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

Unlabelled: 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.

Conclusions: 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.