A comparative study of pulmonary toxicity between hypofractionated and conventionally fractionated radiation therapy in postmastectomy carcinoma breast

Abstract

Background: Hypofractionated schedule has multiple advantages over conventional fractionation radiation therapy in terms of logistics and patient compliance. However, pulmonary toxicity is a major concern in breast cancer radiotherapy about which there are limited data comparing these two radiation regimens. Objective: This study aimed at comparing these two radiation schedules in terms of acute pulmonary toxicity and parameters of pulmonary function. Materials and Methods: Postmodified radical mastectomy patients with nonmetastatic carcinoma breast were randomized into two groups: study-arm patients received hypofractionated radiotherapy with 42.5 Gy in 16 fractions, over 3.5 weeks, whereas control-arm patients received conventionally fractionated radiotherapy with 50 Gy in 25 fractions, over 5 weeks. Patients underwent pulmonary function test (PFT) before radiotherapy (baseline), then at one and 3 months after completion of radiotherapy for changes in parameters of PFT and acute toxicities. Results: PFT changes were comparable in both the arms at day 30 and day 90 postradiation. Incidences of cough 1 month after radiotherapy and 3 months after radiotherapy were comparable (P = 0.3 and 0.07). Higher grade dyspnea at 3 months posttreatment, though numerically was higher in the study arm, was not significant (P = 0.44). In study arm at 90 days postradiation, Grade 2 and Grade 3 radiation pneumonitis were numerically more (15% vs. 3% and 3.5% vs. 0%), but not statistically significant (P = 0.08). Conclusion: Both conventional and hypofractionated arms showed almost similar results in terms of acute pulmonary toxicity and change in PFT parameters. Hence, considering the logistic advantages, the hypofractionated schedule can be considered an effective alternative to conventional radiotherapy for postmastectomy breast cancer patients.