The effects of iodine 131 treatment on chromosomal and oxidative DNA damage in papillary thyroid carcinoma.

Papillary thyroid carcinoma (PTC) is a common endocrine cancer with a good prognosis. Radioactive iodine is thought to be useful for individuals who have had a total or almost total thyroidectomy, but its effects are still controversial. The effects of radioactive iodine-131 (I-131) treatment on oxidative and chromosomal damage in PTC patients were examined in this study, which was carried out with 16 patients newly diagnosed with PTC and 20 healthy control subjects with similar age and gender. Blood samples were taken from patients with PTC at five sampling times (before total thyroidectomy, after total thyroidectomy, and seven days, six months, and one year after treatment) and from control subjects. The cytokinesis block micronucleus cytome (CBMN-cyt) assay parameters in peripheral blood lymphocytes of patients with PTC and controls were evaluated and plasma 8-hydroxydeoxyguanosine (8-OHdG) levels were measured. Furthermore, genome instability and oxidative DNA damage in peripheral blood lymphocytes and plasma of patients with PTC were evaluated before total thyroidectomy (n=16), after total thyroidectomy (before I-131 treatment) (n=16), seven days (n=10), six months (n=5), and one year after treatment (n=5). The numbers of CBMN-cyt assay parameters (micronucleus; MN and nucleoplasmic bridges; NPB) and 8-OHdG levels in patients with PTC were determined to be significantly higher than in those of the control subjects and these values significantly decreased after total thyroidectomy (before I-131 treatment). While the number of MN, apoptotic, and necrotic cells increased after I-131 treatment, it significantly decreased after six months and one year after treatment. The results achieved in this study suggest that I-131 treatment may pose a threat to cells and that radioactive iodine therapy should be avoided (if possible) for patients with PTC after total thyroidectomy.

Efficacy and Safety of 125I Seed Implantation in the Treatment of Pelvic Recurrent Cervical Cancer Following Radiotherapy: A Single-Arm Meta-Analysis of Chinese Patients.

BACKGROUND: The study aimed to assess the efficacy and safety of 125I seed implantation in the treatment of pelvic recurrent cervical cancer following radiotherapy. This meta-analysis was registered in PROSPERO. We looked up relevant studies in the databases of CNKI, Wanfang, CBM, PubMed, Embase, Cochrane Library, and Web of Science. The endpoint measures include the objective response rate, disease control rate, progression-free survival, overall survival, and adverse events. RECENT FIDINGS: The meta-analysis included six studies and a total of 246 patients. The pooled ORR of tumor response was 63%, and the DCR was 87%. The median PFS was 9.09 months, and the median OS was 13.46 months. The incidence of adverse events of Grade ≥III was 6%. CONCLUSION: In conclusion, this meta-analysis confirmed that 125I seed implantation has a good local control rate and high safety in the treatment of pelvic recurrent cervical cancer following radiotherapy, and can be used as a remedial treatment for pelvic recurrent cervical cancer following radiotherapy to prolong the survival time of patients. TRIAL REGISTRATION: PROSPERO: CRD42023423857.

Comparison of perioperative and subacute postoperative complications between LDR and HDR monotherapy brachytherapy for prostate cancer.

PURPOSE: We aim to investigate perioperative and subacute postoperative complications in patients undergoing LDR or HDR monotherapy for prostate cancer. We hypothesize a low rate of complications, and a favorable toxicity profile in patients treated with HDR compared to LDR. MATERIALS AND METHODS: A prospectively collected institutional database was queried for patients treated with HDR or LDR prostate monotherapy between 1998 and 2021. Toxicities were determined per CTCAE. Claims based billing codes were obtained to identify additional events. Events occurring within 4 months of treatment were defined as perioperative or subacute postoperative complications. RESULTS: 759 patients were identified, 446 received LDR with 125I, and 313 received HDR with 192Ir. HDR patients had higher risk features: 75.7% with Gleason score 7+ versus 2.4% of LDR, and 16% with initial PSA 10+ ng/mL versus 2.7% of LDR. Toxicities were mild with the most common being grade 1 GU frequency and nocturia at ∼50%. HDR patients had significantly less grade 2 dysuria (2.6% vs. 9.0%), frequency (4.8% vs. 9.4%), hematuria (1.0% vs. 5.2%), nocturia (3.8% vs. 9.4%), and urinary obstructive symptoms (7.3% vs. 11.2%), all statistically significant. 11 (1.4%) patients had infection requiring antibiotics: 8 (1.8%) from the LDR group and 3 (1%) from the HDR group. Cardiopulmonary events were low at <2% overall, without difference between HDR and LDR. CONCLUSIONS: Overall toxicity rates support the safety of prostate brachytherapy. HDR monotherapy is associated with significantly less perioperative and subacute postoperative GU events when compared to LDR monotherapy. Cardiopulmonary events were equally rare in both groups.

Clinical and forensic aspects of potassium iodide: Suddenly in high demand across Europe due to fears of radiation poisoning from a nuclear attack in Ukraine.

Potassium iodide has demonstrated several therapeutic applications over time, being the choice for shielding the thyroid during radiation emergencies involving radioiodine release. Amidst the ongoing military conflict between Ukraine and Russia and the growing concern regarding the potential deployment of nuclear weapons, there has been a surge in the demand for potassium iodide across Europe. This work aimed to comprehensively review the current knowledge regarding the pharmacology, physiology, adverse effects, the protective role in reducing the risk of thyroid cancer and recommendations for potassium iodide use during radiation emergencies. Evidence on adverse effects is scarce, as potassium iodide is generally well-tolerated. Guidelines for thyroid blocking with potassium iodide during radiation emergencies suggest that, among populations vulnerable to radioiodine exposure, the benefits of potassium iodide outweigh the risks of adverse effects. Controversial topics surrounding the utilization of potassium iodide in radiation emergencies include the prophylaxis in iodine-deficient regions and following the detonation of dirty bombs, whether granule formulations versus tablets should be used and mental health concerns. Although the rise in demand seems to be a justified security measure, it is essential to recognize that potassium iodide protects the thyroid from radioiodine and does not impact the body's absorption of other radioactive materials or defend against external radiation exposure.

Radiation proctitis after iodine-125 low-dose-rate prostate brachytherapy utilizing SpaceOAR hydrogel.

OBJECTIVE: We retrospectively evaluated the efficacy of combining the SpaceOAR (SOAR) hydrogel with prostate brachytherapy, using colonoscopy findings to assess for radiation proctitis. METHODS: Among 731 patients undergoing iodine-125 low-dose-rate prostate brachytherapy (LDR-BT), SOAR was utilized in 394 patients (53.9%). Colonoscopy was performed for 97 patients (13.3%) to assess the presence, location, condition, and treatment of radiation proctitis. We also investigated treatment factors associated with the occurrence of radiation proctitis. RESULTS: Radiation proctitis was observed in 57 patients (7.8%) and 17 (2.3%) were treated with argon plasma coagulation (APC). The incidence of radiation proctitis was 12.2% in the non-SOAR and 4.1% in the SOAR group (p < 0.001). In the non-SOAR group, the incidence of radiation proctitis was 6.6% for LDR-BT monotherapy and increased to 22.0% when combined with external beam radiation therapy (EBRT) (p = 0.001). However, in the SOAR group, these rates significantly decreased to 3.3% and 5.7% for monotherapy and combination therapy, respectively (p = 0.035, p < 0.001). With SOAR, inflammation was observed directly above the DL in most patients (87.5%), and only one patient (6.3%) required APC. The absence of SOAR (p < 0.001, HR = 0.29) and the concurrent use of EBRT (p = 0.018, HR = 2.87) were identified as significant risk factors for the occurrence of radiation proctitis. CONCLUSION: The use of SOAR significantly reduced the incidence of radiation proctitis in patients undergoing LDR-BT monotherapy and combined EBRT. Inflammation primarily occurred directly above the DL; further examination is necessary to clarify its cause.

Update on lacrimal apparatus dysfunction associated with differentiated thyroid cancer after I-131 therapy.

PURPOSE: The most prevalent lacrimal apparatus dysfunctions associated with differentiated thyroid cancer(DTC) after I-131 therapy are dry eye and nasolacrimal duct obstruction(NLDO), leading to ocular discomfort and lower quality of life for patients. It is crucial to diagnose and manage lacrimal apparatus dysfunction associated with I-131 therapy for DTC. Therefore, this review aims to comprehensively summarize and analyze the advances in mechanisms and therapeutic options underlying lacrimal apparatus dysfunction induced by I-131 therapy for DTC. METHODS: A comprehensive search of CNKI, PubMed, and Wed of Science was performed from the database to December of 2023. Key search terms were "Thyroid cancer", "I-131", "Complications", "Dry eye", "Epiphora", "Tear", "Nasolacrimal duct" and "NLDO". RESULTS: The research indicates that I-131 therapy for DTC causes damage to the lacrimal glands and nasolacrimal duct system, resulting in symptoms such as dry eye, epiphora, and mucoid secretions. Moreover, recent research has focused on exploring relevant risk factors of the condition and experimental and clinical treatments. However, there is some controversy regarding the mechanisms involved, whether it is due to the passive flow of I-131 in tears, active uptake of I-131 by the sodium-iodide symporter (NIS) in the lacrimal sac and nasolacrimal duct, or secondary metabolic and hormonal disturbances caused by I-131. CONCLUSION: It is crucial for early detection and preventive measures by ophthalmologists and the need for further studies to elucidate the mechanisms underlying the disease.

Eye-Related Adverse Events After I-131 Radioiodine Therapy: A Systematic Review of the Current Literature.

OBJECTIVE: Although I-131 is relatively safe, there is limited focus on probable eye-related side effects after radioactive iodine (RAI) therapy. Thus, we aimed to provide evidence for the adverse outcomes of I-131, exclusively in patients with thyroid cancer. METHODS: A systematic review based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines was designed to examine the ocular complications of RAI therapy. Databases including PubMed, Scopus, and Web of Science were searched until October 2023 with specific thyroid neoplasms, ophthalmology and iodine terms. After thorough screening and review, relevant data were extracted. RESULTS: The database search yielded 3434 articles, which resulted in the final 28 eligible studies. These studies investigated ophthalmic symptoms following RAI therapy, classifying them as obstructive diseases (for example, nasolacrimal duct obstruction; median incidence rate: 6.8%), inflammatory symptoms (median incidence rate: 13%), and cataracts (median incidence rate: 2.5 and 5%). The most common time interval between RAI therapy and the onset of symptoms was within the first 12 months and then declined in the preceding years. A strong positive correlation was observed between higher I-131 doses of more than 100 to 150 mCi (3.7-5.55 GBq) and the risk of symptom development. Ages older than 45 also showed a significant association with nasolacrimal duct obstruction. CONCLUSION: The risk of ophthalmic complications is associated with various factors, including the administration of high I-131 doses, age of more than 45 years, and time to event within the first 12 months. Considering these conditions may help enhance patient care and prevent adverse outcomes that may limit patients' quality of life.

Prevalence of Thyroid Nodules in Residents of Ukraine Exposed as Children or Adolescents to Iodine-131 from the Chornobyl Accident.

Background: Although childhood exposure to radioactive iodine-131 (I-131) is an established risk factor for thyroid cancer, evidence for an association with thyroid nodules is less clear. The objective of this study is to evaluate the association between childhood I-131 exposure and prevalence of ultrasound-detected thyroid nodules overall and by nodule histology/cytology (neoplastic/suspicious/non-neoplastic), size (<10 mm/≥10 mm), and number (single/multiple). Methods: This is a cross-sectional study of radiation dose (mean = 0.53 gray, range: 0.0003-31 gray) and screen-detected thyroid nodules conducted in 1998-2000 (median population age 21.5 years) in a cohort of 13,243 residents of Ukraine who were under 18 years at the time of the Chornobyl accident on April 26, 1986. Excess odds ratios per gray (excess odds ratio [EOR]/Gy) and confidence intervals (CIs) were estimated using logistic regression. Results: Among 13,078 eligible individuals, we identified 358 (2.7%) with at least one thyroid nodule. Significantly increased dose-response associations were found for all nodules and nodule groups with doses <5 Gy except individuals with non-neoplastic nodules. Among individuals with doses <5 Gy, the EOR/Gy for neoplastic nodules (5.35; CI: 2.19-15.5) was significantly higher than for non-neoplastic nodules (0.24; CI: 0.07-0.74), but the EOR/Gy did not vary by nodule size or number. Conclusions: Childhood exposure to I-131 is associated with an increased risk of thyroid nodules detected 12-14 years following exposure, and the risk for neoplastic nodules is higher than for non-neoplastic nodules. Analyses of incident thyroid nodules may help clarify dose-response patterns by nodule characteristics and provide insights into thyroid nodule etiology.

The prophylactic antiemetic therapies in management of differentiated thyroid cancer patients with radioactive iodine therapy: a single-center, non-randomized clinical trial.

Objective: The present study was to investigate three different single-drug regimens to show which was more effective to reduce radioactive iodine therapy (RAI) associated nausea and vomiting, and to compare the occurrence of long-term gastrointestinal diseases after RAI therapy. Method: We performed a single-center, non-randomized clinical trial among patients who underwent RAI therapy from March 2016 to July 2022. Enrolled patients were divided into four cohorts based on the date of the treatment. cohort 1, with no preventive antiemetics; cohort 2, received 20 mg of pantoprazole per day for 3 days; cohort 3, received a 10 mg metoclopramide tablet two times daily for 3 days; cohort 4, oral ondansetron, 8 mg, twice daily for 3 days. The primary endpoints were proportion of patients who experience vomiting episodes and nausea during the 7-day hospital period. Secondary end points included Functional Living Index Emesis (FLIE) quality-of life questionnaires and the occurrence of gastrointestinal diseases. Results: A total of 1755 patients were analyzed, comprised of 1299 (74.0%) women and 456 (26.0%) men, with a median age of 44 years (range 18-78 years). The characteristics of patient were similar within the four groups. 465 (26.4%) patients developed RAI-associated nausea, and 186 (14.4%) patients developed RAI-associated vomiting. The rate of nausea was significantly decreased in the patients who were taking ondansetron when compared with the other cohorts (P<0.05), while the rate of vomiting (≥6 episodes) was slightly lower. As secondary endpoint, FLIE measures ondansetron scored highly compared to other cohorts, from baseline (mean score of 110.53 ± 17.54) to day 7 (mean score of 105.56 ± 12.48). In addition, 48 (2.7%) patients were found to be with gastrointestinal diseases at the end of one year follow up. Multiple RAI therapy and higher dose of I-131 per body weight revealed a significantly independent risk factors of developing gastrointestinal disorders. Conclusions: In conclusion, the present study demonstrated that short-term ondansetron could be an effective prophylactic agent in controlling RAI-associated nausea and vomiting. Furthermore, the risk of developing gastrointestinal disorders was significantly higher for patients with multiple RAI therapy and higher dose of I-131 per body weight.

Salivary, lacrimal and nasal (SALANS) measure to assess side effects following radioactive iodine treatment: development, psychometric properties, and factor structure.

PURPOSE: This study aimed to develop and psychometrically evaluate a patient-reported outcome measure (PROM), SAlivary, LAcrimal, NaSal (SALANS), to document patients' symptoms after radioactive iodine (RAI) treatment for differentiated thyroid cancer (DTC). METHODS: We generated and iteratively revised SALANS items based on expert input, focus group discussions and feedback from cognitive testing (n = 17). We administered an initial SALANS measure with 39 items to patients diagnosed with DTC in the past two years (n = 105). Exploratory factor analysis (EFA) examined the factor structure of the SALANS items. We assessed the consistency reliability and related the total and subscale scores of the final SALANS to existing PROMs to assess validity. RESULTS: The final SALANS consisted of 33 items and six subscales (sialadenitis, taste, xerostomia, dry eyes, epiphora, and nasal) with six factors extracted by EFA. The six subscales demonstrated good internal reliability (α range = 0.87-0.92). The SALANS total score showed good convergent validity with the Xerostomia Inventory (r = 0.86) and good discriminant validity with a measure of spirituality (r = - 0.05). The mean SALANS total score was significantly higher (d = 0.5, p < 0.04) among patients who had RAI compared to those who did not have RAI. CONCLUSION: Preliminary evidence suggests that SALANS is a novel and reliable PROM to assess the type and frequency all symptoms experienced after RAI treatment for DTC. Future work is needed to further validate and develop the scale.

Disrupted gut microecology after high-dose 131I therapy and radioprotective effects of arachidonic acid supplementation.

BACKGROUND: Despite the potential radiotoxicity in differentiated thyroid cancer (DTC) patients with high-dose 131I therapy, the alterations and regulatory mechanisms dependent on intestinal microecology remain poorly understood. We aimed to identify the characteristics of the gut microbiota and metabolites in DTC patients suffering from high-dose 131I therapy and explore the radioprotective mechanisms underlying arachidonic acid (ARA) treatment. METHODS: A total of 102 patients with DTC were recruited, with fecal samples collected before and after 131I therapy for microbiome and untargeted and targeted metabolomic analyses. Mice were exposed to total body irradiation with ARA replenishment and antibiotic pretreatment and were subjected to metagenomic, metabolomic, and proteomic analyses. RESULTS: 131I therapy significantly changed the structure of gut microbiota and metabolite composition in patients with DTC. Lachnospiraceae were the most dominant bacteria after 131I treatment, and metabolites with decreased levels and pathways related to ARA and linoleic acid were observed. In an irradiation mouse model, ARA supplementation not only improved quality of life and recovered hematopoietic and gastrointestinal systems but also ameliorated oxidative stress and inflammation and preserved enteric microecology composition. Additionally, antibiotic intervention eliminated the radioprotective effects of ARA. Proteomic analysis and ursolic acid pretreatment showed that ARA therapy greatly influenced intestinal lipid metabolism in mice subjected to irradiation by upregulating the expression of hydroxy-3-methylglutaryl-coenzyme A synthase 1. CONCLUSION: These findings highlight that ARA, as a key metabolite, substantially contributes to radioprotection. Our study provides novel insights into the pivotal role that the microbiota-metabolite axis plays in radionuclide protection and offers effective biological targets for treating radiation-induced adverse effects.

Factors affecting timing of hypothyroidism following radioactive iodine therapy (RAIT) for patients with Graves' disease: A 12-month observational study.

BACKGROUND: This retrospective study analyzed factors influencing hypothyroidism development after radioactive iodine therapy for Graves' disease. PATIENTS AND METHODS: Three hundred and three patients with Graves' disease treated with radioactive iodine (RAI) from 2013 to 2022 at two Egyptian hospitals were included. Data collected included demographics, lab values, thyroid imaging, RAI doses, and outcomes. Patients were followed for ≥1 year to assess hypothyroidism onset. RESULTS: At the end of 1 year, around 79.5% of the individuals developed hypothyroidism while 12.5% continued to experience hyperthyroidism. The onset of hypothyroidism occurred earlier in those with thyroid volume (≤75.5 cm 3 ), lower thyroid weight (≤84.7 g), thyroid uptake (≤18.8%), and higher RAI dose/volume (≥0.1022 mCi/ml) ( P  < 0.001). Additionally, there was a correlation between anti-thyroid peroxidase (anti-TPO) antibodies and faster development of hypothyroidism compared to those who were negative for antibodies (2.9 vs 8.9 months, P  = 0.001). When considering factors in analysis it was found that anti-TPO antibodies were the only independent predictor, for developing hypothyroidism (hazard risk 30.47, P  < 0.001). Additionally, thyroid volume and uptake independently predicted successful treatment outcomes ( P  < 0.05). CONCLUSION: Positive anti-TPO antibodies strongly predict hypothyroidism risk after RAI therapy for Graves' disease. Smaller thyroid size, lower uptake, and higher RAI dose/volume correlate with earlier hypothyroidism onset but are less significant predictors than anti-TPO status. Findings can guide RAI therapy personalization to optimize outcomes.

Protective effects of Panax Ginseng against 131I-induced genotoxicity in patients with differentiated thyroid cancer.

BACKGROUND: Radioiodine (131I) therapy (RAIT) is associated with oxidative stress (OS)-induced DNA damage in patients with differentiated thyroid cancer (DTC). The goal of this study was to evaluate the possible ameliorating effects of Panax Ginseng (PG) on RAIT-induced genotoxicity in patients with DTC. MATERIALS AND METHODS: Forty DTC patients who had received 131I (100 to 175 mCi) were enrolled in this study. The patients were randomly classified (n = 10) into control, placebo, PG1 groups (receiving 500 mg/day of PG for 2 days before RAIT), and PG2 group (receiving 500 mg/day of PG for 2 days before to 1 day after RAIT). Blood samples were collected before and 2 days after RAIT. Lymphocyte micronuclei (MN) frequency was measured using the MN assay. Serum total antioxidant capacity (TAC) and ischemia-modified albumin (IMA) were measured using colorimetric assays. Serum albumin, blood urea nitrogen (BUN), creatinine, aspartate aminotransferase (AST), and alanine aminotransferase (ALT) were measured using commercial kits. RESULTS: The mean of baseline MN frequency was the same in the four groups. RAIT increased the MN frequencies to at least three times the baseline values in the control (39 ± 5) and placebo groups (38 ± 6) (P < 0.001). PG caused a significant decrease in the MN frequencies in the treated groups compared to the control and placebo groups (P < 0.001). RAIT and PG administration had no significant effects on the serum IMA, TAC, and markers of liver and kidney toxicity. CONCLUSION: PG could be considered a useful remedy for the protection against RAIT-induced chromosomal damage in DCT patients.

Does Radioactive Iodine Treatment Damage the Lacrimal System?

PURPOSE: In this prospective study, we aimed to make a quantitative assessment of the lacrimal glands before and after radioactive iodine (RAI) treatment in patients with hyperthyroidism and thyroid cancer. METHODS: The study included 80 eyes of 40 patients. There were 25 patients in group 1 (hyperthyroid group) and 15 patients in group 2 (thyroid cancer group). Group 1 has received low dose ( 131 I) and group 2 high dose ( 131 I). Before, and at the first and sixth month after RAI treatment, all patients underwent ophthalmological examinations, Schirmer tests, TBUT tests, tear osmolarity (TO), and ocular surface examinations. RESULTS: The age and sex characteristics of both groups were similar. Although no significant change was observed in tear film tests before and after treatment in group 1, a significant decrease in Schirmer and TBUT values and a significant increase in TO were observed in group 2 in the first month after treatment. These values returned to normal in the sixth month. Although no Schirmer test was observed lower than 10 mm in any patient before RAI treatment, the Schirmer test was measured 5 to 10 mm in 4 (10%) patients in group 2 in the first month after treatment. Again, in these patients, TBUT was below 10 seconds and TO was greater than 308 mOsm/L. CONCLUSIONS: In this study, although no change was observed in tear function tests in patients receiving low doses of RAI, a decrease in tear secretion and an increase in TO were detected in patients receiving high doses in the early period.

Cancer Risk in Graves Disease with Radioactive 131I Treatment: A Nationwide Cohort Study.

Radioactive 131I (RAI) therapy has potential effects for the treatment of Graves disease (GD). However, whether RAI therapy for GD increases cancer risk remains controversial in medicine and public health. We aimed to investigate whether the risk of cancer increases in patients with GD receiving RAI therapy compared with those who did not. Methods: We used the Korean National Health Insurance Service's National Health Information Database from 2004 to 2020 and defined GD as prescribing antithyroid drugs, RAI, or thyroidectomy as a treatment for GD (International Classification of Diseases, 10th revision, E05 group). We investigated the hazard ratios (HRs) of overall and site-specific cancers associated with RAI in patients with GD. Subsequent cancer was defined as a primary malignancy treated at least 1 y after RAI therapy. Results: In total, 10,737 patients with GD who received RAI therapy (7,193 women, 67.0%; mean age, 43.7 ± 13.4 y) were matched to 53,003 patients with GD who had never received RAI treatment (35,471 women, 66.9%; mean age, 43.8 ± 13.2 y) in a 1:4-5 ratio by age, sex, and health checkup data. The median follow-up duration was 8.7 y (interquartile range, 5.2-12.1 y), and the median cumulative RAI dose was 555 MBq (interquartile range, 370-630 MBq) in the RAI therapy group. During 2004-2020, the overall subsequent cancer rates were 5.66 and 5.84 per 1,000 person-years in the RAI and non-RAI groups, respectively, with an unadjusted HR of 0.97 (95% CI, 0.88-1.06); this remained at 0.96 (95% CI, 0.83-1.10) after adjustment for multiple clinical confounding factors. For cancer subtypes, the risk of leukemia was significantly increased, with an HR of 2.39 (95% CI, 1.17-4.91). However, a loss of statistical significance was observed after adjusting for confounding factors, which may be attributed to the limited number of absolute events. Moreover, cancer-specific mortality was not different between the RAI and the non-RAI groups, with an adjusted HR of 0.99 (95% CI, 0.66-1.47). Conclusion: This study identified that the overall cancer risk in patients with GD who received RAI therapy compared with those who did not was not significant in Korea. Further long-term studies are needed to determine the risks and advantages of RAI therapy in patients with GD.

Blood pressure in hyperthyroid cats before and after radioiodine treatment.

BACKGROUND: Hyperthyroid cats commonly have systemic hypertension, with a reported prevalence of 7% to 48%. Although hypertension might be expected to resolve once treatment restores euthyroidism, it can persist or only first develop after treatment. OBJECTIVES: To determine the proportion of hyperthyroid cats with hypertension (systolic blood pressure [SBP] ≥160 mm Hg), persistence or first development of hypertension after successful radioiodine treatment, and correlation of post-treatment hypertension with azotemia or hypothyroidism. ANIMALS: Four hundred one hyperthyroid nonazotemic cats were included in the study. METHODS: Prospective, cross-sectional and before-and-after studies. All hyperthyroid cats had SBP measured by Doppler; 255 had SBP rechecked 6 months after successful radioiodine (131I) treatment. RESULTS: Of untreated hyperthyroid cats, 108/401 (27%) were hypertensive. A higher proportion of hypertensive cats were nervous/excited compared with normotensive cats (47% vs 12%; P < .001). Of the initially hypertensive cats, 87/108 cats were reexamined after 131I treatment; 43/87 (49%) cats normalized SBP, whereas 44/87 (51%) remained hypertensive. Of the initially normotensive cats, 16/168 (9.5%) first developed hypertension after successful 131I treatment. 7/60 (12%) of the 131I-treated hypertensive cats were azotemic and 9/60 (15%) were hypothyroid. A higher proportion of cats remaining hypertensive had nervous/excited demeanor than did normotensive cats (50% vs 17%; P < .001). CONCLUSIONS/CLINICAL IMPORTANCE: Hypertension, when present, resolves in many hyperthyroid cats after successful treatment. Hyperthyroid cats uncommonly develop new hypertension after treatment. Persistent or newly detected hypertension was unrelated to azotemia or iatrogenic hypothyroidism. More frequently perceived nervousness/anxiety in radioiodine-treated hypertensive cats suggests that many of these cats might have "situational" hypertension, as hyperthyroid-induced hypertension should resolve after treatment.

Incidence of Strabismus Post-Plaque Brachytherapy in Patients With Uveal Melanoma.

PURPOSE: To determine the incidence and type of strabismus in patients with uveal melanoma treated with plaque brachytherapy. DESIGN: Multicenter, retrospective incidence estimation study. METHODS: A total of 438 eyes of 438 patients with uveal melanoma treated with plaque brachytherapy between October 2011 and May 2021. Intervention was Iodine 125, and Palladium 103 plaque brachytherapy. The variables reviewed included incidence of nonresolving strabismus post-plaque brachytherapy, type of strabismus developed, extraocular muscles operated, and modality of treatment received. RESULTS: A total of 438 patients underwent plaque brachytherapy treatment for uveal melanoma. Eleven patients developed strabismus post-plaque brachytherapy (2.5%, n = 11/438). Of these patients, 5 (1.1%, n = 5/438) developed strabismus immediately postoperation. Specifically, 2 patients (0.5%, n = 2/438) developed strabismus immediately postoperation due to slipped muscles, 2 patients (0.5%, n = 2/438) due to decompensated phorias, and 1 patient (0.5%, n = 1/438) due to a fibrotic muscle. Six patients (1.4%, n = 6/438) developed late-onset sensory strabismus. A total of 355 patients (81.1%, n = 355/438) had their extraocular muscles disinserted during surgery, with the lateral rectus being the most common, accounting for 45.4% (n = 161/355), followed by the superior rectus at 26.8% (n = 95/355). Strabismus surgery was the most common treatment modality, comprising 72.7% (n = 8/11) of patients. CONCLUSIONS: The incidence of strabismus after plaque brachytherapy treatment for uveal melanoma was low and primarily classified as late-onset sensory strabismus. Previous studies may underestimate the long-term incidence of strabismus after plaque brachytherapy by focusing primarily on strabismus present immediately postoperatively.

Prophylactic effect of pilocarpine on acute sialadenitis following radioactive iodine therapy in thyroid cancer patients.

Purpose: Our aim was to evaluate the effect of prophylactic pilocarpine on acute salivary symptoms after radioactive iodine (RAI) therapy in patients with differentiated thyroid cancer. Methods: We enrolled 88 patients (76 women and 12 men; mean age: 47 years; range: 20-74 years) with differentiated thyroid cancer who received RAI. Patients were divided into pilocarpine (51 patients) and control (37 patients) groups. Pilocarpine was given orally, at a dose of 5 mg three times a day, from 2 days before and 12 days after RAI therapy. Symptoms and signs of acute sialadenitis within 3 months of RAI therapy were recorded. Results: During the 3 months after RAI therapy, 13 of the 88 patients (14.7%) developed acute symptomatic sialadenitis (swelling or pain of salivary glands). Acute salivary symptoms were reported by 4 (7.8%) and 9 (24.3%) patients in the pilocarpine and control groups, respectively. Acute salivary symptoms were less frequent in the pilocarpine than control group (p = 0.04), but did not differ by age, sex, or RAI dose (p = 0.3357, p = 0.428, and p = 0.2792). Conclusions: Pilocarpine reduced the likelihood of acute sialadenitis after RAI therapy in patients with differentiated thyroid cancer.