Radioactive Iodine Therapy Research Articles

Recombinant Human Thyrotropin Plus Radioactive Iodine Among Patients With Thyroid Cancer

Radioactive iodine (131I or RAI) therapy has long been the standard of care for most patients with differentiated thyroid cancer (DTC) after primary surgery. However, no multicenter prospective studies have identified the optimal administered activity and stimulation method for RAI therapy in patients with intermediate-risk DTC. To compare the efficacy and safety of recombinant human thyrotropin (SNA001) with thyroid hormone withdrawal (THW) plus 3.7 GBq RAI in patients with intermediate-risk DTC. This noninferiority, open-label, phase 3 randomized clinical trial was conducted at 19 sites in China from April 16, 2020, to September 9, 2021, with a follow-up period of 8 months. Patients aged 18 to 70 years with DTC who had undergone a total or near-total thyroidectomy and had no distant metastasis were enrolled in the trial. Statistical analysis followed the full analysis and per-protocol analysis sets and was performed between November 18, 2021, and April 18, 2022. Patients were randomly assigned 1:1 to receive SNA001, 0.9 mg, intramuscular injection daily for 2 days or to undergo thyroid hormone withdrawal for 3 to 6 weeks. The primary end point was the success rate after 6 to 8 months of RAI therapy. Success was defined as a negative diagnostic whole-body scan result and a stimulated thyroglobulin level less than 1.0 ng/mL. A total of 307 patients (192 females [62.5%]; median [range] age, 40 [19-69] years) were randomized: 154 to the SNA001 group and 153 to the THW group. Baseline characteristics were evenly matched between the 2 groups. Noninferiority in the success rate of RAI therapy between groups was met, with success rates of 43.8% in the SNA001 group and 47.1% in the THW group (risk difference, -3.3; 95% CI, -14.8 to 8.3 percentage points). Forty-six patients (29.9%) in the SNA001 group reported adverse events compared with 90 (58.8%) in the THW group during RAI therapy (P < .001). No treatment-related adverse events leading to discontinuation and drug modification occurred in the SNA001 group. This randomized clinical trial showed that SNA001 was noninferior to THW plus 3.7 GBq RAI in patients with predominantly intermediate-risk DTC. SNA001 also demonstrated a favorable safety profile compared with THW and had a lower incidence of adverse events. Chinese Clinical Trial Registry Identifier: ChiCTR2100046907.

Long-term effect of postoperative radioactive iodine therapy on parathyroid function in patients with differentiated thyroid cancer.

The study aimed to assess the impact of postoperative radioactive iodine (RAI) therapy on parathyroid function in patients who underwent total or subtotal thyroidectomy for differentiated thyroid cancer (DTC). Data from 150 patients treated with RAI for DTC and 76 patients with low-risk DTC not receiving RAI were retrospectively analyzed. Clinical characteristics, preoperative and 1-month postoperative biochemical parameters, and adjusted calcium, phosphorus, parathyroid hormone (PTH), and 25-hydroxyvitamin D3 (25-OH-D) levels at 3months, 1year, 3years, and 5years post-RAI (or in the low-risk group) were recorded. A total of 226 DTC patients were included in the study (80.5% female, mean age 42.7 ± 13.2years). Total thyroidectomy was performed in 97.3% (n = 220) of patients, with central lymph node dissection (CLND) in 41.6% (n = 94). No significant preoperative differences in PTH, aCa, P, Mg, or 25-hydroxyvitamin D3 levels were observed. However, patients receiving ≥ 3.7GBq (or 100mCi) RAI (n = 70) had lower calcium and PTH levels at the end of the first year following RAI treatment (p = 0.048, p = 0.032). The non-RAI group showed significantly higher calcium levels at one month postoperatively (p = 0.031) and lower rates of CLND and neck dissection. No significant differences in biochemical parameters were found at the five-year follow-up, except for one patient who developed normocalcemic hyperparathyroidism after RAI. High-dose RAI therapy may lead to transient decreases in calcium and PTH levels in the early post-treatment period. However, long-term parathyroid function appears to remain unaffected in DTC patients, regardless of the RAI dose administered. Nonetheless, close monitoring of calcium and PTH levels is recommended, particularly in the early post-treatment period, to promptly manage any potential transient hypoparathyroidism.

Systemic Immune-Inflammation Index and Systemic Inflammation Response Index Predict the Response to Radioiodine Therapy for Differentiated Thyroid Cancer.

This research sought to evaluate the clinical value of systemic immune-inflammation index and systemic inflammation response index in predicting the response to radioactive iodine (RAI) therapy in individuals diagnosed with differentiated thyroid cancer. This retrospective study included 406 patients with differentiated thyroid cancer who received initial RAI therapy and follow-up from December 2019 to December 2023. Patients were divided into two groups based on imaging and serum indicators to evaluate the response to radioactive iodine treatment: the ER group (excellent response) and the non-ER group (suboptimal response). Systemic immune-inflammation index and systemic inflammation response index were calculated based on peripheral blood cell counts before treatment. Multivariable logistic regression analysis was used to assess the independent associations of these indices with the therapeutic response to radioiodine treatment. Receiver operating characteristic (ROC) curves were graphed and the area under the curve (AUC) was calculated to evaluate their predictive ability. Compared to the ER group, patients in the non-ER group had significantly elevated systemic immune-inflammation index and systemic inflammation response index levels (p < 0.001). After adjusting for confounding factors, there was a significant association between these indices and the response to radioactive iodine treatment in patients with differentiated thyroid cancer. The optimal cutoff values for predicting the response to RAI treatment were 668.91 for systemic immune-inflammation index (AUC=0.692, sensitivity 58.2%, specificity 73.1%, 95% CI: 0.639-0.745, p < 0.001) and 0.47 for systemic inflammation response index (AUC=0.664, sensitivity 85.6%, specificity 42.7%, 95% CI: 0.612-0.717, p < 0.001). Systemic immune-inflammation index and systemic inflammation response index could be valuable for predicting the response to RAI treatment in individuals diagnosed with differentiated thyroid cancer. Further research is needed to explore their practical utility, and these novel inflammation markers could serve as adjunct tools in clinical practice.

Malignancy Risk Associated with Radioactive Iodine Therapy for Graves’ Disease

BackgroundRadioactive iodine therapy (RAI) is a frequently chosen therapy for Graves’ disease. The aim of this study was to determine whether RAI for Graves’ disease increases the risk of thyroid malignancy. MethodsA retrospective analysis was performed of all Graves’ disease patients who underwent thyroidectomy at a single institution between 2013-2022. Comparative analyses were performed with cohorts based on RAI therapy as the primary grouping variable. Results413 patients were identified, of which 38 received RAI prior to surgery. RAI treated patients were more likely to undergo surgery for known malignancy or indeterminate nodules. RAI patients were also more likely to have malignancies larger than 1cm. Among RAI treated patients, those who developed malignancy were older at the time of Graves’ diagnosis and received early RAI therapy. ConclusionsUse of RAI for treatment of Graves’ disease increases the progression of thyroid carcinoma, but not the prevalence. Older age and early RAI therapy may be risk factors for malignancy in RAI treated patients.

Primary Adrenal Neuroblastoma in an Adult: A Rare Case Report

ABSTRACT Neuroblastoma (NB), an embryonal malignancy originating from neural crest cells, is predominantly a pediatric disease, making adult cases exceedingly rare. This case report documents the presentation and diagnostic process of a 23-year-old female diagnosed with adrenal NB, a condition scarcely encountered in adults. The patient presented with abdominal pain and a palpable mass. Imaging through computed tomography scan revealed a large necrotic mass in the left adrenal region. Ultrasound-guided fine-needle aspiration cytology (FNAC) showed round cells with scant cytoplasm and characteristic nuclear features, suggesting a round cell tumor, potentially NB. Surgical excision confirmed the diagnosis of poorly differentiated NB with low mitotic-karyorrhectic index. Adult NB, with an incidence of 1 in 10 million per year, has a notably worse prognosis compared to pediatric cases. The literature lacks consensus on optimal treatment protocols for adult patients, though a multimodal approach including surgery, chemotherapy, and possibly radioactive iodine therapy is often employed. This case underscores the utility of FNAC in preliminary diagnosis and highlights the clinical challenges posed by adult NB, emphasizing the need for more comprehensive studies to develop standardized treatment guidelines.

Assessment of YouTube Videos Related to Radioactive Iodine Therapy for Thyroid Cancer for Patient Education.

Thyroid cancer is the most common cancer diagnosis among those aged 15-29, with a noticeable increase in cases over the last decade. YouTube, one of the most frequented websites on the internet, serves as a common platform to obtain health information. This study uses a systematic approach to characterize YouTube videos related to radioactive iodine (RAI) therapy for thyroid cancer. The first 50 videos across four distinct YouTube search terms related to RAI therapy for thyroid cancer were identified after applying exclusion criteria. A previously validated video assessment tool was utilized to evaluate the videos. Two independent reviewers assessed a random sample of 10 videos, while the remaining 40 videos were evaluated by one reviewer as there were minimal discrepancies in coding. Among the identified videos, 26 videos were published within the past 3years, with a median video length of 4min and 53s. The three most common publishers' affiliations were non-profits (15 videos), personal accounts (12 videos), and health care facilities/organizations (11 videos). Most of the videos originated in the United States, used an interview format, featured physician presenters, and were directed towards patients. Highly covered topics included "side effects and risks" and "RAI therapy overview". The findings underscore the significant role YouTube plays in aiding patient comprehension of RAI therapy for thyroid cancer based on video parameters and content. These results can inform physicians' discussions with patients regarding YouTube and contribute to the development of new, high-quality YouTube videos to support thyroid cancer education.

RAI therapy in low-risk papillary thyroid cancer: recurrence reduction and long-term outcomes in the Turkish population

PurposePapillary thyroid cancer (PTC) is the most common thyroid malignancy, characterized by its slow progression and favorable prognosis. This study re-evaluates the efficacy of radioactive iodine (RAI) therapy versus no RAI in low-risk PTC patients following total thyroidectomy.MethodsA retrospective analysis was conducted on 588 patients treated between 2010 and 2016 at a major tertiary center in Turkey. Patients were divided into two cohorts: those receiving total thyroidectomy (TT) with high-dose RAI (100 mCi) and those receiving TT alone. A matched cohort of 138 patients per group was analyzed to minimize bias.ResultsFollow-up data indicated that at 24 months, the RAI group demonstrated a higher percentage of excellent treatment responses (86%) compared to the non-RAI group (74%). Long-term follow-up showed that 99.3% of the RAI group achieved no evidence of disease (NED), versus 90.6% in the non-RAI group. Recurrence rates were significantly lower in the RAI group (1%) compared to the non-RAI group (5.8% with a > 2.0 ng/ml cut-off for biological events).ConclusionIn summary, the findings from this study underscore the efficacy of RAI therapy in reducing recurrence rates and enhancing long-term disease control in low-risk papillary thyroid cancer patients. While total thyroidectomy alone is effective, the addition of RAI therapy provides a marked improvement in treatment responses and reduces the risk of disease recurrence. This indicates that personalized treatment plans incorporating RAI may offer significant advantages in managing low-risk PTC.

TERT promoter mutations contribute to adverse clinical outcomes and poor prognosis in radioiodine refractory differentiated thyroid cancer

Telomerase reverse transcriptase promoter (TERTp) mutations are associated with non-radioiodine avidity. However, the role of these mutations in the clinical outcomes of patients with radioiodine-refractory differentiated thyroid cancer (RAIR-DTC) remains unknown. Herein, we aim to analyze gene mutations and clinical manifestations to verify TERTp’s role in driving disease progression to RAIR-DTC and clinical outcomes. Next-generation sequencing data and clinical data were obtained from 243 patients with DTC. Of the 25 patients with TERTp mutations, 80% (20/25) had RAIR-DTC. RAIR-DTC was significantly less prevalent in patients with BRAFV600E (9/143, 6.3%) than those with both BRAFV600E and TERTp mutations (14/17, 82.4%). Patients with RAIR-DTC harboring both BRAFV600E and TERTp mutations were more likely to have > 3 distant metastatic sites (85.7%, 12/14) than those with BRAFV600E alone (33.3%, 3/9). Only one patient with both BRAFV600E and TERTp mutations had non-RAIR-DTC. The time from initial radioactive iodine therapy to RAIR-DTC diagnosis was significantly shorter in patients with TERTp mutations than in those without. Patients with BRAFV600E and TERTp mutations progressed faster to RAIR-DTC than those with BRAFV600E alone (p < 0.01). Our findings suggest that molecular testing for TERTp and other mutations like BRAFV600E may inform early diagnosis, prognosis, and treatment strategies before progression to RAIR-DTC.

8135 A Rare Case of Late Recurrence of Graves’ Disease Decades After Radioactive Iodine Therapy: Is it Really a Definitive Treatment?

Abstract Disclosure: K.S. Hill: None. R. Osman: None. Graves’ disease (GD) is the most common cause of hyperthyroidism in the US and worldwide. Radioactive iodine (RAI) therapy has excellent success rates in treatment of GD. Studies have demonstrated that RAI successfully treats GD with a single session in the majority of cases. Recurrence after RAI, if it occurs, is most commonly seen in the first year after RAI. However, this is rare particularly in patients who have developed evidence of successful treatment in the form of post-ablative hypothyroidism. Only a few case reports have demonstrated recurrence of GD more than 10 years after treatment of GD with RAI and development of post-ablative hypothyroidism. We report a case of GD recurrence approximately 30 years after ablation. A 69 y/o woman presented for evaluation of hyperthyroidism and newly discovered thyroid nodule. Her history was significant for GD with orbitopathy diagnosed in the early 1990s and treated with RAI. Following the ablation, she developed hypothyroidism and was managed for over 20 years on levothyroxine therapy. In recent years she began to develop symptoms of palpitations and heat intolerance with biochemical evidence of thyrotoxicosis despite reductions in her levothyroxine dose. She also developed recurrence of her orbitopathy, confirmed by ophthalmology. During this time, a neck CT incidentally described an atrophic thyroid gland with a 9 mm soft tissue nodule in the left thyroid bed. Follow up ultrasound showed a 1.1 cm nodule with increased vascularity in the left thyroid bed with an otherwise atrophic gland and no lymphadenopathy. Her levothyroxine was stopped for one month in preparation for a thyroid uptake scan, during which TSH increased to 15 mcU/mL. Scan showed overall severely decreased radioactive iodine uptake of the gland consistent with prior ablation although there was a faint uptake most focally conspicuous on the left side inferiorly. Thyroid stimulating immunoglobulin (TSI) was elevated at 1.35 IU/L (Ref 0.00-0.55). After discussion with the patient, the decision was made for surgical treatment with thyroidectomy. Pathology was benign. She was continued on her prior dose of levothyroxine 75 mcg daily however now with clinical and biochemical evidence of hypothyroidism requiring continued increase in levothyroxine dose to normalize TSH levels. GD is the most common cause of hyperthyroidism and RAI therapy is the most common definitive treatment for GD in the US. Recurrence of GD after ablative hypothyroidism is rare, particularly in the case of late recurrence decades after ablation. Only a few cases are reported in the literature, ours with the longest interval-to-relapse. Recurrence of orbitopathy may be the first clue. Our case highlights the need to continue to monitor clinically for recurrence of Graves’ disease long after RAI use. Presentation: 6/3/2024

5103 Synthroid Absorption Conundrum: A Case Deciphered

Abstract Disclosure: H. Nadeem: None. O. Alzohaili: None. Hypothyroidism is a disorder requiring lifelong Synthroid therapy. Untreated patients have high morbidity rate and suffer from weight gain, cold intolerance, fatigue and constipation. Inadequate therapeutic outcomes may result in the case of malabsorption, like GI tract conditions, medication interactions and dietary ingredients. Here, we describe the case of a 50-year-old woman who despite compliance to therapy, had refractory hypothyroidism. Complexity of unexplained Synthroid malabsorption is highlighted, emphasizing the importance of managing and optimizing thyroid hormone replacement therapy. A 50-year-old woman with a history of papillary carcinoma s/p thyroidectomy and radioactive iodine therapy came in with fatigue, weight gain and constipation. Despite taking Synthroid 150 mcg, thyroid function tests (TFTs) remained high with TSH 150 uIU/mL and fT4 0.25 ng/dL. Her dose was gradually increased until it reached 1800 mcg yet repeat TFTs showed refractory hypothyroidism with TSH 179 uIU/mL, fT4 0.8 ng/dL. Compliance was addressed to which she demonstrated strict adherence, while avoiding concurrent intake of food, supplements or medications interfering with the absorption. Autoimmune conditions were ruled out and no dietary patterns affecting absorption were identified. A thyroid absorption test was then performed, during which 2100 mcg of Synthroid were given orally in the AM, and thyroid hormones were measured for 8 hours. She was found to have a TSH in 200s uIU/mL and fT4 &amp;lt;0.10 ng/dL, deeming her to have refractory hypothyroidism. She was seen by GI and had an EGD/ colonoscopy, revealing no abnormalities. In a follow up visit, she was still complaining of the same symptoms, periorbital edema, and mild confusion. Her TSH was still elevated at 225 uIU/mL. She was then started on IV 500 mcg of weekly Synthroid infusions and after several weeks, she reported symptoms improvement. Subsequent TFTs showed a progress in TSH, now 26.6 uIU/mL, with fT4 1 ng/dL, indicating successful management of Synthroid malabsorption. During this process, she had a nutritional assessment and was consistently having hyperlipidemia with LDL 243 mg/dL. She was compliant with Praluent and max dose of atorvastatin 80 mg, but LDL only decreased to 134 mg/dL after adjusting her thyroid hormone levels. With nonadherence being the top cause of medication non responsiveness, ruling out causes of malabsorption is vital. In this case, compliance, nutritional assessment, medication interactions, GI abnormalities, autoimmune conditions were all addressed and no interfering factors were identified. IV treatment with unexplained thyroid hormone malabsorption was the effective treatment, ultimately improving outcomes. With the hope to transition her to oral medication, the possibility of it happening is still not clear. More research is necessary to discover the underlying causes in such an exceptional case. Presentation: 6/2/2024

5150 When Few Options Exist: Graves’ Disease Treated with Potassium Iodide and Levothyroxine Block-and-Replace Therapy

Abstract Disclosure: O. Magvanjav: None. S.K. Majumdar: None. Background: In the US, methimazole and propylthiouracil are effective first-line agents for the treatment of Graves’ disease. However, side effects including liver dysfunction may limit their use. In such instances, alternative non-conventional agents such as potassium iodide (KI) may be considered. Here, we present a case of a patient with Graves’ disease successfully treated with KI, drawing on the example of similar treatment experiences in Japan. Clinical case: Our patient is a 29-year-old woman who presented with a 3-week history of palpitations accompanied by fatigue, heat intolerance, itchiness, insomnia, and unintentional weight loss. Exam was notable for tachycardia (135 bmp), elevated blood pressure (BP) (150/81 mmHg), normal temperature, slight thyromegaly, brisk reflexes, mild anxiousness, and tremulousness. She was found to have a TSH of 0.007 mIU/ml (normal: 0.270-4.200 mIU/ml), elevated free T4 of 5.19 ng/dl (normal: 0.80-1.70 ng/dL), total T3 of 330 ng/dl (normal: 72.0-153.0 ng/dl), total T4 of 12.1 ug/dl (normal: 4.5-11.7 ug/dl), and positive antibodies (TSI 443%; TRAB 5.42 IU/L). A thyroid ultrasound showed diffuse hyperemia and a 1.4 cm right lobe TR3 nodule. She had a normal baseline neutrophil count with mild eosinophilia; a baseline hepatic function panel was not obtained. She was started on methimazole 20 mg daily and metoprolol XL 50 mg daily for symptom control. One week into treatment, a hepatic function panel showed elevated liver enzyme levels: AST 70 U/L (normal: 10-35 U/L) and ALT 223 U/L (normal: 10-35 U/L); previous values from 2 years prior were normal. Repeat levels a few days later showed increasing liver enzyme levels (AST 83 U/L; ALT 268 U/L) despite decreasing thyroid hormone levels. Methimazole was stopped, and she was then seen by a gastroenterologist, who concurred with the possibility of an adverse drug reaction to methimazole. She declined definitive therapy with surgery or radioactive iodine therapy and wanted to pursue alternative and less invasive options. Drawing on a previous successful experience from Japan, we initiated her on KI (50 mg twice daily), which resulted in normalization of her thyroid hormones within two weeks of initiation. She subsequently developed hypothyroidism 2 months later, at which point we initiated block-and-replace therapy with the addition of 50 mcg of levothyroxine. Her liver enzymes normalized with normalization of thyroid hormones. Conclusions: We present a patient with symptomatic Graves’ disease who was successfully treated with KI in the setting of limited treatment options, specifically an adverse reaction to methimazole (transaminitis), and who declined both surgery and radioactive iodine. This case demonstrates that KI may be useful in Graves’ disease as either a bridge to more definitive therapy when thioamides are not tolerated, or perhaps as a treatment option for those most likely to go into remission. Presentation: 6/1/2024

12387 Late New-onset Graves' Orbitopathy: 14 Years Post-radioactive Iodine Treatment Of Graves' Disease: Case Report

Abstract Disclosure: F.F. Altaleb: None. K. Alaybaa: None. N. Aljohani: None. Introduction: Graves' orbitopathy (GO) is an autoimmune condition affecting the orbit and retro-ocular tissues, often accompanied by hyperthyroidism associated with Graves' disease, but it is rarely observed in euthyroid or hypothyroid individuals. Radioactive iodine (RAI) therapy for Graves' disease and smoking are recognized risk factors for GO development and progression. Individuals who smoke and undergo RAI treatment are significantly more likely to experience ocular lesions and worsening of GO compared to non-smokers. The exacerbation of GO post RAI therapy is attributed to elevated levels of TSH receptor antibodies, which may persist for up to a year post-treatment. Our case presents a rare occurrence of severe new-onset GO manifesting 14 years after achieving prolonged euthyroid status and successful RAI treatment for Graves' disease, accompanied by persistent TSH receptor antibody positivity that is unlikely to be suppressed by long term levothyroxine therapy. Clinical case: A 55-year-old male who’s a smoker and previously diagnosed with Grave’s hyperthyroidism, received treatment with RAI ablation therapy 14 years ago. At the time of diagnosis, there were no symptoms or signs of GO, and no history of thyroid eye disease was detected. Following the RAI treatment, he developed hypothyroidism and was promptly started on a daily dosage of 100 mcg of levothyroxine.Upon ocular examination: Visual acuity: 20/30 in both eyes. Significant restriction in extraocular muscle movements, with reported diplopia and pain. Bilateral lid retraction, proptosis, right conjunctival chemosis, and injection of the bulbar conjunctiva and caruncle, as well as lagophthalmos, were evident. No relative afferent pupillary defect observed. Color vision: 3/15 in the right eye, 15/15 in the left eye. Intraocular pressure: 22 mmHg (right eye), 16 mmHg (left eye). Optic discs unremarkable. Proptosis measurements: 26 mm (right eye), 23 mm (left eye). Ophthalmopathy clinical activity score: 7.Our laboratory analysis indicated normal thyroid function test However, the TSH receptor antibody and TPO antibody returned positive.We initiated treatment with IV methylprednisolone at a dosage of 500 Mg weekly for a duration of 4 weeks. Additionally, we introduced local measures, along with selenium supplementation. Within a week of initiating treatment, the conjunctival chemosis resolved, and there was improvement in ocular movement, resulting in mild to moderate restriction in all directions of gaze. Conclusion: This case illustrates the unexpected development of GO in a patient who had been euthyroid and effectively cured of Grave's disease for a span of 14 years following RAI treatment. The presence of TSH receptor antibodies, which are likely unresponsive to suppression by levothyroxine, as well as smoking cigarette might have contributed to the late new onset of the disease. Presentation: 6/3/2024

7786 Successful Use of Lithium in Hyperthyroidism Following a Carbimazole-Induced Agranulocytosis: A Case Report

Abstract Disclosure: J.G. Sazon: None. D.V. Bawal: None. J.V. Chua: None. J. Reyes: None. Graves' disease (GD) constitutes a significant proportion of global thyrotoxicosis cases. Carbimazole is an ATD with a notably and a rare yet severe complication of ATD with substantial adverse implications for health, is agranulocytosis. This condition is reversible if recognized early and treated accordingly. We report a case of successful use of lithium prior to radioiodine ablation (RAI) in management of thyrotoxicosis in the context of Carbimazole-induced agranulocytosis. This is a case of a 38-year-old female newly-diagnosed with Graves' Disease presenting with palpitations. Diagnostics showed FT4 &amp;gt;100 (11.9 – 21.6 pmol/L), TSH at &amp;lt;0.005 (0.270 – 4.200 mIU/L) and positive TSH receptor antibodies (TRAb) at 13.9 IU/L (normal value: &amp;lt;1.76 IU/L). Electrocardiogram revealed Atrial Fibrillation. She was initiated on Carbimazole 30 mg/tab OD, Apixaban 10 mg/tab OD, and Bisoprolol 10mg/tab OD. After 28 days of drug-intake, she developed fever (TMax 38.5°C) and work-up revealed severe neutropenia with an ANC of 0. Peripheral blood smear showed agranulocytosis. A seven-day course of piperacillin-tazobactam and moxifloxacin was administered, along with G-CSF at a dose of 300ug BID. Subsequently, was scheduled for Radioactive Iodine (RAI) therapy for definitive treatment. In the interim, with persistent tachycardia and elevated thyroid function tests (FT3 22.20 pmol/L, FT4 47.24 pmol/L) Lithium 450mg/tab BID and Prednisone 40mg/day was initiated, providing significant relief from hyperthyroid symptoms. RAI was administered with a dose of 24mci. Ten days post-RAI, thyroid hormone levels further improved. Four weeks after RAI, repeat tests revealed hypothyroidism. Levothyroxine was initiated at 12.5 mcg and gradually adjusted. Pre-RAI administration of lithium serves to mitigate alterations in serum thyroid hormone concentrations and augments the efficacy of RAI therapy. In this study, the utilization of lithium aimed to regulate thyrotoxicosis and preemptively curtail the elevation of FT4 levels. Lithium emerges as a particularly suitable therapeutic option for patients experiencing adverse effects related to ATDs prior to undergoing definitive therapies such as RAI or thyroidectomy. Furthermore, imperative to the prevention of agranulocytosis, an enhanced understanding of its deleterious effects through patient education is deemed vital. Presentation: 6/2/2024

8049 Beyond Metastasis: Parasitic Thyroid Tissue Mimicking Thyroid Cancer

Abstract Disclosure: M.S. Shah: None. S. Humayon: None. N.A. Mungo: None. This case study details a complex clinical scenario involving a patient with diaphoresis and a familial history of thyroid cancer. Initial suspicions of functionally active metastatic thyroid cancer led to a thyroidectomy and cervical lymph node dissection, only to reveal unexpected parasitic thyroid tissue. This case highlights the importance of meticulous evaluation and follow up similar presentations, shedding light on the rarity of this phenomenon.The patient, experiencing a year of diaphoresis unresponsive to estradiol therapy, underwent imaging revealing multiple thyroid nodules. A left superior nodule (TI-RADS 4) and a more concerning right mid-posterior nodule (TI-RADS 5) prompted fine needle aspiration (FNA). FNA of the right thyroid nodule exhibited Bethesda category III atypia, no molecular samples were taken at that time, while cervical lymph node FNA yielded nondiagnostic results.Subsequent ultrasound showed no interval change in the right thyroid nodule but raised concerns about increased solid components and decreased echogenicity in other nodules. Due to patient concerns of positive family history of thyroid cancer, the lymph node was biopsied. The result yielded a low cellular sample, but follicular thyroid tissue was present. The patient elected to undergo thyroidectomy as she did not want to continue monitoring. Pathology revealed parasitic thyroid tissue in the lymph node and nodular follicular thyroid disease, with no evidence of papillary thyroid carcinoma in the gland. Notably, the patient had no history of thyroid surgeries, ruling out traumatic rupture or implantation from a follicular adenoma. However, the possibility of follow-up metastatic follicular carcinoma cannot be entirely excluded on histologic grounds.Follow-up tests were recommended, encompassing mutational analysis, whole-body scans, and thyroglobulin (Tg) monitoring. Molecular analysis did not favor cancer. Tg levels remained at (18 ng/ml, n&amp;lt; 35ng/ml) of initial evaluation six weeks post surgery and repeat testing is pending. Ablative radioactive iodine therapy may be appropriate as resection of all parasitic thyroid tissue can prove difficult.This case emphasizes the diagnostic challenges posed by the rare occurrence of parasitic thyroid tissue, often mistaken for metastatic thyroid cancer. The findings contribute to our understanding of uncommon thyroid pathologies. The clinical implications of this case extend to the importance of heightened clinical suspicion in intricate endocrine cases. Presentation: 6/3/2024

Melanoma after radioactive iodine therapy for thyroid cancer

Melanoma after radioactive iodine therapy for thyroid cancer

7911 High Dose Serial Radioactive Iodine Therapies Facilitated byAutologous Stem Cell Cryopreservation in a Patient with Exceptionally Avid Metastatic FTC

Abstract Disclosure: S. Paknikar: None. D. Toro Tobon: None. J. Durski: None. H. Alkhateeb: None. M.M. Ryder: None. Introduction: Radioactive iodine (RAI) therapy-induced myelosuppression is a dose-limiting toxicity for RAI avid metastatic differentiated thyroid cancers. We describe a patient with exceptionally RAI avid metastatic follicular thyroid cancer (FTC) who underwent autologous stem cell cryopreservation (ASCC) to enable high dose I-131 treatments. Case: A 60-year-old woman with T1bN0M0 FTC underwent two-stage thyroidectomy and three doses of I-131 between 2002-2007 (434 mCi cumulative activity) due to incomplete biochemical response. She presented to our institution in 2015 with rising thyroglobulin (Tg) levels and lung nodules that were intensely RAI avid. She enrolled in a clinical trial of selumetinib versus placebo (for 1 month) followed by 150 mci I-131. She had a profound response with an 80% reduction in Tg and 50% tumor shrinkage. The following year her Tg rose to 8381 ng/mL and she developed biopsy proven, well differentiated metastatic FTC in the hip and liver. Lenvatinib treatment resulted in partial tumor and Tg response but was halted due to grade 3/4 toxicities. Tumor genomic interrogation revealed NRAS, PIK3CA, and TSH-R activating mutations, providing a causal explanation of her intensely RAI avid and responsive disease. Repeat I-131 therapy was facilitated by GM-CSF stimulated ASCC (8.57 x10(6) CD34+ cells/kg for two cycles) as a tool to help mitigate future potential RAI-induced myelosuppression. The patient received 295 mci I-131 followed by a 98% decrease in Tg and 20-25% shrinkage of liver metastases. Transient pancytopenia ensued but did not require autologous stem cell transplantation (ASCT). Due to insurance issues, the patient was lost to follow-up for two years. She returned with cachexia from severe, untreated thyrotoxicosis due to widespread functional, thyroxine producing metastatic disease. Anti-thyroid drug therapy (ATD) restored euthyroid status with significant clinical improvement. A non-stimulated I-123 whole body scan showed diffuse RAI avid disease with 88% whole body radioiodine retention at 48h. She received 125 mci I-131 with initial tumor response but with progression of bone marrow, calvaria, and retinal metastases. Six months later, a final dose of 253 mCi I-131 (cumulative activity 1,370 mCi) resulted in mixed tumor responses. Unfortunately, resection of a RAI refractory calvaria lesion postoperatively resulted in serious complications. ASCT and salvage treatments could not be pursued due to her impaired functional status. The patient pursued hospice care and passed away 20 years after her diagnosis. Conclusion: We characterize a patient with NRAS, PIK3CA and TSH-R mutant metastatic, thyroxine-producing FTC whose recurrences over 20 years retained intense RAI avidity and response to I-131 therapy. In cases with potential benefit from multiple high dose RAI therapies, ASCT may be a tool to mitigate I-131-induced myelosuppression. Presentation: 6/1/2024

7478 Effects of RAI on Papillary Thyroid Carcinoma with Positive Lymph Nodes

Abstract Disclosure: K.N. Rachmasari: None. A. Osman: None. D. Toro Tobon: None. S.B. Lund: None. D.J. Merlino: None. A.R. Hsu: None. M.M. Ryder: None. Background: In low-risk papillary thyroid cancer (PTC), radioactive iodine (RAI) remnant ablation has shown no impact on disease recurrence rates, which are overall low. The role of adjuvant RAI in intermediate risk disease (i.e. T3, N1) remains unproven with no randomized clinical trials to objectively assess efficacy. Thus, in our institution, its use is highly heterogenous. We retrospectively investigated the effects of adjuvant RAI on recurrence and recurrence free survival (RFS) in patients with PTC and positive cervical lymph nodes (CLN). Methods: We performed a retrospective review of patients who underwent surgery at Mayo Clinic Rochester, MN for PTC between January 2007 and December 2016. Adult patients with Tx-T3 disease according to the 8th edition of American Joint Committee on Cancer (AJCC) were identified. Patients with positive CLN (N1) and a minimum follow up of 36 months were included. Demographics, clinicopathologic characteristics, use of RAI therapy and recurrence were analyzed. Results: A total of 367 patients with PTC, Tx-3, N1, M0 were identified, of which 187 received adjuvant RAI and 180 did not. Most patients were female (63.8%), with a median age of 44 years (IQR 34-54), and a median follow up of 77 months (IQR 58.5-101.5). There were no differences in age, type of surgery, histology, multifocality, and follow up period between the RAI and no RAI subgroups. Adjuvant Thyrogen-stimulated or thyroid hormone withdrawal-based RAI was recommended at the discretion of the treating provider and/or per patient preference. Diagnostic I-123 whole body scans were performed in all patients and mostly demonstrated remnant uptake. The median dose of I-131 was 75 mCi (range 50-100). Recurrence was defined by new occurrence of disease after at least a year of absence of clinical, biochemical, and imaging evidence of disease since initial surgery. Within the entire cohort, 35 (9.5%) developed recurrence with a median time of 41 months (28-59.5). Overall, recurrence rate and RFS were not significantly different between both subgroups (p = 0.2). A subanalysis was performed in patients with clinically detectable nodal disease (n = 161), defined by abnormal cervical lymph node on preoperative neck ultrasound with or without positive fine needle aspiration biopsy. Overall recurrence rates were 17 (10.6%) in this group. There were no differences in recurrence rates and RFS in those that received RAI versus those that did not (p = 0.8). Conclusions: In patients with intermediate risk PTC defined by nodal disease and/or T3 disease, recurrences were not different between patients that did or did not receive adjuvant I-131 therapy postoperatively. A randomized, noninferiority study of adjuvant I-131 compared to no I-131 postoperatively for N1 disease is needed to determine the benefit of near total thyroidectomy and adjuvant I-131 for this cohort. Presentation: 6/3/2024

Joker Sign After Drooling Radioactive Saliva.

A 28-year-old man underwent high-dose radioactive iodine therapy after total thyroidectomy due to papillary thyroid carcinomas. After 2 weeks, a linear reddish line was observed extending from the right corner of the mouth to the cheek, resembling the appearance of the Joker. Through a detailed interview, it was determined that the patient had developed radiation dermatitis because of radioactive saliva drooling while sleeping on one side. Although this is expected to be infrequent, educating patients on avoiding saliva contact with the skin during and after radioactive iodine therapy is crucial due to the potential skin damage and cancer risk.

Interaction of MMP-9 in the active phase of Graves' disease with and without ophthalmopathy.

Thyroid eye disease (TED) is expressed as orbital inflammation, and serum levels of several proinflammatory cytokines have been studied among patients with Graves' disease (GD) with and without TED; however, a more sensitive and specific marker for the different phases of GD and TED is still lacking. Seventeen active TED, 16 inactive TED, 16 GD without TED, and 16 healthy controls were recruited. Serum IL-17A, MMP-2, MMP-3, and MMP-9 were measured by multiplex bead assay. TED hormone and eye parameters were evaluated, and their relationship with cytokine levels was analyzed. Serum MMP-9 was higher in active TED than healthy controls, whereas IL-17A was lower among these patients than in GD without TED and healthy controls. No differences were found in MMP-3 and MMP-2 concentrations. MMP-9 levels were lower in patients with inactive TED who underwent radioactive iodine (RAI) therapy and those on levothyroxine replacement. MMP-9 levels were elevated in patients on methimazole. A negative correlation was found between age at assessment and time of follow-up with MMP-9 levels in inactive TED. Free T3 and ophthalmometry values were positively correlated with MMP-9 in the GD without TED and inactive TED groups, respectively. In conclusion, serum MMP-9 was increased in patients with active TED and was related to the RAI treatment, longer follow-up time, and higher ophthalmometry in patients with inactive TED, as well as thyroid function in GD without TED. MMP-9 may be involved in both the active phase of TED and the active phase of inflammation related to GD.NEW & NOTEWORTHY Our study addresses clinical aspects of specific ophthalmological examination and serum cytokine concentrations of patients with Graves' disease (GD) with and without ophthalmopathy. Our findings suggest that MMP-9 may be involved in the active phase of ophthalmopathy and in the active phase of GD. The central question is whether MMP-9 is a potential target for future treatments.

Track recurrence after remote-access thyroid surgeries: A systematic review.

Remote-access thyroidectomies have gained popularity, but track recurrence, which is the implantation of thyroid tissue or lesions along the surgical access route, has been reported in case studies. This systematic review aims to review cases of track recurrence following remote-access thyroidectomies. A comprehensive literature search was conducted using PubMed, the Web of Science, the Cochrane Library, and Google Scholar to identify case reports on track recurrence after endoscopic or robotic thyroidectomy up to June 2024. Data included patient demographics, details of the initial surgery and diagnosis, methods and timing of recurrence detection, and management strategies. The search yielded 1578 articles, of which 17 case reports comprising 18 patients were included. The patients (16 females and two males) had a mean age of 34.6±14.9years. The mean size of initial tumors was 3.9±1.2cm, with diagnoses of eight cancers and 10 benign lesions. The initial surgeries included 12 endoscopic and six robotic procedures. Track recurrence was most often detected by palpable nodules followed by routine imaging and elevated serum Tg levels. The interval between initial surgery and recurrence ranged from 3months to 8years. Management varied from surgical resection and radioactive iodine therapy to close observation. There were no further recurrences in all but one case postoperatively. Track recurrence after remote-access thyroidectomy is rare but significant. Proper surgical techniques, careful handling of thyroid tissue, and rigorous postoperative monitoring are essential to minimize this risk. Awareness and prompt management of track recurrence may lead to favorable outcomes.