In stage I, cohorts of 3-6 patients each receive escalating doses of dimesna until the maximum tolerated dose (MTD) is reached. The MTD is defined as the highest dose at which no more than 1 of 6 patients experiences dose limiting toxicity (DLT). The MTD of dimesna is then used in stage II of the study, in which the volume of pre and post cisplatin intravenous saline hydration is reduced in cohorts of 3-6 patients each. The MTD intensity of cisplatin is defined as the least saline hydration volume at which no more than 1 of 6 patients experience DLT.