[99mTc Tetrofosmin in diagnosis of distant metastases from differentiated thyroid cancer]

Technetium 99mTc(TF), non-specific tumor-searching tracer was evaluated for its ability to detect distant metastases of differentiated thyroid carcinoma (DTC) and its reliability in the follow-up of DTC. Whole body scintigraphy (wbs) was performed 20-30 min after intravenous injection of 740 MBq 99mTc tetrofosmin by means of a dual-head gamma-camera (followed by spot images if needed) in 61 patients (pts) with DTC; 52 pts with distant metastases in 131I whole body scintigraphy (34) or in other methods (x-ray, CT, ultrasound) (7) or with negative 131I whole body scan and elevated thyroglobulin (11). In the group of 52 pts with signs of neoplasm dissemination, 36 showed positive TF whole body scan (69%), 16 (31%) pts were TF-negative. 23 of 34 131I positive wbs were also TF positive (68%), 11 out of 34 were TF negative (32%). In a group of 7 pts with metastases in x-ray, CT or ultrasound 4/7 were positive (57%), 3/7 were TF negative (18%). In a control group of 11 persons (2 diseases-free, 9 with DTC in clinical remission) TF whole body scans were negative in all cases.

Technetium 99mTc tetrofosmin is clinically useful for detecting distant metastases of differentiated thyroid carcinoma and deserves complementary clinical application in follow-up in such patients.