The Chine phase 3 CHN HYPOPMRT trial comparing 43.5 Gy/15 versus 50 Gy/25 3D-conformal postmastectomy radiation to flat chest walls now has >11-year median follow-up. Ten-year locoregional recurrence was 12% vs 10%, with no significant difference in disease-free or overall survival. Grade 1–2 pulmonary fibrosis was higher with hypofractionation (20% vs 12%), but there were no grade 4–5 events including brachial plexopathies. | Sun, ASTRO 2026
