The long-term retention of platinum in human tissues following the administration of cisplatin or carboplatin for cancer chemotherapy.

Mass spectrometry has been used to study the distribution and retention of platinum in the tissues of patients following the administration of cisplatin or carboplatin. Blood platinum was measured up to 2 years and renal excretion up to 5 years after treatment. Platinum concentrations in plasma and red cells fell according to a power function, approximately as the inverse square of the time after administration. The concentration in the urine fell more slowly. Necropsy samples were used to examine the distribution of platinum in various human organs up to 17 months after treatment. The highest concentrations were found in the liver, which retained approximately 2% of the dose. Although the results were scattered between patients, there was little loss of platinum after about 1 month. The prolonged retention of platinum may be relevant to long-term toxicity.