Comparative Study of Heart and Lung Doses in Left-Sided Breast Cancer Radiotherapy with and Without Active Breath Control (ABC)

Abstract Background: In left-sided breast cancer radiotherapy, minimizing cardiac and pulmonary exposure is crucial to reducing long-term treatment-related complications. Active Breath Control (ABC) has been proposed as an effective technique to achieve this reduction. Objective: To compare the heart and lung radiation doses in patients undergoing left-sided breast cancer radiotherapy with and without the use of Active Breath Control (ABC). Methods: A comparative study was conducted on 30 patients with left-sided breast cancer. Statistical analysis was performed using SPSS version 20.0. Descriptive data were summarized as frequency, percentage, mean, and standard deviation. Paired t-tests were used to compare dosimetric parameters between treatment plans with and without ABC, with a p-value <0.05 considered statistically significant. Results: The mean age of the patients was 48.4 ± 10.04 years. Most patients (60%) were aged between 34–53 years. With ABC, 90% of patients had a Planning Target Volume (PTV) margin of 5 mm, while without ABC, all patients had a PTV margin of 7 mm. The mean heart volume was significantly reduced with ABC (11.07 ± 4.44) compared to without ABC (12.82 ± 4.68; p < 0.001). Similarly, the left lung volume was significantly lower with ABC (22.78 ± 3.05) compared to without ABC (26.81 ± 3.83; p < 0.001). For the right lung, a statistically significant reduction was also observed (0.00 ± 0.00 with ABC vs. 0.30 ± 0.65 without ABC; p = 0.017). Conclusion: The use of Active Breath Control in left-sided breast cancer radiotherapy significantly reduces heart and lung doses. Incorporating ABC in treatment protocols may potentially lower the risk of radiation-induced cardiopulmonary toxicity, thereby improving patient outcomes.