SGRT and OSMS assisted DIBH reduces heart and LAD doses in left-sided breast radiotherapySurface Guided Radiotherapy May Lower Heart Dose in Breast Cancer

BackgroundDeep-inspiration breath-hold (DIBH) reduces cardiac and pulmonary radiation exposure during radiotherapy for left-sided breast cancer. Surface-guided radiotherapy (SGRT) and optical surface monitoring systems (OSMS) can support patient positioning and breath-hold monitoring, but evidence specific to SGRT/OSMS-assisted DIBH workflows remains fragmented.MethodsPubMed, Web of Science, Embase, and Cochrane CENTRAL were searched from inception to May 21, 2026. Studies using SGRT/OSMS-assisted DIBH and reporting extractable dosimetric or image-verified setup outcomes were eligible. Effects were expressed as mean differences (MDs) with 95% confidence intervals (CIs); dosimetric MDs were defined as SGRT/OSMS-assisted DIBH minus FB, with negative values indicating lower doses. Random-effects meta-analyses were used for dosimetric and comparative setup outcomes, whereas single-arm setup data were pooled separately.ResultsA total of 52 studies were included. Compared with free breathing (FB), SGRT/OSMS-assisted DIBH was associated with lower mean heart dose (MD = -1.21 Gy, 95% CI -1.48 to -0.93), mean left anterior descending coronary artery (LAD) dose (MD = -7.05 Gy, 95% CI -9.39 to -4.71), ipsilateral (left) lung mean dose (MD = -0.88 Gy, 95% CI -1.34 to -0.42), and ipsilateral lung V20 (MD = -2.30 percentage points, 95% CI -3.27 to -1.32). Comparative meta-analyses found no statistically significant pooled between-group differences in image-verified 3D-vector, left-right/lateral (LR/LAT), superior-inferior/longitudinal/craniocaudal (SI/LNG/CC), or anterior-posterior/vertical (AP/VRT) residual setup errors; this finding does not establish equivalence or non-inferiority. Sensitivity analyses generally supported the main conclusions, although the magnitude of the ipsilateral lung V20 effect was sensitive to the statistical model.ConclusionsSGRT/OSMS-assisted DIBH was associated with lower cardiac, LAD, and ipsilateral lung doses in left-sided breast radiotherapy. Comparative setup analyses found no statistically significant pooled differences from the comparator workflows reported in the primary studies; this does not establish equivalence or non-inferiority. Current evidence supports SGRT/OSMS for external positioning, real-time DIBH monitoring, and quality assurance, while appropriate internal image verification should be retained according to target complexity, the SGRT system, and the local quality assurance program.Systematic review registrationhttps://www.crd.york.ac.uk/PROSPERO/view/CRD420261439818, identifier CRD420261439818.