Distribution of misonidazole in human tumours and normal tissues

Levels of misonidazole in human tumours, normal tissues and blood have been measured in patients given a 1g oral dose of drug before surgery or biopsy. The results show that 50--70% of the blood level was found in a wide range of tumours and that similar levels were found in adjacent normal tissues. Good penetration of drug was achieved within tumours, and up to 90--100% of the blood level was found in the necrotic cyst fluid at the centre of some tumours. CSF studies showed free diffusion into the CNS, which was confirmed by finding 50--70% of the blood level within brain tumours. A delay of passage of drugs into the CSF was noted, which was not found for drug diffusion into bile and saliva.