[Development of new hypoxic cell radiosensitizer in Japan].

Basic studies in hypoxic cell radiosensitizers developed in Japan were reviewed. Because of the unsuccessful clinical trials of misonidazole (MISO), many efforts have been made to find a new hypoxic cell sensitizer which is more effective and/or less toxic than MISO. Already over a thousand drugs were tested, but the majority of them did not work in vivo or were very toxic to the animals.