- Design
- phase 3, international, open-label randomised clinical trial, 1:1 allocation, 136 centres
- Population
- 698 men with localised intermediate-risk prostate cancer (T1-T2b, grade group 1 or 2); median age 68
- Primary outcome
- clinically important decline in urinary irritative and bowel domains at 2 years, and disease-free survival at 3 years
- Effect
- bowel decline 34.9% vs 43.8% (P = .03); grade 3-4 genitourinary events 0.6% vs 2.5% (P = .04); 3-year disease-free survival 88.6% vs 92.1%
NRG-GU005 randomised 698 men with localised intermediate-risk prostate cancer — clinical stage T1-T2b, grade group 1 or 2 with defined prostate-specific antigen limits — at 136 centres across four continents, to stereotactic body radiotherapy at 36.25 Gy in five fractions or moderately hypofractionated intensity-modulated radiotherapy at 70 Gy in 28 or 60 Gy in 20. Median follow-up was 3.2 years. The trial was designed to test whether the shorter course was superior on both patient-reported outcomes and disease-free survival.
On toxicity the shorter course did better, though not on the endpoint that was the headline concern. The urinary irritative and obstructive domain did not differ at two years (35.4% against 33.7% with a clinically important decline, P = .68). But bowel decline was less common with stereotactic treatment (34.9% against 43.8%, P = .03), grade 3 or 4 genitourinary adverse events were fewer (0.6% against 2.5%, P = .04), and continence at one and two years and sexual function at one year both favoured it.
Disease control went the other way. Three-year disease-free survival was 88.6% (95% CI 85.2-92.1) with stereotactic radiotherapy and 92.1% (88.9-95.2) with the longer course. The trial's own conclusion is that stereotactic treatment was not superior; the authors also note prostate-specific antigen failure was not improved.
So the counselling conversation changes shape rather than acquiring an answer. A man choosing five visits over 20 to 28 is buying a real and measurable gain in bowel function, continence and severe genitourinary toxicity, against a disease-free survival figure that at three years favours the longer course by about three and a half percentage points. That trade is legitimate to offer and should be offered explicitly — particularly in India, where 20 to 28 daily visits to a radiotherapy centre is often the binding constraint on whether a man completes treatment at all.
- Present the trade explicitly: fewer bowel and continence problems with five fractions, against a three-year disease-free survival difference favouring the longer course
- Quote three-year disease-free survival as 88.6% against 92.1% rather than describing the difference qualitatively
- Note that the urinary irritative and obstructive outcome — the main toxicity concern — did not differ between schedules
- Weigh travel and completion: in settings where daily attendance is difficult, a five-fraction course a man finishes may be the better option
- Do not describe stereotactic treatment as equivalent; this trial tested superiority and the disease-free survival result did not favour it
Why it matters
The assumption has been that a shorter course costs nothing in disease control, and at three years this trial does not support that.
Don't overread it
Median follow-up of 3.2 years is short for prostate cancer, and this trial tested superiority — it does not establish that the two schedules are equivalent.
The statistics, in plain English
Disease-free survival intervals overlap (85.2-92.1 against 88.9-95.2), but the trial was designed to test whether stereotactic treatment was superior and it was not; a one-sided test was used, which answers only that question and not whether the longer course is better. Follow-up of 3.2 years is short for prostate cancer, where differences in disease control typically widen over a decade, so this gap could grow or close. The quality-of-life outcomes are patient-reported on a validated instrument, which is the right measure, but the trial was open-label, so men knew which schedule they had received.
Read the rest in the app
You have read your two free briefings this month. The app carries all 27 specialties, every morning, free — and this finding is waiting in it.
Scan to keep reading on your phone. No account needed to start.
Tomorrow morning, before your first patient
One edition a day for urology, written by the desk, every claim tied to its paper. Six minutes.
Get the app — free