Uptake and retention of platinum in patients undergoing cisplatin therapy

Results of in vivo measurements of the platinum concentration in kidneys and tumours of patients treated with cisplatin for testicular carcinoma, head and neck tumours and brain tumours are presented. The measurements were performed with an x-ray fluorescence technique. Our earlier studies have shown that maximum platinum levels in kidneys were reached 3-4 h after an intravenous injection of cisplatin. The present study showed that, at that time, the ratio between the concentration of platinum in kidney and in blood serum was 22 +/- 7 (+/- 1 S.D.). Between 24 and 72 h after administration this ratio was 10 +/- 3, as shown in another group of patients. Measurements of platinum concentration in brain tumours showed varying maximum uptake, between 14 and 40 micrograms/g, 5-15 h after administration. There was an indication that radiotherapy may increase the uptake of cisplatin in normal brain tissue. The technique described can be used for further studies of the platinum concentration in tumours and risk organs in connection with cisplatin therapy. Such studies are needed to find out how to improve the therapeutic effects and lower the toxic ones.