Radioactive Iodine Ablation Therapy Research Articles

Association of Radioactive Iodine Administration With Outcome Among Patients With Low-Risk Differentiated Thyroid Cancer: A Real-World Data Analysis.

Despite the generally favourable long-term prognosis of low-risk differentiated thyroid cancer (DTC), questions remain about disease-free survival (DFS) after initial treatment, particularly regarding the use of radioactive iodine (RAI). Although there are RCT trial confirming that RAI ablation therapy is not superior to follow-up in terms of the 3-year DFS rate in low-risk thyroid cancer, its longer-term prognosis remains to be established. The objective of this study was to assess the impact of RAI ablation on the presence of structural persistent/recurrent disease in patients with low-risk DTC. We retrospectively identified 720 low-risk DTC patients who had undergone total or near-total thyroidectomy (TT) at a tertiary medical centre between January 2008 and July 2018. Propensity scores were calculated using a multivariable logistic regression model that accounted for age, sex, tumour size, neck dissection, multifocality, capsular invasion and lymph node (LN) metastasis. We compared DFS between patients who received RAI and those who did not using log-rank tests and multivariate Cox analyses. Subgroup analyses were also conducted. Of the total cohort, 180 (25.0%) patients received RAI, while 540 (75.0%) did not before matching. The median follow-up duration was 59.5 months. After matching, the RAI group comprised 135 (39.8%) patients and the non-RAI group comprised 204 (60.2%) patients. In the entire cohort, the 5-year DFS rate was 97.6% for patients receiving RAI compared to 96.8% for those not receiving RAI (p = 0.704). In the matched cohort, the rates were 98.5% and 95.6%, respectively (p = 0.090). Matched multivariate Cox analysis demonstrated that RAI was neither significantly nor independently associated with DFS (hazard ratio [HR] = 0.29; 95% CI 0.06-1.37; p = 0.118). Further subgroup analyses reaffirmed that RAI ablation did not significantly reduce the risk of developing structural persistent/recurrent disease. Administering RAI ablation following TT did not result in improved DFS for low-risk DTC patients. Our findings suggest that decisions regarding RAI should be made judiciously to avoid overtreatment in this clinical scenario.

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

Low dose radioactive iodine ablation therapy (1.11GBq) for differentiated thyroid cancer in Western Turkey

ObjectiveAblation therapy is employed in low-risk differentiated thyroid cancer (DTC) cases to facilitate patient monitoring by reducing thyroglobulin (Tg) levels to measurable levels below after surgery by eliminating residual thyroid tissue. However, there is still uncertainty about the minimum activity dose required for effective ablation. Opting for low-dose [131I]-NaI for ablation offers several advantages for both patients and healthcare services. Particularly in this tumor group with a high life expectancy (approximately 90–95 % at 10 years), [131I]-NaI treatment should not pose a risk to the patient's post-treatment life and should not compromise their quality of life. However, there is a need for a well-defined identification of factors predicting successful ablation. MethodsClinical data, laboratory findings, and imaging tests of 287 patients with low-dose 1110 MBq (30 mCi) [131I]-NaI ablation therapy for DTC were retrospectively reviewed. Post-ablation imaging and laboratory findings categorized ablation success/failure. The successful ablation group was determined according to the excellent response criteria outlined in ATA criteria. Relationships between clinical, pathological findings, biochemical common variables, and treatment failure were analyzed. ResultsAn excellent response was achieved in 77% of the entire group according to ATA criteria post-ablation. Male gender and high Tg levels on the day of ablation (Tg cut-off: 10 ng/mL and 5.35 ng/mL) were associated with unsuccessful ablation. ConclusionsOur results indicate that a 1110MBq (30mCi) ablation dose is sufficient to achieve an excellent response in most low-risk DTC cases 6–12 months later. When selecting the dose for ablation, besides the histological markers mentioned in guidelines and age, we observed that stimulated Tg values and gender may be important in predicting ablation success.

Radioactive iodine ablation therapy reduces the risk of recurrent disease in pediatric differentiated thyroid carcinoma

BackgroundWhile radioactive iodine (RAI) therapy in older adults with differentiated thyroid carcinoma (DTC) reduces recurrence, data in pediatrics remain limited. We conducted a meta-analysis to quantify outcomes and recurrence risk with RAI versus thyroidectomy alone in the pediatric population. MethodsSystematic literature review identified 34 retrospective studies including 2913 DTC patients under age 22 years (published 2005–2023). Meta-analysis calculated pooled rates of disease persistence and recurrence. Relative risk ratios compared odds of recurrence with RAI versus no RAI. ResultsPatients had mean age 14.7 years (95 % CI, 14.2–15.2) and were 75.9 % female (95 % CI, 73.8–78.1 %). Majority (90.2 %) received RAI. Pooled persistence rate was 30.3 % (95 % CI, 21.7–39.5 %); higher with RAI (31.5 %; 95 % CI, 22.4–41.3 %) than no RAI (4.5 %; 95 % CI, 0.0–18.7 %) (OR 3.28; 95 % CI,1.82–5.91; p < 0.001). Recurrence rate was 8.97 % (95 % CI, 4.78–14.3 %). Those with RAI had 53.1 % lower recurrence risk versus no RAI (RR 0.47; 95 % CI, 0.27–0.82; p = 0.007). Median follow-up was 7.2 years (95 % CI, 5.8–8.5 years), with no association between follow-up duration and recurrence (r = −0.053; p = 0.80). ConclusionsRAI therapy as an adjunct to thyroidectomy is associated with a significantly lower risk of long-term recurrence in pediatric DTC. These findings advocate for the use of RAI in preventing recurrence among high-risk pediatric patients with DTC.

Outcomes of Low-Risk Differentiated Thyroid Cancer (DTC) without Radioactive Iodine (RAI) Ablation Therapy Post-Thyroidectomy: An Experience from a Tertiary Centre in Karachi.

To assess the outcomes of low-risk differentiated thyroid cancer (DTC) with tumour size 1 to 4 cm post-thyroidectomy in patients who never received radioactive iodine (RAI) ablation and to compare the outcomes with those who received RAI therapy. Observational study. Place and Duration of the Study: Department of Nuclear Medicine, Karachi Institute of Radiotherapy and Nuclear Medicine (KIRAN) Hospital, Karachi, Pakistan, from January 2016 to December 2020. A total of 130 consecutive patients of low-risk DTC of both genders aged between 18-75 years were identified who underwent thyroidectomy. Patients were classified as either being treated or not treated with RAI, based on RAI data post-thyroidectomy. Patients were followed up for two to five years depending on their date of diagnosis from 2016 to 2020, using thyroglobulin (Tg), anti-thyroglobulin (anti-Tg), and thyrotropin (TSH) levels and ultrasound neck. Association betweenpatients who received RAI and who did not receive RAI was determined and a p-value<0.05 was considered as statistical significance. Patients had mean age of 34.5 ± 10.4 years with majority of females (75.4%). Majority of the patients (94.6%) had total thyroidectomy with no neck dissection (83.1%). RAI therapy was conducted among 70.8% participants, of which, 56.9% participants received a dose of 100 mci. Most of the patients had positive outcomes as there was no recurrence among 96.2% participants. There was a significant difference in RAI therapy with total thyroidectomy as compared to subtotal, RAI dose, tumour stage, neck dissection, and lymph node involvement (p ≤0.001). After complete tumour resection, a highly selected group of patients with low-risk local disease have shown low rate of recurrence when managed without RAI. Interestingly, the disease recurrence was also only seen in patients who received RAI therapy in comparison to those who did not receive RAI therapy. Outcomes, Differentiated thyroid cancer, Radioactive iodine, Ablation therapy, Post-surgery.

Abstract #1568836: Outcomes of Patients With Low-Risk Differentiated Thyroid Cancer (DTC) Without Radioactive Iodine (RAI) Ablation Therapy Postsurgery: An Experience From a Tertiary Center in Karachi

Abstract #1568836: Outcomes of Patients With Low-Risk Differentiated Thyroid Cancer (DTC) Without Radioactive Iodine (RAI) Ablation Therapy Postsurgery: An Experience From a Tertiary Center in Karachi

SAT469 Risk Factors for Relapse in Graves’ Disease and the Clinical Outcomes of Radioactive Iodine Treatment in Relapsed Cases

Abstract Disclosure: L. WingChing: None. X. Khor: None. F. Carter: None. Q. Ashcroft: None. V. Chandrabalan: None. P. M Joseph: None. Authors: Li Wing Ching, Xiao Ying Khor, Frederick Carter, Ashcroft Quinta, Vishnu Chandrabalan, Joseph Pappachan. Background: Relapse of Graves’ disease occurs in ≈50% of cases after the antithyroid pharmacotherapy. Identifying risk factors associated with relapse is crucial for planning treatment including radioactive iodine (RAI) ablation as well as to inform patients of probable clinical outcome following such treatment. Aims: (1) To identify the factors associated with relapse of Graves’ disease when the condition is first diagnosed. (2) To characterise the clinical outcomes and re-relapse rates after RAI treatment. Methods: Retrospective study of patients treated for Graves’ disease (with positive TSH-receptor antibodies [TRAb] &amp;gt;1.0 IU/L) between April 2004 and May 2021 at Lancashire Teaching Hospitals NHS Trust, UK. Demographic, clinical, laboratory, and treatment data were retrieved from prospectively maintained electronic health records. Data retrieved included known factors associated with high risk of relapse including markedly raised thyroid hormone (Free T4 [FT4] and/or Free T3 [FT3]), and TRAb levels. Outcome data after treatment was also analysed including the effects of RAI therapy such as hypothyroidism and time to its development, failure rate of first dose of RAI and its management. Results: Out of 1450 patients with Graves’ disease, 188 cases with meaningful study data receiving RAI ablation during the study period were analysed. The following factors (median (interquartile range/IQR) of relapsed vs non-relapsed) were associated with relapse requiring RAI ablation: TRAb levels - 10.3 (4.8-20.9) vs 5.1 (2.0-12.4) IU/L; p&amp;lt;0.001, FT4 - 56.7 (39.3 - 73.0) vs 42.6 (30.9-62.4) pmol/L; p&amp;lt;0.01, and FT3 - 24.4 (13.8 - 33.6) vs 16.2 (10.8-26.5) pmol/L; p=0.03. The median age at RAI ablation therapy was 48 (IQR 39-57.3) years with a female preponderance (140 [74.5%] cases). Radioactive Iodine-131 (131I) 555 MBq was used for treatment in all cases. 172 (91.5%) cases developed post-RAI hypothyroidism at a median follow up period of 3 (IQR: 2-11) months. RAI ablation failure occurred in 20 (10.6%) cases of whom 12 (60%) cases were successfully managed by RAI re-ablation, 5 (25%) cases preferred antithyroid pharmacotherapy, one (5%) underwent subtotal thyroidectomy and 2 (10%) cases refused treatment. Conclusions: Graves’ disease cases with high median levels of TRAb ≥10.3 IU/L, FT4 ≥56.7 pmol/L and/or FT3 ≥24.4 pmol/L at initial presentation are at high risk of relapse. RAI ablation should be offered to such patients as first-line treatment at initial presentation of the disease. Hypothyroidism occurs after RAI ablation in ≈92%. Chance of treatment failure with first RAI ablation procedure is only ≈11%. Presentation Date: Saturday, June 17, 2023

SAT543 A Case of Non-iodine-Avid Papillary Thyroid Cancer With a Rare Distant Metastasis to the Pancreas

Abstract Disclosure: A.H. Alcain: None. M.C. Isidro: None. Papillary Thyroid Carcinoma is the most common type of differentiated thyroid cancer. Distant metastasis is rare occurring only in 5% of patients and typically involves the lungs and bones. Metastasis to the pancreas is extremely rare with few cases reported over the years. We present a case of a 65-year-old female, who presented with sudden onset of abdominal pain. A review of the patient’s medical history revealed a history of a non-iodine avid Papillary Thyroid Carcinoma in 2015. The patient underwent Radioactive Iodine (RAI) ablation therapy twice due to elevated Thyroglobulin (Tg) levels. Despite RAI, Tg levels were still elevated with no recurrence nor metastasis noted on scan. Chemotherapy was offered but the patient opted for Tomotherapy. The patient completed Tomotherapy in 2017 but afterward was lost to follow-up. A CT scan of the abdomen showed findings of a pancreatic tail and body mass (10 x 7 cm) with an invasion of the mid-descending colon with pulmonary nodules which are possibly metastatic. The patient underwent an endoscopic ultrasound-guided biopsy, and pathology showed findings of a pancreatic papillary neoplasm (CK and beta-catenin positive, synaptophysin negative). Chemotherapy was given (FOLFOX) and a PET scan was requested to monitor the response to treatment. However, PET-scan showed FDG-avid (SUV 32.1) mass in the pancreatic tail (7.2 x 7.8 x 13.3 cm), FDG-avid (SUV 17.61) nodules in the lungs, and an ill-defined heterogeneous mass in the left surgical site (2.2 x 2.6 x 5.3 cm). Given that patient had a thyroidectomy in 2015, recurrence was considered. The possibility of probable metastasis to the pancreas was entertained hence re-biopsy was done. Serum Tg levels were elevated (4,115 ng/ml NV: 1.59-50.0) and negative for Anti-Tg. Biopsy showed high-grade neoplasm with papillary features. IHC staining showed positive for CK7, Tg, and TTF-1, and negative for CK20 which was consistent with metastatic papillary thyroid carcinoma. The patient was given Lenvatinib and is at present tolerating the treatment well with evidence of decreasing Tg levels suggesting a response to treatment. This is a case of a rare site of distant metastasis of a non-iodine avid papillary thyroid carcinoma. Targeted therapy such as Tyrosine kinase inhibitors can improve the survival rate of patients with Radioiodine Refractory Thyroid cancers. Metastasis should be considered especially in patients with a history of prior malignancy. Presentation Date: Saturday, June 17, 2023

Calcaneus metastasis: a rare presentation of poorly differentiated thyroid cancer.

A 60-year-old woman presented to our clinic with an acute onset 3 months history of right ankle pain. The patient had a history of poorly differentiated thyroid cancer, which was treated with total thyroidectomy, left lateral neck dissection levels II-V and central neck dissection levels VI-VII followed by postoperative I-131 radioactive iodine (131I) ablation therapy 3.7 GBq 6 months ago. The post-131I WBS showed residual iodine-avid thyroid tissue with no other iodine-avid disease or metastasis. SPECT/CT of the neck and chest showed nonavid bilateral pulmonary nodules, discrete nodal masses in mediastinum and nonavid bone lesions. FDG-PET CT scan showed FDG-avid mediastinal lymph nodes (LN), innumerable non-FDG-avid subcentimetric pulmonary nodules and few FDG-avid lytic lesions in the skeleton. X-ray and MRI of the right ankle showed a well-marginated lytic lesion in the posterior body of calcaneus and 5 × 6 cm soft tissue mass lesion, respectively. The histopathology of the calcaneus mass confirmed a positive immunostaining for thyroid origin which includes thyroglobulin and TTF-1 with PAX-8. Endobronchial mediastinal and bronchial LN biopsy confirmed thyroid cancer metastasis. Gene mutation showed HRAS and GNA13 with a high tumor mutational burden. We describe a rare case of poorly differentiated thyroid cancer in a patient who presented with right ankle pain; we confirmed the cause to be a calcaneus metastasis from the thyroid cancer, with calcaneus being an extremely rare site for bone metastases. Gene mutations points toward treatment with immune checkpoint inhibitors. Poorly differentiated thyroid carcinoma (PDTC) usually metastasizes to lung and bone but can rarely occur in the calcaneus. Patients with distant metastases have significantly worse long-term prognosis. Radiotherapy is effective in reducing the metastatic pains as well as reducing the size of the metastasis. PAX-8 staining can be used to differentiate thyroid carcinomas from lung adenocarcinomas. The importance of searching for gene mutations to decide the treatment of PDTC.

Robot-assisted transaxillary surgery for thyroid cancer: Oncologic and surgical outcomes in long term follow-up.

The use of robot-assisted transaxillary thyroidectomy (RATT) has rapidly spread in the last 2decades, although it is mostly limited to Asian countries. We retrospectively enroled all patients with histologic diagnoses of thyroid cancer who underwent RATT at the University Hospital of Pisa from May 2012 to September 2020. The study included 242 patients; 128 (47%) underwent total thyroidectomy and 114 (53%) underwent thyroid lobectomy, among which 28 patients (24.6%) required completion thyroidectomy. Radioactive iodine ablation therapy was required in 90 patients (37%). The complication rate was 5.3%. After a median follow-up of 38months, an excellent response to therapy was achieved in 107 patients (74%), whereas the response was indeterminate in 12 (8%) and incomplete in 16 (11%). No local or distant relapses or increases in thyroglobulin or antibody levels were documented. In experienced hands, RATT represents a valid option for the treatment of thyroid cancer in selected cases.

THYROID STIMULATING HORMONE EVALUATION BETWEEN THREE AND FOUR WEEKS OF LEVOTHYROXINE WITHDRAWAL IN PATIENTS WITH DIFFERENTIATED THYROID CARCINOMA

Most patients with differentiated thyroid cancer (DTC) would require radioactive iodine (RAI) ablation therapy with I-131. Before RAI ablation therapy, levothyroxine is withheld for four to six weeks to increase TSH to over 30 mIU/L. Most people develop hypothyroidism on levothyroxine withdrawal. Reducing levothyroxine withdrawal from four to three weeks would enhance health and hypothyroidism symptoms. This study aims to evaluate the thyroid-stimulating hormone level after three and four weeks of levothyroxine withdrawal in patients with DTC in the Northern Malaysia population. All DTC patients undergoing RAI ablation therapy from January 2018 to November 2019 were enrolled. TSH levels were evaluated three and four weeks after discontinuing levothyroxine. Clinical data were analysed using IBM SPSS (Statistical Package for the Social Sciences) version 26.0.0. One hundred four patients with a mean age of 47.06 years were recruited. Most patients (77.88%) had papillary thyroid carcinoma (PTC) and were female (80.77%) and Malay (53.85%). By week three of levothyroxine withdrawal, 88.46% of patients had TSH levels above 30 mIU/L, with an average of 66.89 mIU/L, and at week four, 99.04% of patients had TSH levels above 30 mIU/L. Cohen's kappa measurement of the agreement was 0.139 between weeks three and four. A TSH level greater than 30 mIU/L was detected in 88.46% of patients who had discontinued levothyroxine for three weeks and 99.04% after four weeks. It is recommended to review the TSH level at 3 weeks instead of 4 weeks in patients who could not tolerate hypothyroidism symptoms.

The "Non-Treated" Versus "LT3-Treated" Protocols of Short-Term Hypothyroidism Induction in Differentiated Thyroid Cancer: An Analysis of Hypothyroid Complications, Mood Disorders, and Quality of Life.

This study aimed to compare "non-treated" versus "levotriiodothyronine (LT3)-treated" protocols of short-term hypothyroidism induction prior to radioactive iodine (RAI) ablation therapy in differentiated thyroid cancer (DTC). A total of 120 DTC patients who had thyroxine withdrawal either via 4-week hypothyroidism induction (non-treated group, n=60) or 2-week administration and then 2-week withdrawal of LT3 (LT3-treated group, n=60) to induce hypothyroid state prior to RAI ablation after initial surgery were included. Complications related to hypothyroidism-induction, Beck Depression Inventory (BDI), Hospital Anxiety-Depression Scale (HADS), and SF-36 health-related quality of life (HRQoL) scores were recorded. In the non-treated group, transition from euthyroid to hypothyroid state was associated with significant increase in the likelihood of moderate-to-severe depression on BDI (p<0.001), presence of depression on HADS-D (p<0.001), presence of anxiety on HADS-A (6.7% during euthyroid state vs. 33.3% during hypothyroid state, p<0.001), and major syndrome on BPRS (0.0 vs. 10.0%, p=0.001) as well as significant decrease in all SF-36 HRQoL domain scores (p<0.001 for each). In conclusion, our findings indicate the likelihood of L3-treatment to enable a more favorable transition period from euthyroid to hypothyroid state without experiencing a deterioration in depression, anxiety, or HRQoL.

ODP452 A Case of Thymic Hyperplasia in Graves’ Disease

Abstract Introduction We report a case of a patient with Graves’ Disease (GD) associated with thymic hyperplasia (TH) which regressed with treatment of GD. The association between these two conditions is under recognized. The causative mechanisms between TH associated with GD are still under investigation. Case Description A 39-year-old male patient presented with hemoptysis, dyspnea, palpitations, tremors and unintentional weight loss. His TSH was suppressed to &amp;lt; 0. 005 and free T4 was elevated to 5.51. As part of his work up a CT scan was performed which revealed a prominent anterior mediastinal mass. He was started on Methimazole and Atenolol. Lab work confirming positive TSI and TRAB antibodies consistent with Graves’ disease. At follow up, he opted for radioactive iodine ablation therapy with 20mCi. He had failure of therapy and was resumed on Methimazole. He ultimately underwent total thyroidectomy with subsequent thyroid hormone replacement with Levothyroxine 150mcg daily. His thyroid function tests normalized, and his symptoms resolved. A repeat CT thorax was performed which showed complete resolution of his mediastinal mass, consistent with GD associated TH. Conclusions GD associated TH was first described in 1914. Data supports TSH receptor antibody mediated thymic enlargement1. TH can be classified in two morphological types, lymphoid hyperplasia unassociated with thymic enlargement and true TH in which an increase in thymic volume is evident 2. Thymic cortical tissue expansion seems to be due to a hyperthyroid state involving increased levels of thymulin, a protein involved in lymphocyte differentiation whereas lymphoid hyperplasia correlates with the immune process in GD 2. Antithyroid drug therapy reduces circulating thyroid hormone levels causing a generalized immunosuppressive effect. This reduces hyperplasia of lymphatic organs including the thymus 3. There are no current guidelines for the management and surveillance of thymic hyperplasia in GD as the course and timeline of regression of TH can vary widely. Thymic biopsies are performed frequently to rule out malignancy, however, it is important to raise awareness that GD associated TH has a benign course and generally resolves with management of the underlying GD 3. It is imperative to avoid unnecessary invasive procedures and their subsequent complications in such GD patients.

PSAT349 New Onset of Grave's Disease In Background of Hashimoto's Thyroiditis, Autoantibodies Switch Phenomenon; A Case Report.

Abstract Introduction Hashimoto's thyroiditis and Grave's disease represent the two spectrums of same autoimmune thyroiditis. The evolution from Graves disease into Hashimoto's thyroiditis is the most common scenario. While the conversion from Hashimoto's thyroiditis into Grave's disease is a rare occurrence. Exact incidence of this conversion is unknown because of its rarity. We present the case of a young female who developed full blown grave's disease in background of hypothyroidism secondary to Hashimoto's disease. Case presentation 56 year old hispanic female with past medical history of osteoarthritis and Hashimoto's thyroiditis (TPO +ve) and euthyroid on levothyroxine 75mcg daily for past 6 years who presented to the Emergency Department with concerns of palpitations and dyspnea on exertion for 4 months. Patient denied any recent change of manufacture and dosage of levothyroxine and reported compliance to medication. Review of symptoms was positive for palpitations, dyspnea on exertion, sleep disturbances, reduced exercise tolerance and unintentional weight loss of 20 lbs over 4 months. Physical exam was notable for tachycardia to 130's at rest, hyper-dynamic precordium with non-displaced heaving apex beat, normal S1/S2, no murmurs/gallops/rubs, visible pulsations in neck bilaterally, pounding pulses throughout the extremities and tremors on out stretched hands; and was negative for exophthalmos, thyromegaly and pedal swelling. EKG showed only Sinus tachycardia; Initial lab work up showed TSH of &amp;lt;0.01mIU/l (0.5-1.5), free T3 of 14.50 pg/ml (1.8-4.6), free T4 of 5.5 ng/dl (0.9-1.8). Patient was educated; levothyroxine was held and she was started on atenolol 25mg daily for symptoms control. Further workup revealed Thyroid stimulating immunoglobulin (TSI) of 5.69 IU/L (0.0-0.55); thyroid receptor antibodies levels of 8.14 IU/L (0.0-1.75); TPO antibodies levels of 20.1 IU/L (&amp;lt;=34.9). Small right upper lobe nodule was found on prior thyroid USG with interval decrease in size on repeat imaging. Radioactive iodine uptake scan was delayed because patient underwent CT pulmonary angiogram at presentation to ED and pulmonary embolism was ruled out. Later scan showed thyromegaly with heterogenous uptake of 82% in both lobes in 24 hours. Patient was diagnosed with Grave's disease. Patient opted for radioactive iodine ablation therapy. Post ablation, her symptoms resolved completely; she developed hypothyroidism and was started on maintenance levothyroxine. Conclusion Conversion of Hashimoto's thyroiditis to Graves's disease is a rare phenomenon and in literature review, It has been postulated to be due to a combination of atypical destructive autoimmune thyroiditis and change of thyroid receptor antibodies from blocking (TRAb) to stimulating ones (TSAb), a phenomenon known as "switch" resulting in hyperthyroidism. It is important to note that treatment with thyroxine itself can induce this switch. Clinicians should suspect this possibility in a patient who suddenly becomes hyperthyroid in setting of hypothyroidism so that appropriate management could be offered. Presentation: Saturday, June 11, 2022 1:00 p.m. - 3:00 p.m.

Retrospective evaluation of radioactive iodine ablation therapy in the Noninvasive Follicular Thyroid Neoplasm with Papillary-Like Nuclear Features (NIFTP) and Thyroid tumors with uncertain malignity potential

Background: Noninvasive Follicular Thyroid Neoplasm (NIFTP), Well differantiated thyroid tumor with uncertain malignity potential (WDT-UMP), follicular thyroid tumor with uncertain malignity potential (FT-UMP), and Hurtle cell neoplasia with uncertain malignity potential (HCN-UMP) have been included in the classification of thyroid tumors by WHO, with the incidence of thyroid cancer increasing every passing year. There is no consensus regarding the follow-up and treatment processes of these tumors. Our study aims to shed light on our clinical practice by evaluating the follow-up processes of the groups with and without radioactive iodine ablation in patients followed up with these diagnoses.&#x0D; Material and Methods: The 49 patients older than 18 years of age and followed for at least 12 months, who were performed subtotal and total thyroidectomy between 2015 and 2020 and were diagnosed with WDT- UMP, FT-UMP, HCN-UMP, and NIFTP according to histopathological examination were included to the study.&#x0D; Results: Tumor type rates did not differ between the groups that received and did not receive RAI treatment (p=0.361). The mean follow-up period did not differ between the groups that received and did not receive RAI treatment. Also the rates of RAI treatment according to tumor size did not differ (p=0.413). Tumor size was larger than 4 cm in 13 patients, and 1 patient from this group had received RAI treatment. Recurrence was not detected in the 49 patients included in our study who received or not receive RAI treatment. &#x0D; Conclusions: Some studies recommend giving RAI to these borderline thyroid tumors larger than 4 cm. But in our study no recurrence was detected in patients who did not receive RAI. That supports the view that patients could be followed without RAI treatment even if they are large tumors.

Birth of the Beta-knife Thyroidectomy: The Radiance of Saul Hertz.

This is the story of how one man's life's work allowed for Iodine-131 (I-131) to become a therapy for hyperthyroidism and thyroid cancer. What is now a standard in our times arose from Saul Hertz's rather challenging and humble beginnings. Thyroid lobectomy and total thyroidectomy were therapeutic mainstays for thyroid disease until Hertz treated his first patient with radioactive iodine (RAI) ablation therapy at Massachusetts General Hospital (MGH) on March 31, 1941. His concepts for using beta particle emission from RAI to ablate thyroid tissue were revolutionary. Hertz's RAI therapy translated to research with thyroid cancer by the mid-1940s. The high-energy beta particles produced cytolethal effects on remnant thyroid tissue left behind by total thyroidectomy, thereby accomplishing completion thyroidectomy in some patients. Progressive surgeons from the Hertz era incorporated RAI into their practice. MGH surgery resident Francis Moore took sabbatical from clinical training to do translational research with RAI and other radioisotopes. Irving Ariel of New York became known as a nuclear surgeon in the wake of Hertz's work. George Crile Jr of Cleveland became an RAI advocate for the surgical community, implementing several paradigm-changing concepts in thyroid disease along the way. Hertz was a visionary who sparked this movement, predicting many of the molecular dilemmas with RAI-tumor avidity that clinical researchers continue to navigate today. This timely history for surgical oncologists and endocrine surgeons traces the development of RAI therapy through the life of Saul Hertz, a biographical window influenced by social stigma, political controversy, and mainstream media.

Prognostic Value of Serum Thyroglobulin and Anti-Thyroglobulin Antibody in Thyroid Carcinoma Patients following Thyroidectomy.

Well-differentiated thyroid cancer (WDTC) is a malignant head and neck tumor with a very high incidence. Thyroidectomized WDTC patients have been referred to nuclear medicine for radioactive iodine (RAI) ablation therapy and/or annual follow-up with diagnostic whole-body imaging. Serum thyroglobulin (TG) and thyroglobulin antibodies (TGAb) are biochemical tumor markers used to monitor WDTC. A global rise in the prevalence of WDTC is increasing the number of thyroidectomized patients requiring lifelong monitoring for persistent or recurrent diseases. The present study aimed to identify the most successful prognostic factors in well-defined thyroid carcinoma patients following total thyroidectomy and RAI therapy, followed by an estimation of the cutoff value of TG and TGAb. In this context, a total of 100 subjects were recruited and classified as follows: 60 thyroid carcinoma patients underwent total thyroidectomy and successful RAI therapy, while 40 normal healthy individuals matched for age, sex, and socioeconomic status constituted the control group. Interestingly, the levels of TG did not differ significantly between the relapsed and non-relapsed cases, but the levels of TGAb differed significantly between the relapsed and non-relapsed cases. Collectively, TG and TGAb are considered the most successful prognostic factors in well-defined thyroid carcinoma patients after total thyroidectomy and RAI therapy. The present study also concluded that the TGAb determination was better than that of the TG level, with a cutoff value of 10 ng/mL. These findings provide baseline information for follow-up and lifelong monitoring of thyroidectomized WDTC patients. Further research is warranted to explore more about serum TG and TGAb in thyroid carcinoma patients on a larger scale.

First case of huge classic papillary thyroid cancer rupturing spontaneously leading to ischemic necrosis, perforation and inflammation of overlying skin: Case report and review of the literature.

IntroductionPapillary thyroid cancer (PTC) is the commonest form of well-differentiated endocrine carcinoma. It is categorized into indolent and aggressive, where the indolent subtypes (classic, follicular) rarely demonstrate aggressive behavior. We present a classic PTC presenting with a rapidly growing huge anterior neck mass that subsequently spontaneously ruptured subcutaneously resulting in ischemia, necrosis, and perforation of overlying skin leading to inflammation.Presentation of caseA 37-year-old female with no comorbidities presented to our emergency department with a neck swelling of 2 years duration that rapidly enlarged one week prior to presentation. Though the mass initially appeared of inflammatory nature, the tumor was a PTC, and she underwent total thyroidectomy with selective right side neck dissection and debridement of necrotic skin. The gross specimen revealed a fragmented non-intact right thyroid lobe mass causing pressure ischemia, necrosis and perforation of the skin. Histopathology showed a 9 × 9 × 5 cm classic PTC staged as pT3b N1b. Postoperative course was uneventful, she was discharged by the eighth postoperative day, and then she received a high dose of radioactive iodine ablation (RAI).DiscussionClassic PTC is usually of a smaller size and a relatively benign course compared to other PTC subtypes and thyroid cancers. It is indolent with favorable prognosis. Although it is associated with increased risk of lymph node metastases at the time of diagnosis, it is slow growing with high survival rates approaching 95%.ConclusionDespite that classic PTC progresses slowly, it should still be suspected in neck swellings presenting with rapid and aggressive behavior. Prompt and systematic assessment is required with surgical intervention and radioactive iodine ablation therapy.

Is Postoperative Adjuvant Radioactive Iodine Ablation Therapy Always Necessary for Intermediate-Risk Papillary Thyroid Cancer Patients With Central Neck Metastasis?

Papillary thyroid cancer (PTC) is commonly associated with neck lymph node metastasis (LNM), and recurrence does occur after radioactive iodine (RAI) ablation therapy. This study aimed to analyze the effectiveness of RAI ablation with regard to disease recurrence in intermediate-risk PTC patients with neck LNM. In addition, the study identified possible predisposing risk factors that might benefit from RAI ablation and analyzed common RAI therapy complications among these patients. A retrospective analysis of 349 intermediate-risk PTC patients with neck LNM who underwent thyroidectomy with neck dissection was performed. The oncologic results and clinicopathologic characteristics of these patients together with the incidence of postoperative RAI therapy complications were evaluated. Of the 349 patients, disease recurrence after treatment occurred for 27 patients (8%) during a mean follow-up period of 58.7 months (range 7-133 months). The recurrence-free survival curve of the patients who received postoperative RAI therapy (n = 208) did not differ significantly from that of the patients who did not receive it (n = 141) (P = 0.567). Nine patients without adjuvant RAI therapy (6%, 9/141) had recurrence. The recurrence rate for the central LNM patients without RAI therapy was only 2% (2/106). Both of these patients with recurrence had pathologic extranodal spread (ENS) and a high number (> 5) of metastatic central LNs. Postoperative RAI-related complications were observed in 24 patients (12%). Postoperative RAI is not necessary for intermediate-risk papillary thyroid cancer patients with central LNM, especially for patients with negative ENS and low number (< 5) of metastatic lymph nodes.

Metastatic Follicular Thyroid Carcinoma Presenting as Thoracic Cord Compression

Follicular thyroid carcinoma (FTC) is an uncommon cancer and the incidence of FTC is higher in endemic areas of iodine deficiency or endemic goiter. Up until the 1990s Fiji was listed as an iodine deficient country. We report a rare case of a 53-year-old native Fijian man who presented to our hospital with spinal cord compression due to a metastatic deposit of an undiagnosed FTC. He underwent emergent neurosurgical treatment for his cord compression, with histology of the lesion at the level of T5 identifying metastatic FTC. Despite the emergent surgery, he did not have any neurological recovery. Total thyroidectomy confirmed the presence of a large left-sided FTC and the patient was assessed for radioactive iodine treatment. Nuclear medicine imaging revealed extensive distant bony metastatic disease. Unfortunately due to his significant distant disease burden, he was unable to undergo radioactive iodine ablation therapy. After significant allied health input he was discharged home with community palliative care input. J Med Cases. 2021;12(5):177-180 doi: https://doi.org/10.14740/jmc3658