Background: Acute radiation dermatitis is a very common side effect of radiation therapy in large numbers of cancers including breast cancer. Despite high prevalence rate of acute radiation dermatitis and also wet desquamation, a few trials on prophylaxis of this complication using topical treatment have been conducted. Despite effectiveness of topical corticosteroids in treatment of acute radiation dermatitis which are focused in the literature, yet there are some controversy about their usage in this regard. For this reason we attempted to investigate this subject via conducting a clinical trial.

Materials and Methods: This trial included 76 patients with pathologic diagnosis of breast cancer for whom radiotherapy has been planned. Patients were 27-70 years old. Patients with radical mastectomy received 5000 cGy within 5 weeks, and those with conservative surgery received 6000 cGy within 6 weeks divided in 200 centigray fractions. Patients were divided randomly into two groups, betamethasone and placebo, 38 patients in each group. In placebo group, 3 patients did not attend for weekly assessment. Additional one patient did not refer during follow-up period. Thus, they were excluded from the study. One group was given betamethasone 0.1% and other group was administered base of ointment as placebo.All patients consumed drug or placebo from the 1st day of treatment until one week after treatment completion as twice daily within tangential field. Patients were monitored for assessing dermatitis severity and its symptoms and also possible drug adverse effects one week after the therapy commenced and afterwards by one-week intervals as well as in an appointed day. Three weeks after termination of therapy, patients were also visited, and each examination provided information about dermatologic complications which were registered in the questionnaire.

Results: Mean times development of dermatitis in both betamethasone and placebo groups were 3.2500 and 2.2571 (weeks) respectively (t=-3.898 , p< 0.001). Maximal dermatitis intensity during treatment in betamethasone group was 3.5% 0, 86.8% I, 7.9% II, 0% III, 0% IV and in base of ointment receiving group were 0 %, 60% , 37.1%, 2.9% and 0% (P = 0.008), respectively. Maximum severity of complaints stated by patients in terms of burning and pruritus had been lesser in betamethasone group (P< 0.001). No significant differences were observed between two groups in terms of pain intensity.

Conclusion: Betamethasone valerate ointment is statistically significantly more effective than base of ointment alone in reducing acute radiation dermatitis. Iran . J. Radiat. Res. 2003, 1(2): 105 – 111.