Highlight
– In a pooled secondary analysis of 3 randomized trials (NRG/RTOG 0129, 0522, 1016), radiotherapy (RT) interruptions were common (28% of patients) and, when quantified by duration, were associated with clinically meaningful increases in locoregional failure (LRF) and worse overall survival (OS).
– Each additional 7 days of RT interruption corresponded to a hazard ratio of ~1.45 for LRF and ~1.41 for OS; absolute 3‑year LRF increases were larger for p16‑negative or non‑oropharyngeal cancers and for advanced T/N stage.
