Combination of radiosensitizers and hyperthermia in tumour radiotherapy

Specific metabolic properties of hypoxic (and therefore radio-resistant) tumour cells are responsible for the selective effect of radiosensitizers (such as misonidazole) and hyperthermia upon these cells in respect of radiosensitization as well as cytotoxicity. Radiosensitizers and hyperthermia should therefore be used to improve the results of tumour radiotherapy; enhancement ratios of 2-4 have already been attained experimentally with this combined treatment. In spite of these good results, certain problems exist, and up to now the combination of radiosensitizers and hyperthermia has not been used to any great extent for tumours in humans.