in Group I, 24 hours after administration, were 3528 µSv/h, 968 µSv/h, and 295 µSv/h at 5 cm, 15 cm, and 30 cm, respectively. In Group II, the corresponding values at the same distances were 5525 µSv/h, 1763 µSv/h, and 566 µSv/h. Conclusion: According to our findings, dental examination and treatment of hyperthyroid patients who received ≤444 MBq of I-131 within the first 3 days pose a radiation safety concern. For patients treated with >444 MBq of RAI, the safe approach time for dental procedures was determined to be 5 days. In the case of female and pregnant dentists, these periods should be doubled to ensure adequate radiation protection. Hyperthyroidism treatment radioiodine (I-131) therapy dentist radiation safety radiation dose to dentist radiation exposure Figures Figure 1 Figure 2 Figure 3 Introduction Hyperthyroidism is an endocrine disorder that occurs when the thyroid gland produces an excessive amount of thyroid hormones (T3 and T4) beyond the body’s physiological requirements. Thyroid hormones regulate the metabolic rate; therefore, their overproduction leads to an abnormally accelerated metabolism. The most common primary forms of hyperthyroidism are Basedow-Graves disease (Graves’ disease) and toxic nodular goiter. Radioactive iodine (RAI, I-131) has been widely used for the treatment of these benign thyroid diseases for many decades [1]. The radionuclide I-131 emits beta radiation with an average energy of 606 keV and gamma photons with a maximum energy of 364 keV. It has a physical half-life of 8.05 days. In the treatment of hyperthyroidism, this radionuclide is administered orally in sodium iodide (NaI) form, with empirically determined activities ranging from 222 to 1110 megabecquerels (MBq) [2]. More recently, dosimetric methods have been preferred, with patient-specific administered activities ranging between 436 and 1060 MBq [3]. According to the European Association of Nuclear Medicine (EANM) guidelines, patients must remain in lead-shielded hospital rooms until their whole-body radiation level decreases below 400 MBq, in order to ensure radiation protection for the public and the environment. Following treatment, patients are discharged once the external dose rate measured with a radiation detector at 1 meter from the abdominal level falls below 20 µSv/h [4]. However, discharge dose rate limits vary between countries; for example, < 50 µSv/h in the United States and < 30 µSv/h in Türkiye [5]. Outpatients treated with RAI for hyperthyroidism may still carry relatively high radiation levels at discharge. Therefore, written and verbal instructions are provided regarding approach distances and contact times with family members and close contacts, and patients are expected to comply with these recommendations. For individuals who are not classified as radiation workers, the annual permissible radiation dose is limited to 1 mSv [6,7]. Approach criteria for non-radiation workers are generally determined based on dose rate measurements at 1 meter. For instance, for a patient treated with 7400 MBq of RAI, the allowable contact time at a 1-meter distance during the first 48 hours after discharge has been reported as only 2 hours [8]. Similarly, for a hyperthyroid patient treated with 800 MBq, avoidance of distances closer than 1 meter for a period of 24 days has been recommended [9–11]. Radiation intensity decreases proportionally with the square of the distance. In this context, a dentist performing dental procedures on a patient treated with RAI works at distances much closer than 1 meter. The longer the procedure duration, the higher the radiation dose to which the dentist is exposed. In the literature, working distances during dental procedures have been reported as 5–15 cm and 30 cm [12–14]. Understanding the temporal variation of radiation levels emitted by patients after RAI therapy is crucial for making informed decisions regarding radiation safety. In patients treated for hyperthyroidism, I-131 uptake typically occurs in the thyroid gland and, to a lesser extent, in the salivary glands. The biological clearance of RAI is slower in hyperthyroid patients compared to other conditions, with an average effective half-life of approximately 5.5 days [15]. During this period, and beyond, approach distances to the patient remain restricted for radiation safety reasons. Current guidelines are limited, often based on small patient cohorts [2,5,11]. However, the lack of a detailed description of early post-therapy dose rate changes highlights the need for more comprehensive studies with higher accuracy. The thyroidal uptake of RAI in hyperthyroid patients can reach up to 90%, which increases the likelihood of radiation exposure to a dentist performing clinical procedures. The aim of this study was therefore to determine the safe working distance and duration for dentists to provide care to hyperthyroid patients treated with RAI, in order to ensure compliance with radiation safety principles. Materials and Methods Patient characteristics A total of 50 patients (33 women and 17 men) with a mean age of 57.8 ± 17.2 years (range, 27–76 years) who had been treated at our institution between 2023 and 2025 were included in this study. Patients were divided into two groups according to the administered RAI activity for hyperthyroidism treatment. Group I consisted of 26 patients who received ≤ 444 MBq of RAI (16 with Graves’ disease and 10 with toxic nodular goiter). Group II consisted of 24 patients who received > 444 MBq of RAI (15 with Graves’ disease and 9 with toxic nodular goiter). Inclusion and exclusion criteria Normal serum levels were defined as free T4 (fT4) 0.93–1.7 ng/dl and TSH 0.27–4.2 µIU/ml. Eligible patients had elevated fT4 and suppressed TSH levels before treatment. Patients with a history of thyroid surgery or those who failed to attend scheduled follow-up measurements were excluded from the study. Dose rate measurement technique All patients underwent a pre-therapeutic I-131 uptake test, and 2- and 24-hour uptake values were determined. External radiation dose rate measurements from the thyroid region were performed within 60 minutes following RAI administration, and the maximum dose rate (µSv/h) for each patient was recorded. After therapy, patients were instructed to attend at least five follow-up visits for repeated measurements. Post-discharge dose rate measurements were performed at standardized time points (days 1, 3, 5, 7, and 10). Patients who missed scheduled measurements were excluded. Considering that RAI remains longer in the thyroid tissue of hyperthyroid patients, all measurements were performed with the patient seated, from the anterior neck region. For standardization, a measuring rod was fixed parallel to the ground between the cricoid cartilage and the suprasternal notch. Measurements were performed using an ionization chamber survey meter (Ludlum, Model 9DP) at distances of 5 cm, 15 cm, 30 cm, 60 cm, and 100 cm from the thyroid level. Calculation of dentist radiation exposure Radiation exposure doses for dentists were estimated under three different clinical scenarios. Dental procedures were assumed to be performed at distances of 5–15 cm, 15–30 cm, 60 cm, and 100 cm. Based on measured dose rates, cumulative exposure doses at these working distances were calculated using Table 1 as reference. Statistical analysis Dose rates measured in patients with Graves’ disease and toxic nodular goiter were compared within each group using the Mann–Whitney U test. A p-value of < 0.05 was considered statistically significant. Results A total of 50 hyperthyroid patients were included in the study. Among them, 31 patients (59.6%) had Graves’ disease (19 women, 7 men) and 19 patients (38%) had toxic nodular goiter (8 women, 11 men). Normal reference values were: Free T3 (fT3) 2.0–4.4 pg/ml, free T4 (fT4) 0.93–1.7 ng/dl, and TSH 0.27–4.2 µIU/ml. Before treatment, all patients had elevated fT4 and suppressed TSH levels (Table 1). None of the patients had a prior history of thyroid surgery. Ophthalmopathy was present in three patients (11%) with Graves’ disease. In Group I, the mean thyroid uptake values at 2 and 24 hours were 44 ± 12.5% and 72 ± 23%, respectively. In Group II, the mean 2- and 24-hour uptake values were 45 ± 14.1% and 76 ± 18%, respectively. Based on clinical judgment, Graves’ disease patients received a mean therapeutic activity of 384 ± 50.5 MBq (range, 296–444 MBq), while toxic nodular goiter patients received a mean activity of 490.8 ± 116 MBq (range, 555–925 MBq). Table 1. Correlation of dose rates measured at 30 cm distance at the 24th hour in patients with Graves’ disease and toxic nodular goitre. Gender Age (years) Weight (kg) 24.h Uptake (%) T4 (ng/dl) TSH (µIU/ml) Female (n=18) 59.6 ± 14.0 57.0 ± 5.4 70± 24 4.2± 1.6 0.11±0.001 Group I Male 47.11 ± 15.2 70.5 ± 4.3 74± 18 4.1± 1.1 0.12±0.001 (n=8) Female (n=16) 62.2 ± 16.5 61.3 ± 8.3 68± 14 4.8± 2.4 0.11±0.001 Group II Male (n=8) 59.15 ± 14.4 57.4 ± 6.2 72± 22 4.9± 1.8 0.14±0.02 Dose rate measurements were initiated between 4 and 6 hours after RAI administration, which was designated as day 0. Subsequent measurements were performed on days 1, 3, 5, 7, and 10 (Table 2). The working distances of 5–15 cm and particularly 15–30 cm, where dentists spend the most time with their patients during procedures, were identified as critical distances in terms of radiation dose exposure. Since RAI accumulates predominantly in the anterior neck region, including the thyroid and salivary glands of hyperthyroid patients, this anatomical area was selected as the reference site for all measurements (Figure 1). Table 2. Measured external exposure rates (µSv/h) The radioiodine activity levels used for treatment ranged from 222 MBq to 925 MBq. The most commonly used I-131 treatment regimen was 370 MBq, followed by 555 MBq (Figure 2). The dose rates measured separately in the two disease groups were analyzed using the Mann–Whitney U test, and no statistically significant difference was observed between them (p = 0.32). However, a relatively strong correlation was found between the dose rates of the Graves’ disease and toxic nodular goitre groups (R² = 0.83) (Figure 3). The administered activities of I-131 for hyperthyroidism treatment may vary across different nuclear medicine centers, with the main contributing factor being the empirical dosing approach. Therefore, normalized dose rates are also reported in the literature, allowing for easier comparison and interpretation of the dose rate variations observed in clinical practice (Table 3). Table 3. Normalized dose rate measurements after I-131 therapy in hyperthyroid patients: literatüre review (5, 16-18). Study (Years) Patient type/administered activity Measurement distance Time points Normalized dose rate &units Jørgensen et al. (2006) Hyperthyroid patients, (74-555) MBq 0.3 m, 0.6 m, 1 m, 2 m 0.5 h–12 days 0.234–0.325 µSv/h/MBq Liu et al. (2018) Hyperthyroid patients, (370–740) MBq 0.3 m, 0.6 m, 1 m 5-24 h ~ 0.035 ± 0.007 µSv/h/MBq Demir et al. (1996) Hyperthyroid patients, (296–740) MBq 30 cm 30 min-1 day 0.17 µSv/h/MBq Cui S et al (2014) Hyperthyroid patients, (74–555) MBq 30 cm 4 h-1 day ~0.28 µSv/h/MBq Exposure dose determination scenarios Considering the workflow of the dental clinic where this study was conducted, the following average durations and distances were taken into account: 15–30 minutes for dental procedures performed at 5–10 cm, 10–15 minutes for giving instructions, observation, or finger guidance at 15–30 cm, and 5–10 minutes for computer use or verbal communication with the patient at 60–100 cm. Based on the above time–distance data and dose rate measurements presented in Table 1, radiation exposure doses for dentists were calculated using three different scenarios. The treatment process was defined as involving patient interactions at 5–15 cm, 30 cm, and 60 cm distances across three separate procedures. Cumulative doses on day 1 after treatment were calculated using Table 1. Group I, Scenario 1: With procedure times of 15 min at 5 cm, 15 min at 15 cm, 15 min at 30 cm, and 5 min at 60 cm, the total exposure dose was estimated at 1580 µSv. Scenario 2: With procedure times of 15 min at 5 cm, 15 min at 15 cm, 10 min at 30 cm, and 5 min at 60 cm, the total exposure dose was 1501 µSv. Scenario 3: With procedure times of 10 min at 5 cm, 15 min at 15 cm, 10 min at 30 cm, and 5 min at 60 cm, the total exposure dose was 1086 µSv. In all scenarios within this group, exposure doses decreased to <1 µSv by day 3. In Group II, radiation doses for scenario 1, scenario 2 and scenario 3 were found to be 2836 µSv, 2650 µSv and 2030 µSv, respectively. Discussion Although treatment of Graves’ disease with radioactive iodine (RAI) has been practiced for more than 70 years, the vast majority of published studies to date demonstrate that no universally accepted standard exists regarding the optimal ¹³¹I activity to be administered to the thyroid gland or the associated radiation exposure dose [19–21]. It may even be reasonable to expect that a consensus on this issue will never be reached, since such standard values may not conceptually exist. Therefore, radiation protection measures tailored to specific clinical situations should be considered. The success rate of RAI therapy in hyperthyroidism is considerably high. However, given that ionizing radiation is a well-established carcinogenic factor and numerous studies have demonstrated a dose-dependent relationship between radiation exposure and malignancy development, it is essential to evaluate this therapy also in terms of its environmental impact [22,23]. After oral administration of I-131, thyroidal uptake progressively increases and reaches its maximum at approximately 24 hours. Due to its relatively long physical half-life of 8 days and the high affinity of hyperthyroid tissue for radioiodine, the radionuclide may remain in the thyroid gland for up to one month. While radioactive decay within the thyroid exerts its therapeutic effect via β-radiation of 606 keV, concomitant emission of 364 keV γ-rays contributes to external radiation exposure, particularly affecting individuals in the immediate vicinity of the patient. In this context, healthcare professionals such as dentists, who are required to provide close-contact care to patients following RAI therapy, may face potential radiation risks that warrant careful consideration. During dental procedures, the distance between the dentist and patient often falls below 30 cm. Therefore, if a patient undergoes dental examination or treatment within the first few days after hospital discharge, the dentist may be exposed to a significant level of external radiation. This risk is further compounded in cases of repeated procedures or prolonged close contact within a single day, potentially leading to exceedance of annual dose limits. Accordingly, careful planning regarding patient counseling and appointment scheduling is of great importance. In Europe, 24-hour thyroid uptake values are generally interpreted as normal at 15–35%, and as indicative of hyperthyroidism at > 55–60%. In the present study, the mean uptake values of patients in the first and second groups were 72 ± 23% and 76 ± 18%, respectively. Two approaches are commonly employed to determine the RAI activity administered for hyperthyroidism: (i) empirical dosing based on clinician experience, and (ii) patient-specific dosimetry-based methods. The latter is considered more accurate and associated with fewer complications [27]. For instance, according to EANM guidelines, 300–400 Gy is recommended for the ablation of autonomous nodules. In Graves’ disease, a 150 Gy absorbed dose is suggested to achieve euthyroidism, while 200–300 Gy is advised for complete ablation [28]. The calculated activity required to deliver 200 Gy in Graves’ patients was reported as 436 ± 381 MBq, whereas 622 ± 332 MBq was needed to achieve 300 Gy in toxic nodules [29]. In our study, Graves’ disease patients received an average of 370 ± 50.5 MBq (296–444 MBq), and toxic nodular goitre patients received an average of 490.8 ± 116 MBq (555–925 MBq). These activity levels correspond to absorbed thyroid doses of approximately 200 Gy and 300 Gy, respectively. No statistically significant difference was observed between the dose rates of the two disease groups; however, a relatively strong correlation was identified (R² = 0.83). These findings indicate that dentists should adopt radiation protection measures when treating hyperthyroid patients post-RAI therapy, regardless of the underlying disease type. Dental procedures, especially those involving high-speed handpieces such as ultrasonic scalers, air turbines, and air–water sprays, generate aerosols containing saliva, blood, and microbial content. Studies investigating aerosol exposure in dentists have shown that the most frequent working distance is approximately 30 cm, though procedures may be performed between 5 and 60 cm, with aerosol exposure decreasing at greater distances. Furthermore, exposure was reported to increase with procedure duration [30,31]. In our study, radiation exposure was most pronounced at 30 cm from the thyroid, which also corresponded to the distance associated with the longest procedure durations. Although no studies specifically addressing radiation safety for dentists managing hyperthyroid patients post-RAI therapy exist, some reports have evaluated the exposure risks of family members. Culver et al. measured maximum dose rates at 30 cm from 19 patients receiving 444–1110 MBq of RAI and reported values of 18 mR/h (180 µSv/h), 10 mR/h (100 µSv/h), and 7 mR/h (70 µSv/h) at 2–4, 5–7, and 8–11 days post-therapy, respectively. They recommended time restrictions at ≤ 30 cm for the first 2–4 days, and at 60 cm only during day 1, with additional restrictions for pregnant women and children thereafter [2]. Demir et al. suggested a 3-day restriction at 30 cm for patients receiving 370 MBq. Similarly, Barrington et al. recommended restrictions of 5, 11, 14, and 16 days for patients treated with 200, 400, 600, or 800 MBq of RAI, respectively [8]. From a dental perspective, our findings suggest that patients receiving ≤ 444 MBq of RAI can be safely managed after day 3, whereas those receiving > 444 MBq should be deferred until after day 5. ICRP-60 and the 1994 NRC reports set the annual dose limits at 1 mSv for the general population and 0.5 mSv for children and pregnant women [32,33]. Our findings are consistent with published time-restriction recommendations. In addition, dentist–patient interaction times and distances (5–100 cm) were derived from both clinical experience and aerosol exposure data obtained during the COVID-19 pandemic. External dose rate measurements at these distances were then used to calculate estimated radiation exposures for dentists. Conclusion This study evaluated the radiation exposure of dentists when providing care to hyperthyroid patients following RAI therapy. Our results indicate that dental examination and treatment of patients receiving ≤ 444 MBq of RAI within the first 3 days after therapy poses a potential radiation safety risk. For patients treated with > 444 MBq, a safe interval before dental procedures appears to be 5 days. In cases where the treating dentist is female and/or pregnant, it is recommended that these intervals be doubled. Declarations Acknowledgements: Not applicable Funding : Not applicable Data availability : The datasets used and analyzed in this study can be obtained from the corresponding author upon reasonable request. Conflict of interest : We have no conflicts of interest to disclose. Ethics approval : This study was conducted at the Radionuclide Therapy Unit of the Nuclear Medicine Department, Cerrahpasa Medical Faculty. A group of patients was randomly selected from individuals presenting to the clinic for hyperthyroidism treatment. All procedures conducted in this study were carried out in strict accordance with the ethical principles outlined in the 1964 Declaration of Helsinki and its later revisions or equivalent ethical standards. The study protocol received approval from the Institutional Clinical Research Ethics Committee (document number: 19451483/604-01-02-52947), and written informed consent was obtained from all participants. Informed consent : Patients signed an informed consent form References Sawin CT, Becker DV. Radioiodine and the treatment of hyperthyroidism: The early history. Thyroid. 1997;7(2):163–76. Culver CM, Dworkin HJ. Radiation safety considerations for post-iodine-131 hyperthyroid therapy. J Nucl Med. 1991;32(1):169–73. Abuqbeitah M, Sağer S, Demir M, Yeyin N, Akovalı B, Sönmezoğlu K. The impact of different computational assumptions in 131I dosimetry for hyperthyroidism therapy. Med Phys. 2020;47(11):5810–16. Campennì A, Avram AM, Verburg FA, Iakovou I, Hänscheid H, de Keizer B, et al. 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Washington, DC: NRC; 1994. Additional Declarations Competing interest reported. No conflict of interest 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-7410574","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":513563856,"identity":"644f5947-ebaf-4ec8-82bf-7f94d3545398","order_by":0,"name":"E. Tuna Akdoğan","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA3klEQVRIiWNgGAWjYJACxgY2EMV8AEhIyBBUzoPQwpYA0sJDihYeA5gAfmAvkXvw44wyG7v+2T2fX92oseBhYD98dANeWyTykiU3nEtLnnHn7DbrnGNAh/Gkpd3AryXHQPJh2+Fkhhu524xz2IBaJHjMCGkx/gnSIn8j55lxzj/itJhJbmw7bGdwI4f5cW4bMVrOvDGznHEuLcHwRpoZc26fBA8bIb+wt+cY3+wps7GXu5H8+HPOtzo5fvbDx/BqgYHEBmBcSoBYbMQoBwF7IGb+QKzqUTAKRsEoGFkAAIjnR0EGuk3QAAAAAElFTkSuQmCC","orcid":"","institution":"Istanbul Kent University","correspondingAuthor":true,"prefix":"","firstName":"E.","middleName":"Tuna","lastName":"Akdoğan","suffix":""},{"id":513563857,"identity":"90ccfd25-3dbd-431f-852f-d8891bfe1f65","order_by":1,"name":"Mustafa Demir","email":"","orcid":"","institution":"Istanbul University-Cerrahpaşa","correspondingAuthor":false,"prefix":"","firstName":"Mustafa","middleName":"","lastName":"Demir","suffix":""}],"badges":[],"createdAt":"2025-08-19 16:38:14","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7410574/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7410574/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":91328700,"identity":"2577038c-e402-4b24-b6bc-c5793125445b","added_by":"auto","created_at":"2025-09-15 10:24:03","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":107050,"visible":true,"origin":"","legend":"\u003cp\u003eThe critical distance of 30 cm during interventional procedures.\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-7410574/v1/21f6d64d5d15ae4f090a725f.png"},{"id":91328699,"identity":"2d0eee8f-3df3-464b-a391-77e9c9a9574b","added_by":"auto","created_at":"2025-09-15 10:24:03","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":10865,"visible":true,"origin":"","legend":"\u003cp\u003eDistribution of radioiodine activity applied for treatment among patients\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-7410574/v1/d2f37a729139c9899e1df79a.png"},{"id":91328703,"identity":"e34e77de-e3e8-442e-8539-a5e54cc3213c","added_by":"auto","created_at":"2025-09-15 10:24:05","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":19970,"visible":true,"origin":"","legend":"\u003cp\u003eCorrelation of dose rates measured at 30 cm distance at the 24th hour in patients with Graves’ disease and toxic nodular goitre.\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-7410574/v1/259b6bccc368aede68626ea1.png"},{"id":92233265,"identity":"4ae9505f-8b79-438e-adf1-40c411b81433","added_by":"auto","created_at":"2025-09-26 06:55:02","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":655746,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7410574/v1/c817cd83-d898-4f45-bc00-d0d4812ce455.pdf"}],"financialInterests":"Competing interest reported. No conflict of interest","formattedTitle":"Dental Management of Hyperthyroid Patients Undergoing Radioiodine Therapy: A Radiation Safety Perspective","fulltext":[{"header":"Introduction","content":"\u003cp\u003eHyperthyroidism is an endocrine disorder that occurs when the thyroid gland produces an excessive amount of thyroid hormones (T3 and T4) beyond the body\u0026rsquo;s physiological requirements. Thyroid hormones regulate the metabolic rate; therefore, their overproduction leads to an abnormally accelerated metabolism. The most common primary forms of hyperthyroidism are Basedow-Graves disease (Graves\u0026rsquo; disease) and toxic nodular goiter. Radioactive iodine (RAI, I-131) has been widely used for the treatment of these benign thyroid diseases for many decades [1]. The radionuclide I-131 emits beta radiation with an average energy of 606 keV and gamma photons with a maximum energy of 364 keV. It has a physical half-life of 8.05 days. In the treatment of hyperthyroidism, this radionuclide is administered orally in sodium iodide (NaI) form, with empirically determined activities ranging from 222 to 1110 megabecquerels (MBq) [2]. More recently, dosimetric methods have been preferred, with patient-specific administered activities ranging between 436 and 1060 MBq [3].\u003c/p\u003e\u003cp\u003e According to the European Association of Nuclear Medicine (EANM) guidelines, patients must remain in lead-shielded hospital rooms until their whole-body radiation level decreases below 400 MBq, in order to ensure radiation protection for the public and the environment. Following treatment, patients are discharged once the external dose rate measured with a radiation detector at 1 meter from the abdominal level falls below 20 \u0026micro;Sv/h [4]. However, discharge dose rate limits vary between countries; for example, \u0026lt;\u0026thinsp;50 \u0026micro;Sv/h in the United States and \u0026lt;\u0026thinsp;30 \u0026micro;Sv/h in T\u0026uuml;rkiye [5]. Outpatients treated with RAI for hyperthyroidism may still carry relatively high radiation levels at discharge. Therefore, written and verbal instructions are provided regarding approach distances and contact times with family members and close contacts, and patients are expected to comply with these recommendations. For individuals who are not classified as radiation workers, the annual permissible radiation dose is limited to 1 mSv [6,7]. Approach criteria for non-radiation workers are generally determined based on dose rate measurements at 1 meter. For instance, for a patient treated with 7400 MBq of RAI, the allowable contact time at a 1-meter distance during the first 48 hours after discharge has been reported as only 2 hours [8]. Similarly, for a hyperthyroid patient treated with 800 MBq, avoidance of distances closer than 1 meter for a period of 24 days has been recommended [9\u0026ndash;11].\u003c/p\u003e\u003cp\u003eRadiation intensity decreases proportionally with the square of the distance. In this context, a dentist performing dental procedures on a patient treated with RAI works at distances much closer than 1 meter. The longer the procedure duration, the higher the radiation dose to which the dentist is exposed. In the literature, working distances during dental procedures have been reported as 5\u0026ndash;15 cm and 30 cm [12\u0026ndash;14]. Understanding the temporal variation of radiation levels emitted by patients after RAI therapy is crucial for making informed decisions regarding radiation safety. In patients treated for hyperthyroidism, I-131 uptake typically occurs in the thyroid gland and, to a lesser extent, in the salivary glands. The biological clearance of RAI is slower in hyperthyroid patients compared to other conditions, with an average effective half-life of approximately 5.5 days [15]. During this period, and beyond, approach distances to the patient remain restricted for radiation safety reasons. Current guidelines are limited, often based on small patient cohorts [2,5,11]. However, the lack of a detailed description of early post-therapy dose rate changes highlights the need for more comprehensive studies with higher accuracy.\u003c/p\u003e\u003cp\u003eThe thyroidal uptake of RAI in hyperthyroid patients can reach up to 90%, which increases the likelihood of radiation exposure to a dentist performing clinical procedures. The aim of this study was therefore to determine the safe working distance and duration for dentists to provide care to hyperthyroid patients treated with RAI, in order to ensure compliance with radiation safety principles.\u003c/p\u003e"},{"header":"Materials and Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\u003ch2\u003ePatient characteristics\u003c/h2\u003e\u003cp\u003eA total of 50 patients (33 women and 17 men) with a mean age of 57.8\u0026thinsp;\u0026plusmn;\u0026thinsp;17.2 years (range, 27\u0026ndash;76 years) who had been treated at our institution between 2023 and 2025 were included in this study. Patients were divided into two groups according to the administered RAI activity for hyperthyroidism treatment. Group I consisted of 26 patients who received\u0026thinsp;\u0026le;\u0026thinsp;444 MBq of RAI (16 with Graves\u0026rsquo; disease and 10 with toxic nodular goiter). Group II consisted of 24 patients who received\u0026thinsp;\u0026gt;\u0026thinsp;444 MBq of RAI (15 with Graves\u0026rsquo; disease and 9 with toxic nodular goiter).\u003c/p\u003e\u003c/div\u003e\n\u003ch3\u003eInclusion and exclusion criteria\u003c/h3\u003e\n\u003cp\u003eNormal serum levels were defined as free T4 (fT4) 0.93\u0026ndash;1.7 ng/dl and TSH 0.27\u0026ndash;4.2 \u0026micro;IU/ml. Eligible patients had elevated fT4 and suppressed TSH levels before treatment. Patients with a history of thyroid surgery or those who failed to attend scheduled follow-up measurements were excluded from the study.\u003c/p\u003e\n\u003ch3\u003eDose rate measurement technique\u003c/h3\u003e\n\u003cp\u003eAll patients underwent a pre-therapeutic I-131 uptake test, and 2- and 24-hour uptake values were determined. External radiation dose rate measurements from the thyroid region were performed within 60 minutes following RAI administration, and the maximum dose rate (\u0026micro;Sv/h) for each patient was recorded. After therapy, patients were instructed to attend at least five follow-up visits for repeated measurements. Post-discharge dose rate measurements were performed at standardized time points (days 1, 3, 5, 7, and 10). Patients who missed scheduled measurements were excluded. Considering that RAI remains longer in the thyroid tissue of hyperthyroid patients, all measurements were performed with the patient seated, from the anterior neck region. For standardization, a measuring rod was fixed parallel to the ground between the cricoid cartilage and the suprasternal notch. Measurements were performed using an ionization chamber survey meter (Ludlum, Model 9DP) at distances of 5 cm, 15 cm, 30 cm, 60 cm, and 100 cm from the thyroid level.\u003c/p\u003e\n\u003ch3\u003eCalculation of dentist radiation exposure\u003c/h3\u003e\n\u003cp\u003eRadiation exposure doses for dentists were estimated under three different clinical scenarios. Dental procedures were assumed to be performed at distances of 5\u0026ndash;15 cm, 15\u0026ndash;30 cm, 60 cm, and 100 cm. Based on measured dose rates, cumulative exposure doses at these working distances were calculated using Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e as reference.\u003c/p\u003e\u003cdiv id=\"Sec7\" class=\"Section2\"\u003e\u003ch2\u003eStatistical analysis\u003c/h2\u003e\u003cp\u003eDose rates measured in patients with Graves\u0026rsquo; disease and toxic nodular goiter were compared within each group using the Mann\u0026ndash;Whitney U test. A p-value of \u0026lt;\u0026thinsp;0.05 was considered statistically significant.\u003c/p\u003e\u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003eA total of 50 hyperthyroid patients were included in the study. Among them, 31 patients (59.6%) had Graves\u0026rsquo; disease (19 women, 7 men) and 19 patients (38%) had toxic nodular goiter (8 women, 11 men). Normal reference values were: Free T3 (fT3) 2.0\u0026ndash;4.4 pg/ml, free T4 (fT4) 0.93\u0026ndash;1.7 ng/dl, and TSH 0.27\u0026ndash;4.2 \u0026micro;IU/ml. Before treatment, all patients had elevated fT4 and suppressed TSH levels (Table 1). None of the patients had a prior history of thyroid surgery. Ophthalmopathy was present in three patients (11%) with Graves\u0026rsquo; disease. In Group I, the mean thyroid uptake values at 2 and 24 hours were 44 \u0026plusmn; 12.5% and 72 \u0026plusmn; 23%, respectively. In Group II, the mean 2- and 24-hour uptake values were 45 \u0026plusmn; 14.1% and 76 \u0026plusmn; 18%, respectively. Based on clinical judgment, Graves\u0026rsquo; disease patients received a mean therapeutic activity of 384 \u0026plusmn; 50.5 MBq (range, 296\u0026ndash;444 MBq), while toxic nodular goiter patients received a mean activity of 490.8 \u0026plusmn; 116 MBq (range, 555\u0026ndash;925 MBq).\u003c/p\u003e\n\u003cp\u003eTable 1.\u0026nbsp;Correlation of dose rates measured at 30 cm distance at the 24th hour in patients with Graves\u0026rsquo; disease and toxic nodular goitre.\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\" width=\"608\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" style=\"width: 12.0748%;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 12.585%;\"\u003e\n \u003cp\u003eGender\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 18.0272%;\"\u003e\n \u003cp\u003eAge \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; (years)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 15.3061%;\"\u003e\n \u003cp\u003eWeight \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; (kg)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 14.2857%;\"\u003e\n \u003cp\u003e24.h Uptake (%)\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 11.9048%;\"\u003e\n \u003cp\u003eT4 \u0026nbsp; (ng/dl)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 15.8163%;\"\u003e\n \u003cp\u003eTSH (\u0026micro;IU/ml)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 18.0272%;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 15.3061%;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 11.9048%;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 12.0748%;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 12.585%;\"\u003e\n \u003cp\u003eFemale (n=18)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 18.0272%;\"\u003e\n \u003cp\u003e59.6 \u0026plusmn; 14.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 15.3061%;\"\u003e\n \u003cp\u003e57.0 \u0026plusmn; 5.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 14.2857%;\"\u003e\n \u003cp\u003e70\u0026plusmn; 24\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 11.9048%;\"\u003e\n \u003cp\u003e4.2\u0026plusmn; 1.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 15.8163%;\"\u003e\n \u003cp\u003e0.11\u0026plusmn;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 12.0748%;\"\u003e\n \u003cp\u003eGroup I\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" style=\"width: 12.0748%;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 12.585%;\"\u003e\n \u003cp\u003eMale\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 18.0272%;\"\u003e\n \u003cp\u003e47.11 \u0026plusmn; 15.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 15.3061%;\"\u003e\n \u003cp\u003e70.5 \u0026plusmn; 4.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 14.2857%;\"\u003e\n \u003cp\u003e74\u0026plusmn; 18\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 11.9048%;\"\u003e\n \u003cp\u003e4.1\u0026plusmn; 1.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 15.8163%;\"\u003e\n \u003cp\u003e0.12\u0026plusmn;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 12.585%;\"\u003e\n \u003cp\u003e(n=8)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 12.0748%;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 12.585%;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 18.0272%;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 15.3061%;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 14.2857%;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 11.9048%;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 15.8163%;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 12.0748%;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 12.585%;\"\u003e\n \u003cp\u003eFemale (n=16)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 18.0272%;\"\u003e\n \u003cp\u003e62.2 \u0026plusmn; 16.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 15.3061%;\"\u003e\n \u003cp\u003e61.3 \u0026plusmn; 8.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 14.2857%;\"\u003e\n \u003cp\u003e68\u0026plusmn; 14\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 11.9048%;\"\u003e\n \u003cp\u003e4.8\u0026plusmn; 2.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 15.8163%;\"\u003e\n \u003cp\u003e0.11\u0026plusmn;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 12.0748%;\"\u003e\n \u003cp\u003eGroup II\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 12.0748%;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 12.585%;\"\u003e\n \u003cp\u003eMale \u0026nbsp; (n=8)\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 18.0272%;\"\u003e\n \u003cp\u003e59.15 \u0026plusmn; 14.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 15.3061%;\"\u003e\n \u003cp\u003e57.4 \u0026plusmn; 6.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 14.2857%;\"\u003e\n \u003cp\u003e72\u0026plusmn; 22\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 11.9048%;\"\u003e\n \u003cp\u003e4.9\u0026plusmn; 1.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 15.8163%;\"\u003e\n \u003cp\u003e0.14\u0026plusmn;0.02\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003eDose rate measurements were initiated between 4 and 6 hours after RAI administration, which was designated as day 0. Subsequent measurements were performed on days 1, 3, 5, 7, and 10 (Table 2). The working distances of 5\u0026ndash;15 cm and particularly 15\u0026ndash;30 cm, where dentists spend the most time with their patients during procedures, were identified as critical distances in terms of radiation dose exposure. Since RAI accumulates predominantly in the anterior neck region, including the thyroid and salivary glands of hyperthyroid patients, this anatomical area was selected as the reference site for all measurements (Figure 1).\u003c/p\u003e\n\u003cp\u003eTable 2. Measured external exposure rates (\u0026micro;Sv/h)\u003c/p\u003e\n\u003cp\u003e\u003cimg 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ETWCgSgRERERNYKBKBERERE1goEoERERETWCgSgRERERNYKBKBERERE1goEoERERETWCgSgRERERNYKBKBERERE1goEoERERETWCgSgRERERNYKBKBERERE1goEofRiWZcGyLPi+b2YR7ZTnOSzLqqTFcby1TZVlqfIsy0KappV8KQxDWJYF13XNrHcRhmHta6dpqspWly+labqR7/u+em4cx5W8fXBdt1J/8rOQD5Pruq/W+77JMuZ5bmZVyl6WZSVPtgfLshCGYSXvEMx2a5ZP0ts+UdMYiNKH4LoukiSBEAIXFxeNdPL0cbXb7cp2mqa4ubmBEAJCCNi2XQlGu90uoiiCEAJZlqHf71e+1OUXflmWEEJgtVqpvPfiui6m06mZjDzPsVwuVdmxDi5NZVmi3+9X0sIwxGg0Usc1HA73GuyFYYiiKNR2WZYYj8eq7J7nVQJl3/cxn88hhECSJOj3+7XB4D7FcbzRXiTXdVXZoyiq9ENxHKPT6UAIgaIoMJ1ODxLo67rdripfEARwHMfcBZZlVdo+UeME0ZFLkkQ4jlNJAyCKoqikEdXxPE8kSSL07k6m6fQ2BUBkWVbJM7fN5+9DFEUbbd98X/PYJM/zNp5vPtfzPBEEQSXtvSRJosom39d8/yzLVL0XRVGpYyGEcBxHRFFUSTuEoig2PnOZLmVZJjzPU9vmsQVBUMnfN/P9646hqfok2oUjonT0lsslut1uJc1xHDw+PlbSiExxHGM0GpnJWK1WeH5+rqTpbcrzPFxeXgLr0dMgCNBqtYD1awZBgNFo1Mj0Zq/Xq2x/+fJlY+QrDENMJpNKGmqea9s2zs7OKmnvoSxLLJfLjfczt09OToB1OWzbVnUsua6L09PTSlqTbNtWf7fb7Uodm8d2dnZW2X/fzPeX7y3rWC7TWCwWr07dEx0SA1E6emVZbnxZuq67EUgQ6eSUrhncYD2FORwOK2n6FPLDwwOwnsZcLpeVgOPm5gZlWaopZMdxaqfGD+Xnz58Yj8dqO01TdDqdNwVB8/kcg8HATP5r2wJh0+PjI6IoMpOV1Wq1EWA1Ta4Dfc1iscD19bWZfDB5niMIAtUObm9vAUAtzfA8b+MCn6gJDESJ6J80Ho+3BlmTyQSO41Ru7ACA8/NztY/rugiCANPpVK2jLMsSRVFgMpmoL/jxeIzZbNbY6NJisVDB2raRyDppmlYC2Pfy1iAU6+Bo22cUx7EKno7JZDJRgZzjOLWfe57nuLi4eNPFwL6Mx+PK5zCbzTAajdSF2Wg0QlEUB1+DS2RiIEpHz7ZtPD09VdJWq9VRTdnRcYnjGLPZTAWZ8qYdS7sTerVaVW7s8DxPBQ6u62I0GmEymbx604wevB6a7/tq9BYAfvz4gel0qo57OByiKIqNadjfCVh/R1mWmE6nlSAfAPr9/sYNhrsC1l2j2cdC1vuvX7/MrJ0XQYewbUmK7pjrlj4XBqJ09DqdzsaoQ1EUjQYAdNwGg4EKMsX6Dmz8d0fPxhdwnueYTqfqi1uOesq1db1eD57n4efPn7Btu3Z9suM4Bx/9knfA6+RonXxEUQTHcSDWvwwgdbvdrUHg37Btu/L+Yn1XdpIklfeTd5jX1Zm8s77JQO6tzLW5WF/E6BcHhyZH7812LtuwydyP6NAYiNLR6/V6WK1WapQkDMPK2ieiPyV/qifLMvWFLNvV/f292m82m+Hr168AgKurq8rPIoVhiKurK7V9CGEYotPpqDKXZfnmnwqyLKvyc1NxHG9c6O2TLKc+GitHS8uyRLfbrQRy5kjqsZA3/+iBnOu6mM/nlX22jaTvQ5qmWC6XlSBe1t/l5SWGw6H6rGU/StQ48zZ6omMFQAA46E+i0L/B/ImjIAgEgI2fRpLkT9/Ih/nTOFEUqbx9/fyR53mVMsifDnIcp5Ju5uv0n2+SP5VkPvZ9Pun1Zx6TfGRZpj4j87Gv+t3GLIf8uSOz/vRyme1FPra1r32Qbdp86G1XP7Z9f+5Eb2UJOXdCRERERHRAnJonIiIiokYwECUiIiKiRjAQJSIiIqJGMBAlIiIiokYwECUiIiKiRjAQJSIiIqJGMBAlIiIiokYwECUiIiKiRjAQJSIiIqJGMBAlIiIiokYwECUiIiKiRjAQJSIiIqJGMBAlIiIiokYwECUiIiKiRjAQJSIiIqJGMBClDyNNU1iWhbIszSyiWq7rwrIsWJaFPM/N7Eq+7/sqPc9zlW5ZVuU5AOD7fu3z3lMYhuo9wjA0swEAZVmqfdI0Ven6cW177j7Fcby1fvQyWzXns5kfx3Elf99e++ybrttdzLoz6xbrduW6rplM1BgGovQhhGGIfr9vJhNt5fs+5vM5hBBIkgSXl5eV/DzPMR6PIYSAEAIPDw/A+stcT/c8r/LFHccxVquVyl+tVu8eLMVxjLIs1XuUZbkR9IRhCMdxkGUZhBDo9Xoq3XVd9dzpdFoJUvdNvpd8/9lsVim7XuYsy+A4TiVgur+/R1EU6vmDwUDl7VtZlmi32+r9kySpBKNN1+1rut2uKlsQBHAcp5Lvui6m02kljahpDETpQ5hMJsiyzEwm2moymcC2bQDA+fm5mY27uzsVvOkeHx9VUAoAo9EIRVGoYOnp6Qndblfld7tdPD09qe33cHNzg9FopLYnk0klgIjjWAXZrVZLpWMdTF1cXKhtz/Pw/Pxc2Wff9OAxiiLM53NgHaR6nqfK3Gq1EAQB7u/v1f5PT0/qczu0+/t7BEGg3r/X68HzPBVsHkPdbpOmKVarldq+vr4G1hdc0mq1QhRFapvoGDAQJaJ/kh7MdLtd3N7equ08zzGdTmunfs3g9OTkBNBer9PpYDqdqi/46XSKyWRSec7fKooCLy8valu+t3zP4XCIq6ur2unri4sLDIdDlGWJsiyxWq0OOqpo1t/p6akaUX5+fq4ESwBwdnaGxWIBrANs+bnULaXYt6enp43pbNu2sVwugSOo213MepdtRrZfomPFQJSI/llyrWJRFJX0k5MTNYU5HA5r1wJKj4+PlVGkXq+HKIrQbrdhWRaEEJX934PneZURUT04StNUTbnK6ePhcKgCt8FgoKZlu93uRuB3aMvlUh3L169fURRFZTpbH03+9u2bmrJvt9sb60v3rdPpYDabVYJgve6PrW53yfO8MrpLdKwYiBLRP2swGKj1cu12WwUY+pezWK8DNddgSre3t7WjXjI43Uew9PDwgKIo1IinDDxbrRaWyyW63a4qU6/Xg+M4uLu7q7xGFEUoimLrcR2CDOL0qfgoitDv99WxTadTNd0tP5dWqwWxXl96yDWYvV5PtRVZvtlshk6nU9nvGOr2NePx+N1H6on2gYEoEf3zJpMJHMepTHfrRqPRxpQs1jenmF/mcRzj6elJBbnmzTjvRY7YykA5CAJzF0VfsxqGIc7OzjAYDFAUBabT6cbyg0Opqz9Zb3LkE+uR0DpRFB18DeZkMlHlS5IE0Ka9j6lud4njuDKiTnTMGIgS0afw2k/WmFOYcRyj0+lspC8WC5ydnantJEnUzTj7kKYpZrOZuvmk0+nUvp8ctZvP5zg9PQXWxxRFkVqDeUi+728EoabLy8tXp4/lsTSh3+9XlmUcS93uIkeQzZvYiI4VA1Ei+ufleY7VarVxQ4d0eXlZCZrkKJe+vxz1tG0bNzc3Kl1Ole+D/Nmyoigqd3IXRaHKKG+8kmV1XbdyY9Zisajc6X0Ivu9jNBpVbrLSp9jL9e9ddrvdrcFqWZZYLBZbP7N9kr8lGkVRZVnGMdTtLmmaYrlcVsq8j9F6oncliD6AKIoEAPVIksTchUgpiqLSXjzPq+QHQVDJL4pC5XmeV8mTjyzLavcxX/s9yNff9drbyi+EEI7jqLwgCCp5+2bWm3wIIUSWZbX1KenldhzHzN67JEm21qnUZN3uYrZp+dD7SrNtbztGokOyxD5u+SQiIiIiegWn5omIiIioEQxEiYiIiKgRDESJiIiIqBEMRImIiIioEQxEiYiIiKgRDESJiIiIqBEMRImIiIioEQxEiYiIiKgRDESJiIiIqBEMRImIiIioEQxEiYiIiKgRDESJiIiIqBEMRImIiIioEQxEiYiIiKgRjQWivu/Dsiz1yPMccRybux1cmqaVcrmua+7y23zf33psaZpufY+yLGFZFsqyNLMQx7EqYxiGZrZiHs+2h+/75lOPyluPl0jnuq5qN2mamtmVfP0cyPO8cn6Y9P5r3+eO3vZNso8wj08ve57nleccgl7muvqR5X7tM6nL3zf9/eVD73P0Y2uibt/Csqyt3znbjouoMaIBAITjOJU0z/MEAFEURSW9KY7jiCRJzOSdkiQRZpVGUSQAiCiKKulCCFEURW1dSI7j7KwT+fxd+9TVq3lsr5WjaUmSVOoPgMiyrLIPkcnzPNXu5bmpt5ssy2rP8aIohOd5atvzvMq5EUVRZdtxnNrz+z3sOi+DINg4JrEujyT7n239wz7Una9BEFTyZb9l1v9rn9m+JUmyUVee56kyJElSqd9D1+1rsixTdVvXJpMkOWh9Er3FwUdEfd+H4zhYrVaV9IeHB0RRhF+/flXSPwJ5dblcLvFf3/QfebXsOI629/8IwxBRFJnJwDpvPB6byRW2bSMIAjiOgx8/fpjZyPMctm2byRts20YURSiKonb0tWnn5+cYDAZq2/O8Sj6RqSxLjEYj1f57vR4cx8HPnz/VPnd3d+j1etqz/vP4+IiHhwe1PRqNKufG09MTut2uyu92u3h6elLb78V1XURRtNFXYj0qN5/PIYRAq9VS6XmeYz6fq2153jw+Pqq0Q9DP1yiKKmXq9XqVflJ6y2e2b+fn55U+syxLrFYrVcej0ajSL0dRVNv3NqXVakEIsfU7Z7lcVtoL0TE4aCBaliVms9nWAGswGKiTRE6NhWFYmULQp0Ws9VSVPj0lgz9z2/d9hGGoXs/aMuX9VvrrCCEghMBkMqnsMx6PKx2yLgzDjf2lNE3R6XTw5csXM6vW1dUVptPpxvHc3d3h+vq6krbNzc0NPM+rdML6MeZ53tg0jl6mOI5h2zY7U9qpro24rovT01Ng3b9Mp1NYNVOYZnB6cnICaO2w0+lgOp2qvmU6nW49l/+UXLKzWCxq+6vhcIirqyuVJ4+h1WptXHw6jvPmvuQ9mPV3enq6dfmR7rXP7BDMuru/v8fV1RWw/p4pigLn5+cq//T0tBJkH7M0TVWbb2LJA9E2Bw1E5VX5a51iWZZot9sAgLOzMxXkpWmKm5sbFfh5ngfLsmDbNoqiqLyGfsUdhiFmsxmm0yk6nY56rj6q8Tssy1KvU3dlj3Xgq4+q6GSgaXZ6WB/7crnc6Mx3kcHu/f29SjODUlO/31dfYpZl4erqqlLeMAxRlqU6xsvLy8rzD01ebAyHQzOL6E1Wq5U6r05OTlTbHg6HsGrWX0qPj4+VmYter4coitBut9WF6Hu7vb0F1iNwZn+Vpqka8RJCIEkSDIfD2vWKZVnCdd2NAO+QlsslRqORmfwm+mfWhMViga9fvwKAmq3T++0vX75sfPccq/PzcwghUBQF+v3+my4OiA7hoIHoNuYNNff398iyDADw7ds3tZ85LSJHIV67uptMJvA8D0EQqE7NnG77HUIILJdLWFtuZorjeGvH+1qguWukdJcoiipB2v39/c7R0CRJ1Bex+WVcluXGKM+fBu3vxbZtCCGQZRmm02ljo7P0McVxrII7GMGEDPS2tanb29vamQ0ZnNbdjPO3ZrMZRqNRZUq4KArkeY7lcolut6vKJKew7+7ujFcBfvz48Uf9yXuR/eufBMLmZ3ZopTEt/9HJNi/7UqzrmKhpBw1E5UioueZHrhlyHAdJktR2+gA2rjxt24bjOHh+fq6kv4WcbvtTk8kEQgjM53MVQMsvsuFwqEZLLMtCURQYDofwfR8/fvxQ0yNyhK8oCliWhf/zf/4PZrOZypOjwo7jvBpsyzqTHcvT01PtiOs2sm7jOK698j8WrVYLURT90QUEfU5ypHBXQDEajWrbVN2FYRzHeHp6wmAwgBACs9lsaxD7XnaVHVsuFHfNvBxKXf29xVs+s33Tp+WhfWfo7eTl5WXresxjNx6P97K2meh3HTQQbbVacBwHw+GwttN/jeM4WC6XZvJfrSH6205aXl0KIdDpdNRUnf5wHAdRFOHh4UEFsPIRRREcx4EQAv/7f//vSp4cFS6KYusIqk6OiqZpiu/fv5vZb6J3TH/yGR3C33ze9LmUZblzrbbO7AviOK4N5BaLBc7OztR2kiTvvk7Q87yNC3as+9BOp1P7fp1OR/0tR07f0m/si+/7fxSE/s5ntk83NzeVGTk58KHfUPv8/Fx7EfBR6O2YqCkHDUQBqA7UcZzfDnTkTTnyaln+2+v11JfFy8sLoI0MtttttZ/eef/48QNBEKjt97DtbtBDkZ3m7e3tb48kyM70+/fv6oJh36M8f2o0Gm1d+kAklWWJbre7sfa5zuXlZSVokv2HHsjJ59q2jZubG5Uup8rf0+XlZeWCPQxD1V/1ej0URaHKKG+8kmXN8xzj8bhyPNuOe19836/cAZ/n+auzOvjNz2yf8jyH67obFyHj8VgtDyvLEsPhcOcSqGM2Go0aD/aJgP/WRzVC/gae/pC/z6b/Fpr5O23yd/H0/evy5N/yN9M8z1O/qQmg8juBOv037ure40/s+p1B8zcJdbIe6n6nTj9WfZ8gCNRv89XV8a6H/vty+m+Uyof+W4CHpH9u2FIfRDrzPDbbsHlu6G3KbG/yoZ8fb+lL/pZ+DHXvUVd+s1+Qj239zz6Y7y0fktm/y8/ktc/skPR+1KTX8bH9JqfZb5u/h1v3eRA1zRJNDuEdkO/7sG37j6aKTPKmnm3+xSqVoxLvUX9EREREaGJq/l9grgE1H0RERET0uk8RiPq+r35HtIn1Rh9dGIaYTqesPyIiInpXn2ZqnoiIiIiOy6cYESUiIiKi48NAlIiIiIgawUCUiIiIiBrBQJSIiIiIGsFAlIiIiIgawUCUiIiIiBrBQJSIiIiIGsFAlIiIiIgawUCUiIiIiBrBQJSIiIiIGsFAVBOGIfI8N5MPxvd9lGVpJhMRERH9kxiIrvm+j06ng1arZWb9Ecuy1GNbcJumqdqnLEs8PDzAcZyt+392vu+r+nJd18wmquX7PnzfN5MRx3HlPN0mDEOEYWgmb33d91aWpeojpDzPd/Yxu/IORfZvuy6u6+rWdV1V9jRNK3mHEobh1rZxDHX7GsuyEMexmQysj439Jx0TBqLrL6SLiwv0ej0z64+4rgshBIQQiKII7XZ7ozN2XRf9fl/tZ9s2AEAIgXa7XdmX/vsyvri4UPW1Wq3MXYg2WJaF2WxmJiPPcwyHQxRFASEEgiCoDSrTNMV0OjWTt77uPnS7XTMJ7XYbSZJACIEkSSp9xlv6n30LwxD9ft9MrqirW9/3MZ/P1XH1+/3Ggj1Zh0IIlXYMdbuLvEDZxnXdjTonatqnD0TLssRwOMRgMDCz/kie55jP52pbvu7j46NK830f3W630sHpoijaGCX47H78+PFunxF9HjLINL28vMBxHHUB2Ol0Ni5uyrLEcrmE53mVdOx43fcWhiHG43ElTQY+5+fnlX/LsnxT/3MIk8kEWZaZyUpd3ZZlidFopD6TXq8Hx3Hw8+dP7Zn7F8cxrq+vzeSjqdtdWq0WhBBwHMfMAgCsVitEUWQmEzXq0wei9/f3G18ockoJ2jSMnObQp43qHq1WS3WkkuM4+PLlC7DuzOQX3rbpna9fv/KqVVOWJabTKSzLYoBO7+L8/BxFUajz+vb2Fre3t5V9wjDEZDKppB1SmqbodDqq75Bs24bjOOpcuL+/RxRFsG371f7nWNTVrSy/znVdnJ6eVtL2bTgcwnGcjRHyj1K3RB/Npw9EF4sFzs7O1Hae52pKybIsNUU0HA6B9RWlPmVjPkxlWcJ1XdXB3t3dwXVddDodNapiTsXLfY9pyqdpsn7n8zmsV9adEb3Gtm1kWYbhcAjLsjAajSpBUF2gdEhyxHDbcqHVaoXZbKYumLfNFpj9zzH4nbpdrVZb62AfyrKs9OV1AwXSMdYt0Uf06QNRU6vVQpIkwDr4AfBXV7w/fvyodLrz+RyXl5eqc5VTQHWL8n/9+mUmfUr6KMRqtUIQBBwZpXchpyn1i0E5EmmOfh3SW4I1z/PgeR6Gw+HWYMnsf5r2O3Ubx/HGKPW+6eV6eHhAFEW4vLys7CMdW90SfVQMRH/Ta1Pzurd0unKajd7u+vp6Yz0f0e/I8xyXl5cYDAYQQsDzPHUn8Wg0Qr/fV+f0bDbDdDo92J3GaZqq0U7LslSQ7DiOumC1LAuTyUQFS3U3zbyl/zm0t9atDKybHm0cDAYoisJMPsq6JfqoPn0g+rsdyVun5vM8r51a63a7WC6XlTRoNxzQ25hfXES/4+fPn5U2NJlMUBQFyrLcOMc9z0MQBAe7+On1epX3lzf9FEWBXq+ngjTZdw0GAziOU7lpZlv/07S31G1ZlhiPx1uXGxyaOVBwrHVL9FF9+kD07OwMi8XCTP4reZ5jPB5Xpm3kVPL3798xnU7Vl0kcx3BdtxIQH8towLF6y7Ql0S6np6eYzWZqFPHx8bFyF/0xOzk5AbTlPGVZoigKdTG7q/85dmVZotvt4uHhQaU1WfYwDCvLAz5y3RIdLfHJFUUh9GpIkkQAUI8syyrbr4miqLK/fERRpPbRX9NxnMrzxfo1giAwkz8ts06zLDN3IarlOM7W89dsV9t4nrdxPu563fcm+4uiKDbSzHPCPCb50PufQzDLkSSJuYsQRt2afa98mHW/T2YZ9HKbx9RU3e4iv8/kw/O8Sr7neZV8vU0RNcUS+nzyJyV/wuVYpoKs9d36RERERP+yTz81j3UAulgstv6XaIfkuu7OH4ImIiIi+lcwEF17eHjA09PT1p9BOQT539txbSgRERF9BpyaJyIiIqJGcESUiIiIiBrBQJSIiIiIGsFAlIiIiIgawUCUiIiIiBrBQJSIiIiIGsFAlIiIiIgawUCUiIiIiBrBQJSIiIiIGsFAlIiIiIgawUCUiIiIiBrBQJSIiIiIGsFAlD4Ey7I2HnEcm7sRbfB9H77vm8kAgDiOYVmWmQysnyfbmilNU5WXpqmZ/S7099/1Hr7vb5wL8rgsy0Ke55W8Q9Drx3VdM1sJwxBhGJrJjdLLbrYbvV71xzHRy2W2C6JjxECUjl4cxxBCVB6O4+Dbt2/mrkQVlmVhNpuZycA6gBsOh2YysA6QbNuGEAJZllWCqTzP0e/3VVscjUbvHuyFYYjRaKTev9/vm7sA63PDPL40TXFzc6PK1263UZZlZZ99Muvn6uqqNhhN0xTT6dRMblSe51gul6rsq9Vq4yJA74eSJEEQBJX8Jvm+jyAIIIRAURQYDofv3jaJ3hsDUTp6ZsCZ5zlc14Vt25V0IpMQYmug8PDwgCRJzGSUZYnpdIrr62sAQKvVguu6KiAZj8eIokjtPx6PMR6P1fZ7uL6+RqvVAtbvX0cGGI7jVNJHo1GlPFEU4cePH5V99unu7q5SP4PBANDKi3UdL5dLeJ6n0o7ByckJJpOJ2u52u+rvsizVsUi3t7f4/v17Ja1Jq9UKnU4HAGDbNhzHwcvLi7kb0VFhIEpHzww47+7ucHl5WUkjei+Pj49wHKfS7mzbxnK5BADMZjN8/fpV5X358mVjVPJv6e/t+35twDwejzcCo7IsURQFzs/PVdrp6Snm83llv30qyxJPT0+VNNd18fPnT7UdhmEl4DsWer2naYqyLNHr9TbysD7O1Wq19UKhCd1uV42eywt2WX6iY8VAlD6c+Xxe+aIlek/Pz88bU8lnZ2coy1JNcZ+cnKg8+fd7T3/LtYp1Qa7v+3h4eDCT8evXL8AImr58+YKiKLS99uvi4gLT6bRSH6vVSv19rEGozrKsrcshpMfHx8qI6TGYTCbwPA+WZWE8Hte2EaJjw0CUPhROy9Nn0ev1IIRAFEXo9/tqaUAcxxiNRubuR2MwGMDzPDiOo26aKYoCX79+RZqm6HQ6R3/+yjWWs9ls44Yl6dim5XVRFGE2m/FmJfoQGIjSh8Jpedq309PTyggeADw9PcG2bRVAyZFH/e99BVcysHt+fgYADIdDtNvtSpA3HA7h+37t6OzLy8vGOtJ9e3h4UDf0RFEEx3HQarUwGo3Q7/dV2WezGabT6cYI9DGwbRtJkmy0BRzptDzWI+WXl5cYDAbIsgzD4XDjZiuiY8NAlD6U6XTKNU+0V+fn5xtT2WVZqptAPM+r3ADy8vKy95tu9CBXv2tbrH9BIooiPDw8qBtU9ED5+fm5sSnksiwxHA7VzVOr1apSds/zEARBbbB3DL58+WImAQDu7+9xdXVlJjduNpupMrdaLQRBoNY2Ex0rBqL0YaRpuvUOaKL3Yts2giBQ05ppmmK1WqkLoNFoVJka7/f7e50ql3fxmzcmbaPfxS8DQfkLAIeUpikcx0GSJB/24nHbLyLc3Nxs/JrHMXAcB3d3d2p7Pp+rCyiioyWIPgjP80SWZWYy0VaO4wgA6qELgqCSZ7Ytz/NqnyeEEEmSqLwkSczsv6aXy3EcM7vCcRwRRVElLYqirce1b/p7v8bzPBEEgZncmNfahBBCZFkmPM8zk4+GXn6zXRAdI0v813CJiIiIiA6KU/NERERE1AgGokRERETUCAaiRERERNQIBqJERERE1AgGokRERETUCAaiRERERNQIBqJERERE1AgGokRERETUCAaiRERERNQIBqJERERE1AgGokRERETUCAaiRERERNQIBqJERERE1AgGokRERETUCAaiRERERNQIBqL0YaRpCsuyUJalmQXf92FZFizLMrPok5LtxXzI9hOGoUoLw7Dy3DzPVZ7rupW8Q9HbdBzHZnal/NvafZqmjZUfRj3mea7Sy7KEZVlI07Sy/zHQ201d3el1XtcXHQvXdWvbNtGxYSBKH0IYhuj3+2YysM6zbRtCCGRZVvvlQZ/P8/MzhBDqkWUZPM+DbduI4xidTgdCCBRFgel0qoK9siwxHo/V81zXrQ0E9ykMQ4xGI1Xu4XBYG7Tpx2cqy3LrOXMIvu+j3W6jKAoIIdBqtYB1oOc4jrn7UcjzHMvlslKnvu+rfNd1VV4URUcZ5MlA+urqCkIITCYTcxeio8JAlD6EyWSCLMvMZJRliel0iuvrawBAq9WC67q1X9r0uXz79q2yfXd3h8vLSwDA6ekper0eAMC2bQRBgMViofZ9eHhQf19cXKi/D6XT6ajArdVqwfM8LJdLlR/HsWrz24RhiCiKzOSDkAGaEAK2bVfyer1ebeB8DF5eXiqB23g8xmw2U9vz+Vz9/fXrV/X3scjzHP1+H0VRYDAYmNlER4mBKH1oj4+PcByn8mVn23blS5s+JzMAmk6nKviU/0pnZ2dqf/15eZ7j5ubm4F/qZvls28bZ2ZnaHg6HcBynMlqnC8OwsZEweXF4cXGhprA/yoWhWe9fvnypjN7qbaPdbjdWx9uMx2NEUQTHcWBZ1tb2QXRMGIjSh/b8/LwxFX92dnbUa7fo8PI8h+d5ZrKyWCw2Rhhd10W73a6kNWU+n6tguCzLytSxuf4yTVN0Op2NQPxQ7u/vVV3LKex+v/8hz8mfP39iPB5X0uTa3GNTliVmsxmenp4g1ktOZrPZwZeVEP0uBqJE9M/Tp+VNeZ7j4uJiI3BbrVbqC9282DmkNE0rwZBezoeHB0RRpI6tLEssl8uNkb1DWiwWuLi4UIGz/Pf+/t7Y8/gtFouNupxMJhBCwPM8OI5zNAG2nB2So7RyycnNzY25K9FRYSBKH9rp6SlWq1Ul7enpaSOooM9Nn5Y3jcfjnVPvWZahKAoz+SDeElgOBgNVvh8/fmA6naop8eFwiKIoGr/De9do9LHyfb+yVtgk8379+mVmHY1Op2MmER0dBqL0oZ2fn28ECWVZsgMmJU1TBEFgJgPr6fddwQYAnJycmEkH0+1237QOUa5jlKN1+p3djuPU3jS0LxcXF5Ubv6RjvLlnG/mrBa85prv/ZV9oXnB0u93KNtGxYSBKH5qcfpLroNI0xWq12jmCRJ/L7e0tvn//bibDdd3KXdBpmlbWWko/fvxo5O5zy7Iqo/1xHG8EGVgHTbe3t2ZyY759+4bZbKZuUJLnpPwVgGMXhmHlVwvKsqxdZyl/o/VYjsu2bXieV/lJqX6/X9v2iY6KIPoAoigSANQjSZJKvud5Ko9IKopCOI6zkaa3JfmQ+73W1vYty7KNsgEQnucJIYRIkuTN5YuiaOP4D8GsY515fEEQVPKb5DjORr0DEEVRHHW5dXpfuKttEB0LSxzrD7oRERER0T+NU/NERERE1AgGokRERETUCAaiRERERNQIBqJERERE1AgGokRERETUCAaiRERERNQIBqJERERE1AgGokRERETUCAaiRERERNQIBqJERERE1AgGokRERETUiIP8X/OWZZlJRERERLRnBwjz/spBAlEiIiIiIhOn5omIiIioEQxEiYiIiKgRDESJiIiIqBEMRImIiIioEQxEiYiIiKgRDESJiIiIqBEMRImIiIioEQxEiYiIiKgRDESJiIiIqBEMRImIiIioEQxEiYiIiKgRDETpw7AsC5Zlwfd9M4uolu/7b2o3lmUhz3O1nee5ep5lWZV9ASBNU5WXpqmZ/S70ssdxXMnT39913UoeALiuq/LDMDSzAQBlWcKyLJRlaWb9Nb3uzGOQ77ut/vSym3mHIj9/vU2YeXVlDMNw43ibEsfxRpvf1aaIGiOIPgDHcUSSJEIIIaIoEkEQmLsQVURRJBzHUduO44goiir7CCGE53kCgMiyTAghRFEUwvO8Sr7+OlmWCb3rdBxHPfe9BEGgXlO+n2z/WZZV2r/jOJXyBkFQ2dafq3McRwAQRVGYWX+lro4dx1Hvo38O8thknud56u8kSSqfy6FEUSQAbH3vbX1PFEWqnoui2EvdvpWsV7NdbGtTRE3iiCgdPTni0Ov1AACDwQDT6XQvIzn073h6ekK321Xb3W4XT09PlX3iOMbl5WUl7fHxEQ8PD2p7NBqhKArV3sbjMaIoUvnj8Rjj8Vhtv4dOp4NWqwUAaLVa8DwPy+USAPDy8oLJZKL2HY/HmM1marssS1xcXKhtz/Pw/PystrEeuXvvMkvfvn2rbOd5Dtd1Yds2AKAoCnz9+hVYHxsA/Pr1C2VZYjQaqf16vR4cx8HPnz+1V9u/wWCAoijMZGBdt2dnZ2YysD5u2UfZtg3HccxdDmY8HiMIgkrarjZF1CQGonT0lstlJaAAAMdx8Pj4WEkj0nU6HUynUzW9Op1OKwGcTD8/P1dp0C54pJOTE2AdXADAbDZTgRQAfPnypRIIvgezDLZtqwDIzPvy5Usl6Lm4uMBwOERZlijLEqvVCoPBQOWnaYpOp4MvX76otPck60m6u7urBPue56ntNE0RBAFarRZs21aBkuS6Lk5PTytpTfrx4weGwyGsmiUN+nGHYYirq6uNujgE3/crF1KS2W70NkXUJAaidPTqRiFc190Y5SHS9Xo9RFGEdrsNy7Lw3yz1/xiPx5UAbZvHx0c1AiqDDxmc6n+bgcl7ms/nW8v68+fPyujmYDBAEARwHAfdbher1UrllWWJ5XK5EZTs03w+rwT7MkiyLAvL5bJycWBarVYHLetrrq+vIYRAkiRwHGdj/a1cPzqdTivphxLHMUajkZlca1ebIjokBqJE9E+TQaR+48a2UaM6t7e3jX5hp2m6cxp9sVjUBmtRFKEoikqwFIbhzsDvvZnT8pLrugiCANPpdOsNSXEc4/b21kxulL5soCiKyog71lPeMlAdDocHvSFIlsMcVa7zWpsiOihz0SjRsQmCYOMGAf3mJaI65k1tANQNG/JmFPNh3mgTBMHGDSfmTSzmzUvvqSiKjbav029GkYIgUMchb5qRN9KYxysf+zqXgiDYeG395q5tNyRlWbbxWRySrDezXKa645Pq+q19kjfd1T10r7UpokPjiCgdvU6nszHtWRTFxto+It1isags6UiSBPP5XI1ayYe8MSXLssrIZxzH6HQ6G6N5nufh5eVFbb+8vMDzvMo+76Xb7W4dwQzDsHYadj6fq3WVtm0jiiI1aqofd5ZlwPpcqhtRfQ/T6bTy2mVZoigKtZyh1+vB87zKDUllWb552cQx2LbW1lxOtG8PDw+VzzcIAniet7EkZVebImoCA1E6er1eD6vVSk09hWGIIAg2AgQinW3buLm5Udt1N71tI6dU9SBKTnGPRqNKANjv92sDwr9lWVZlfWccx+qCLAzDyl3QZVmqMruuW5nSXiwWlbvoD0XeiKST5+z9/b1K02/+KssS3W63smzCXId5LF6bCh8Oh7i+vjaTG7WrTRE1xhwiJTpWcpqpbjqSqI4+Xbmt3ZjTsNumOPVpWn2ae9vU7J/atnRAll/+/qf50JcQ6Ptsm4Y1f8PzvXmeVzu1LevbrL9tSwe2lX9fzHLoSwT0dLM9mZ9L0wLt92Rfa1NETbKEOW5PRERERHQAnJonIiIiokYwECUiIiKiRjAQJSIiIqJGMBAlIiIiokYwECUiIiKiRjAQJSIiIqJGMBAlIiIiokYwECUiIiKiRjAQJSIiIqJGMBAlIiIiokYwECUiIiKiRjAQJSIiIqJGMBAlIiIiokYwECUiIiKiRjAQpQ8jTVNYloWyLM0solplWcKyLPWI47iS77quyvN9X6XneV55num1130vYRjCdV0zuVJu+QjD0NwNvu9vHJtMsywLaZpW9n9P+vvUHQOAnfUXhuHO5+6T/PzzPK+kx3G8Ue9WTfuQfZXVQH+lv7d5DLJOm6pXolqC6AMIgkAAEABEURRmNlGtKIq2tpcsy0SSJGayKIpCeJ6ntj3PE47jVPbZ9brvxXEcAWDjvZMk2Xhvz/NElmVqO8syAUAEQVDZLwgCtZ/cZx+KohBRFJnJShRFAsDW+gdQ+QwOSZYNQKVOZZ4uSZKNOpafW1PM8khJklTK5Xne1n2JDqm5s4XoN8kvTvNLmGibXV+02/LM4Kiu3W177nuLomgjEDXbf1EUlX1kIGcGUTJPt6+AaVf9mAGRaVuAekh1dWjWnai5AGg6uNt2cSXWbUkP7s1toqZwap6I/klxHGM6nW5MT2I99SrzzGnhXq9X2T45OQEA2LYNvPK6hyDLId3f3+Pq6kpt//jxA1EUod1ub0zB6s/1fR9Jkqjt91KWpaqfuuUCo9EIURSpKWJ9nziOEQQBRqPR1mnvppj1XpYlVqsVWq0WsG5Tq9UK0JYcHLp9jMdj9Pv92nr7+vUrZrOZWo5xc3ODyWRi7kZ0cAxEieif9O3bNwghkGUZ2u12ZZ3kyckJ1jNCGA6HtV/c0uPjI6IoUtu7XrcJi8UCX79+VdvT6RSLxUIdX1EUlWBPriGczWYq7b3J957P57C0dZJ5nqMoCrVPlmWYTqeV4KgsS8zncwgh4DhO4/W7zePjI7rdrtq+u7uD67rodDoQQiAIArTb7cpz9m0ymUAIoQJ9/SKr1WohSRIVqM7n843gmqgR5hAp0bGqmyIleqtdU767plRfm77c9bp/q25qXmdOy9et+5RrHk271mm+pyAIVB3WTQd7nic8z1PT4fr5LafxD33O103Nm8xpecdxKnUpX2Pf9btNXX+ZJIn63He1K6JD4ogoEX0KURTh+fnZTAbW08V1dzeHYfjq9OWu1903c1q+jj5aqhsMBvA8b+9lv76+VlPWdS4uLswk5fz83Ew6Cua0fB3btuE4jpl8MK1WC57n4devX8B6JPz29haDwQD/XT/9tzyDqGkMRIno0zg9PTWTFHOaMo5jdDqdjfQ6u153n25ubvDt2ze1ra9X1HmeV9mW3nJs70GuU5XrFE0XFxcqcHt8fKzkOY5zsHK+Vd0FQLfbxXK5rKThCIJpucZ5uVxW6vH29rb2syA6OHOIlOhY1U01Eb1FYfwkk8mcpoyiaOOneuqm7l973b+1a2o+y7La9w6CoPIcc8pYklPH+yan3SXHcVRdmtPx5jICz/M2PodDeG1q3nGcjX5I9k/yOXXLEA5JTsNLZt02XT4iaf+9ENE7kJ2ofNR9sRLp5O851q2H03+X1ry48TyvkicfMsDY9brvySyHGfgEQbD1PNCPTw9G9NfbV9nNc7UumNPr0MzXn18X/O+bXJdaV39ixwWA0ILRfdbvNjJ43lV3ers4dPmItrGEXCxCRERERHRAXCNKRERERI1gIEpEREREjWAgSkRERESNYCBKRERERI1gIEpEREREjWAgSkRERESNYCBKRERERI1gIEpEREREjWAgSkRERESNYCBKRERERI1gIEpEREREjWAgSkRERESNYCBKRERERI1gIEpEREREjWAgSkRERESNaCwQ9X0flmWpR57niOPY3O3g0jStlMt1XcRxXEnzfd982m8LwxBhGJrJwLoMruuayYqsL5Ne9l1lzPO8cjzbHrte49D0z2BbvRGZXNdV7UY/Z8qy3GjvlmUhTVO1j95HbSPPpX0Jw7C2L9DP9bp8qa4v0c//Q/S5rutW6hXG+WxZFsqyVHl6vTfVB8k6qutnt5Ub689L5jXdT8VxvLX+9PonapxoAADhOE4lzfM8AUAURVFJb4rjOCJJkkoaAJFlWSVNCCGyLPutsidJIgCIIAjMLFEURW39SLKe6sohAdi5TxAEG/nm8b5WjkNKkkREUaS2zbIT1fE8T52TSZJU2rLeniS9OwyCQJ2fWZZtPQ/kubYPjuPUnoNZllX6DsdxhOd5lX3ElnNYpsl68Txvo597T7KvMd+jru8T689FL6/jOLWf1T5FUbS1DzXbkF7vURSp45T1fOiyS/I7qa5dmG2CqGkHHxH1fR+O42C1WlXSHx4eEEURfv36VUn/CFqtFoQQ6Ha7r17Fl2WJ5XIJz/PMLGB9RR1FkZkMrK9iLy8vzeQNQRDA8zyMx2Mza+MKfhvbthFFEYqiePNz9uX8/ByDwUBtb6s7It1kMoFt28C6Dem+fftW2U7TFEEQAOtzZDqd4vr6Glif33Wjer7vI0mSStp7Wq1WtX3By8sLJpOJ2h6Px5jNZpV9sKUv+fHjB4IgUPUyGo0wGo0q+7yXNE3R6XTMZKRpiu/fv5vJAICnpyd0u1213e128fT0VNln3waDAYqiMJMBAPP5XP399evXSt7p6Sl6vR6w7j+DIMBisajscyjj8Vi1Z53ruoiiaOP7l6hJBw1Ey7LEbDarDZCw7gBarRagTY3IqQ45zWFO6cCYZpNTKea27/tqOnzbtMrfWq1WEEJgNBqp9zC/vMIwrHyJ6HblyeMwv1C3uby8xGw225haur+/V1+wr7m5uYHneepLC0b9p2l6kOkn8/1t21bthGgbvd10u13c3t7W5gHA7e2tCo4eHx/hOE5lH9u2sVwu1XYcx3sL4F4jgx3py5cvcBynkratL5nP55Xg8OTkZC8Xm/KC2ywr1sFvu93eWDIAAJ1OB9PpVPVb0+m09jiaoreJdrtdKZt5rGdnZxvt7BB838fDw4OZrJZpLBaLvX0HEv2Jgwaij4+PwLrj3KUsS7TbbWB9MgshMJlMkKYpbm5uIISAEAKe58GyLNi2vXEF+98MxH/CMMRsNsN0OkWn01HP1a+835McIRVCYLlcqhHSbV8O0EYPtnVc4/G4Mir4ml6vB8dxcHd3V0lfLBZb36Pf71eC/Kurq0qHFsdxpf5vb28P1pHJi43hcGhmEW0lL5zM/sE0m83Uxc3z8/NGkHR2dqbaugySjuVi6OfPn5WL+119SVEUlf5X7vPeM1G7+rr5fF6ZQdIv1nu9HqIoQrvdhmVZlX78WMjBjNcsFos3X/S/l10XSPJCbDQa7f07kOh3HDQQ3UZfeG9ZFu7v75FlGWBMoY1Go0qHKzs6c9TRNJlM4HkegiBQV62j0WgvIwGSHNHtdDp4eHjY+eWwa/QAO65wXzMejzGdTtUxpmm6tZMCgCRJVJAphMBwOKx0uMPhsDKqdHFxof7eN9u2IYRAlmWYTqcHGYmlj28wGEAIgSAI0G63N2YIYEzLv8XvXhTu22KxUH3Ha33JIewKQqEFv5PJBEmSoN/vm7uoJQW7ljk1ZTKZqEDOcZza75A8z3FxcVHb3+/LaxdIs9kMo9FI5cvvwLpzguigzEWj+yQXUG9bwK3fMFN3A1Ddone5mF0uDtcXl+vbnudVFsibi/ZN5s07wni9beQNBuYicZluPhzHUQv66x7/9//+3400+dhWj+aNDHJbT8crNysJY8F9XX2Zi/UPpan3pY+tro2Ldd+gnwvmjU1Cu3lJv5HFfLzWN/wJ8+Ydk3ke7OpLiqLYqIO68/pvyNere2y7QclxHPX+URRt9FPbnrdPdd8ndbbtY34uhyBvZK17iC1lrUsjOrSDjoi2Wi04joPhcFh7Ffkax3Eq67Sk09NTM+nN3uOKVf85FDntZI5gyvWj8iFHaFerlbrClo8oiuA4DoQQ+F//639V8uQUY5ZlbxqVkaOi224ceAv9ZoH3nsL7E3/zedPnZU63Yz2CuFqtKqNI5+fnG1P5ZVmi0+moEVb5kDcrCSG2jkTtSxiGGzMcu/oS27bR7Xbx/Pys9v/169fGeti/IWcu9AfWsy1vGSVdLBY4OztT6UmSVG4QOjbm2lys25nZ/x/Cw8NDpd7lTavyM/A8Dz9//jSfdvB2S2Q6aCAK7a7DbVMau1xdXVUWsst/e72e6sheXl6A9VoZrBeUy/30Dk3ePfoe9DWh79Whvxd9KcLvTtfJ9UPfv3+HbdvwPO9Nd+3v2z7v9KV/U57nWK1WG+fA/f09rq6uKmn2+o5n2YekaVr73CaFYYhOp6OCiLIs3/SboNfX15V11peXl1tvHj2EOI4r72/bNm5ubtT2crk82nWM8uYfPZBzXbfyPZOm6dFMfV9eXlYGgcIwfLfvQKK/Yg6RHkrdFJKcgpLT8vJhTgeb+9flyb/1qXl96mLb1In8jU/9PczpuG3P/R3mUgHdrum4XVNGZtnlPlEUqWl881hee5jvY+a/R128xpxyeq9pRPp3mVPE29qpPi1s0tvdNvKc24dt7X7bMp+646jrS/T+ddvynvcEbUmV2bfXvf9b+ul9MvtRWUaz7HVLvcyHWfeHFATBRv3px2bmETXFEnLc/h/n+z5s2945PUS/J45jLBaLRqahiIiI6OM7+NQ8ERERERE+SyDq+776HVH+7M/7iOMYw+EQs9nsKH9ihYiIiI7fp5maJyIiIqLj8ilGRImIiIjo+DAQJSIiIqJGMBAlIiIiokYwECUiIiKiRjAQJSIiIqJGMBAlIiIiokYwECUiIiKiRjAQJSIiIqJGMBAlIiIiokYwECUiIiKiRjAQ1YRhiDzPzeSD8X0fZVmayURERET/JAaia77vo9PpoNVqmVl/xLIs9dgW3KZpqvYpyxIPDw9wHGfr/p+d7/uqvlzXNbOJNriuq9pMmqaVvDiOK+epycyvu0gMw3Bv7VG+9rbX1/Pryo91H1P33H3T6y4MQzNbkfvEcazS9H7R/MwOJc9zWFv6bv3YduU3oSzLnW1C70ObqluiDYJEFEUiiiIz+Y85jqP+jqJIABBFUWzss636t6V/ZkVRvOtnRP8+z/PUeZckiQAgsiwTQgiRZVnlvAyCQHieV3l+EASVbV1RFALAxnPeiyyv5HneRnnMbZMso94fHUKSJJVzVa93SfaLSZJU0uXnIjmOs/HcfZNlqyt3kiSV+jT7ds/z1HOboJctCIJKGwmCYKP9Ex2DT98SZWf9XrIs2wg6zQ637ktFF0XRzvzPiPVBv6Moio0gwnEcFSCZAUXdtvl8nXlOv7coiipBbt222c+YPM8TURQdPBA1y+V5XqUuzSBbJ8ssJUmyt2B/F/m9YLYBx3Eqn3tdX73r+PbJrPckSSplM/ObKCNRnU/fEl/rSOTVrewc5Ujmtkcd/ao+yzLhOI4IgkA9x+zseLVaJb8UAGx8VkRv5XmeCiJkm5LntRksyfO8LoiTfYbeF7w32QfI8jqOUwkk5PtuC9KCIBDFehah7hgOpa5/lRcEdee02R821RfWBaIyTf8czAsYmdZEmXWvDbDo5wJR0z79GtHFYoGzszO1nec5+v0+sF6/JIRAkiQYDocAgNVqhXUAX/swlWUJ13XV2tO7uzu4rotOpwMhBIIgQLvdrjxH7lu3Ju2zkvU7n89hbVmvR7TLarVCr9cDANi2jSzLMBwOYVkWRqNRZX34fD6HEALdbndjPd3NzQ3KslT7OI4D3/dV/ntotVpIkgT9fh+WZWE+n8O2bWDdL+j9jblWMU1TdDodtX8T5FpF2W9KeZ6jKApgfU5nWYbpdIo0TdU5fXJyovaXfx/D+f7r1y9g3XakL1++qOM5Fr7vw3EcMxnQ1t/OZjMzi6gxnz4QNckvAKw7Sqw7mz/148cPTCYTtT2fz3F5eam+EK+vr4F1B2GSHd9np3f8q9UKQRDsvAGCyBTHMW5vb81kRFEEABsXg7LNTSYTFRBiHRAVRYHJZKL2GY/HmM1mewmWZPm63a5K08+Hh4cHRFGEy8tLYF2+5XKp+pem2LZdCTTl+frz5094nofBYACs+1vP82o/G/ozDw8P6gLJvGGp1+tBCIEoitDv92u/d4gOjYHob9Lvwq176N4yMmHb9tarV6p3fX2N1WplJhPVkqOF+ohnnue4vLzEYDCAEAKe5229u7zX68FxnK2B5vn5uZn019I0xe3trSof1iNddQaDgRqV+/HjB6bTqeqPhsMhiqKA1dAsQqvVQhRFO9/74uIC0AJs/QK8bhSyKXWjsy8vL0fbf8/nc2DLaPJgMIDneXh+fjaziA7u0weiv9vBvXVqPs/z2pGJbreL5XJZScOevsz+ZduCBiJdWZYYj8dqBE76+fNnpQ1NJhMURVH7pS3Ztq0uHB8fHyt5juP8dl+yy3K5rLze7e3tzulUGQxNJpNKfxRFERzHgRDiXcv3O05PT9XfX79+rT0OGYx6noeXlxeV/vLyAs/ztD2bIz97PVB+fn6ujFYfk9c+79fyiQ7GXDT62Zh3o4qaxea/u2A+y7KN15QL8uVryUXwde//u+/32Xjaz/IQbVMUxcaNJPI8lOe4bEd1N51IURRt3Cmtn5/mnd7vwXyPun5C0n+Wx9T0zUqi5ieY5M2aouYGIHkzp2TeMHQodTcrCeMufrPs+j7H0H/X3SgmvXYzE9EhffqWaJ6QshORDxkUysdr9LtB9Yf+RaW/Zt2XxK4O5DMy69T8ciAymeexfOjnldmuJPOcrwsyt931/Z70X9bQ+wnz2Hbd/dxEIOppv6WJmkBNGL8+Yp7P+vHtOrZ9MevX/Pz1z94su/6Z1eXv02vl1vMO3SaIdrGEPp/8Scn/1cOcvmuKtb5bn4iIiOhf9unXiGIdgC4Wi8p/M9cU13WRZZmZTERERPTPYSC69vDwgKenp9r/O/hQfN/HfD5/t//vnoiIiOiYcWqeiIiIiBrBEVEiIiIiagQDUSIiIiJqBANRIiIiImoEA1EiIiIiagQDUSIiIiJqBANRIiIiImoEA1EiIiIiagQDUSIiIiJqBANRIiIiImoEA1EiIiIiagQDUSIiIiJqBANR+hAsy9p4xHFs7ka0wfd9+L5vJiOOY9WWXsu3LAtlWZq7IM9zWJZlJr8b/f3DMFTp8n3lI8/zrc+rK/e+7arbsix3li9NU5WXpmkl7xBc162UzzLqXs/X04/Ba3WLHW2KqDGC6MhFUWQmCcdxRFEUZjJRBQABQHieV0lPkkQ4jqO2gyDY2CcIgsp2Hfn6+5AkiciyzEwWYv2+SZIIsd5PL4N+XFEUbRzXviVJUjlnAVTqEoA6rizLBAB1LsttyXGcrXWwD0mSbPQrnuepMpjtRP8cjoHZps22uatNETWFI6J09L59+1bZzvMcruvCtu1KOpFJCIEgCMxk3N7eYjweq+3JZILZbKZGkNI0xffv37VnbPJ9H0mSmMnvZrlcotVqmcmqjOfn55V/Zfp8Plf7fv36Vf19SIPBQP0dRZEqU5qm8DxPHVer1UIQBLi/vwcAjMdjRFGknjsejyuf076dn59X+pWyLLFarVR5y7LExcWFyvc8D8/Pz2q7SWmaYrVaqe3r62tg3V9K29oUUZMYiNLRMwPOu7s7XF5eVtKIfsdqtdoIIBzHwePjIwBgNBqh3W7Ddd3KPlIcxxiNRmbyu0nTFNPptHZ62rZtOI6jplXv7+8RRZE6T/Tzpd1uYzKZqO1D6PV6le3T01NVj8/Pz5VgCQDOzs6wWCwAALPZrBI8f/nyBbPZTNt7v8y+5v7+HldXV2r74uICw+EQZVmqIFUPuptk1rs8lpOTE+CVNkXUJAai9OHM53M1CkT0J7rdLobDYSWtKAr193w+hxAC3W5344tbjjDtc2Tp/PwcQggURYF+v78REK9WK8xmM1jr9almMBSGocpr2nK5VEH7169fURRFpT6fnp4AbURXBk7633VrHQ9hsVhUAuPBYIAgCOA4Drrd7kZQfUzyPEcQBCogfa1NETWFgSh9KJyWp/cwmUzgOE7lxg1o09yyfU0mEyRJgn6/r547Ho83Ar/3po9u/rcU8b9RWJ3nefA8D8PhcONmpclkAiEEPM+D4ziNBXLyffWp+CiK0O/3Vb1Pp9PKdPexMKfldVEUoSiKo77ZZzweV0bD39KmiJrAQJQ+FE7L03tZrVYQQqh1pJ7n1V7g9Ho9FczFcaxGIi3LUgGqVXPn+nsaj8dq5BDr95tMJnh4eEAURWi327XB5sPDAwDg169fZtZBhGG4sTRgMBioes+yDFivA5d1r5dV/l33ueybOS2P9fGcnZ1hMBigKApMp9OjDObesnTEbFNETWEgSh/KdDrdWAtF9DfyPMd0On31i9u27UoQJYRQNysJIWpHzt7T2dkZoC0NkMHZYDCorG81OY5jJh2E7/sbQajp8vKyMn3seR5eXl5U/svLCzzP055xODc3Nxs3Ss7nc5yengLr+o+iSK1vPRZy2cNb2qNsU0RNYiBKH0aaprV3QBP9qTiO0W63kWXZ1i/uOI4Peud2ndFopJYD6DefYD2FXBRF7brpNE3huu7WY9sX3/cxGo1UgJnneWVdaLn+vctut1sJVkejUeWCoN/vv3qBsA/blgC5rovb21u1vVgsjmpZQZqmWC6XlaUj25YP6G2KqFHm7zkRHSv99/yI3sJxHPVbn3p3J39jUf/dRUn+lqV81P2OrWT+hud78TyvttySWUbzdznl4y2/hfre9Pc3j0Ev37ZzWdYpGvyNziAItr633qaaqN9tZJs2H/I4XmtTRE2xhFy1TERERER0QJyaJyIiIqJGMBAlIiIiokYwECUiIiKiRjAQJSIiIqJGMBAlIiIiokYwECUiIiKiRjAQJSIiIqJGMBAlIiIiokYwECUiIiKiRjAQJSIiIqJGMBAlIiIiokYwECUiIiKiRjAQJSIiIqJGMBAlIiIiokYwECUiIiKiRjAQpQ8jTVNYloWyLM0s+L4Py7JgWZaZRZ+c7/vwfd9MRhiGqs3EcVzJy/Nc5W1rU9te973obTpN00qeWb48zyv5el7d+bJvcRyr9zfryCy7ST9u83M5FL1tmGV0XVelh2FYyTsW2+pOPy7Xdc1sokYwEKUPIQxD9Pt9MxlY59m2DSEEsixjB0uKZVmYzWZmMuI4RqfTgRACRVFgOByqgK0sS4zHYwghIISA53kbbWrb676XMAwxGo1UmzbbfrvdRpIkEEIgSRK0222V57quKnsURQcPlmTQLMswm81UGV6rW/1cFkLg5uamNqA6BFkGIYRKC8OwUr/T6XTjIqFJMsivk6YpptOpKrvrugdvG0R1GIjShzCZTJBlmZmMsiwxnU5xfX0NAGi1WnBd96i+HKg5QggEQWAm49u3b+j1egAA27bhOI7Ke3x8xMPDg9oejUYoiqIysrjtdd/L9fU1Wq0WsG7TOlmO8/Pzyr8yfT6fq32/fv2q/j6kwWCg/o6iSJXptbrVz2UAuL29xc3Njdo+hDiOK2XQlWWJi4sLte15Hp6fnyv7NKnVakEIUWnP0vPzMzzPU9sXFxeNjJYTmRiI0of2+PgIx3Fg27ZKs20by+Wysh+RTm8vYRji6upKpckAVTo5OQGM5+yb/l6+7yNJkkqe4zhqNOv+/h5RFKnn6M9tt9uYTCZq+xDM+js9PVWjnmaeXrcyKPr161cl37wI2LfhcAjHcTaWFGAdvMnR87IssVqtKkH3Mfv69Stms5m6SL+5uTl42yCqw0CUPrTn5+eNadOzs7ODfnHRxySnMafTqZlV8fj4iCiKzOS9k2ui65YArFYrzGYzNQ1rBkNyLeAxWC6XGI1GZjJg1K0MsMfjscrXg9JDKMuyMh1vGetvB4MBgiCA4zjodrtYrVbas49bq9VCkiTo9/uwLAvz+fygF1dE2zAQJaJPSU5jJkmC4XC4dS3i7e3tRqB3CL1eD2K9zrPf728sN/E8D57nYTgcbtysNJlMINZrMB3HaezCTL6vubxAMut2Pp+rANuyLLTb7Y0Zj33S3+fh4QFRFOHy8rKyD9bLDYqi+JBrLGXg3+12zSyiRjAQpQ/t9PR0Y1Ti6enpYF9c9PH1ej0EQYCnpyczC2EYNj59ORgMNtYiWpaFyWSigqV2u10bbMr1mIceWZR21V9dnq3dqCTXOl5dXVX2OaTBYICiKNR2GIY4OztT6dPpdOsFzLFJ01QF/nLEt275AdGhMRClD+38/LzyRYH1KEyn06mkEe1ydnZmJqk764/hokYvgxz9lGmDwQCO4+Dx8VHto6u7ceUQfN/fCDSlt9RtHMcoiqKR0WidXn/z+Rynp6fAuv6jKMJisdD2Pl7L5bJS37e3t7XLPogOjYEofWi2bSMIAjUqkaYpVqvVxk0RRLsMh8PKndKyPentqKlp2HL9yxAyIJM3+Mip+rIsURSFuntel6YpXNfdOjW+L77vYzQaqcAnz3NV3rfUre/7GA6HauSuKWEY4vb2Vm27rlvZXiwWlbvoj9nZ2VllPfTPnz8rd9ETNUYQfQBRFAkA6pEkSSXf8zyVRyQ5jlNpN6+lC6Mt6Y8sy970/Pegv7bjOGa2yLKstmxmehAE5lP3zqw3vY5eq1tZr02UWwghkiSplMvsZ4Tx2TdVzm2KoqiU3/O8Sn4QBCqvrl0RNcESTV9yEhEREdGnxKl5IiIiImoEA1EiIiIiagQDUSIiIiJqBANRIiIiImoEA1EiIiIiagQDUSIiIiJqBANRIiIiImoEA1EiIiIiagQDUSIiIiJqBANRIiIiImoEA1EiIiIiasRB/q95y7LMJCIiIiLaswOEeX/lIIEoEREREZGJU/NERERE1AgGokRERETUCAaiRERERNQIBqJERERE1AgGokRERETUCAaiRERERNQIBqJERERE1AgGokRERETUCAaiRERERNQIBqJERERE1AgGokRERETUCAaiRERERNSI/x8628rqDuThBAAAAABJRU5ErkJggg==\"\u003e\u003c/p\u003e\n\u003cp\u003eThe radioiodine activity levels used for treatment ranged from 222 MBq to 925 MBq. The most commonly used I-131 treatment regimen was 370 MBq, followed by 555 MBq (Figure 2).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe dose rates measured separately in the two disease groups were analyzed using the Mann\u0026ndash;Whitney U test, and no statistically significant difference was observed between them (p = 0.32). However, a relatively strong correlation was found between the dose rates of the Graves\u0026rsquo; disease and toxic nodular goitre groups (R\u0026sup2; = 0.83) (Figure 3).\u003c/p\u003e\n\u003cp\u003eThe administered activities of I-131 for hyperthyroidism treatment may vary across different nuclear medicine centers, with the main contributing factor being the empirical dosing approach. Therefore, normalized dose rates are also reported in the literature, allowing for easier comparison and interpretation of the dose rate variations observed in clinical practice (Table 3).\u003c/p\u003e\n\u003cp\u003eTable 3. Normalized dose rate measurements after I-131 therapy in hyperthyroid patients: literat\u0026uuml;re review (5, 16-18).\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\" width=\"571\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 106px;\"\u003e\n \u003cp\u003eStudy \u0026nbsp; \u0026nbsp; \u0026nbsp;(Years)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 131px;\"\u003e\n \u003cp\u003ePatient type/administered activity\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 115px;\"\u003e\n \u003cp\u003eMeasurement distance\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 102px;\"\u003e\n \u003cp\u003eTime points\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 117px;\"\u003e\n \u003cp\u003eNormalized dose rate \u0026amp;units\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 106px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 115px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 106px;\"\u003e\n \u003cp\u003eJ\u0026oslash;rgensen et al. (2006)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 131px;\"\u003e\n \u003cp\u003eHyperthyroid patients, \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; (74-555) MBq\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 115px;\"\u003e\n \u003cp\u003e0.3 m, 0.6 m, \u0026nbsp; \u0026nbsp; \u0026nbsp;1 m, \u0026nbsp; \u0026nbsp; \u0026nbsp;2 m\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 102px;\"\u003e\n \u003cp\u003e0.5 h\u0026ndash;12 days\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 117px;\"\u003e\n \u003cp\u003e0.234\u0026ndash;0.325 \u0026micro;Sv/h/MBq\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 106px;\"\u003e\n \u003cp\u003eLiu et al.\u003c/p\u003e\n \u003cp\u003e(2018)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 131px;\"\u003e\n \u003cp\u003eHyperthyroid patients, \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;(370\u0026ndash;740) MBq\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 115px;\"\u003e\n \u003cp\u003e0.3 m, 0.6 m, \u0026nbsp; \u0026nbsp; \u0026nbsp;1 m\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 102px;\"\u003e\n \u003cp\u003e5-24 h\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 117px;\"\u003e\n \u003cp\u003e~ 0.035 \u0026plusmn; 0.007\u003c/p\u003e\n \u003cp\u003e\u0026micro;Sv/h/MBq\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 106px;\"\u003e\n \u003cp\u003eDemir et al.\u003c/p\u003e\n \u003cp\u003e(1996)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 131px;\"\u003e\n \u003cp\u003eHyperthyroid patients, \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;(296\u0026ndash;740) MBq\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 115px;\"\u003e\n \u003cp\u003e30 cm\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 102px;\"\u003e\n \u003cp\u003e30 min-1 day\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 117px;\"\u003e\n \u003cp\u003e0.17 \u0026micro;Sv/h/MBq\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 106px;\"\u003e\n \u003cp\u003eCui S et al (2014)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 131px;\"\u003e\n \u003cp\u003eHyperthyroid patients, \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; (74\u0026ndash;555) MBq\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 115px;\"\u003e\n \u003cp\u003e30 cm\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 102px;\"\u003e\n \u003cp\u003e4 h-1 day\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 117px;\"\u003e\n \u003cp\u003e~0.28 \u0026micro;Sv/h/MBq\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003ch3\u003eExposure dose determination scenarios\u003c/h3\u003e\n\u003cp\u003eConsidering the workflow of the dental clinic where this study was conducted, the following average durations and distances were taken into account: 15\u0026ndash;30 minutes for dental procedures performed at 5\u0026ndash;10 cm, 10\u0026ndash;15 minutes for giving instructions, observation, or finger guidance at 15\u0026ndash;30 cm, and 5\u0026ndash;10 minutes for computer use or verbal communication with the patient at 60\u0026ndash;100 cm.\u003c/p\u003e\n\u003cp\u003eBased on the above time\u0026ndash;distance data and dose rate measurements presented in Table 1, radiation exposure doses for dentists were calculated using three different scenarios. The treatment process was defined as involving patient interactions at 5\u0026ndash;15 cm, 30 cm, and 60 cm distances across three separate procedures. Cumulative doses on day 1 after treatment were calculated using Table 1.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eGroup I, Scenario 1:\u003c/strong\u003e With procedure times of 15 min at 5 cm, 15 min at 15 cm, 15 min at 30 cm, and 5 min at 60 cm, the total exposure dose was estimated at 1580 \u0026micro;Sv.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eScenario 2:\u003c/strong\u003e With procedure times of 15 min at 5 cm, 15 min at 15 cm, 10 min at 30 cm, and 5 min at 60 cm, the total exposure dose was 1501 \u0026micro;Sv.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eScenario 3:\u003c/strong\u003e With procedure times of 10 min at 5 cm, 15 min at 15 cm, 10 min at 30 cm, and 5 min at 60 cm, the total exposure dose was 1086 \u0026micro;Sv. In all scenarios within this group, exposure doses decreased to \u0026lt;1 \u0026micro;Sv by day 3.\u003c/p\u003e\n\u003cp\u003eIn Group II, radiation doses for scenario 1, scenario 2 and scenario 3 were found to be 2836 \u0026micro;Sv, 2650 \u0026micro;Sv and 2030 \u0026micro;Sv, respectively.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eAlthough treatment of Graves\u0026rsquo; disease with radioactive iodine (RAI) has been practiced for more than 70 years, the vast majority of published studies to date demonstrate that no universally accepted standard exists regarding the optimal \u0026sup1;\u0026sup3;\u0026sup1;I activity to be administered to the thyroid gland or the associated radiation exposure dose [19\u0026ndash;21]. It may even be reasonable to expect that a consensus on this issue will never be reached, since such standard values may not conceptually exist. Therefore, radiation protection measures tailored to specific clinical situations should be considered.\u003c/p\u003e\u003cp\u003eThe success rate of RAI therapy in hyperthyroidism is considerably high. However, given that ionizing radiation is a well-established carcinogenic factor and numerous studies have demonstrated a dose-dependent relationship between radiation exposure and malignancy development, it is essential to evaluate this therapy also in terms of its environmental impact [22,23]. After oral administration of I-131, thyroidal uptake progressively increases and reaches its maximum at approximately 24 hours. Due to its relatively long physical half-life of 8 days and the high affinity of hyperthyroid tissue for radioiodine, the radionuclide may remain in the thyroid gland for up to one month. While radioactive decay within the thyroid exerts its therapeutic effect via β-radiation of 606 keV, concomitant emission of 364 keV γ-rays contributes to external radiation exposure, particularly affecting individuals in the immediate vicinity of the patient. In this context, healthcare professionals such as dentists, who are required to provide close-contact care to patients following RAI therapy, may face potential radiation risks that warrant careful consideration.\u003c/p\u003e\u003cp\u003eDuring dental procedures, the distance between the dentist and patient often falls below 30 cm. Therefore, if a patient undergoes dental examination or treatment within the first few days after hospital discharge, the dentist may be exposed to a significant level of external radiation. This risk is further compounded in cases of repeated procedures or prolonged close contact within a single day, potentially leading to exceedance of annual dose limits. Accordingly, careful planning regarding patient counseling and appointment scheduling is of great importance.\u003c/p\u003e\u003cp\u003eIn Europe, 24-hour thyroid uptake values are generally interpreted as normal at 15\u0026ndash;35%, and as indicative of hyperthyroidism at \u0026gt;\u0026thinsp;55\u0026ndash;60%. In the present study, the mean uptake values of patients in the first and second groups were 72\u0026thinsp;\u0026plusmn;\u0026thinsp;23% and 76\u0026thinsp;\u0026plusmn;\u0026thinsp;18%, respectively. Two approaches are commonly employed to determine the RAI activity administered for hyperthyroidism: (i) empirical dosing based on clinician experience, and (ii) patient-specific dosimetry-based methods. The latter is considered more accurate and associated with fewer complications [27]. For instance, according to EANM guidelines, 300\u0026ndash;400 Gy is recommended for the ablation of autonomous nodules. In Graves\u0026rsquo; disease, a 150 Gy absorbed dose is suggested to achieve euthyroidism, while 200\u0026ndash;300 Gy is advised for complete ablation [28]. The calculated activity required to deliver 200 Gy in Graves\u0026rsquo; patients was reported as 436\u0026thinsp;\u0026plusmn;\u0026thinsp;381 MBq, whereas 622\u0026thinsp;\u0026plusmn;\u0026thinsp;332 MBq was needed to achieve 300 Gy in toxic nodules [29]. In our study, Graves\u0026rsquo; disease patients received an average of 370\u0026thinsp;\u0026plusmn;\u0026thinsp;50.5 MBq (296\u0026ndash;444 MBq), and toxic nodular goitre patients received an average of 490.8\u0026thinsp;\u0026plusmn;\u0026thinsp;116 MBq (555\u0026ndash;925 MBq). These activity levels correspond to absorbed thyroid doses of approximately 200 Gy and 300 Gy, respectively. No statistically significant difference was observed between the dose rates of the two disease groups; however, a relatively strong correlation was identified (R\u0026sup2; = 0.83). These findings indicate that dentists should adopt radiation protection measures when treating hyperthyroid patients post-RAI therapy, regardless of the underlying disease type.\u003c/p\u003e\u003cp\u003eDental procedures, especially those involving high-speed handpieces such as ultrasonic scalers, air turbines, and air\u0026ndash;water sprays, generate aerosols containing saliva, blood, and microbial content. Studies investigating aerosol exposure in dentists have shown that the most frequent working distance is approximately 30 cm, though procedures may be performed between 5 and 60 cm, with aerosol exposure decreasing at greater distances. Furthermore, exposure was reported to increase with procedure duration [30,31]. In our study, radiation exposure was most pronounced at 30 cm from the thyroid, which also corresponded to the distance associated with the longest procedure durations.\u003c/p\u003e\u003cp\u003eAlthough no studies specifically addressing radiation safety for dentists managing hyperthyroid patients post-RAI therapy exist, some reports have evaluated the exposure risks of family members. Culver et al. measured maximum dose rates at 30 cm from 19 patients receiving 444\u0026ndash;1110 MBq of RAI and reported values of 18 mR/h (180 \u0026micro;Sv/h), 10 mR/h (100 \u0026micro;Sv/h), and 7 mR/h (70 \u0026micro;Sv/h) at 2\u0026ndash;4, 5\u0026ndash;7, and 8\u0026ndash;11 days post-therapy, respectively. They recommended time restrictions at \u0026le;\u0026thinsp;30 cm for the first 2\u0026ndash;4 days, and at 60 cm only during day 1, with additional restrictions for pregnant women and children thereafter [2]. Demir et al. suggested a 3-day restriction at 30 cm for patients receiving\u0026thinsp;\u0026lt;\u0026thinsp;370 MBq, and 5\u0026ndash;7 days for those receiving\u0026thinsp;\u0026gt;\u0026thinsp;370 MBq. Similarly, Barrington et al. recommended restrictions of 5, 11, 14, and 16 days for patients treated with 200, 400, 600, or 800 MBq of RAI, respectively [8]. From a dental perspective, our findings suggest that patients receiving\u0026thinsp;\u0026le;\u0026thinsp;444 MBq of RAI can be safely managed after day 3, whereas those receiving\u0026thinsp;\u0026gt;\u0026thinsp;444 MBq should be deferred until after day 5.\u003c/p\u003e\u003cp\u003eICRP-60 and the 1994 NRC reports set the annual dose limits at 1 mSv for the general population and 0.5 mSv for children and pregnant women [32,33]. Our findings are consistent with published time-restriction recommendations. In addition, dentist\u0026ndash;patient interaction times and distances (5\u0026ndash;100 cm) were derived from both clinical experience and aerosol exposure data obtained during the COVID-19 pandemic. External dose rate measurements at these distances were then used to calculate estimated radiation exposures for dentists.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eThis study evaluated the radiation exposure of dentists when providing care to hyperthyroid patients following RAI therapy. Our results indicate that dental examination and treatment of patients receiving\u0026thinsp;\u0026le;\u0026thinsp;444 MBq of RAI within the first 3 days after therapy poses a potential radiation safety risk. For patients treated with \u0026gt;\u0026thinsp;444 MBq, a safe interval before dental procedures appears to be 5 days. In cases where the treating dentist is female and/or pregnant, it is recommended that these intervals be doubled.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgements:\u003c/strong\u003e Not applicable\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e: Not applicable\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData availability\u003c/strong\u003e: The datasets used and analyzed in this study can be obtained from the corresponding author upon reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConflict of interest\u003c/strong\u003e: We have no conflicts of interest to disclose.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval\u003c/strong\u003e: This study was conducted at the Radionuclide Therapy Unit of the Nuclear Medicine Department, Cerrahpasa Medical Faculty. A group of patients was randomly selected from individuals presenting to the clinic for hyperthyroidism treatment. All procedures conducted in this study were carried out in strict accordance with the ethical principles outlined in the 1964 Declaration of Helsinki and its later revisions or equivalent ethical standards. The study protocol received approval from the Institutional Clinical Research Ethics Committee (document number: 19451483/604-01-02-52947), and written informed consent was obtained from all participants.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eInformed consent\u003c/strong\u003e: Patients signed an informed consent form\u003c/p\u003e"},{"header":" References","content":"\u003col\u003e\n \u003cli\u003eSawin CT, Becker DV. Radioiodine and the treatment of hyperthyroidism: The early history. Thyroid. 1997;7(2):163\u0026ndash;76.\u003c/li\u003e\n \u003cli\u003eCulver CM, Dworkin HJ. Radiation safety considerations for post-iodine-131 hyperthyroid therapy. 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EJNMMI Phys. 2020;7:6.\u003c/li\u003e\n \u003cli\u003ePena S, Arum S, Cross M, Magnani B, Pearce EN, Oates ME, et al. 123I thyroid uptake and thyroid size at 24, 48, and 72 hours after the administration of recombinant human thyroid-stimulating hormone to normal volunteers. J Clin Endocrinol Metab. 2006;91(2):506\u0026ndash;10.\u003c/li\u003e\n \u003cli\u003eLassmann M, H\u0026auml;nscheid H. Thyroid imaging and dosimetry. In: Handbook of Nuclear Medicine and Molecular Imaging for Physicists. CRC Press; 2022, pp:207\u0026ndash;22.\u003c/li\u003e\n \u003cli\u003eStrigari L, Konijnenberg M, Chiesa C, Bardies M, Du Y, Gleisner KS, et al. The evidence base for the use of internal dosimetry in the clinical practice of molecular radiotherapy. Eur J Nucl Med Mol Imaging. 2014;41:1976\u0026ndash;88.\u003c/li\u003e\n \u003cli\u003eAbuqbeitah M, Sağer S, Demir M, Yeyin N, Akovalı B, S\u0026ouml;nmezoğlu K. The impact of different computational assumptions in 131I dosimetry for hyperthyroidism therapy. Med Phys. 2020;47(11):5810\u0026ndash;16.\u003c/li\u003e\n \u003cli\u003eVeena HR, Mahantesha S, Joseph PA, Patil SR, Patil SH. Dissemination of aerosol and splatter during ultrasonic scaling: a pilot study. J Infect Public Health. 2015;8(3):260\u0026ndash;65.\u003c/li\u003e\n \u003cli\u003eHarrel SK, Molinari J. Aerosols and splatter in dentistry: A brief review of the literature and infection control implications. J Am Dent Assoc. 2004;135(4):429\u0026ndash;37.\u003c/li\u003e\n \u003cli\u003eInternational Commission on Radiological Protection. 1990 Recommendations of the International Commission on Radiological Protection (ICRP Publication 60). Oxford: Pergamon Press; 1990.\u003c/li\u003e\n \u003cli\u003eNuclear Regulatory Commission. Regulatory analysis on criteria for the release of patients administered radioactive materials. Washington, DC: NRC; 1994.\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":"Hyperthyroidism treatment, radioiodine (I-131) therapy, dentist radiation safety, radiation dose to dentist, radiation exposure","lastPublishedDoi":"10.21203/rs.3.rs-7410574/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7410574/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground:\u003c/strong\u003e Hyperthyroidism is an endocrine disorder characterized by the excessive production of thyroid hormones (T3 and T4) by the thyroid gland. The treatment of this disease in Nuclear Medicine clinics is performed by the outpatient oral administration of radioactive iodine (RAI or I-131). The gamma radiation emitted from the patient’s body after I-131 administration may lead to radiation exposure for individuals in close proximity.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eObjectives:\u003c/strong\u003e The aim of this study was to determine the safe distance and duration for a dentist to provide services to a patient who has undergone hyperthyroidism treatment, in order to ensure radiation protection.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMaterials and Methods:\u003c/strong\u003e A total of 50 randomly selected patients who presented for hyperthyroidism treatment were included in this study. Of these, 31 patients were diagnosed with Graves’ disease and 19 with toxic nodular goiter. Patients were divided into two groups according to the administered therapeutic I-131 activity. Group I: ≤444 MBq (n=26), Group II: \u0026gt;444 MBq (n=24). External radiation exposure (dose rate) measurements were performed using a radiation detector at distances of 5 cm, 15 cm, 30 cm, 60 cm, and 100 cm from the thyroid region of each patient.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults:\u003c/strong\u003e The administered radioiodine activities ranged from 222 MBq to 925 MBq. The most frequently used I-131 therapeutic regimen was 370 MBq, followed by 555 MBq. Dose rate measurements in Group I, 24 hours after administration, were 3528 µSv/h, 968 µSv/h, and 295 µSv/h at 5 cm, 15 cm, and 30 cm, respectively. In Group II, the corresponding values at the same distances were 5525 µSv/h, 1763 µSv/h, and 566 µSv/h.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusion:\u003c/strong\u003e According to our findings, dental examination and treatment of hyperthyroid patients who received ≤444 MBq of I-131 within the first 3 days pose a radiation safety concern. For patients treated with \u0026gt;444 MBq of RAI, the safe approach time for dental procedures was determined to be 5 days. In the case of female and pregnant dentists, these periods should be doubled to ensure adequate radiation protection.\u003c/p\u003e","manuscriptTitle":"Dental Management of Hyperthyroid Patients Undergoing Radioiodine Therapy: A Radiation Safety Perspective","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-09-15 10:23:26","doi":"10.21203/rs.3.rs-7410574/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":"3be63ffd-490c-4db7-be12-645e4db44ce3","owner":[],"postedDate":"September 15th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-09-26T06:54:33+00:00","versionOfRecord":[],"versionCreatedAt":"2025-09-15 10:23:26","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7410574","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7410574","identity":"rs-7410574","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}