Table 4.

Predictor importance and relative importance in the RSF^a model.

Predictor	Importance	Relative importance
PSAb prior sRTc (ng/mL)	0.071	1
Pelvic nodal recurrence on PETd	0.065	0.920
pT statuse	0.055	0.777
ISUPf grade	0.050	0.705
Dose to prostatic fossa (Gyg)	0.029	0.415
ADTh	0.021	0.299
R statusi	0.014	0.190
Pelvic local recurrence on PET	0.012	0.175
PSA persistence	–0.008	–0.116

^aRSF: random survival forest.

^bPSA: prostate-specific antigen.

^csRT: salvage radiation therapy.

^dPET: positron emission tomography.

^epT status: pathological T status.

^fISUP: International Society of Urological Pathology.

^gGy: gray (a unit of radiation dose).

^hADT: androgen deprivation therapy.

ⁱR status: residual disease status.