Abstract Purpose: To report the results of a randomised study comparing the efficacy of Hydrosorb® versus control (water based spray) in the topical treatment of grade 1 and 2 radiation dermatitis in population of patients treated for early stage breast cancer (BC) with normo fractionated radiotherapy (RT). Patients and Methods: Breast cancer patients with grade 1-2 radio-induced dermatitis during normo fractionated postoperative radiotherapy were eligible (according to the CTCAE v3 scale). They were randomised to receive either Hydrosorb® (A) or water based spray (B). The primary endpoint was local treatment failure defined as interruption of radiotherapy because of skin radiotoxicity or and/or change of local cares for skin alteration. Secondary endpoints were the evaluation of skin colorimetry, pain, and quality of life. Pain was assessed according to two classes with a VAS cut-off of 2. Results: Two-hundred seventy eight patients were enrolled (A = 142, B = 136). There were 186 successfully treated patients (82 in Hydrosorb® arm, and 74 in the control arm). There were 60 "failures" in the Hydrosorb® arm, and 62 in the control arm (p = 0.72), but mostly without interruption of the radiotherapy. Twenty-four patients stopped the radiotherapy treatment for local cares (16 in Hydrosorb®, arm and 8 in control arm). No risk factors were associated with failure to local treatment. The average absolute reduction of colorimetric levels between day 28 and day 0 was 4 in the Hydrosorb®, and 4.2 in the water spray groups, respectively (p = 0.36). Forty-eight patients in the Hydrosorb® arm had a VAS > 2 versus 51 patients in the placebo arm, i.e. 34% and 38%, respectively (p = 0.45). A significant reduction of pain was observed on D7 (p = 0.04) and D21 (p = 0.01) in the Hydrosorb® arm. Sixty patients in the Hydrosorb® arm and 55 patients in the placebo arm had moderately to severely altered quality of life (p = 0.76). Conclusions: The present study showed no significant difference between Hydrosorb® and simple water spray in the treatment of acute radio-induced dermatitis even if there was a trend to an improvement in pain at the first weeks after the treatment. Systematic prevention measures and modern breast cancer radiotherapy techniques now allow excellent tolerability, but the place of topical treatment to optimize this tolerability has yet to be defined. Citation Format: Bazire L, Fromentin I, Diallo A, de Lalande B, Pernin V, Dendale R, Fourquet A, Savignoni A, Kirova Y. Hydrosorb® versus control (water based spray) in the management of radio-induced skin toxicity: Results of multicentre controlled randomized trial. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P3-12-16.