Radioiodine Ablation for Thyroid Cancer. Historical and Modern Aspects. Literature Review

Thyroid cancer is the most common oncological pathology of the endocrine system organs with a continuing trend towards an increase in the incidence. Radioiodine therapy (RIT) is the second stage of combined treatment, it is carried out only as an adjuvant treatment, it is an uncontested method of radio-targeted therapy for distant metastases of differentiated thyroid cancer (DTC). The method of radioiodine therapy is based on the unique natural affinity of iodine atoms for the follicular epithelium of the thyroid gland and DTC cells. Determination of indications for RIT is based on stratification of recurrence risk, persistence, and disease prevalence. Over the past 15 years, the world’s leading professional communities have repeatedly revised approaches to risk stratification. Consideration of the mutational profile of the tumor and the theranostic approach have become significant innovations.Radioiodine therapy can be presented in the form of three modes: ablation of residual thyroid tissue, treatment of residual tumor and treatment of distant metastases. These regimens differ in the administered therapeutic activity of 131I, which looks logical from the point of view of the necessary personalization of the treatment. At the same time, in scientific circles, disputes about the absence of significant differences in the used therapeutic activities of 131I prescribed for radioiodine ablation outside the personalized approach do not subside.

Potential Use of Biomarker γ-H2AX on Peripheral Blood Patient Who Underwent Radioiodine Ablation Treatment in Indonesia

Thyroid cancer is one of the most common endocrine malignancies. Although the 10-year survival rate of differentiated thyroid cancer (DTC) is about 90% after conventional treatments, a small proportion of patients still suffer from tumor recurrence or drug resistance. DNA doublestrand breaks (DSBs) are important cellular lesions that can result from ionizing radiation exposure. The biomarker for DSB formation is the phosphorylated form of the histone H2 variant H2AX (γ-H2AX). We propose the use of γ-H2AX as a DNA DSB biomarker in thyroid cancer patients receiving radioiodine treatment as a possibility to detect the potential of instability genome after receiving the treatment. Evaluating DNA DSB damage with γ-H2AX biomarker might be important in managing thyroid cancer.

The Diagnostic Usefulness of 131I-SPECT/CT at Both Radioiodine Ablation and during Long-Term Follow-Up in Patients Thyroidectomized for Differentiated Thyroid Carcinoma: Analysis of Tissue Risk Factors Ascertained at Surgery and Correlated with Metastasis Appearance

131I Single-photon emission computerized tomography/computerized tomography (SPECT/CT) in the management of patients thyroidectomized for differentiated thyroid carcinoma (DTC) was further investigated. Retrospectively, 106 consecutive DTC patients were enrolled at the first radioiodine ablation, 24 at high risk (H), 61 at low risk (L) and 21 at very low risk (VL). 131I whole-body scan (WBS) and SPECT/CT were performed after therapeutic doses using a hybrid dual-head gamma camera. At ablation, SPECT/CT correctly classified 49 metastases in 17/106 patients with a significantly (p < 0.001) more elevated number than WBS which evidenced 32/49 foci in 13/17 cases. In this case, 86/106 patients could be monitored in the follow-up including 13/17 cases with metastases already at post-therapeutic scans. SPECT/CT after radioiodine diagnostic doses more correctly than WBS ascertained disease progression in 4/13 patients, stable disease in other 4/13 cases and disease improvement in the remaining 5/13 cases. Further 13/86 patients with only residues at post-therapeutic scans showed at SPECT/CT 16 neck lymph node (LN) metastases, three unclear and 13 occult at WBS. Significant involvement of some tissue risk factors with metastasis appearance was observed, such as minimal extrathyroid tumor extension and neck LN metastases. These risk factors should be carefully considered in DTC patient follow-up where 131I-SPECT/CT routinely use is suggested as a support tool of WBS.

The role of Hashimoto thyroiditis in predicting radioiodine ablation efficacy and prognosis of low to intermediate risk differentiated thyroid cancer

Objective The baseline treatment of differentiated thyroid cancer (DTC) consists of thyroidectomy followed by postoperative risk-adapted radioiodine therapy (RAIT) when indicated. The choice of most appropriate RAI activities to administer with the aim to reach an efficient remnant ablation and reduce the risk of recurrence is yet an open issue and the detection of basal factors that may predict treatment response seems fundamental. The aim of this study was to investigate the potential role of Hashimoto thyroiditis (HT) in predicting 1-year and 5-year treatment response after RAIT and prognosis. Methods We retrospectively included 314 consecutive patients (174 low-risk and 140 intermediate-risk) who received thyroidectomy plus RAIT. One-year and 5-year disease status was evaluated according to 2015 ATA categories response based upon biochemical and structural findings. Results HT was reported histopathologically in 120 patients (38%). DTC patients with concomitant HT received a higher number of RAITs and cumulative RAI activities. Initial RAIT reached an excellent response in 63% after one year and 84% after 5 years. The rate of excellent response one year and 5-year after first RAIT was significantly lower in HT groups, compared to not HT (p < 0.001). Instead, HT did not have a prognostic role considering PFS and OS; while stimulate thyroglobulin (sTg) at ablation was significantly related to survival. Conclusions HT may affect the efficacy of RAIT in low to intermediate risk DTC, particularly reducing the successful rate of excellent response after RAIT. Instead, HT did not have a prognostic impact such as stimulated sTg.

Lingual thyroid: An incidental cytological finding

Lingual thyroid (LT) is a developmental defect due to the failure of the thyroid gland to descend to its normal cervical location during embryogenesis. Lingual thyroid has an overall prevalence of 1 in 100,000 to 1in 3,00,000 and is seven to ten times more common in females than in males .Lingual position represents the most frequent ectopic location accounting up to 90% of ectopic cases. It is found at the junction of the anterior two thirds and the posterior third, between the epiglottis and the circumvallate papillae. Most cases are asymptomatic, however, increase in size can cause local symptoms like upper airway obstruction, dysphagia and hemorrhage at any time from infancy to adulthood. Thyroid scintigraphy, neck ultrasound, CT- scan, MRI are some diagnostic modalities that play a vital role in diagnosing ectopic thyroid gland. Treatment of this anomaly includes exogenous L-thyroxine hormone administration, radioiodine ablation therapy and surgery. We hereby report a rare case of lingual thyroid in a young girl reported by fine needle aspiration cytology.

Henoch–Schönlein Purpura (IgA Vasculitis) in Association with Thyrotoxicosis

Graves’ disease is the most common cause of hyperthyroidism, which is characterized by thyroid antibodies and the following clinical manifestations: goiter, ophthalmopathy, and pretibial myxedema. On the other hand, Henoch–Schönlein purpura is an IgA-mediated small-vessel vasculitis. Review of the literature showed a relationship between propylthiouracil overdose and the following Henoch–Schönlein purpura (IgA vasculitis) as a side effect. The patient was a 31-year-old woman with a chief complaint of tremor and significant weight loss who contracted pruritic palpable purpura during her disease course. Then, she underwent the treatment of hyperthyroidism by methimazole which intensified her cutaneous lesions. The diagnosis of Henoch–Schönlein purpura (IgA vasculitis) was confirmed after skin biopsy. Finally, she was treated with colchicine, prednisolone, and radioiodine ablation, which caused her lesions to disappear. The temporal priority of pruritic palpable skin lesions to hyperthyroidism treatment with methimazole suggested that Henoch–Schönlein purpura (IgA vasculitis) was related to hyperthyroidism and was intensified by antithyroid agents in this patient.

A Case of Rare Autoimmune Pancytopenia Due to Graves’ Disease

Introduction: Graves’ disease has been associated with cytopenias, most commonly anemia. Pancytopenia is a rare complication and is not often encountered. Case Presentation: A 54-year-old woman with history of multiple sclerosis on alemtuzumab was referred for abnormal thyroid function tests. At the initial visit, the patient reported a 20-pound unintentional weight loss, tremors, sweating and heat intolerance. She was 3 years post-menopausal and had no history of recent viral illness, contrast exposure or family history of thyroid disease. Physical exam revealed an anxious appearing woman with fine tremors in both hands, hyperreflexia but no lid lag or exophthalmos. Labs included TSH &lt;0.005 uIU/mL (0.400-4.2), free T4 2.89 ng/dL (0.80-1.50), TSH receptor binding antibody 8.24 IU/L (&lt; 2.00), TSI 7.27 IU/L (&lt;0.56), WBC 2900/uL (4500-11000), ANC 1746/uL (1900 - 8000), hemoglobin 11.4 g/dL (11.7-15.0) and platelet 207,000/uL (150,000-450,000). Thyroid ultrasound noted sub-centimeter hypoechoic/cystic nodules and 24-hour thyroid uptake showed 56.4% symmetric uptake (upper limit of normal 30%). Due to leukopenia, the patient was started on propranolol and underwent radioiodine ablation with 14.8 mCI. Two weeks later, she reported easily bruising and gum bleeding and her blood work was significant for pancytopenia. The patient was referred to hematology and two bone marrow samples were obtained. Though MDS/MPN was initially suspected based on atypia in both specimens, there were no immunophenotypic, cytogenetic or molecular abnormalities suggesting a neoplastic process. Instead the patient was thought to have autoimmune pancytopenia secondary to Graves’ and the atypia was believed to be secondary to peripheral consumption. She was started on prednisone 1 mg/kg/day with resolution of her cytopenias. Discussion: Graves’ disease has been associated with hematological abnormalities including isolated anemia (the most common), thrombocytopenia or leukopenia. Pancytopenia is an uncommon complication and is rarely described in the literature. The exact mechanism remains unclear, but may be related to either reduced production of hematopoietic cells from the bone marrow or increased destruction of mature hematopoietic cells due to autoantibodies. Since thyroid hormones are known to increase erythropoietin, this leads to an exaggerated consumption of iron, folic acid and vitamin B12 and can cause various forms of anemias. Leukopenia may be secondary to immunologic destruction whereas thrombocytopenia may be due to antiplatelet antibodies or increased splenic sequestration. Pancytopenia is rare. Our patient was treated with high dose prednisone with resolution of her pancytopenia, which suggests an autoimmune process as the mechanism. Our case showcases a rare complication of Graves’ disease and highlights that high dose steroid therapy may improve cytopenias associated with this condition.