Cytotoxicity of radiosensitizers in multicell spheroids: combination treatment with hyperthermia.

Spheroids of EMT6 tumour cells were grown in spinner culture. As with V79 cell spheroids, the combination of 1.5mM misonidazole and hyperthermia at 42.5 degree C for 1 or 2 h cuased greater cytotoxicity than either heat or drug alone. Radioresistant hypoxic cells at the centre of the spheroids were eliminated but other cells were also killed.