The response of human tumour metastases to radiation and misonidazole.

In an attempt to investigate the radiosensitivity effect of the nitroimidazole misonidazole in man, sequential tumour volume measurements have been performed in 4 patients with metastatic malignant disease in order to compare the growth delay induced by radiation given before of 4 hours after the oral administration of the drug. One study was not completed, and there was no evidence of radiation sensitization in 2 patients. The results in the fourth patient were consistent with a small enhancement of radiation effect. Drug blood levels were followed on 9 occasions and tumour drug concentration measured in 1 patient.