Sensitivity of human malignant intracranial tumors against MCNU in vitro in comparison to ACNU and BCNU.

An in vitro chemosensitivity test was carried out in 50 specimen of human malignant intracranial tumors. Aim of the study was to evaluate the proportion of sensitivity against MCNU (Ranomustine) in comparison to ACNU and BCNU. 47 tests were evaluable. Mean viability of the specimen was 83.3 +/- 18.7%, mean plating efficiency was 0.068 +/- 0.051%. 9/47 settings revealed sensitivity against MCNU in vitro (ACNU: 10/47; BCNU: 16/46). There was no advantage of MCNU concerning age or sex of the patients. Brain metastases seemed to be slightly more frequent sensitive against MCNU than primary brain tumors. Cross resistance between ACNU, BCNU and MCNU was rather high. The results of this in vitro series do not encourage a clinical trial of MCNU as an alternative to the commonly used nitrosoureas.