Utility of Stimulated Thyroglobulin in the Differentiate Thyroid Cancer

Introduction: The treatment of differentiated thyroid cancer has changed considerably, total thyroidectomy and radioactive iodine ablation represented the initial treatment for these patients, currently with a great debate around the choice of which patient should undergo ablation with radioactive iodine in the post-surgical period. Objective: To determine the values of stimulated thyroglobulin (in hypothyroidism) in patients with differentiated thyroid carcinoma who have had surgery and its relationship with the ATA 2015 recurrence risk stratification and the presence of distant or locoregional metastasis in post ablative total body scan with I131 Methodology: Retrospective study, which included patients with differentiated thyroid carcinoma, patients who have had total thyroidectomy surgery and subsequent ablation with I131 in 45 days at the Central Hospital of Instituto de Prevision Social, from 2011 to 2018. There were evaluated: post-surgical thyroglobulin dosage in hypothyroidism, antithyroglobulin antibody measurement, and total body scan results at 72 hours post ablation with I131. There were excluded: Patients with positive antithyroglobulin antibodies, eu /hyperthyroidism, or incomplete data. Results: 100 patients conformed by women (88.0%), whose average age was 44.7 (± 16.1), intermediate risk 60%, high risk 31% and low risk 9%. According to the stimulated thyroglobulin values, 3 groups were classified: Group A thyroglobulin less than 1 ng/dl 32%, Group B 1 to 10 ng/dl 39%, Group C greater than 10 ng/dl 29%. Of the patients at intermediate risk n: 60, 23 (38%) belonged to group A, 27 (45%) to group B and 10 (17%) to group C. Of high-risk patients n: 31, 7 (22%) belonged to group A, 8 (26%) to group B, and 16 (52%) to group C. Of low risk patients n: 9, 2 (22%) belonged to group A, 4 (44%), group B, and 3 (33%) to group C. Post-ablative body scan detected locoregional or distant metastases in 23 (23%) patients, of which 2 (8.6%) belonged to group A, 6 (26%) to group B, 15 (65%) to group C. They were intermediate risk 10 (43%) and high risk 13 (57%) of them. No low-risk patient presented a positive RCT. There was found a relationship between thyroglobulin and high ATA risk (p <0.05) with positive RCT. Association between thyroglobulin> 10ng / dL and the presence of metastasis (p = 0.0001), Exp (B) 15.1 with R2 25 and 35%. Conclusion: A stimulated postoperative thyroglobulin dosage greater than 10 ng/ dL increases the chances of recurrence 15 times, with 25 to 37% chance of it. So, it would be important to consider ablation with iodine 131 in this type of patients.