A DOUBLE-BLIND, RANDOMIZED, PROSPECTIVE TRIAL TO EVALUATE TOPICAL VITAMIN-C SOLUTION FOR THE PREVENTION OF RADIATION DERMATITIS

Purpose: The object of this study was to ascertain the value of topica l ascorbic acid in the prevention of radiation dermatitis. Methods and Materials: Patients with primary or metastatic brain tumors were elig ible. Patients applied a topical solution, twice per day prior to and throughout the course of radiotherapy, to the left and right sides of the head. The radiotherapist and the patient were blinded as to the co ntents of the solutions. The bottle for one side of the head contained topical ascorbic acid solution. The bottle for the other side of the head contained only vehicle. During and after the course of treatment the radiotherapist scored the skin reaction on both the left and right sides of the irradiated head using a skin reaction scale. The data we re analyzed with a matched pair analysis. Since each patient received both treatments (ascorbic acid and control solutions) the statistical analysis concentrated on the paired difference in scores based on the probability of a ''preference'' for the treatment or control. Results: Eighty-four patients entered the study. Sixty-five were suitable for analysis. In 10 patients there was a preference for ascorbic acid solu tion (15%), in 20 patients there was a preference for placebo (31%), a nd there was a preference for neither in 35 patients (54%). Ascorbic a cid solution could be considered to have an effect if the percentage o f preferences favoring ascorbic acid over placebo, among those subject s with a preference, significantly exceeded the 50% expected by chance . The observed percentage of preferences for ascorbic acid was only 33 % (10 of 30 with a preference; p = .10, two-sided sign test). Patient age, race, sex, and total dose of irradiation had no detectable influe nce on the comparative skin toxicity scores. Conclusion: There is no d iscernible benefit to ascorbic acid lotion, in the manner in which we used it in this trial, for the prevention of radiation dermatitis.