Radiation response of two human malignant melanomas grown in athymic nude mice

Abstract

The radiation response of two human malignant melanomas (V.N. and G.E.) irradiated as solid tumours in athymic nude mice was studied by measuring single cell survival in soft agar. Survival curves were determined for cells from tumours irradiated either in air-breathing mice or in mice killed by cervical dislocation 15 min before irradiation. The hypoxic fractions, determined from the vertical displacement of these two curves, were 12–17% for V.N. melanoma and 26–36% for G.E. melanoma. The D₀-values were 3.43 Gy (air-breathing mice) and 3.05 Gy (dead mice) for V.N. melanoma and 3.00 Gy (air-breathing mice) and 3.35 Gy (dead mice) for G.E. melanoma. Survival curves of cells irradiated in dead mice showed n = 4.6 and D_q = 4.6 Gy for V.N. melanoma and n = 2.0 and D_q = 2.2 Gy for G.E. melanoma.