onc brain

About · curated by Nick Boehling, MD · @nb2276

    2026-07-26

    digest generated 2026-07-27

    PACE-B: 5yr PROMs near-identical for prostate SBRT vs conventional RT (pad-free 91% vs 90%) — no continence penalty for ultra-hypofractionation.
    TL;DR
    Prostate carried the only data today. PACE-B's 5yr patient-reported outcomes show SBRT and conventionally fractionated RT tracking together across urinary, bowel, and sexual domains, with erectile decline arm-independent rather than SBRT-specific. No between-arm effect sizes reported, but the late-QoL signal supports SBRT as comparable, not worse.

    Prostate

    A 5yr quality-of-life readout on ultra-hypofractionation, benchmarked against robotic-prostatectomy PROMs.

    Confirmatory

    PACE-B

    ForLocalised prostate cancer, definitive external-beam RT (SBRT or conventional)

    TL;DR5yr PROMs comparable for SBRT vs conventional RT: pad-free 91% vs 90%, mod/big urinary leak 6% vs 4%, bowel bother 5% both arms.

    Why it mattersRadiation oncology

    The RT read is tolerability parity at maturity: 5yr urinary, bowel, and sexual PROMs track together for SBRT and conventional fractionation (pad-free 91% vs 90%, mod/big bowel 5% both). Sexual decline is arm-independent, not an SBRT penalty. Removes late toxicity as a reason to prefer the longer schedule.

    9 details 1 trial watching
    Design

    Phase 3 international RCT randomising localised prostate cancer to SBRT vs conventionally fractionated RT; this report is the 5yr patient-reported outcomes secondary analysis, presented as waffle charts for visual alignment with surgical PROMs.

    Radiotherapy

    SBRT and CRT dose/fractionation not reported in the source abstract, so transferability of the exact schedule to a reader's practice cannot be gated from this text.

    Endpoints

    PROMs across urinary (leak-free, pad-free, leakage bother), sexual (intercourse-adequate erections, sexual bother), and bowel (bother, stool incontinence) domains, baseline to 5yr.

    Results

    Urinary continence favourable and comparable; erectile function declined similarly in both arms; bowel effects low in both. See domain tables for proportions.

    5yr outcomeSBRTCRT
    Leak-free64% (164/258)69% (172/249)
    Pad-free91% (233/257)90% (225/250)
    Mod/big urinary leak bother6% (15/250)4% (9/244)
    Sexual PROMSBRT (baseline→5yr)CRT (baseline→5yr)
    Intercourse-adequate erections35% (133/374) → 17% (43/250)40% (157/391) → 20% (47/240)
    Mod/big sexual bother24% (87/367) → 31% (74/242)22% (85/382) → 32% (77/238)
    Bowel PROMSBRT (baseline→5yr)CRT (baseline→5yr)
    Mod/big bowel bother2% (7/397) → 5% (12/265)2% (9/415) → 5% (13/253)
    Mod/big stool incontinence<1% (1/374) → 2% (4/240)<1% (1/395) → 3% (7/238)
    Applies to
    men with localised prostate cancer receiving definitive external-beam radiotherapy
    Does not represent brachytherapy, higher-risk or node-positive disease, or an RT-vs-surgery comparison.
    Limitations

    PRO completion counts decline over follow-up, so 5yr estimates carry attrition and responder bias. Waffle-chart format aids cross-modality reading but the trial did not randomise against surgery, so the visual surgery benchmark is informal.

    Rationale

    Prespecified PRO secondary analysis of a phase 3 RCT; descriptive proportions only, no between-arm inferential test. Reinforces recognised prostate SBRT tolerability.

    Monday clinic

    In men with localised prostate cancer choosing a definitive external-beam schedule, mature 5yr PROMs support 5-fraction SBRT as QoL-comparable to conventional fractionation; it does not inform SBRT vs surgery or higher-risk/node-positive disease.

    Open questions

    Sourced from Cooper et al.

    📚 Sources · 📄 1 paper
    📄 PAPER Cooper; Patel; Moore et al. · European urology (2026-07)
    Patient-reported Outcomes After Prostate Stereotactic Body Radiotherapy at 5 yr: Results from the PACE-B Trial.
    PMID 42476886 → doi
    Abstract
    Patient-reported outcome measures (PROMs) complement oncological endpoints by capturing what matters most to patients. The TrueNTH surgical collaboration presented 1-yr PROMs following robotic prostatectomy using accessible visual formats. We present 5-yr PROMs from the phase 3, international PACE-B trial, which randomised men with localised prostate cancer to stereotactic body radiotherapy (SBRT) or conventionally fractionated radiotherapy (CRT). PROMs are reported from baseline to 5&#xa0;yr and presented using waffle charts to enable visual alignment with surgical outcomes. At 5&#xa0;yr, urinary incontinence outcomes were favourable and comparable between SBRT and CRT. Leak-free rates were 64% (164/258) for SBRT and 69% (172/249) for CRT, pad-free rates were 91% (233/257) for SBRT and 90% (225/250) for CRT, and moderate or big urinary leakage problems were reported by only 6% (15/250) for SBRT and 4% (9/244) for CRT. Intercourse-adequate erections declined in both groups from baseline to 5&#xa0;yr: from 35% (133/374) to 17% (43/250) for SBRT, and from 40% (157/391) to 20% (47/240) for CRT. Moderate or big sexual problems increased in both groups, from 24% (87/367) to 31% (74/242) for SBRT and from 22% (85/382) to 32% (77/238) for CRT. Bowel effects were low and comparable between groups, with moderate or big bowel problems reported by 2% (7/397) at baseline and 5% (12/265) for SBRT at 5&#xa0;yr, and 2% (9/415) at baseline and 5% (13/253) for CRT at 5&#xa0;yr. Stool incontinence as a moderate or big problem rose from <1% (1/374) to 2% (4/240) in the SBRT group and from <1% (1/395) to 3% (7/238) in the CRT group.

    Radiation Curative Phase 3 RCT Confirmatory