Detection of melanoma metastases with Tc-99m-tetrofosmin

Aim: The aim of this study was to evaluate Tc-99m-tetrofosmin whole-body imaging in the detection of metastases in patients with malignant melanoma. Methods: In 30 patients with suspected melanoma metastases we performed whole body imaging. After administration of about 600 MBq Tc-99m-tetrofosmin dynamic images up to 10 min were performed in 7 patients (1 image per 10 sec) to evaluate the optimal tracer uptake in the metastases. In all patients whole-body images were performed 5-10 min p. i. using an acquisition time of 5 min per image. The final diagnosis was confirmed by surgical histology in 30 lesions, by computertomogaphy and clinical course in the remaining lesions. Results: Out of 64 melanoma metastases 49 were detected using Tc-99m-tetrofosmin scintigraphy (49 rp., 15 fn. ). The overall sensitivity for the detection of malignant lesions was 77%. Referring only to the lymph node metastases, the sensitivity was 87% (26 rp.; 4 fn.). The maximal tracer uptake was reached 1 min after injection, with a slow decrease in the following 10 minutes. The size of the lesions ranged between 0.5 and 7.0 cm and the T/B ratios between 1.3 and 3.0 (mean 1.88). Conclusions: Tc-99m-tetro-fosmin whole body imaging is a simple and side-effectless method for the detection of melanoma metastases especially of lymph node metastases. The results are comparable to Tc-99m-sestamibi and TI-201 scintigraphy.