[Pharmacokinetics of plasma and cerebrospinal fluid cisplatin in patients with malignant glioma and metastatic brain tumor after selective intraarterial or intravenous and intracarotid administration of etoposide and cisplatin].

CSF and plasma platinum levels were examined in patients with malignant glioma after administration of etoposide and cisplatin each at doses of 60 mg/m2 by 60-minute selective intraarterial infusion. These same factors were also examined in patients with metastatic brain tumors after administration of cisplatin at a dose of 60 or 100mg/m2 by 60-minute intracarotid or intravenous infusion. Plasma and CSF samples taken through an Ommaya reservoir placed in the lateral ventricle or postoperative cavity were analyzed for platinum content by atomic absorption spectroscopy. Plasma and CSF platinum levels were dose dependent. The overall plasma platinum curves were biphasic, with mean half-lives of 35 minutes and 56 hrs. The mean peak total CSF concentration was 10.0% of the peak total plasma platinum and 20.2% of the peak free plasma platinum in patients with malignant glioma. In patients with a solid metastatic brain tumor, the mean peak total CSF concentration was 1.9% of the peak total plasma platinum and 4.0% of the peak free plasma platinum after i.v. infusion. After intracarotid infusion, the mean peak total CSF concentration was 3.4% of the peak total plasma platinum and 7.0% for the peak free plasma platinum. In patients with meningeal carcinomatosis, the mean peak CSF concentrations were 7.7% of the peak total plasma platinum and 13.7% of the peak free plasma platinum. The free to total platinum ratio in plasma decreased quickly and that in CSF increased and was maintained at the high levels of 80% for two hours or more.(ABSTRACT TRUNCATED AT 250 WORDS)