Comparative assessment of skin toxicity in prone vs supine positions during preoperative breast radiotherapy: A systematic review and meta-analysis.

Abstract

e24148 Background: Skin toxicity remains one of the most common side effects of breast radiotherapy and can meaningfully affect patient comfort and treatment tolerance. Prone positioning has been proposed as a way to reduce skin dose, but results across studies have been inconsistent. We conducted a systematic review and meta-analysis to better define how patient positioning influences acute and late skin toxicity during preoperative whole-breast radiotherapy. Methods: We searched PubMed, Embase, and Scopus for studies comparing prone and supine positioning during preoperative whole-breast radiotherapy. Nine studies met inclusion criteria after screening 132 records. Outcomes of interest included moist desquamation, acute skin toxicity by grade, pain, and fibrosis. Pooled risk ratios (RRs) with 95% confidence intervals (CI) were calculated using random-effects models, and heterogeneity was assessed with I² statistics. Results: Across three studies including 834 patients, prone positioning was associated with a significantly lower risk of moist desquamation compared with supine treatment (RR:0.48, CI:0.26–0.88; p=0.02), with moderate heterogeneity (I²=49%). Although the magnitude of benefit varied, the overall direction of effect consistently favored prone positioning. For more severe acute skin reactions (Grade ≥ 2 dermatitis or erythema), prone positioning showed a trend towards benefit, but results were mixed and did not reach statistical significance. Patients treated prone also experienced slightly less acute pain, with a borderline significant reduction in Grade ≥1 pain and highly consistent findings across studies. For higher-grade erythema or dermatitis, no statistically significant differences were observed between positions, although absolute event rates were generally higher in the supine group. In contrast, prone positioning showed a tendency toward more mild (Grade 1) erythema, suggesting that toxicity may shift toward lower severity rather than being eliminated altogether. Analyses combining broader toxicity categories showed no clear differences, but interpretation was limited by heterogeneity. Importantly, late toxicity outcomes were reassuring. Across three studies, the risk of fibrosis was similar between prone and supine positioning, with highly consistent findings. Conclusions: Prone positioning during preoperative breast radiotherapy is associated with fewer clinically significant skin reactions, particularly moist desquamation, and may reduce treatment-related pain without increasing late toxicity. While mild skin changes may be more common, overall toxicity severity appears lower. These findings support the selective use of prone positioning to improve patient comfort and skin tolerance during breast radiotherapy.