[Detection of melanoma metastases with Tc-99m-tetrofosmin]

The aim of this study was to evaluate Tc-99m-tetrofosmin whole-body imaging in the detection of metastases in patients with malignant melanoma.

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 computertomography and clinical course in the remaining lesions.

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).

Tc-99m-tetrofosmin 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 Tl-201 scintigraphy.