The Absolute Effect / Evidence / RTOG 0534 SPPORT
Prostate Cancer · Radiation Oncology · Post-prostatectomy Biochemical Recurrence

RTOG 0534 SPPORT

Clinical question

Does adding short-term ADT and pelvic nodal RT improve freedom from progression after prostatectomy salvage RT?

Trial context
Population
1,716 eligible men with PSA persistence or biochemical recurrence after prostatectomy
Intervention
Prostate-bed RT + short-term ADT + pelvic nodal RT vs prostate-bed RT alone
Key endpoint
5-year freedom from progression
Time horizon / follow-up
5 years
Absolute Effect

What changes for patients?

At 5 years, freedom from progression was 87.4% with prostate-bed RT plus short-term ADT and pelvic nodal RT versus 70.9% with prostate-bed RT alone, an absolute improvement of 16.5 percentage points (NNT 7). Adding ADT to prostate-bed RT alone produced an intermediate 81.3% rate. Acute grade 2+ toxicity was 44.6% vs 19.7% with pelvic nodal treatment, so the benefit comes with greater short-term toxicity.

NNT: 7

Treatment burden / harm

Acute grade 2+ adverse events

NNH: 5

Relative effect

HR: 0.50 for pelvic nodal RT + ADT vs prostate-bed RT alone

97.5% CI 0.39–0.64

Clinical interpretation

SPPORT supports improved freedom from progression by adding short-term ADT to salvage RT and further improving control with pelvic nodal RT in selected patients.

Primary publication

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Current-practice context · reviewed 14 October 2026

SPPORT supports adding short-term ADT to salvage prostate-bed RT and, for appropriate higher-risk patients, adding pelvic nodal RT to improve freedom from progression after prostatectomy. Field and hormonal intensity should be tailored to PSA, nodal risk, pathology, imaging and comorbidity; the endpoint is progression control, not proof that every patient requires pelvic nodal RT or long-term ADT.

RTOG 0534 SPPORT primary/registry source ↗ · Current guideline guidance ↗