<qa>  How many patients will be enrolled in the trial?This is a pilot trial of topical MTS-01 in patients receiving MMC, 5-FU, and IMRT for definitive management of carcinoma of the anal canal. Fifteen patients will be enrolled. MMC will be delivered at a dose of 10mgm2 on days 1 and 29. 5-FU will be delivered as 1000mgm2day as 96 hour continuous infusion beginning on day 1 and 29. RT will be delivered to a total dose of 50-54 Gy based on tumor characteristics. Tempol gel will be applied to the bilateral groins and the gluteal cleft, avoiding a 3 cm radius from the anal verge, immediately prior to each fraction of RT. RTOG grading will be used to evaluate skin toxicity in both the groin and gluteal cleft weekly during treatment and at 4 weeks, 3 months and 6 months after completion of treatment. The duration of treatment, number of treatment breaks, opiate requirements, and level of pain will be evaluated weekly during treatment and at 4 weeks and 3 months after the completion of treatment. Disease control will be assessed at 4 weeks, 3 months, 6 months, 9 months, and 12 months of follow-up. 