BACKGROUND & PURPOSE: Radiotherapy plays a key role in breast cancer treatment however, radiation-induced dermatitis can impact on treatment delivery and patient quality of life.The primary outcome was to compare Mepitel® Film versus standard treatment in preventing radiotherapy skin toxicity onset. METHODS: A multicentre randomised controlled phase III study compared standard treatment (aqueous-urea cream - Excipial U hydrolotion applied at the beginning of radiotherapy and antiseptic cream - Flammazine or Ialugen Plus applied at the onset of moist desquamation) versus Mepitel® Film in patients with breast cancer undergoing post-operative radiotherapy. The primary outcome was the proportion of moist desquamation (RTOG score ≥ 2) in the experimental and control groups. RESULTS: During the study (2016-2020), 161 patients were randomized, 154 (95.7 %) were evaluable. Skin toxicity Radiation Therapy Oncology Group (RTOG) score ≥ 2 was observed in 9.5 % and 13.9 % of experimental and control groups respectively (Relative Risk = 0.68, 95 %CI 0.28-1.66
p = 0.393). RTOG scores >
0 were 90.5 % and 94.9 % in experimental and control groups respectively (Relative Risk = 0.95, 95 %CI 0.87-1.04
p = 0.294).Multivariable analysis, controlled for age, diabetes, BMI and smoking exposure, showed a risk reduction of RTOG >
0 of 38 % (HR = 0.62 95 %CI 0.49-0.96, p = 0.028), and a risk reduction of RTOG >
1 of 33 % (HR = 0.67 95 %CI 0.26-1.76, p = 0.420) in the experimental group.The median time to recovery from RTOG grade >
0 toxicity was 17 and 32 days for experimental and control groups, respectively (p = 0.027). At multivariable analysis, time to recovery was 38 % faster in the experimental group (HR = 1.38 95 %CI (0.99-1.93) p = 0.059). CONCLUSIONS: Although the study did not demonstrate a statistically significant reduction in RTOG >
2 skin toxicity, there was evidence of a reduction in the rate of skin toxicity and an improvement in time to recovery. The device was well tolerated by patients.