Effectiveness of Continuous Positive Airway Pressure (CPAP) for Heart Sparing during Left-Sided Breast Radiotherapy
Abstract
Purpose
Adjuvant radiotherapy following breast-conserving surgery or mastectomy reduces recurrence and improves survival of breast cancer patients. Left-sided breast radiotherapy, however, increases the risk of radiation-induced heart toxicity due to the proximity of the heart to the target region. Continuous positive airway pressure (CPAP), a positive airway pressure ventilator, maintains the airways continuously open and subsequently inflates the thorax, thereby distancing heart away from the chest wall, potentially affecting the radiation dose to the heart during left-sided breast radiotherapy. Here, the available evidence investigating the efficacy of CPAP in heart sparing, considering both dosimetric and geometric factors, were evaluated.
Methods
In accordance with the PRISMA guideline, a systematic literature search was conducted in PubMed database up to November 15, 2025. From the identified original articles, information regarding dosimetric and geometric aspects was extracted.
Results
A total of 7 studies involving 414 patients were included. Overall, patients well tolerated CPAP. Under CPAP breathing, the heart was displaced caudally, significantly increasing the shortest distance between the target and heart (approximately 6 mm). Compared with free-breathing radiotherapy (FB-RT), CPAP-assisted breathing radiotherapy (CPAP-RT) significantly reduced mean radiation dose to the heart (up to 61%) and left anterior descending (LAD) artery (up to 78%), especially in patients with internal mammary nodal irradiation. Compared with FB-RRT, CPAP-RT did not significantly extend patient setup time. CPAP-RT enhanced treatment precision with increasing inter-/intra-fraction heart position reproducibility.
Conclusion
CPAP-RT can provide a practical, effective, and reproducible method for heart sparing during left-sided breast radiotherapy, especially in resource-limited radiotherapy clinics.