In vitro cellular radiosensitivity of human malignant melanoma.

The agar diffusion chamber assay was used to construct in vitro radiation cell survival for two human malignant melanoma xenografts. Both tumors had survival curves of shoulder-exponential shape with large shoulders (Dq 2.38, 2.92 Gy). Comparison with previous studies of 4 human tumor xenografts in the same system suggests that large shoulders are more common in melanomas than other tumor types. This supports the case for large fraction irradiation in the clinical therapy of melanoma.