Evaluation of the neurotoxicity of paclitaxel and carboplatin by current perception threshold in ovarian cancer patients.

OBJECTIVES Combination chemotherapy consisting of paclitaxel and carboplatin has recently started to be given as the regimen of first choice for epithelial ovarian cancer. One of its side effects, however, is neurotoxicity, and this neurotoxicity has been reported to be the dose-limiting factor. Since it is necessary to measure the severity of the neurotoxicity objectively and quantitatively, we evaluated it on the basis of current perception threshold (CPT) values, which is easy and non-invasive. METHOD Sixteen patients with epithelial ovarian cancer were given paclitaxel (175 mg/m(2), 3 hours) and carboplatin (area under the curve of 5) every three weeks, and the CPT values were measured at two sites on the day before and several times after administration. RESULTS All patients exhibited mild neurotoxicity, but it was never so severe that chemotherapy could not be continued. The CPT values peaked on day 4 during one course of chemotherapy, but decreased thereafter and returned almost to the baseline by three weeks, in the same way as the patients' complaints. The CPT values decreased with the number of courses, and patients' complaints gradually increased. The CPT values increased more in the cases previously treated with cisplatin than in the other cases. These changes were seen at 2,000 Hz, which generally corresponds to large, myelinated nerves. CONCLUSION There were correlations between the changes in the patients' CPT values and their degree of neurotoxicity. We expect to be able to predict severe neurotoxicity and evaluate the effect of drug therapy for neurotoxicity by measuring CPT values.