ESTRO 2025 - Abstract Book

S543

Clinical - Breast

ESTRO 2025

Sírio-Libanês, São Paulo, Brazil. 15 Department of Oncology, Union Oncology Centre, Hong Kong, Hong Kong. 16 Caring Futures Institute, Flinders University, Adelaide, Australia. 17 Department of Radiation Therapy, University of Otago, Wellington, New Zealand. 18 Vancouver Coastal Health, Lions Gate Hospital, North Vancouver, Canada. 19 Department of Radiation Oncology, Magee-Womens Hospital, Pittsburgh, USA Purpose/Objective: Mepitel film (MF) significantly reduces the incidence of severe acute radiation dermatitis (RD) compared to standard-of-care (SoC) in randomised controlled trials (RCT) in patients with breast cancer. However, its implementation involves extra costs and nursing procedures, which limit its widespread use. This study utilised data from a Canadian RCT to perform a cost-effectiveness analysis comparing MF to SoC from a Canadian healthcare payer’s perspective. Material/Methods: A decision model was constructed to perform a cost-effectiveness analysis for MF in comparison with SoC (moisturisers) for the prevention of grade 2 or higher RD following adjuvant hypo-fractionated (40 Gy in 15 fractions) whole-breast radiotherapy (RT) for patients with breast cancer. Clinical parameters were obtained from a Canadian randomised multicentre Phase III trial. Cost data was collected for MF, direct and indirect costs for managing RD including topical corticosteroids, antibiotics and hourly wage of nursing staff. All costs, reported in Canadian dollars (CAD) were based on medical expenses at three provincial oncology centres in Canada. Quality of life utility values were derived from mapping the Dermatology Life Quality Index (DLQI) score for patients with grade 2 or higher RD at week 6 of RT to the EQ-5D. Two arms were compared using the incremental cost-effectiveness ratio (ICER). A willingness-to-pay (WTF) threshold of CAD 50,000 per quality-adjusted life years (QALY) gained was used as the cost-effectiveness criteria for this study. One-way sensitivity analysis was performed to account for uncertainty in decision model assumptions. Results: Base case analysis demonstrated that MF is cost-effective in preventing grade 2 or higher RD as compared with SoC with an ICER of CAD 3,366 per QALY gained. An incremental cost of CAD 70.69 resulted in an incremental effectiveness gain of 0.02 QALYs. When including nurse resources, MF resulted in an ICER of CAD 2823 per QALY gained compared to SoC. One-way sensitivity analysis showed that the results were most sensitive to the quality of life utility value for RD, variation of grade 2 or higher RD rate without MF use, and quality of life utility value without RD in order. All sensitivity variations remained well below the WTP threshold of CAD 50,000 per QALY gained. Conclusion: MF is a cost-effective intervention for preventing high-grade RD in breast cancer patients undergoing adjuvant RT and it should be recommended for breast cancer patients at high risk of RD in the context of the Canadian healthcare system.

Keywords: Breast cancer, Radiation dermatitis, Mepitel film

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Digital Poster Impact of molecular profile in breast cancer on locoregional recurrence-free survival: comparison of conventional vs. hypofractionated radiotherapy Gerardo Cuamani Mitznahuatl 1 , Miguel Ángel Souto del Bosque 1 , Cindy Sharon Ortiz Arce 2 , Catalina Tenorio 3 , Dolores De la Mata 3 1 Radiotherapy Clinical Department, Unidad Medica de Alta Especialidad No. 25; Instituto Mexicano del Seguro Social, Monterrey, Nuevo León, Mexico. 2 Clinical Research Department, Unidad Medica de Alta Especialidad No. 25;