Parathyroid Hormone Level Changes Following Radioiodine Therapy for Thyroid Cancer: A Prospective Observational Study

ObjectiveOur objective was to analyze the effect of radioiodine (RAI) therapy on parathyroid hormone (PTH) secretion.MethodsA total of 137 patients were included and divided into 2 groups based on pretherapy PTH levels. The residual thyroid tissue volume was classified into 4 grades (0-3), and a value of 0 indicated that there was no apparent residual tissue. We analyzed the PTH level changes among different time points in each group and the factors that could predict the PTH level changes.ResultsIn 113 patients with normal parathyroid gland function, the PTH level at baseline, 1 day, 7 days, 1 month, 3 months, and 6 months after RAI therapy did not show any significant difference; in 24 patients with decreased parathyroid gland function, the level of PTH immediately decreased after the implementation of RAI therapy but gradually returned to a pre-RAI therapy level within 6 months. On the seventh day after therapy, the mean value of PTH in patients with a residual thyroid tissue volume of extent of 0/1 was 8.0 ± 2.3 pg/mL, which was significantly higher than that in patients with a residual thyroid tissue volume of extent of 2/3 (P = .011). Similar phenomena were observed 1 month, 3 months, and 6 months after therapy.ConclusionRAI therapy had a significant transient adverse effect on parathyroid gland function in patients with decreased PTH secretion pretherapy, and the extent was associated with the amount of residual thyroid tissue.     

Recombinant Human Thyroid-Stimulating Hormone To Stimulate 131-1 Uptake For Remnant Ablation And Adjuvant Therapy

ObjectiveTo review the current literature with regard to the use of recombinant human thyroid stimulating hormone (rhTSH) as an adjunct to radioactive iodine (RAI) remnant ablation and adjuvant therapy.MethodsLiterature review of clinical studies examining rhTSH and/or thyroid hormone withdrawal preparations for RAI remnant ablation. The primary endpoints evaluated were (1) effectiveness at ablating the thyroid bed as demonstrated by the lack of significant uptake in the thyroid bed on follow-up diagnostic imaging and (2) effectiveness in facilitating the adjuvant therapy function of RAI ablation as manifested by follow-up thyroid stimulating hormone (TSH)-stimulated serum thyroglobulin levels and clinical outcomes (recurrence rates, likelihood of having no evidence of disease at final follow-up).ResultsRAI remnant ablation can be successfully achieved using either traditional thyroid hormone withdrawal or recombinant human TSH preparation. While initial studies included primarily thyroid cancer patients at low risk of recurrence, more recent studies suggest that rhTSH can also be effectively used as preparation for RAI ablation in patients with an intermediate or high risk of recurrence. Furthermore, while early studies focused primarily on the endpoint of thyroid bed remnant ablation, more recent retrospective studies suggest that final clinical outcomes (recurrence rates, likelihood of achieving no evidence of disease status at final follow-up) over 5-10 years of follow-up are very similar with either method of preparation.ConclusionrhTSH is an effective alternative to thyroid hormone withdrawal in preparation for RAI remnant ablation in patients without evidence of distant metastases who are at low, intermediate, or high risk of recurrence.     

Residual Pyramidal Lobe Increases Stimulated Thyroglobulin and Decreases Endogenous Thyroid Stimulating Hormone Stimulation in Differentiated Thyroid Cancer Patients

ObjectiveTo determine the frequency of pyramidal lobe remnants after total thyroidectomy (TT) and the effect on stimulated thyroglobulin (Tg).MethodsThe study included 1740 differentiated thyroid cancer (DTC) patients who were followed up by our center. The department database was searched to identify DTC patients with residual pyramidal lobe after TT. All postoperative technetium-99m pertechnetate thyroid scintigraphy images were re-evaluated for pyramidal lobe residue. Serum stimulated Tg and thyroid stimulating hormone (TSH) levels measured within the first 6 months after TT were retrieved from the database.ResultsPyramidal lobe residue was detected in 10.4% of the patients who underwent TT. Evidence of the pyramidal lobe was present on preoperative ultrasonography in 1.6% of the patients with residual pyramidal lobe. Stimulated Tg in patients with pyramidal lobe residue was significantly higher than that in patients without residue (P = .01). Endogenous stimulated TSH in patients with residual pyramidal lobe was significantly lower than that in patients without residue (P = .036). In 5.7% of patients with pyramidal lobe residue, a TSH level of >30 mIU/L was not achieved, which was a significantly higher rate than that in patients without pyramidal lobe residue (P = .034) and is the level required for maximum radioiodine uptake.ConclusionPyramidal lobe residue was found in almost 10% of DTC patients. The pyramidal lobe is often missed on preoperative ultrasonography. Residual pyramidal lobe increased stimulated Tg and decreased endogenous stimulated TSH. Residual pyramidal lobe may complicate the follow-up of DTC patients.     

超声弹性成像联合血清TSH、TT3、TT4在甲状腺结节良恶性诊断的临床价值研究

目的:探讨超声弹性成像联合血清促甲状腺激素(TSH)、总三碘甲状腺原氨酸(TT3)、总甲状腺素(TT4)在甲状腺结节良恶性诊断的临床价值.方法:选择2018年1月至2019年12月我院收治的甲状腺结节患者80例,根据病理检查结果分为良性结节组(48例),恶性结节组(32例),所有患者术前进行血清TSH、TT3、TT4及...     

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     

Potential Use of Recombinant Human Thyrotropin in the Treatment of Distant Metastases in Patients with Differentiated Thyroid Cancer

ObjectiveIn order to effectively treat differentiated thyroid cancer (DTC) with radioiodine (RAI) it is necessary to raise serum TSH levels either endogenously by thyroid hormone withdrawal (THW) or exogenously by administration of recombinant human TSH (rhTSH). The goal of this review is to present current data on the relative efficacy and side effects profile of rhTSH-aided versus THW-aided RAI therapy for the treatment of patients with distant metastases of DTC.MethodsWe have searched the PubMed database for articles including the keywords "rhTSH", "thyroid cancer", and "distant metastases" published between January 1, 1996 and January 7, 2012. As references, we used clinical case series, case reports, review articles, and practical guidelines.ResultsExogenous stimulation of TSH is associated with better quality of life because it obviates signs and symptoms of hypothyroidism resulting from endogenous TSH stimulation. The rate of neurological complications after rhTSH and THW-aided RAI therapy for brain and spine metastases is similar. The rate of leukopenia, thrombocytopenia, xerostomia, and pulmonary fibrosis is similar after preparation for RAI treatment with rhTSH and THW. There is currently a controversy regarding RAI uptake in metastatic lesions after preparation with rhTSH versus THW, with some studies suggesting equal and some superior uptake after preparation with THW. Analysis of available retrospective studies comparing survival rates, progression free survival, and biochemical and structural response to a dosimetrically-determined dose of RAI shows similar efficacy after preparation for therapy with rhTSH and THW.ConclusionThe rhTSH stimulation is not presently approved by the FDA as a method of preparation for adjunctive therapy with RAI in patients with metastatic DTC. Data on rhTSH compassionate use suggest that rhTSH stimulation is as equally effective as THW as a method of preparation for dosimetry-based RAI treatment in patients with RAI-avid metastatic DTC. (Endocr Pract. 2013;19:139-148)     

Thyroid Tuberculosis With Abnormal Thyroid Function-Case Report And Review Of The Literature

ObjectiveTo report an extremely rare case of thyroid tuberculosis (TT) with abnormal thyroid function and to review the related literature.MethodsWe present the patient's history, clinical findings, laboratory test results, imaging examinations, cytological data, management, and follow-up. In addition, we perform a review of the previously published cases of TT and give special attention to those with hypothyroidism.ResultsA 45-year-old Indian man presented to the outpatient clinic with neck swelling and respiratory and constitutional symptoms. Cervical ultrasound revealed a thyroid nodule and a necrotic right cervical adenopathy. Fine-needle aspiration cytology (FNAC) was performed and purulent material was removed from thyroid and lymph node. In both specimens, the culture was positive for Mycobacterium tuberculosis complex, and a cytological examination revealed epithelioid cell granulomas and necrosis. Mycobacterium tuberculosis complex was also identified by sputum culture. Antibiotic testing revealed sensitivity to all first-line drugs. A diagnosis of disseminated tuberculosis with thyroid and cervical lymph node involvement was made. Thyroid function was consistent with subclinical hyperthyroidism that subsequently evolved to hypothyroidism, requiring thyroid hormone replacement, and reflected tuberculous thyroiditis. Anti-tuberculosis drugs were started with good therapeutic response.ConclusionTT is a rare condition and its association with thyroid function abnormalities is even rarer. To our knowledge this is the third report of hypothyroidism related to TT and the first to identify a period of hyperthyroidism preceding hypothyroidism. Despite its rarity, TT should be considered in the differential diagnosis of neck mass. FNAC is a useful procedure and thyroid function should be monitored.     

Factors Associated With Radioactive Iodine Therapy–Acquired Nasolacrimal Duct Obstruction

ObjectiveTo identify factors associated with radioactive iodine (RAI)-acquired nasolacrimal duct obstruction (NLDO).MethodsRetrospective chart review and telephone surveys of patients who received RAI therapy for thyroid carcinoma at an academic institution were conducted. Telephone surveys were used to screen for post-RAI NLDO diagnoses. Databases were reviewed for documented NLDO, demographics, RAI dose, total number of RAI treatments, and sialadenitis. Routine post-RAI whole-body scintigraphy (WBS) images were analyzed for the presence or absence of ¹³¹I sodium iodide (I-131) in the nasolacrimal duct. Intranasal I-131 activity was graded as none, low, moderate, and high; those with moderate or high activity were considered to have “increased” activity. Logistic and ordinal logistic regression models were used to evaluate the associations with NLDO while adjusting for I-131 dose.ResultsOf the 209 patients who completed the survey, 15 (7%) had NLDO diagnoses. Increased intranasal I-131 activity on WBS, presence of nasolacrimal I-131 WBS activity, presence of documented post-RAI sialadenitis, and history of >1 RAI treatment were associated with the development of NLDO from univariate analyses (P ≤ .013). After adjusting for the administered dose of I-131, the presence of sialadenitis and nasolacrimal I-131 activity on WBS were the remaining 2 factors significantly associated with NLDO development (P < .001 and P = .01, respectively).ConclusionsThe presence of sialadenitis and nasolacrimal I-131 activity on WBS are I-131 dose-independent correlative factors for RAI-associated NLDO. Patients with these characteristics should be counseled on their increased risk of NLDO after RAI therapy for thyroid carcinoma.     

Therapeutic Implications of Diffuse Hepatic Uptake Following I-131 Therapy for Differentiated Thyroid Cancer

ObjectiveTo determine if diffuse hepatic uptake (DHU) of radioactive iodine (I-131) following radioactive iodine treatment has prognostic implications in otherwise scan-negative patients.MethodsThis is a retrospective review of patients treated for differentiated thyroid cancer (DTC) at Beth Israel Deaconess Medical Center between January 1990 and June 2006. This group included patients receiving therapy to ablate presumed remnant tissue, as well as treatment for persistent disease as measured by thyroglobulin or imaging. All patients included in the study had no remnant uptake and otherwise negative posttherapy scans. A total of 57 patients with 63 scans met these criteria. The scans were then scored for DHU on a scale of 0 to 5, with 0 being no uptake and 5 being intense uptake relative to background.ResultsSixteen of 63 treatments were remnant ablations. Ten of 57 patients had positive thyroglobulin antibodies. Average DHU was similar in the ablation and therapeutic groups (1.9 vs. 2.3, P = .3). There was no correlation with either I-131 dose or the presence of thyroglobulin antibodies. There was a difference for DHU in the rate of disease-free survival, (undetectable thyroglobulin and no clinical or radiographic evidence of metastasis); 50% of patients with hepatic uptake scores of 0-2 were disease-free compared to 15% with scores of 3-5 (P<.01). The average length of follow-up for disease-free patients was 4.6 years.ConclusionIn patients with DHU with otherwise negative whole-body scans following I-131 treatment, more intense hepatic uptake is associated with lower likelihood of complete response to I-131 treatment. (Endocr Pract. 2013;19:263-267)     

Lithium Andadjunct to Radioactive Iodine for the Treatment of Hyperthyroidism: A Systematic Review and Meta-Analysis

BackgroundRadioactive iodine (RAI) is commonly used in the treatment of hyperthyroidism but is not uniformly successful. Lithium increases thyroidal iodine retention without reducing iodide uptake, increasing the radiation dose to the thyroid when administered with RAI. Although these actions suggest that adjuvant lithium may increase the efficacy of RAI, its role as an adjunct to RAI remains contentious.ObjectiveTo evaluate the safety and efficacy of adding lithium to RAI to treat hyperthyroidism.MethodsRelevant studies were identified by a search of Medline and the Cochrane Central Register of Controlled Trials. To be included, a study had to be a controlled trial comparing the effect of RAI alone to RAI with lithium in the treatment of hyperthyroidism. Relevant data were extracted and meta-analyses were performed.ResultsOf the 75 identified studies, 6 met the inclusion criteria; 4 of these studies were interventional and 2 were observational trials. Meta-analysis of the observational trials (N = 851), both of which were retrospective cohort studies, showed significant improvement in the primary outcome (i.e., cure rate) with adjunctive lithium (odds ratio [OR], 1.92; 95% confidence interval [CI], 1.24 to 2.96). The combined interventional trials (N = 485) also showed an improvement in cure rate, but the difference did not reach statistical significance (OR, 1.28; 95% CI, 0.85 to 1.91). Adjunctive lithium reduced time to cure and blunted thyroid hormone excursions after RAI. Lithiumrelated side effects were infrequent and usually mild.ConclusionThe observational trials demonstrated significant improvement in the cure rate of hyperthyroidism when lithium is added to RAI. The improvements shown in the interventional trials did not reach statistical significance due to the effect of a single, large negative trial. (Endocr Pract. 2014;20:737-745)     

Thyrotoxicosis due to Ectopic Lateral Thyroid Tissue Presenting 5 Years After Total Thyroidectomy

ObjectiveTo describe a patient who, 5 years after total thyroidectomy to treat Graves disease, presented with thyrotoxicosis due to nonmalignant lateral ectopic thyroid tissue.MethodWe describe the laboratory, imaging, and physical findings of the study patient and review the relevant literature.ResultsA 32-year-old white woman with a history of Graves disease presented with recurrent hyperthyroidism 5 years after total thyroidectomy. A radioactive iodine scan was performed, which revealed elevated uptake (40%) and positive imaging in the left mid-neck. Ultrasonography examination of the neck confirmed the absence of any thyroid tissue within the thyroid bed, but documented 2 nodular, hypoechoic left upper-neck masses with punctuate hyperlucency. Contrast-enhanced computed tomography was performed to precisely localize the nodules, which were excised surgically via selective neck dissection. Histopathologic examination revealed chronic lymphocytic inflammatory infiltrate with focal thyroid hyperplasia and papillary infoldings and no evidence of malignancy.ConclusionsTo our knowledge, this represents the first report of ectopic benign thyroid tissue as the sole cause of hyperthyroid symptoms, and this entity should be considered in patients who have undergone thyroidectomy and have persistent hyperthyroidism. (Endocr Pract. 2011;17:70-73)     

Predictors of Prolonged Euthyroidism After Radioactive Iodine Treatment for Graves’ Disease: A Pilot Study

ObjectivePatients with Graves’ disease who remain hyperthyroid under the treatment of antithyroid drugs (ATD) or cannot tolerate ATD usually receive radioactive iodine (RAI) to control disease activity. This pilot study aimed to identify predictors of prolonged euthyroidism > 12 months after receiving RAI.MethodsDemographic, clinical, and laboratory data from 117 patients receiving RAI were retrospectively collected, including age, gender, body surface area, smoking status, free thyroxine, thyrotropin, thyrotropin binding inhibiting immunoglobulin, microsomal antibody, thyroglobulin antibody, medication history, and thyroid volume. Only 85 patients without missing values were included in statistical analysis. The calculated RAI dose was the estimated thyroid volume × 0.4. The difference and ratio between the actual and calculated RAI doses were examined. A stepwise logistic regression analysis was conducted to identify important predictors of prolonged euthyroidism > 12 months. The cut-off values for discretizing continuous covariates were estimated by fitting generalized additive models.ResultsAmong the 85 patients on RAI, 18 (21.2%) achieved prolonged euthyroidism > 12 months, 38 (44.7%) remained hyperthyroid with decreased ATD doses, but 29 (34.1%) suffered permanent hypothyroidism and needed long-term levothyroxine. Logistic regression analysis revealed that patients with age > 66 years, 33 < age ≤ 66 years, quitting smoking vs nonsmoking or current smoking, 600 < micorsomal antibody ≤ 1729 IU/mL, 47% < thyrotropin binding inhibiting immunoglobulin ≤ 81%, 7 < thyroglobulin antibody ≤ 162 IU/mL, 0.63 < ratio between actual and calculated RAI doses ≤ 1.96, or taking hydroxychloroquine would have a higher chance of reaching prolonged euthyroidism > 12 months after receiving RAI. Its area under the Receiver Operating Characteristic (ROC) curve was 0.932.ConclusionPatients with Graves’ disease who received an actual RAI dose close to the calculated RAI dose achieved prolonged euthyroidism > 12 months if they also took hydroxychloroquine during RAI treatment.     

Predictors of Hypothyroidism Following Empirical Dose Radioiodine in Toxic Thyroid Nodules: Real-Life Experience

ObjectiveWe aimed to determine the factors predicting hypothyroidism after radioactive iodine (RAI) treatment in patients with toxic adenoma and toxic multinodular goiter.MethodsWe retrospectively collected the data of 237 patients with toxic multinodular goiter or toxic adenoma who had consecutively received RAI treatment between 2014 and 2020 at 2 medical centers. Patients who received the second RAI treatment and whose medical records could not be accessed were excluded from the study. Finally, 133 patients were included in the study. RAI was administered at an empirical dose of 15 or 20 mCi.ResultsThe median age of the 133 participants was 69 years (interquartile range, 62-75 years), and 64.7% of the participants were women. A total of 42.1% of the patients had toxic adenoma, whereas 57.9% of patients had toxic multinodular goiter. The median follow-up was 24 months (interquartile range, 11-38 months). During the follow-up, 61.7% of patients became euthyroid, 30.8% developed hypothyroidism, and 7.5% remained hyperthyroid. The median month of hypothyroidism onset was 4 months (interquartile range, 2-9 months). Regression analysis revealed 2 factors that could predict hypothyroidism: thyroid-stimulating hormone (odds ratio, 2.548; 95% CI, 1.042-6.231; P = .04) and thyroid volume (odds ratio, 0.930; 95% CI, 0.885-0.978; P = .005).ConclusionOverall, 30.8% of the cases developed hypothyroidism after the RAI treatment. Approximately 78% of hypothyroidism developed within the first 10 months. The risk of hypothyroidism was higher in patients with higher thyroid-stimulating hormone and smaller thyroid volume.     

Increased Risk of Radioiodine Treatment Failure Associated with Graves Disease Refractory to Methimazole

Objective: Iodine 131 (I-131) radioactive iodine (RAI) therapy has been the preferred treatment for Graves disease in the United States; however, trends show a shift toward antithyroid drug (ATD) therapy as first-line therapy. Consequently, this would favor RAI as second-line therapy, presumably for ATD refractory disease. Outcomes of RAI treatment after first-line ATD therapy are unclear. The purpose of this study was to investigate treatment failure rates and potential risk factors for treatment failure, including ATD use prior to RAI treatment.Methods: A retrospective case control study of Graves disease patients (n = 200) after I-131 RAI therapy was conducted. Treatment failure was defined as recurrence or persistence of hyperthyroidism in the follow-up time after therapy (mean 2.3 years). Multivariable regression models were used to evaluate potential risk factors associated with treatment failure.Results: RAI treatment failure rate was 16.5%. A majority of patients (70.5%) used ATD prior to RAI therapy, predominantly methimazole (MMI) (91.9%), and approximately two-thirds of patients used MMI for >3 months prior to RAI therapy. Use of ATD prior to RAI therapy (P = .003) and higher 6-hour I-123 thyroid uptake prior to I-131 RAI therapy (P<.001) were associated with treatment failure. MMI use >3 months was also associated with treatment failure (P = .002).Conclusion: More patients may be presenting for RAI therapy after failing first-line ATD therapy. MMI use >3 months was associated with RAI treatment failure. Further studies are needed to investigate the association between long-term first-line ATD use and RAI treatment failure.     

Unusual Initial Manifestation of Metastatic Follicular Carcinoma of the Thyroid with Thyrotoxicosis Diagnosed by Technetium Tc 99m Pertechnetate Scan: Case Report and Review of Literature

ObjectiveTo report a case of metastatic thyroid cancer diagnosed on a technetium Tc 99m pertechnetate (TcO₄^–) thyroid scan.MethodsWe present the clinical findings, laboratory results, imaging studies, and surgical pathology report in a man with thyrotoxicosis in whom metastatic well-differentiated thyroid cancer was diagnosed incidentally on a routine TcO₄ ^– thyroid scan in the setting of a presumed diagnosis of benign toxic thyroid disease. In addition, we review the literature regarding coexistence of metastatic thyroid cancer and thyrotoxicosis.ResultsA 68-year-old man with thyrotoxicosis was referred for radioiodine therapy. A routine TcO₄^- thyroid scan revealed high-grade extrathyroidal uptake in the right upper hemithorax as well as in the left side of the thorax. In view of this finding, radioiodine treatment was deferred; further imaging with computed tomography revealed a 6.5-cm mass in a rib on the right side. A biopsy of the rib confirmed the presence of metastatic follicular carcinoma of the thyroid. Scintigraphy revealed sites of metastatic involvement predominantly in the bones along with a cold nodule in the left thyroid lobe, consistent with the primary tumor.ConclusionThis case emphasizes the impact of scintigraphic findings on determining the correct management of a patient who would have otherwise undergone inappropriate treatment. Through an extensive literature review, the incidence of malignant involvement in hyperfunctioning thyroid glands and the possible role of sodium iodide symporter expression by thyroid cancer metastatic lesions in preoperative detection of metastatic sites are addressed. (Endocr Pract. 2009;15:458-462)     

Nodule thyroïdien bénin fixant le 99mTc-MIBI

ObjectivesTo illustrate a case of intense uptake of ^99mTc-MIBI on benign thyroid nodule and to recall the mechanisms of this uptake.Case presentationA patient of 25 years old had a parathyroid scintigraphy for suspected right lower parathyroid adenoma. The exam showed intense uptake of ^99mTc-MIBI at the infero-lateral region of the right thyroid lobe. Low levels of PTH prompted to perform a thyroid scintigraphy for better diagnostic orientation. The scan revealed a large cold right basilobar thyroid nodule. The patient underwent a right loboisthmectomy. The histological analysis found a 3 cm diameter vesicular adenoma with oncocytic cells of the lower pole of right thyroid lobe.Discussion/conclusion^99mTc-MIBI is used in the imaging of hyperparathyroidism. Radiotracer uptake is correlated to the parathyroid adenoma content in oxyphil cells. These cells are rich in mitochondria and retain the ^99mTc-MIBI. This radiotracer can bind also on thyroid nodules. The specificity of this uptake for the diagnosis of malignancy is low. It is relevant to the nodule's wealth in oncocytic cells. These cells possess numerous mitochondria and can sequester ^99mTc-MIBI like parathyroid oxyphil cells.     

Time to Normalization and Sustainable Normal Serum Thyrotropin Concentrations in Patients with Hyperthyroidism: Comparison of Methimazole and Radioactive Iodine Treatments

ObjectiveThe aim of this study was to compare the “time to euthyroidism” and “time spent in euthyroidism” following methimazole (MMI) and radioactive iodine (RAI) treatments.MethodsThree hundred fifty-eight patients with hyperthyroidism, 178 who underwent long-term MMI treatment and 180 patients who underwent RAI treatment, were analyzed. The time to normalization of increased serum values of free thyroxine and triiodothyronine and suppressed serum thyroid-stimulating hormone (TSH) values as well as the percentage of time that the thyroid hormone levels remained within normal ranges during a mean follow-up time of 12 years were compared.ResultsThe mean time to euthyroidism was 4.59 ± 2.63 months (range, 2-16 months) in the MMI group and 15.39 ± 12.11 months (range, 2-61 months) in the RAI group (P < .001). During follow-up, the percentage of time spent in euthyroidism was 94.5% ± 7.3% and 82.5% + 11.0% in the MMI and RAI groups, respectively (P < .001). Serum TSH values above and below the normal range were observed in 5.3% and 0.2% of patients, respectively, in the MMI group and 9.8% and 7.7% of patients, respectively, in the RAI group (P < .001). The time to euthyroidism and the percentage of time spent in euthyroidism in 40 RAI-treated patients with euthyroidism were similar to those in the MMI group and significantly shorter than those in the RAI-treated hypothyroid and relapsed subgroups. In patients who continued MMI therapy for >10 years, the percentage of time spent in euthyroidism was >99%.ConclusionIn our cohort of selected patients, MMI therapy was accompanied by faster achievement of the euthyroid state and more sustained normal serum TSH levels during long-term follow-up compared with RAI therapy.     

Comparison of Radioiodine Utilization in Adolescent and Young Adult and Older Thyroid Cancer Patients

ObjectiveDifferentiated thyroid cancer (DTC) is 1 of the most common cancers in adolescents and young adults (AYA, ages 15-39). Although most AYAs with DTC are considered low risk compared to older patients, there are no specific postoperative radioiodine (RAI) treatment recommendations despite the potential adverse effects specific to this age group, namely secondary malignancies and fertility difficulties. This study compares factors influencing RAI utilization in AYA and older patients.MethodsA total of 5,687 primary DTC patients were identified from the SEER (Surveillance, Epidemiology, and End Results) database between January 1, 2004 and January 31, 2009. The 2009 American Thyroid Association (ATA) guidelines were used to classify patients as low (LR) or intermediate/high risk (IHR) based on tumor characteristics. Multivariate logistic regression analysis was performed.ResultsOverall, 56.9% of AYA (n = 1,963) patients received postoperative RAI compared to 52.2% of older (n = 3,724) patients (odds ratio [OR]: 1.21, 95% confidence interval [CI]: 1.09-1.35, P = .001). For AYA patients, having a total thyroidectomy (TTx) (OR: 3.53, 95% CI: 2.7-4.61, P < .001) predicted RAI in a multivariate model whereas LR status (OR: 0.52, 95% CI: 0.43-0.63, P < .001) and northeast residence (OR: 0.39, 95% CI: 0.29-0.52, P < .001) decreased the probability. All 3 factors similarly affected older patients in addition to an increased likelihood after lymph node (LN) dissection. Additionally, after selecting for TTx (n = 1,077), no factor influenced the use of RAI for AYA patients, whereas LR (OR: 0.30, 95% CI: 0.21-0.43, P < .001) and northeast residence (OR: 0.39, 95% CI: 0.19-0.79, P = .008) were associated with decreased RAI use in older patients.ConclusionDespite their excellent prognosis, AYA thyroid cancer patients are more likely to receive postoperative RAI compared to older patients. Increased awareness of the unique survivorship implications for AYA patients will be an important aspect to address going forward. (Endocr Pract. 2014;20:405-411)     

Tall-Cell Variant Papillary Thyroid Carcinoma Arising from Struma Ovarll

ObjectiveTo present a case of tall-cell variant (TCV) papillary thyroid carcinoma (PTC) arising from Struma ovarii (SO) and to discuss special considerations in the management of this patient.MethodsThe clinical presentation and relevant pathologic features of a patient with PTC-TCV developing from SO are described, and a concise review of literature regarding this topic is also presented.ResultsA 36-year-old woman with a history of stable right ovarian dermoid cyst presented with amenorrhea and was found to have a significantly enlarged right ovary with multiple cysts. Following laparoscopic cystectomy, pathology revealed mature cystic teratoma (SO) with associated PTC-TCV. Based on this finding, she underwent right salpingo-oophorectomy, right pelvic lymph node dissection, and partial omentectomy. Pathology was negative for extra-ovarian disease, and her tumor was staged as pT1pN0M0. Total thyroidectomy was performed in preparation for radioactive iodine (RAI) therapy. A diagnostic iodine-131 (I-131) scan showed residual uptake in the neck with faint uptake in the lower left quadrant of the abdomen and was followed by therapy with 90 mCi of I-131. The patient had an unremarkable course with no clinical or biochemical evidence of disease recurrence to date.ConclusionsThis is to our knowledge the first reported case of TCV-PTC arising from SO. The presence of this aggressive variant of PTC factored into our decision to proceed with thyroidectomy and I-131 ablation, despite the lack of conclusive evidence in the literature. Recent discoveries on the natural history of thyroid-derived TCV-PTC were critical in choosing the appropriate management for this patient’s disease. (Endocr Pract. 2014;20:e24-e27)     

Eliciting Low-Risk Thyroid Cancer Treatment Preferences Using Clinical Vignettes: A Pilot Study

ObjectiveWhile surgical resection has been the traditional standard treatment for small (≤1 cm), differentiated thyroid cancers, active surveillance (AS) and radiofrequency ablation (RFA) are increasingly considered. The aim of this study was to explore patient preferences in thyroid cancer treatment using a series of clinical vignettes.MethodsThyroid cancer survivors and general population volunteers were recruited to rank experience-driven clinical vignettes in order of preference. Rankings were compared using Wilcoxon signed rank. Formative qualitative methods were used to develop and refine clinical vignettes that captured 4 treatments—thyroid lobectomy (TL), total thyroidectomy (TT), AS, and RFA—along with 6 treatment complications. Content was validated via interviews with 5 academic subspecialists.ResultsNineteen volunteers participated (10 survivors, 9 general population). Treatment complications were ranked lower than uncomplicated counterparts in 99.0% of cases, indicating excellent comprehension. Counter to our hypothesis, among uncomplicated vignettes, median rankings were 1 for AS, 2 for RFA, 3.5 for TL, and 5 for TT. Trends were consistent between thyroid cancer survivors and the general population. AS was significantly preferred over RFA (P = .02) and TT (P < .01). Among surgical options, TL was significantly preferred over TT (P < .01).ConclusionWhen treatments for low-risk thyroid cancer are described clearly and accurately through clinical vignettes, patients may be more likely to choose less invasive treatment options over traditional surgical resection.