Pretreatment nomogram predicting ten-year biochemical outcome of three-dimensional conformal radiotherapy and intensity-modulated radiotherapy for prostate cancer.
OBJECTIVE
To update our previously published nomogram predicting for biochemical outcome with 10-year data from a larger cohort of patients treated with three-dimensional conformal radiotherapy (RT) or intensity-modulated RT for localized prostate cancer.


METHODS
From 1988 to 2004, 2253 patients were treated with three-dimensional conformal RT or intensity-modulated RT for clinical Stage T1-T3 prostate cancer. Prescription doses ranged from 64.8 to 86.4 Gy. The median follow-up time was 7 years. The nomogram was developed using a proportional hazards regression model predicting for the probability of biochemical relapse after RT according to the nadir plus 2 ng/mL definition of prostate-specific antigen (PSA) relapse.


RESULTS
The 10-year PSA relapse-free survival rate was 62%. The nomogram incorporated the following variables to predict likelihood of PSA failure after RT: pretreatment PSA level, Gleason score, radiation dose, use of neoadjuvant androgen deprivation, and clinical stage. The concordance index of this long-term nomogram was 0.72.


CONCLUSIONS
A nomogram predicting the 10-year probability of biochemical control after three-dimensional conformal RT or intensity-modulated RT for prostate cancer was reasonably accurate and discriminating. The nomogram also provided evidence that long-term biochemical control can be achieved after conformal RT for the treatment of localized prostate cancer.
Zelefsky
Michael J
MJ
Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York 10021, USA. zelefskm@mskcc.org
Kattan
Michael W
MW
Fearn
Paul
P
Fearon
Bertha L
BL
Stasi
Jason P
JP
Shippy
Alison M
AM
Scardino
Peter T
PT
D000368:Aged; D000369:Aged, 80 and over; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D049451:Nomograms; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000097:blood* / Q000532:radiotherapy*; D011879:Radiotherapy Dosage; D020266:Radiotherapy, Conformal / Q000379:methods*; D013997:Time Factors