RESUMO
The evidence on products for the prevention of radiodermatitis is limited. The primary objective was to analyse the effectiveness of the spray skin protectant 'non-burning barrier film' in the prevention of radiodermatitis with moist desquamation in patients with the anal canal and rectal cancer followed in nursing consultations compared to a standardised moisturiser based on Calendula officinalis and Aloe barbadensis. Single-blind randomised clinical trial. The study was performed in a hospital in Rio de Janeiro, Brazil, with 63 patients undergoing anal canal and rectal cancer treatment, randomised into one of the following two groups: an experimental group, which used a spray skin protectant and a control group, which used a moisturiser. Data were collected using an initial and subsequent evaluation form and were assessed using descriptive and inferential analyses. Participants who used the spray skin protectant had a lower chance of presenting radiodermatitis with moist desquamation and a longer time without this outcome when compared to the control group. The overall incidence of radiodermatitis was 100%, with 36.5% being severe. Furthermore, 17.5% of participants discontinued radiotherapy due to radiodermatitis. There were no differences between the groups regarding the severity of radiodermatitis and the number of patients who discontinued radiotherapy. The skin protectant was effective in preventing radiodermatitis with moist desquamation amongst patients with anal canal and rectal cancer.