Comment on "Is rectal preparation necessary in contemporary image-guided prostate radiotherapy?".

This correspondence comments on the study by Alexander et al. evaluating whether routine rectal preparation is necessary during contemporary image-guided prostate radiotherapy. Although the reported motion differences were clinically small and support reducing burdensome preparation, interpretation is limited by structural differences between treatment schedules, non-equivalent definitions of patient motion, possible clustering of repeated fraction-level measurements, and differing planning rescan thresholds. Enema use was associated with radiotherapy prescription, making direct comparison between preparation groups difficult. Analyses using patient-level summaries or mixed-effects models, adjustment for treatment and anatomical factors, and schedule-normalized outcomes would provide more reliable estimates. The findings are therefore best viewed as supporting risk-adapted deimplementation rather than universal omission of rectal preparation. Prospective regimen-balanced studies incorporating geometric accuracy, delivered dose, toxicity, patient burden, and resource use are needed to determine which patients can safely avoid routine enemas.