A randomised clinical feasibility trial of a breast immobilisation device: the SuPPORT 4 All (S4A) bra.

Background Despite the breast being a mobile organ there is currently no standard suitable immobilisation device to optimise radiotherapy for women treated after a wide local excision with larger breasts. The SuPPORT 4 All bra (or S4A bra) was co-designed with patients and radiotherapy professionals. The purpose of this study was to test the feasibility of using the S4A bra in the existing breast cancer radiotherapy pathway. Method A randomised feasibility trial was conducted in a single institution; primary feasibility endpoint was recruitment of 50 participants. Efficacy endpoints were also tested including assessment of skin reactions, dose to organs at risk, and patient comfort. Fifty women were randomised to receive either standard radiotherapy with no immobilisation (control) or radiotherapy with the S4A bra (intervention). A separate planning study was undertaken on the cases randomised to receive the S4A bra. Participants in the intervention arm (S4A bra) underwent two planning CT scans, one with the bra on and one without the bra; allowing direct comparison of organs at risk data for S4A bra vs no bra. Results All women that started radiotherapy wearing the S4A bra completed treatment with the bra, and patient comfort did not change across the three weeks of treatment. Positional accuracy using the bra was comparable with existing published accuracy for methods without immobilisation. Mean ipsilateral lung doses showed some improvement when positioning with the S4A bra is compared with the no bra set-up (3.72Gy vs 4.85Gy for right sided cases, 3.23Gy vs 3.62Gy for left sided cases respectively). Conclusions The S4A bra is feasible to use in the radiotherapy pathway with good patient adherence. The S4A bra has potential to reduce dose to organs at risk (specifically ipsilateral lung dose) while maintaining good breast tissue coverage, and improved patient dignity, warranting further investigation on a larger scale.