Background/Aim: To evaluate whether topical use of a film-forming silicone gel (StrataXRT ®) could reduce radiation dermatitis compared to a moisturizing cream (Xderm ®) in patients receiving whole breast radiotherapy. Patients and Methods: A total of 56 patients with breast cancer were randomized to use StrataXRT or X-derm. The severity of radiation dermatitis was graded using physiological skin parameters, clinician-assessed visual rating scales and patient-reported symptoms. Changes in these parameters from baseline to 4 weeks post-radiotherapy were evaluated every two weeks. Results: Two-way repeated-measures ANOVA revealed different patterns of changes in the erythema index (F=3.609, p=0.008) and melanin index (F=3.475, p=0.015). The post hoc analysis demonstrated a significantly lower erythema index and melanin index in the patients allocated to the StrataXRT group. Conclusion: The use of StrataXRT can reduce radiation dermatitis with respect to objectively measured physiological skin parameters. The results of the present study will support the feasibility of conducting a larger randomized controlled trial. Radiation dermatitis (RD) is the most common adverse side effect of radiation therapy (RT), appearing in almost every patient with breast cancer who receives RT (1-3). The symptoms of RD generally include erythema, edema, dryness, hair loss, hyperpigmentation, and most seriously, moist desquamation, ulcers, and skin necrosis, which can cause discomfort in patients and disruption to RT (4-6). Traditionally, RD has been evaluated and graded using visual rating scales, such as the Common Terminology Criteria for Adverse Events (CTCAE) and Radiation Therapy Oncology Group (RTOG) criteria (7, 8). An additional scoring system, the modified 10-point Catterall skin scoring profile (CSSP), has been used to better evaluate RD (9, 10). However, due to the inherent subjectivity of these scales, a number of alternative methods have been developed to objectively quantify the changes in physiological skin parameters, such as electrochemical, reflectance spectrophotometer (erythema index (EI) and melanin index (MI)), trans-epidermal water loss (TEWL), and laser Doppler flowmetry (LDF) methods (11-15). The management of RD, as an inevitable part of RT, is directed toward the palliation of skin symptoms (16). Several agents such as steroids, hyaluronic acid, aloe vera, sucralfate, and adrenergic vasoconstrictors have been used to prevent or reduce the severity of RD (10, 17-22). However, there are no clear guidelines or a consensus supporting the application of any topical agent as a standard of care for RD. Recently, silicone-based barrier-forming products have been used for the management of RD (23, 24). The siliconebased film dressing provides mechanical protection from skin damage and TEWL, and may prevent moist desquamation and reduce the severity of RD. Despite these advantages, this silicone-based film dressing may have limitations, such as small bolus effects, easy detachment particularly when bathing or perspiri...