Endocrine Abstracts

Objective: Recently, radioablation has been offered for patients with thyroid microcarcinoma, however some authors favor just follow-up as the prognosis of this disease is excellent. In this study, we compared the long-term follow-up results, for a period of 16 years, in patients with thyroid microcarcinoma in a group of patients with thyroidectomy only and in another both thyrodectomized and radioablated.

Methods: Two hundred sixty five patients with a proven diagnosis of thyroid cancer <10 mm among 1755 thyroid cancer cases were included in the study. Any patients with unfavorable characteristics such as capsular or perithyroidal invasion, intrathyroidal spread, lymph node invasion or multicentirity were excluded. In group IA, 18 patients (14 female, 4 male; mean age 74), patients were hemi-thyroidectomized only and 64 patients (43 female, 21 male, mean age 66) in group IB had total or near-total thyroidectomy. In group II, 183 patients (123 female, 60 male; mean age; 61) underwent total or near total thyroidectomy and ingested I-131 (dose range; 30-85 mCi) while they were in ahypothyroid state (TSH >40 uIU/L). In the surveillance period, all patients were monitored with periodical serum Tg/ATg measurement and ultrasound of the neck for a period of two to 16 years.

Results: In group IA and IB, lymph node metastasis was detected in 9 patients (11%) with US-guided fine needle aspiration in the surveillance period. No patient asked for additional treatment including surgical intervention and followed by L-T4 suppression only. Serum Tg levels were less than 2 ng/dl (range; 0.2 to 3.9 ng/dl) in 56 patients an in the remaining 26, ranged from 2.0 to 9.8 ng/dl. Serum Tg levels decreased to lower values than 9.8 ng/dl after no more than one year. In group II, lymph node invasion were detected in 19 patients (10%) and 9 of them had neck dissection for a complete cure. Initial serum Tg levels ranged from 2.1 to 19.8 ng/dl in those patients. In 19 patients with lymph node invasion serum Tg levels ranged between 2.2–19.8 ng/dl.

Conclusion: In both groups, approximately 1/10 of patients presented with recurrent or metastatic disease to regional lymph nodes. As the difference between radioablated and not ablated groups is statistically not significant, we do not recommend completion thyroidectomy and radioablation for patients with thyroid microcarcinoma (excluding any poor prognostic factor) and follow-up unless the disease becomes clinically apparent.