Prostate cancer · Radiotherapy
Pre-treatment risk of nodal or distant spread in prostate cancer, and whether to include the pelvis in radiotherapy.
See the studyThe study
The decision to include the pelvis still rests on the Roach formula, which uses only PSA and Gleason score and overestimates risk in contemporary patients. PREDICT uses the full biopsy report and estimates the risk that an adequate lymph node dissection would find.
Proportion of patients with positive nodes in each band of PREDICT risk.
Bars: observed proportion; lines: 95% CI. With dissections of 15 or more nodes, the SEER values were 4.0%, 10.2%, 14.2% and 42.8%.
Per 100 operated SEER patients: who would receive pelvic irradiation under each criterion.
The PREDICT threshold that covers the same proportion of node-positive patients as the POP-RT criterion is 15.3%: 7.0 fewer pelvic fields per 100 patients (95% CI, 4.9 to 8.4).
Reference: pathologic nodal status in 17,164 operated patients without distant metastases. Cross-validated estimates.
AUC for pathologic nodal involvement (95% CI).
PREDICT was applied without refitting or imputation, using the variables recorded in each cohort. Summary: random-effects meta-analysis (I², 0%).
73,203 patients with histologically confirmed prostate adenocarcinoma diagnosed between 2018 and 2022 (SEER, 8 registries); 17,164 operated with lymph node dissection.
Age, PSA, primary and secondary Gleason patterns, positive and examined cores, and clinical T stage. Missing variables are not imputed.
Gradient boosting with monotonic constraints. A single value: the risk of distant metastasis plus the nodal risk — referenced to a 15-node dissection — in patients without them.
Rochester, Seoul, MSKCC and San Raffaele: 1,923 operated patients, 106 node-positive. Compared with the Roach formula at the RTOG 94-13 and POP-RT thresholds.
PREDICT provides a calibrated estimate of dissemination risk from routine variables, transports to external populations and selects patients for pelvic irradiation better than the Roach formula. We recommend its clinical use with a 15% threshold, adjustable to each population.
