Effects of roentgen irradiation on human melanoma metastases in the skin.

Skin metastases of malignant melanomas in 17 patients were irradiated with three different levels of total dose (40 Gy, 60 Gy and 80 Gy), using a constant fraction size of 5 Gy five times a week. The tumors were removed 10 to 14 days after the last irradiation. The morphologic alterations of the tumor tissue correlated with the total dose. More extensive destruction was seen only after 80 Gy, but even at this level and with this fraction size viable appearing tumor cells remained in all cases. The tumors of one patient exhibited exceptional radiosensitivity. No completely resistant tumor was seen.