Brand DH, Tree AC, Ostler P, et al. - In PACE-B, researchers compared standard-of-care conventionally fractionated or moderately hypofractionated radiotherapy with five-fraction stereotactic body radiotherapy in terms of associated acute toxicities, when administered to treat low-risk to intermediate-risk localised prostate cancer. Participants were recruited from 37 centres in three countries (UK, Ireland, and Canada) and were randomly assigned (1:1) to conventionally fractionated or moderately hypofractionated radiotherapy (78 Gy in 39 fractions over 7·8 weeks or 62 Gy in 20 fractions over 4 weeks, respectively) or stereotactic body radiotherapy (36·25 Gy in five fractions over 1–2 weeks). Ultrahypofractionation was associated with higher patient-reported toxicity in previous evidence (from the HYPO-RT-PC trial) but findings of this investigation revealed no increase in either gastrointestinal or genitourinary acute toxicity in correlation with substantially shortening treatment courses with stereotactic body radiotherapy.