Ultra-hypofractionated one-week locoregional radiotherapy for patients with early breast cancer: Acute toxicity results

• DOI: 10.1016/j.ctro.2024.100764
• Publication Date: 2024-03-13T17:45:22Z
• Authors: Ivica Ratosa; Angel Montero; Raquel Ciervide; Beatriz Alvarez; Mariola García-Ar...; Jeannette Valero; Xin Chen-Zhao; Mercedes Lopez; Daniel Zucca; Ovidio Hernando; Emilio Sánchez; Miguel Angel de l...; Rosa Alonso; Pedro Fernandez-L...; Carmen Rubio
• Keywords: Medical physics. Medical radiology. Nuclear medicine; 03 medical and health sciences; Ultra-hypofractionation; 0302 clinical medicine; Breast/chest wall radiotherapy; R895-920; Neoplasms. Tumors. Oncology. Including cancer and carcinogens; Regional node irradiation; Original Research Article; RC254-282

Moderate hypofractionated radiotherapy is the standard of care for all patients with breast cancer, irrespective of stage or prior treatments. While extreme hypofractionation is accepted for early-stage tumours, its application in irradiating locoregional lymph nodes remains controversial.A prospective registry analysis from July 2020 to September 2023 included 276 patients with early-stage breast cancer treated with one-week ultra-hypofractionation (UHF) at 26 Gy in 5 fractions on the whole breast (58.3 %) or thoracic wall (41.7 %) and ipsilateral regional lymph nodes and simultaneous integrated boost (58.3 %). Primary endpoint was assessment of acute adverse events (AEs). Secondarily, onset of early-delayed toxicity was assessed. A minimum 6-month follow-up was required for assessing potential treatment-related early-delayed complications. Acute or late complications attributable to treatment were assessed at inclusion using the Common Terminology Criteria for Adverse Events (CTCAE) v5.0 criteria.With a median follow-up of 19 months (range 1-49 months), 159 (57.6 %) patients reported AEs, predominantly grade (G) 1 (n = 139, 50.4 %) and G2 (n = 20, 7.8 %). Skin acute toxicity was common (G1/2: 134, G3: 14), while breast oedema occurred in 10 patients (G1: 9, G2: 1), and 15.9 % reported breast pain (G1: 42, G2: 2). Ipsilateral arm oedema was observed in 1.8 % patients. For patients with a follow-up beyond 6 months (n = 213), 23.4 % patients reported G1/G2 skin AEs, 8.8 % had G1/G2 breast/chest wall oedema, and 8.9 % experienced arm lymphedema. There were no cases of brachial plexopathy or G3 toxicity in this group of patients.One-week UHF adjuvant locoregional radiation is well-tolerated, displaying low-toxicity profiles comparable to other studies using similar irradiation schedules.