Pract Radiat Oncol. 2025 Apr 29:S1879-8500(25)00108-0. doi: 10.1016/j.prro.2025.03.014. Online ahead of print.
ABSTRACT
PURPOSE: Regional nodal irradiation (RNI) is increasingly utilized in place of axillary lymph node dissection (ALND) in carefully selected breast cancer patients. While hypofractioned whole breast irradiation is standard for node-negative disease, long-term data on hypofractionated regional nodal irradiation (HF-RNI) are limited. This study aims to assess the long-term safety and effectiveness of HF-RNI for breast cancer patients.
METHODS: This retrospective analysis included 154 patients with node-positive or high-risk node-negative breast cancer treated with HF-RNI (>2Gy/fraction) between 2008-2020. Median dose was 40 Gy/16 fractions to the breast, chest wall, or reconstructed breast as well as regional nodes. The primary endpoint was the incidence of chronic toxicity. Secondary endpoints were acute toxicity, local recurrence-free survival (LRFS), regional recurrence-free survival (RRFS), disease-free survival (DFS), and overall survival (OS). Acute toxicities were defined as those occurring during radiation therapy or within 90 days post-treatment; chronic toxicities were defined as those persisting or arising at least 180 days after radiation completion.
RESULTS: Median follow-up was 65.4 months (range, 4-170 months). Median age was 58 years (interquartile range, 48.3-71.0). Sentinel lymph node biopsy was performed in 49.4% of patients, 47.4% underwent ALND, and 3.2% had no axillary surgery. RNI targets included supraclavicular and axillary Level 1-3 nodes in 65.6% of patients, while 34.4% were treated only to the supraclavicular and Level 3 nodes. There were 7 (4.7%) patients that had IMNs treated. Chronic brachial plexopathy occurred in 2.0% of patients, limited range of motion (LROM) in 1.3%, and upper-extremity lymphedema in 10.5%. Late cardiac and lung toxicity rates were low at 0.7% and 3.3%, respectively. Five-year actuarial rates of LRFS, RRFS, DFS, and OS were 98.0%, 99.3%, 90.1%, and 88.1%, respectively.
CONCLUSIONS: HF-RNI demonstrates low rates of chronic toxicity and excellent disease control, supporting wider adoption in clinical practice. Long-term results of randomized trials of HF-RNI are needed for definitive evidence.
PMID:40311918 | DOI:10.1016/j.prro.2025.03.014