Pharmacokinetics of intra-arterial and intravenous cisplatin in head and neck cancer patients.

After administration of cisplatin (50 mg/m2 on days 1 and 2) by intra-arterial or intravenous infusions over 1 or 6 hr to a total of 24 patients with head and neck cancer, the main pharmacokinetic parameters of platinum were determined according to a multicompartmental analysis. Elimination half-life of total platinum is greater than 3 days, the amount of platinum recovered in the urine over 7 days accounting for 15-50% of the administered dose. The half-life of filterable platinum species was calculated from the urinary excretion data: 39 +/- 17 min (i.a./1 hr), 37 +/- 24 min (i.a./6 hr), 58 +/- 17 min (i.v./1 hr) and 51 +/- 22 min (i.v./6 hr). Biopsies of the tumor were also analyzed on day 3 for their platinum content. The mean concentrations of platinum in biopsies were: 2.72 micrograms/g (i.a./1 hr), 3.89 micrograms/g (i.a./6 hr), 1.27 micrograms/g (i.v./1 hr) and 1.38 micrograms/g (i.v./6 hr). Tumor regression, based upon clinical and histological data, was only moderate after this single chemotherapy course.