Misonidazole in the preoperative and radical radiotherapy of bladder cancer.

Measurement of intercapillary distances suggests the presence of significant cell hypoxia in Bilharzial bladder cancer. This tumor seems to be capable of reoxygenation in view of the existence of a correlation between prognosis and immediate tumor shrinkage after irradiation. Two programs are presented: (1) Use of misonidazole with concentrated preoperative irradiation where the reoxygenation properties are not used fully. Two radical radiotherapy regimes are presented. One protocol involves a split course (SC) protracted regime making full use of spontaneous reoxygenation. A second protocol involves hyperfractionation stimulating continuous low-dose-rate irradiation. Complete tumor regression 3 months after irradiation was achieved in 18 of 22 patients with 3T tumors. No neuropathy was encountered in four patients subjected to the HF regimen who also showed complete tumor regression.