ROLE OF INITIAL I-131 WHOLE-BODY SCAN AND SERUM THYROGLOBULIN IN DIFFERENTIATED THYROID-CARCINOMA METASTASES

evaluated the role of first I-131-whole-body scan and of first serum t hyroglobulin (Tg) measurement after surgery in the early diagnosis of metastases from differentiated thyroid carcinoma (DTC). Methods: In 26 9 patients with metastases from DTC, we retrospectively evaluated the results of first whole-body scan (performed 40 days after surgery with diagnostic or therapeutic I-131 dose) and in 69 of them we also evalu ated the result of first Tg measurement (performed the day before the first whole-body scan) in relation to the presence, localization and t ype of metastases. Results: In all patients, the first whole-body scan was positive for the thyroid remnant, and in 54.3% of patients it was also positive for metastases. In the remaining 45.7% of patients, met astases were detected during the follow-up. First Tg levels were >60 n g/ml in 66.7% of patients with metastases. First whole-body scan detec ted metastases in 47.8% of patients with Tg values <60 ng/ml, while Tg values were >60 ng/ml in 61.3% of patients with first whole-body scan negative for metastases. The combined results of both first whole-bod y scan and first Tg measurement allowed the early detection of metasta ses in 82.6% of patients. Whole-body scan detected distant metastases more frequently than local lymph node metastases (p < 0.01). Conclusio n: In more than 80% of patients, metastases were suspected or diagnose d as early as 40 days after surgery in the presence of residual thyroi d tissue by combined evaluation of results of first whole-body scan an d Tg measurement.