Patterns of failure and arm disability following postmastectomy hypofractionated chest wall radiotherapy in resource-constrained tertiary care practice setting: A mono-institutional experience

Introduction: Radiotherapy for breast cancer has evolved over the years in terms of technique and dose fractionation. Hypofractionation for whole-breast radiotherapy has equivalent local control and toxicity profile compared to standard fractionation; however, evidence of the same for post modified radical mastectomy chest wall irradiation is scarce in terms of local control and complications. We undertook this study to determine whether hypofractionated (HF) chest wall irradiation gives comparable outcomes to standard fractionation in terms of locoregional control and late effects like arm and shoulder disability in resource-constrained setup. Materials and Methods: Breast cancer patients presenting at the outpatient department (OPD) from March to December 2015 who underwent postmastectomy chest wall irradiation were taken for the study. Radiotherapy was delivered by clinical planning using THERATRON 780c with cobalt 60, with tangential fields for chest wall and single anterior field for axilla and supraclavicular region. Patients were treated with either conventional fractionation of 50 Gy in 25# or HF to 42.5 Gy in 16 fractionation to both chest wall and regional nodes. Data were analyzed for patient profile, toxicity, and local and distant failure. Late complications in terms of upper limb morbidity was calculated using QuickDASH(short version of disabilities of arm, shoulder and hand questionnaire) score for patients presenting at OPD from June to November 2019 for follow-up. Results: The sample size in the HF and standard arm was 40 and 34, respectively. The hypo# arm had a significantly more number of patients with >3 lymph nodes positive (P = 0.044). The median follow-up of 41 months, the standard and hypo# arm had 6 and 7 failures respectively. The 3-year disease-free survival was 82.4% and 82.5% in the respective arms (P = 0.925). No Grade II or Grade III acute toxicity was noted in both the arms. No Grade II skin or subcutaneous toxicity was noted. The mean QuickDASH score was 5.84 in the standard arm and 6.54 in the HF arm (P = 0.727, Mann–Whitney U test, Nonsignificant). However, the QuickDASH score was found to be significantly more in patients who had a large interfiled distance or who had received axillary radiation. Conclusion: Postmastectomy HF chest wall radiotherapy may be a good alternative to conventional fractionation radiotherapy in terms of locoregional control with no difference in acute toxicity and late complications.