Received Radioactive Iodine Therapy Research Articles

Evaluation of the response levels of non-metastatic thyroid cancer patients in the postoperative twelfth month

Objective: Radioactive iodine (RAI) is used to ablate residual thyroid tissue after total thyroidectomy. The aim of this study was to evaluate the response according to the12th-month results of thyroid cancer patients and to investigate the changes in response level during follow-up.
 Materials and Methods: The study included 97 patients, comprising 88 (90.7%) females and 9 (9.3%) males, with a mean age of 41.68±13.25 years. None of the patients had lymph node or distant metastasis and all received RAI therapy. Thyroid-stimulating hormone (TSH), thyroglobulin (TG), and anti-TG levels and neck USG were examined in the 12th-month. Response to therapy was evaluated as an excellent response, biochemical incomplete response, structural incomplete response, or indeterminate response.
 Results: In the 12th month, 80 patients (82.47%) had excellent response, 13 patients (13.40%) had an indeterminate response, 3 patients (3.09%) had structural incomplete response and 1 patient (1.03 %) had biochemical incomplete response. Of the 80 patients with excellent response, 15 had no follow-up after the 12th month. The remaining 65 patients were followed up for 31.11±9.58 months. The response changed to indeterminate in the 18th month in 1 (1.54%) patient and to structural incomplete response in the 35th month in 1 (1.54%) patient. The 13 patients with indeterminate responses were followed up for 20.61±6.28 months.
 Conclusion: The TG level at 12th months provides accurate data about the course of the disease especially in patients with excellent responses. Patients with excellent response in the 12th month may be followed up less often and those with the indeterminate or incomplete responses should be followed up more often.

Unexpected radioactive iodine accumulation on whole-body scan after I-131 ablation therapy for differentiated thyroid cancer.

ABSTRACTWe retrospectively evaluated the frequency of unexpected accumulation of radioactive iodine on the post-therapy whole-body scan (Rx-WBS) after radioactive iodine (RAI) ablation therapy in patients with differentiated thyroid cancer (DTC). We searched our institutional database for Rx-WBSs of DTC patients who underwent RAI ablation or adjuvant therapy between 2012 and 2019. Patients with distant metastasis diagnosed by CT or PET/CT before therapy, and those had previously received RAI therapy were excluded. In total, 293 patients (201 female and 92 male, median age 54 years) were selected. Two nuclear medicine physicians interpreted the Rx-WBS images by determining the visual intensity of radioiodine uptake by the thyroid bed, cervical and mediastinal lymph nodes, lungs, and bone. Clinical features of the patients with and without the metastatic accumulation were compared by chi-square test and median test. Logistic regression analyses were performed to compare the association between the presence of metastatic accumulation and these clinical factors. Eighty-four of 293 patients (28.7%) showed metastatic accumulation. Patients with metastatic RAI accumulation showed a significantly higher frequency of pathological N1 (pN1) and serum thyroglobulin (Tg) > 1.5 ng/ml under TSH stimulation (p = 0.035 and p = 0.031, respectively). Logistic regression analysis indicated that a serum Tg > 1.5 ng/ml was significantly correlated with the presence of metastatic accumulation (odds ratio = 1.985; p = 0.033). In conclusion, Patients with Tg > 1.5 ng/ml were more likely to show metastatic accumulation. In addition, the presence of lymph node metastasis at the initial thyroid surgery was also associated with this unexpected metastatic accumulation.

Effect of Post-Surgical Rai Therapy on Parathyroid Function in Patients with Differentiated Thyroid Cancer

Objective: Radiotherapy with radioactive iodine (RAI) has become a common treatment for postsurgical differentiated thyroid carcinoma (DTC). The objective of this study was to determine the effect of RAI therapy following surgery on the function of the parathyroid glands in DTC patients. Methods: A total of 81 DTC patients who received RAI therapy after surgery were enrolled in the study. The size of the residual thyroid was detected by technetium-99m (99mTc)-pertechnetate thyroid scan (99mTc thyroid scan) before RAI therapy. The iodine uptake ability of residual thyroid was evaluated by iodine-131 (131I) whole-body scan (WBS). All patients were treated with an activity of 3.7 GBq (100 mCi) 131I. Parathyroid hormone (PTH), serum calcium, phosphorus, and magnesium were evaluated at 1 day before treatment, and at 1 month and 3 months after treatment. Results: The results show that there was no statistically significant difference in blood PTH level observed (P>.05) between 3 time points (pre-treatment, 1 month post-treatment and 3 months post-treatment). The serum calcium and phosphorus did not change significantly (P>.05), but serum magnesium level was elevated after treatment (P<.05). There were no significant differences between PTH changes and sex, age, scores of 99mTc thyroid scan, scores of 131I WBS, Tumor (T) stage, and Node (N) stage. Conclusion: RAI therapy following surgery did not significantly affect parathyroid function in DTC patients. Abbreviations: ATA = American Thyroid Association; DTC = differentiated thyroid carcinoma; FT3 = free triiodothyronine; FT4 = free thyroxine; 131I = iodine-131; PTH = parathyroid hormone; RAI = radioiodine; 99mTc = Technetium-99m; TG = thyroglobulin; TNM = Tumor Node Metastasis; TSH = thyroid-stimulating hormone; WBS = whole-body scan.

Mindfulness-based stress reduction in patients with differentiated thyroid cancer receiving radioactive iodine therapy: a randomized controlled trial.

ObjectiveThe aim of this study was to evaluate the efficacy of mindfulness-based stress reduction (MBSR) on health-related quality of life (QoL), depression, and anxiety in patients with differentiated thyroid cancer (DTC) receiving radioactive iodine therapy (RIT).Patients and methodsA randomized controlled trial of MBSR with 120 DTC patients was performed. They were randomly assigned into the MBSR intervention group and usual care (UC) group. An 8-week MBSR program was administered to the MBSR group starting 8 weeks before RIT. Health-related QoL, depression, and anxiety were measured immediately before the start of MBSR (T1), immediately after RIT hospitalization was concluded (1 week after concluding the last MBSR session, T2), and 3 months after RIT hospitalization (T3), using the QoL Questionnaire Core 30 Items (QLQ-C30), Self-rating Depression Scale (SDS), and Self-rating Anxiety Scale (SAS).ResultsFifty-three patients in the UC group and 49 patients in the MBSR group completed the study and were analyzed. Both the UC and MBSR groups reported low QoL and high SDS and SAS scores immediately after RIT hospitalization. Patients randomly assigned to the MBSR group showed significantly greater improvements in emotional function (P=0.012, d=–0.03 for T2 and d=1.17 for T3), fatigue (P=0.037, d=1.00 for T2 and d=–0.69 for T3), global QoL (P=0.015, d=1.61 for T2 and d=1.56 for T3), depression (P=0.027, d=–1.19 for T2 and d=–0.83 for T3), and anxiety (P=0.043, d=–1.00 for T2 and d=–0.86 for T3).ConclusionAn 8-week MBSR program significantly improved a wide range of scales in health-related QoL and mitigated depression and anxiety among DTC patients receiving RIT.

Factors Associated with Clinical Outcomes of Differentiated Thyroid Cancer Following Radioiodine Therapy in Tanzania

Background: Thyroid cancer is the most common endocrine type of malignancy, accounting for 1-5% of all cancers worldwide. Most of the differentiated thyroid cancers are asymptomatic. Surgery is the mainstay of management to be followed by radioactive iodine (RAI). RAI accessibility is still a challenge in most developing countries including Tanzania. The aim of this study was to determine factors affecting the clinical outcome of patients with differentiated thyroid cancer (DTC) following RAI treatment in a resource limited setting. Methods: This was a prospective cohort study carried out from 2014 to 2018 at the Ocean Road Cancer Institute, in Tanzania. A total of 52 histologically proven differentiated thyroid cancer patients post- near or total thyroidectomy were recruited. All patients received RAI therapy until ablation was achieved, were maintained on thyroxine suppression dose, and were followed for two years. Results: A total of 52 differentiated thyroid cancer patients were recruited after surgery by convenience sampling. The median age of patients was 46 years (range 17-77), and 87% (n=45) were female. Distant metastases were detected in 60% of patients (n=20) at initial presentation. The most common clinical presentation was a neck mass without compression symptoms (85%). Analysis at the end of two years revealed that female gender, clinical-pathological presentation, and the absence of distant metastasis(es) at diagnosis and amount of RAI received, contributed significantly to improved outcome. Conclusion: In a limited resource setting, the outcome of DTC patients post RAI therapy can be improved by early diagnosis hence improving clinical outcome.

Hypothyroidism and its associated factors after radioactive iodine therapy among patients with hyperthyroidism in the Northeast Coast State of Malaysia.

ObjectivesThe aim of this study was to determine the incidence of hypothyroidism and its associated factors within one-year post radioactive iodine (RAI) therapy.MethodsA retrospective study was conducted among patients with hyperthyroidism who received RAI therapy at Nuclear Medicine Clinic, Hospital Universiti Sains Malaysia (HUSM), Kelantan. Data regarding patients’ demographics, gender, aetiology of hyperthyroidism, presence of autoantibodies, dose of RAI used and usage of antithyroid drug post RAI therapy were included in the analysis.ResultsOf a total of 167 screened patients, 137 subjects were eligible for this study. The incidence of hypothyroidism within one year of RAI therapy was 32.9%. Women were found to be less likely to develop hypothyroidism post RAI therapy (adjusted odds ratio, 0.406; 95% confidence interval: 0.181–0.908; p = 0.028). The usage of antithyroid drug post RAI was significantly associated with a lower incidence of hypothyroidism post RAI therapy (adjusted odds ratio, 0.188; 95% confidence interval: 0.081–0.438; p<0.001).ConclusionThis study showed a high incidence of hypothyroidism within one-year post RAI therapy. Gender and usage of antithyroid drug post RAI therapy are significantly associated with the development of hypothyroidism.

Papillary thyroid carcinoma after radioactive iodine treatment for toxic thyroid nodule: Case report

Radioactive iodine (RAI) treatment is recommended as the first choice for toxic thyroid nodules by American Thyroid Association (ATA). Here, we present our second case of papillary thyroid carcinoma after RAI therapy. A fifty fiveyear-old woman received RAI therapy for toxic thyroid nodule in the right lobe in 2005. Pre-treatment fine needle aspiration biopsy (FNAB) revealed benign cytology. She was euthyroid after the therapy. However, 8 years after the treatment she had 15 mm thyroid nodule in the same location. This time, FNAB result was suspected for papillary thyroid carcinoma. The patient underwent bilateral total thyroidectomy and the histopathological evaluation revealed papillary thyroid carcinoma in the nodule. This is the second case with papillary carcinoma after RAI therapy. Papillary carcinoma developed after the RAI therapy. In conclusion, all cases should be closely followed up after RAI therapy for carcinoma development.

Change in BMI after radioactive iodine ablation for graves disease

BackgroundWe aimed to determine the extent of post-treatment weight gain that occurs in pediatric patients in the first year following radioactive iodine (RAI) therapy for Graves disease (GD) and its relationship to clinical characteristics.MethodsA retrospective chart review of patients receiving RAI therapy for GD between 1998–2015 was performed. Change in BMI SDS (∆BMI SDS) from baseline to one year after treatment was determined. We also investigated whether individual clinical and/or biochemical factors were associated with the weight trajectory in these patients.ResultsOne hundred fifty seven patients aged 12.7 ± 3 years (80% girls) were included in the analysis. Average ∆BMI SDS was 0.70 ± 0.71 (p < 0.001) at 1 year. Patients with weight loss at presentation had a greater ∆BMI SDS than those without (0.92 vs 0.56, p = 0.005), whereas no association was seen with gender, pubertal status, use of antithyroid drugs, history of ADHD, or Down syndrome. Baseline BMI SDS was negatively correlated with ∆BMI SDS, with a stronger correlation in males. From baseline to 1 year, the proportion of overweight and obese patients increased from 9.6% to 18.5% and from 6.4% to 21%, respectively. In a subset of 81 patients, a positive correlation was noted between time to euthyroidism and ∆BMI SDS, particularly in boys.ConclusionsThe number of our patients in the overweight category doubled and the number in the obese category more than tripled in the first year following RAI treatment for GD. Anticipatory guidance regarding this important issue is badly needed.

Outcome of Large Noninvasive Follicular Thyroid Neoplasm with Papillary-Like Nuclear Features.

In 2016, encapsulated follicular variant of papillary thyroid carcinoma without invasion was renamed "noninvasive follicular thyroid neoplasm with papillary-like nuclear features" (NIFTP) in order to reduce overtreatment of this indolent tumor. However, many endocrinologists remain uneasy about managing large (≥4 cm) NIFTP conservatively without radioactive iodine (RAI) therapy. The objectives of this study are to characterize the clinicopathologic characteristics and outcome of large NIFTP in order to assist therapeutic decision making. The pathology databases of four tertiary hospitals were searched for large (≥4 cm) NIFTP. Cases with separate foci of carcinoma were excluded. Seventy-nine cases fulfilled the inclusion criteria. Among them, 56 (71%) had at least two years of clinical follow-up (FU), and 49 (62%) had four or more years of FU. The clinicopathologic characteristics were reviewed and documented by four endocrine pathologists. The median size of the NIFTP was 4.5 cm (range 4.0-8.0 cm). The entire capsule was sampled in 50 (63%) tumors, while in the remaining 29 (37%) cases, it was submitted representatively, with a median of 2.1 blocks per centimeter of tumor examined. Large NIFTP had a female preponderance with a male:female ratio of 1:1.8, and presented at a median age of 49 years. There were no lymph node metastases at diagnosis in any of the patients, and none of the patients (n = 25) in whom nodal tissue was available for microscopic examination had positive findings. Twenty-six (33%) underwent thyroid lobectomy alone, and 37 (47%) did not receive RAI ablation. No recurrence was observed in the entire cohort, including all 32 patients with two or more years of FU who did not receive RAI therapy (median FU: 6.7 years). Among patients with four or more years of FU, all 25 individuals without RAI therapy did not recur, with a median FU of 11.2 years. Patients with a larger tumor size tended to receive postoperative RAI ablation (p = 0.001). Similar to their small counterparts, large NIFTP appear to have an extremely low risk of recurrence (zero in this cohort), even when treated conservatively without RAI therapy. Surgical treatment alone, including lobectomy, appears to be adequate for large NIFTP.

Timing of Radioactive Iodine Administration Does Not Influence Outcomes in Patients with Differentiated Thyroid Carcinoma.

Radioactive iodine (RAI) is widely used in the management of differentiated thyroid cancer (DTC). The impact of the time interval between total thyroidectomy (TT) and RAI administration on disease outcome remains controversial. The objective of the present study was to evaluate the impact of the time interval between TT and RAI. This study evaluated a cohort of DTC patients who received RAI therapy for whom data on disease status were available. Patients were allocated to one of two groups, according to the time interval between TT and RAI. "Disease-free" was defined as no clinical, imaging, or biochemical evidence of thyroid cancer. The study included 545 individuals. The TNM stages were: 322 (59.1%) patients in Stage I, 62 (11.4%) in Stage II, 65 (11.9%) in Stage III, and 82 (15.0%) in Stage IV. The median time interval between TT and RAI was six months (P25-75: 3-10 months). Patients were allocated to one of two groups according to RAI timing administration: group A ≤6 months after TT (median 3 months; n = 295), or group B >6 months after TT (median 10.5 months; n = 250). There were no differences for sex, histological type, tumor size, distant metastasis, or RAI dose between the groups (p > 0.1). Patients in group B were older (47.1 vs. 43.1 years; p = 0.02), had less cervical metastasis (73.6% vs. 59.3%; p = 0.002), and were more commonly classified as low ATA risk (48.0% vs. 36.6%; p = 0.027). One year after initial therapy, 59.3% and 65.6% of patients in groups A and B, respectively, were considered disease-free (p = 0.15). Remarkably, the percentage of patients classified as disease-free was similar, even when analyzing a subgroup of high-risk patients (n = 72; 9.5% vs. 10.0%; p = 1.0). These findings did not change after a median of six years of follow-up. Accordingly, further analysis by multiple logistic regression showed that timing of RAI was not associated with persistent disease (relative risk 0.97 [confidence interval 0.80-1.19]). Timing of RAI does not seem to interfere with the disease outcomes in DTC and can therefore be safely planned while taking into account the health system logistics.

Frequency of Flame Sensor Activation in Public Places after Administration of Radioactive Iodine to Treat Graves Disease: A Recent Survey

Ultraviolet (UV)-perception-type flame sensors detect gamma rays emitted from iodine 131 ((131)I). Explaining the possibility of flame sensor activation to patients when they receive (131)I to treat Graves disease or other ablative purposes is important. We investigate the current situation of flame sensor activation after radioactive iodine (RAI) therapy. A total of 318 patients (65 males and 253 females) with Graves disease who received RAI therapy at our clinic between November 2007 and June 2014 participated in this study. Patients were given both written and oral explanations regarding the possibility of flame sensor activation. Participants were surveyed with a questionnaire. The following question was asked: "Did the fire alarm (flame sensor) go off when you used a restroom in places like shopping centers within a few days after your isotope therapy?" To those who answered "yes," we asked where the fire alarm had gone off. Of the 318 patients, 19 (6.0%) answered "yes," 2 of whom were male while 17 were female. Of the 299 (94.0%) patients who answered "no," 63 were male and 236 were female. As to the place of restroom sensor activation, shopping centers were reported by 9 patients; supermarkets by 5; airports by 2; and a bookstore, the Kyushu Shinkansen (bullet train), and a hospital by 1 each. Explaining to patients the possibility of flame sensor activation after RAI therapy is important to avoid some complications, especially in security-sensitive areas. (131)I = iodine 131 RAI = radioactive iodine UV = ultra-violet.

Antithyroid drugs in Graves' disease: Are we stretching it too far?

Introduction:Early and durable achievement of euthyroid or hypothyroid status with low likelihood of relapse is the key to effective treatment of Graves’ disease (GD). Although antithyroid drugs (ATDs) are commonly used first-line agents, likelihood of remission remains highest with radioactive iodine (RAI) therapy and surgery. Data regarding efficacy and economical superiority of RAI therapy over ATDs are lacking from India. This study was designed to study the response to long-term (>12 months) use of ATDs in GD with respect to attainment of remission and to compare the cost of treatment with ATDs versus RAI therapy beyond 12 months.Settings:The study was conducted in a tertiary care center.Study Design:This was a retrospective analysis.Materials and Methods:Patients of GD in our follow-up from February 2009 to March 2016 who had received ATDs for a duration exceeding 12 months were retrospectively analyzed. Patients who underwent radioablation after a period of at least 12 months on ATDs were analyzed and their status was recorded after a minimum of 6 months after radioablation. Patients who remained hyperthyroid beyond 12 months and received RAI therapy were further compared with those who continued on ATDs, for achievement of euthyroid or hypothyroid status. Cost analysis was done for follow-ups and treatment and compared.Statistical Analysis Used:All analyses were done using Fisher's exact test for categorical and descriptive statistics for numerical data.Results:Use of ATDs leading to euthyroid and hypothyroid status in GD patients was only significant beyond 24 years when compared to those at <12–18 months therapy (P = 0.0262 and P = 0.0217, respectively). The patients who ended up with hypothyroid status were significantly greater in RAI group compared to ATD group (P = 0.0003). Cost of therapy per patient beyond 12 months was lower in the RAI group compared to the ATD group (cost difference Rs. 5435.00).Conclusions:Within limitations, our study demonstrates that RAI is effective and economical option in GD.

Radioactive Iodine Therapy Did Not Significantly Increase the Incidence and Recurrence of Subsequent Breast Cancer.

Previous studies on the extent to which radioactive iodine (RAI) therapy for thyroid cancer increases the risk of subsequently developing breast cancer have given conflicting results. This study aimed to evaluate the effect of RAI treatment on breast cancer development and recurrence among female patients with primary thyroid cancer. This was a retrospective cohort study. The risk of subsequent breast cancer associated with RAI and its dose in hazard ratios (HRs) with 95% confidential intervals (CIs) were calculated using time-dependent Cox proportional hazard models. A total of 6150 patients with thyroid cancer enrolled between 1973 and 2009 were followed until December 2012. Of these, 3631 (59.0%) received RAI therapy. During the follow-up period, 99 primary breast cancers were diagnosed. Risk of breast cancer development according to RAI therapy and RAI dose during treatment for primary thyroid cancer. RAI therapy did not significantly increase the incidence of subsequent breast cancer among female patients (hazard ratio [HR], 0.49; 95% confidence interval [CI], 0.22-1.06) when a 2-year latency period was accounted for. High-dose RAI (≥120 mCi) was associated with a reduced incidence of subsequent breast cancer (HR, 0.17; 95% CI, 0.05-0.62) in the cohort with a 2-year latency period. The long-term follow-up results of this study suggest that RAI treatment for patients with thyroid cancer may not increase the risk or recurrence of breast cancer.

Role of RAI in the management of incidental N1a disease in papillary thyroid cancer.

Following total thyroidectomy (TT) for papillary thyroid cancer (PTC), pathological assessment can occasionally reveal incidental perithyroidal lymph nodes (LNs) with occult metastases. These cN0pN1a patients often receive radioactive iodine (RAI) therapy for this indication alone. The aim of this study was to determine the central compartment nodal recurrence-free survival in patients treated without RAI compared to those who received RAI treatment. An institutional database of 3664 previously untreated patients with differentiated thyroid cancer operated between 1986 and 2010 was reviewed. A total of 232 pT1-3 patients managed with TT and no neck dissection were subsequently found to have incidental level 6 LNs on pathology. Patients with other indications for RAI, such as extrathyroidal extension and close or positive margins, were excluded. One hundred and four patients remained for analysis. Kaplan-Meier method was used to determine central neck LN recurrence-free survival (RFS). The median age of the cohort was 40years (range 17-83). The median follow-up was 53months (range 1-211). The median number of positive LNs removed and maximum LN diameter were 1 (range 1-8) and 5mm (range 1-16mm), respectively. A total of 67 (64%) patients had adjuvant RAI and 37 (36%) did not. Patients with vascular invasion (P=0·01), LNs>2mm (P=0·07) and >2 positive nodes (P=0·06) were more likely to be selected for adjuvant RAI therapy. Patients without RAI therapy had similar 5-year central neck LN RFS compared to those treated with RAI: 96·2% vs 94·6%, respectively (P=0·92). There is no difference in the 5-year central compartment nodal recurrence-free survival in patients treated without RAI compared to those who received RAI treatment.

Salivary Function after Radioiodine Therapy: Poor Correlation between Symptoms and Salivary Scintigraphy.

Symptoms of salivary gland dysfunction frequently develop after radioactive iodine (RAI) therapy, but have generally not been correlated with assessment of salivary gland functioning. The aim of this study was to determine whether there was a correlation between salivary symptoms and salivary functioning as assessed by salivary scan parameters. This was a non-randomized observational study. Fifteen patients receiving RAI therapy for differentiated thyroid cancer completed a questionnaire assessing their salivary and nasal symptoms prior to their therapy and 3 and 12 months after their therapy. Salivary gland scanning using technetium-99m pertechnetate was performed at the same time points. In addition, protective measures used at the time of radioiodine administration, such as use of fluids and sour candy, were also documented. Measures of salivary gland accumulation and secretion were correlated with scores of salivary and nasal symptomatology and any effects of protective measures were assessed. The mean number of salivary, nasal, and total symptoms at 3 months increased significantly over the number of symptoms at baseline by 3.7, 2.7, and 6.3 symptoms, respectively (p values 0.001, 0.0046, and <0.001, respectively). The mean increases in the number of salivary, nasal, and total symptoms at 12 months were non-significant at 1.3, 1.3, and 2.5 symptoms, respectively. The mean right parotid gland accumulation and secretion of radioisotope declined significantly at 3 months, compared with baseline. The changes in left parotid and right and left submandibular function were non-significant. There was no association between the increase in salivary, nasal, or total symptoms and the change in scintigraphy measures. However, the increases in nasal and total symptoms were significantly greater in those with co-existent Hashimoto's disease, compared with those without this condition (p values 0.01 and 0.04, respectively). Nasal symptoms decreased (p value 0.04) and total symptoms trended to decrease (p value 0.08) in those who used sour candies, compared with those who did not. Increasing body mass index was significantly associated with increasing nasal symptoms (p value 0.05). Greater decline in salivary parameters at 3 months compared with baseline was generally associated with heavier body weight, decreased thyroid cancer stage, absence of Hashimoto's thyroiditis, and pre-menopausal status. Salivary and nasal symptoms increased and salivary scintigraphy parameters decreased after radioiodine therapy. However, the increased symptoms did not correlate with decrements in salivary gland accumulation or secretion. Moreover, the variables associated with symptoms and changes in salivary scan parameters differed. Therefore, a better understanding of the relationship between salivary gland symptoms and functioning is needed. Factors affecting susceptibility to salivary and nasal damage after radioiodine therapy need to be better elucidated, so that modifiable factors can be identified.

Post-operative stimulated thyroglobulin and neck ultrasound as personalized criteria for risk stratification and radioactive iodine selection in low- and intermediate-risk papillary thyroid cancer.

The purpose of this study was to demonstrate the utility of a personalized risk stratification and radioactive iodine (RAI) selection protocol (PRSP) using post-operative stimulated thyroglobulin (Stim-Tg) and neck ultrasound in low- and intermediate-risk papillary thyroid carcinoma (PTC) patients. Patients with PTC tumors ≥1 cm were prospectively followed after total thyroidectomy and selective therapeutic central compartment neck dissection. Low/intermediate risk was defined as PTC confined to the thyroid or central (level VI) lymph nodes. Stim-Tg and neck ultrasound were performed approximately 3 months after surgery and used to guide RAI selection. Patients with Stim-Tg < 1 µg/L did not receive RAI, while those with Stim-Tg >5 µg/L routinely did. Those with Stim-Tg 1-5 µg/L received RAI on the basis of several clinical risk factors. Patients were followed for >6 years with serial neck ultrasound and basal/stimulated thyroglobulin. Among the 129 patients, 84 (65 %) had undetectable Stim-Tg after initial surgery, 40 (31 %) had Stim-Tg of 1-5 µg/L, and 5 (4 %) had Stim-Tg >5 µg/L. RAI was administered to 8 (20 %) patients with Stim-Tg 1-5 µg/L and 5 (100 %) with Stim-Tg >5 µg/L. Using this approach, RAI therapy was avoided in 17/20 (85 %) patients with tumors >4 cm, in 72/81 (89 %) patients older than 45 years, and in 6/9 (67 %) patients with central lymph node involvement. To date, 116 (90 %) patients in this cohort have not received RAI therapy with no evidence of residual/recurrent disease, whereas among the 13 patients who received RAI, 1 (8 %) had pathologic residual/recurrence disease. Using the proposed PRSP, RAI can be avoided in the majority of low/intermediate-risk PTC patients. Moreover, traditional risk factors considered to favor RAI treatment were not always concordant with the PRSP and may lead to overtreatment.

Acute-on-Chronic Kidney Injury in Thyroid Hormone Withdrawal: A Case with Possible Implications for Radioactive Iodine Planning.

The association between renal dysfunction and hypothyroidism is of increasing clinical importance as thyroid hormone replacement may attenuate decline in renal function and improve cardiovascular outcomes in patients with chronic kidney disease (CKD). Although multiple mechanisms for the induction of renal insufficiency in hypothyroidism have been described, the renal impact of short-term, acute hypothyroidism is unknown, which has possible implications for thyroid cancer patients preparing to receive radioactive iodine (RAI). A 56-year-old gentleman with history of unilateral renal agenesis and CKD stage III presented with intermediate-risk papillary thyroid cancer. In preparation for RAI, he underwent thyroid hormone withdrawal (THW) associated with acute kidney injury (AKI), as marked by a decrease in his estimated GFR from 53 to 32 mL/min/1.73 m2. Upon resumption of thyroid hormone, renal function returned to baseline within months. Although AKI in this case was not otherwise associated with adverse outcome and reversed upon resumption of thyroid hormone, it is possible that this phenomenon could result in potential harm, particularly in the patient with baseline renal insufficiency. In CKD patients, preparation for RAI therapy may require special consideration; future studies should address the role of recombinant TSH to mitigate deleterious renal effects of acute hypothyroidism in this setting.

Effectiveness of Fixed Dose Radioactive Iodine (RAI) for the Treatment of Hyperthyroidism: Experience of a Teaching Hospital in South West Nigeria

Objective: Using radioactive iodine (RAI) as the first line therapy for Graves’ hyperthyroidism and as the treatment of choice for relapsed Graves’ disease is increasing in recent times. However, there has been little consensus on the most appropriate dose to use. So this study is to determine the response of hyperthyroidism to fixed doses of 370 MBq and 555 MBq RAI therapies and determine the incidence of hypothyroidism at 6 months post therapy.Methods: Hyperthyroid patients’ case records treated with radioiodine was retrospectively reviewed to determine the response rate of hyperthyroidism to the two fixed dose regimens. Statistical analysis was done with SPSS version 15.0 and the level of statistical significance was taken as p<0.05. Forty subjects, 6 males (15%) and 34 females (85%) received RAI therapy for Graves’ hyperthyroidism, mean age was 49.4 years (range, 25-75years). The thyroid function status at 6 months post therapy was available for all subjects. 24 patients (60%) received 370 MBq while 16 patients (40%) received 555 MBq.Results: The response for fixed doses of 370 MBq and 555 MBq were similar (100%). Also, the incidence of hypothyroidism in these subjects which was 66.6% with fixed dose of 370 MBq and 62.5% with fixed dose of 555 MBq within 6 months post RAI therapy were similar. Conclusion: SRAI is highly effective for the treatment of hyperthyroidism, with a cure rate of 100%. However, it has proved impossible to determine a fixed dose regimen for individual patients accurately to guarantee an euthyroid state. This is because hypothyroidism is a natural predictable sequel of RAI therapy. Conflict of interest:None declared.

Cohort Study on Radioactive Iodine–Induced Hypothyroidism: Implications for Graves' Ophthalmopathy and Optimal Timing for Thyroid Hormone Assessment

Graves' ophthalmopathy (GO) develops or worsens in up to one-third of patients treated with radioactive iodine (RAI) for Graves' hyperthyroidism. We sought to identify the prevalence of development or worsening of GO in patients treated with RAI for Graves' hyperthyroidism and to identify the risk factors associated with that outcome. We identified a retrospective cohort of consecutive patients treated with RAI at Mayo Clinic (Rochester, MN) between 2005 and 2006. We assessed their medical records for evidence of hypothyroidism and development or worsening of GO in the year after therapy. Hypothyroidism was defined as thyrotropin >3.0 mIU/L or free thyroxine <0.8 ng/dL. We identified 291 consecutive patients who received RAI therapy during the study period, with 195 out of 291 having complete follow-up data for a one-year period. GO was present in 46 out of 195 patients (23.6%) at baseline. After RAI treatment, GO developed or worsened in 25 out of 195 patients (12.8%) and it was associated with hypothyroidism at first follow-up (p=0.011) with an odds ratio (OR) of 3.3 [95% confidence interval (CI) 1.3-8.7]. More smokers than nonsmokers developed new or worse GO (17.7% vs. 11.8%), but that difference did not reach statistical significance (p=0.35). Preexisting GO (24% of patients) was associated with a higher risk for negative GO outcome compared with patients who had no GO at baseline (11%; p=0.021). Both development of hypothyroidism by the first visit after RAI therapy (OR 3.6) and preexistent GO (OR 2.8) remained significant in a multivariate analysis. Development of hypothyroidism was more likely in patients with longer duration to first follow-up (p<0.001). By 6-8 weeks after RAI treatment, the prevalence of hypothyroidism was ∼40%, while that of hyperthyroidism was only 20%. The presence of hypothyroidism at the first assessment of thyroid function after RAI administration is a strong predictor for adverse GO outcome. This risk is highest in patients with preexisting GO. We suggest that in order to prevent clinical hypothyroidism and the associated risk for GO, the optimal time for first measurement of fT4 is before 6 weeks after RAI therapy.

Survival impact of treatment options for papillary microcarcinoma of the thyroid

Evaluate the impact of medical and surgical interventions on the survival of patients with papillary microcarcinoma (PMC) of the thyroid, a common tumor with an increasing worldwide incidence. Cross-sectional population analysis of a prospectively maintained database. Cases of nonmetastatic PMC treated with cancer-directed surgery with or without postoperative radioactive iodine (RAI) therapy were extracted from the Surveillance, Epidemiology and End Results Database (1988-2005). Kaplan-Meier disease-specific survival (DSS) and overall survivals were compared according to extent of thyroidectomy and use of RAI therapy. Cox regression analysis was performed to determine the influence of these factors on survival. A total of 7,818 cases of PMC were identified. Overall actuarial survival rates at 10 and 15 years were 96.6% and 96.3%, respectively. DSS was 99.9% at both time intervals, with a total of 10 thyroid cancer-related deaths. There were no significant differences in DSS for patients who underwent total thyroidectomy, near-total/subtotal thyroidectomy, or lobectomy (P = .239). DSS for patients receiving RAI therapy was not significantly different than that of patients who did not (P = .504). On multivariate analysis, only increasing age at diagnosis, successfully predicted poor DSS (P = .001), whereas gender (P = .481), use of RAI therapy (P = .633), and extent of thyroidectomy (P = .104) did not. PMC carries an excellent prognosis with respect to both overall and disease-specific survival that is independent of surgical extent and the use of RAI therapy. An isolated, fine-needle-aspiration proven unilateral PMC focus in a patient lacking evidence of metastatic disease may be treated with lobectomy alone.