{"entity":{"id":"pace-b","kind":"trial","name":"PACE-B","aka":[],"tldr":"PACE-B showed that five stereotactic treatments control low- and intermediate-risk prostate cancer as well as four to eight weeks of conventional radiotherapy, with similar side effects at five years.","summary":"PACE-B randomised 874 men to stereotactic body radiotherapy (36.25 Gy in five fractions over one to two weeks) or conventional radiotherapy (78 Gy in 39 or 62 Gy in 20 fractions), without hormone therapy. Five-year freedom from biochemical or clinical failure was 95.8 percent with SBRT and 94.6 percent with conventional treatment, meeting non-inferiority; genitourinary toxicity of grade 2 or worse was somewhat higher after SBRT (van As and colleagues, New England Journal of Medicine 2024). Five-fraction treatment is now a standard option.","status":"positive","asOf":"2026-09-16","links":[{"label":"ClinicalTrials.gov NCT01584258","url":"https://clinicaltrials.gov/study/NCT01584258"},{"label":"NEJM 2024","url":"https://doi.org/10.1056/NEJMoa2403365"},{"label":"PACE-B (New England Journal of Medicine 2024)","url":"https://doi.org/10.1056/NEJMoa2403365"},{"label":"PACE-B 5-year patient-reported outcomes (European Urology 2026)","url":"https://doi.org/10.1016/j.eururo.2026.05.034"},{"label":"PACE-B late urinary toxicity factors (European Urology 2026)","url":"https://doi.org/10.1016/j.eururo.2025.07.007"}],"tags":["radiation-wave2"],"related":[],"cancers":["prostate","prostate-low-risk","prostate-intermediate-risk"],"sections":[],"technologies":["sbrt","hypofractionated-radiotherapy"],"targets":[],"drugs":[],"companies":[],"institutions":["royal-marsden","icr-london"],"pathways":[],"terms":["prostate-radiotherapy-fractionation","prostate-treatment-choice-localised"],"trials":["hypo-rt-pc","chhip","partiqol"],"people":["nicholas-van-as"],"bottlenecks":[],"keyPapers":["paper-van-as-n-engl-j-med","paper-pace-b-lancet-oncol-2019","paper-pace-b-lancet-oncol-2022-update"],"journals":[],"dependsOn":[],"notes":["PACE-B enrolled men with stage T1 or T2 prostate cancer, a Gleason score of 3+4 or less and a PSA of no more than 20 ng/mL. Androgen deprivation was not permitted. Median age was 69.8 years, median PSA 8.0 ng/mL, and the NCCN risk category was low for 8.4 percent and intermediate for 91.6 percent. Median follow-up was 74.0 months (New England Journal of Medicine 2024).","The 5-year patient-reported outcomes, presented as waffle charts so they can be compared with surgical series, are the figures to quote to a man choosing between radiotherapy and an operation. Leak-free rates were 64 percent (164 of 258) after stereotactic body radiotherapy and 69 percent (172 of 249) after conventional radiotherapy; pad-free rates 91 percent (233 of 257) and 90 percent (225 of 250); moderate or big urinary leakage problems 6 percent (15 of 250) and 4 percent (9 of 244). Erections adequate for intercourse fell from 35 percent (133 of 374) to 17 percent (43 of 250) after stereotactic radiotherapy and from 40 percent (157 of 391) to 20 percent (47 of 240) after conventional radiotherapy. Moderate or big bowel problems rose from 2 percent at baseline to 5 percent in both arms (European Urology 2026).","A separate PACE-B analysis of 390 men with dose-volume histogram data found grade 2 or higher urinary toxicity at 2 years in 12 percent (44 of 357 with data), associated with higher baseline International Prostate Symptom Score (odds ratio 1.11 per point, 95 percent confidence interval 1.05 to 1.18, p=0.001), baseline urinary medication use (2.32, 1.09 to 4.95, p=0.03) and grade 2 or higher acute urinary toxicity (3.15, 1.35 to 7.37, p=0.008). No association was seen with dose to urinary substructures. The authors recommend counselling men with worse baseline urinary symptoms about their elevated risk and considering moderate hypofractionation for them (European Urology 2026)."],"nct":"NCT01584258","phase":"3","setting":"Low- and intermediate-risk prostate cancer: stereotactic body radiotherapy in five fractions versus conventional or moderately hypofractionated radiotherapy","sponsor":"Royal Marsden NHS Foundation Trust","result":"5-year biochemical or clinical failure-free 95.8% (SBRT) vs 94.6% (conventional), non-inferior.","started":"2012-08-07","startedType":"actual","yearReported":2024,"enrolled":874,"enrolledBasis":"randomised","enrolledNote":"874 men underwent randomisation at 38 centres between August 2012 and January 2018, 433 to stereotactic body radiotherapy and 441 to control radiotherapy.","outcomes":[{"endpoint":"Freedom from biochemical or clinical failure at 5 years","primary":true,"unit":"%","arms":[{"name":"SBRT 36.25 Gy in 5","n":433,"value":95.8},{"name":"Conventional radiotherapy","n":441,"value":94.6}]},{"endpoint":"Freedom from biochemical or clinical failure at 5 years","primary":true,"unit":"%","arms":[{"name":"Stereotactic body radiotherapy, 36.25 Gy in 5 fractions","n":433,"value":95.8,"note":"Confidence interval is 90 percent, as prespecified; critical hazard ratio for non-inferiority 1.45."},{"name":"Control radiotherapy, 78 Gy in 39 or 62 Gy in 20 fractions","n":441,"value":94.6}],"hr":0.73,"ci":[0.48,1.12],"p":"0.004 for non-inferiority","source":"https://doi.org/10.1056/NEJMoa2403365"},{"endpoint":"Late RTOG grade 2 or higher genitourinary toxicity at 5 years","unit":"%","arms":[{"name":"Stereotactic body radiotherapy","n":433,"value":26.9},{"name":"Control radiotherapy","n":441,"value":18.3}],"p":"<0.001","source":"https://doi.org/10.1056/NEJMoa2403365"},{"endpoint":"Late RTOG grade 2 or higher gastrointestinal toxicity at 5 years","unit":"%","arms":[{"name":"Stereotactic body radiotherapy","n":433,"value":10.7},{"name":"Control radiotherapy","n":441,"value":10.2}],"p":"0.94","source":"https://doi.org/10.1056/NEJMoa2403365"}],"replication":"HYPO-RT-PC found seven-fraction ultra-hypofractionation non-inferior in 1,180 men, with the same pattern of worse acute and similar late toxicity."},"route":"/trials/pace-b/","neighbours":{"cancer":[{"id":"prostate-intermediate-risk","kind":"cancer","name":"Localised prostate cancer, intermediate risk","route":"/cancers/prostate-intermediate-risk/"},{"id":"prostate-low-risk","kind":"cancer","name":"Localised prostate cancer, very low and low risk","route":"/cancers/prostate-low-risk/"},{"id":"prostate","kind":"cancer","name":"Prostate cancer","route":"/cancers/prostate/"}],"technology":[{"id":"hypofractionated-radiotherapy","kind":"technology","name":"Hypofractionated radiotherapy","route":"/technologies/hypofractionated-radiotherapy/"},{"id":"sbrt","kind":"technology","name":"SBRT / SABR (stereotactic radiotherapy)","route":"/technologies/sbrt/"}],"institution":[{"id":"icr-london","kind":"institution","name":"The Institute of Cancer Research","route":"/institutions/icr-london/"},{"id":"royal-marsden","kind":"institution","name":"The Royal Marsden","route":"/institutions/royal-marsden/"}],"term":[{"id":"prostate-treatment-choice-localised","kind":"term","name":"Choosing treatment for localised prostate cancer: what each option costs","route":"/terms/prostate-treatment-choice-localised/"},{"id":"prostate-radiotherapy-fractionation","kind":"term","name":"How many radiotherapy visits: the prostate fractionation trials","route":"/terms/prostate-radiotherapy-fractionation/"},{"id":"non-inferiority-margin","kind":"term","name":"Non-inferiority margin and equivalence trials","route":"/terms/non-inferiority-margin/"},{"id":"non-inferiority","kind":"term","name":"Non-inferiority trial","route":"/terms/non-inferiority/"}],"trial":[{"id":"chhip","kind":"trial","name":"CHHiP","route":"/trials/chhip/"},{"id":"hypo-rt-pc","kind":"trial","name":"HYPO-RT-PC","route":"/trials/hypo-rt-pc/"},{"id":"partiqol","kind":"trial","name":"PARTIQoL","route":"/trials/partiqol/"},{"id":"protect","kind":"trial","name":"ProtecT","route":"/trials/protect/"},{"id":"rtog-0415","kind":"trial","name":"RTOG 0415","route":"/trials/rtog-0415/"}],"person":[{"id":"nicholas-van-as","kind":"person","name":"Nicholas van As","route":"/people/nicholas-van-as/"}],"paper":[{"id":"paper-pace-b-lancet-oncol-2019","kind":"paper","name":"Intensity-modulated fractionated radiotherapy versus stereotactic body radiotherapy for prostate cancer (PACE-B): acute toxicity findings from an international, randomised, open-label, phase 3, non-inferiority trial","route":"/key-papers/paper-pace-b-lancet-oncol-2019/"},{"id":"paper-pace-b-lancet-oncol-2022-update","kind":"paper","name":"Intensity-modulated radiotherapy versus stereotactic body radiotherapy for prostate cancer (PACE-B): 2-year toxicity results from an open-label, randomised, phase 3, non-inferiority trial","route":"/key-papers/paper-pace-b-lancet-oncol-2022-update/"},{"id":"paper-van-as-n-engl-j-med","kind":"paper","name":"Phase 3 Trial of Stereotactic Body Radiotherapy in Localized Prostate Cancer","route":"/key-papers/paper-van-as-n-engl-j-med/"}]}}