Clinical outcome of patients treated with 3D conformal radiation therapy (3D-CRT) for prostate cancer on RTOG 9406.
OBJECTIVE
Report of clinical cancer control outcomes on Radiation Therapy Oncology Group (RTOG) 9406, a three-dimensional conformal radiation therapy (3D-CRT) dose escalation trial for localized adenocarcinoma of the prostate.


METHODS
RTOG 9406 is a Phase I/II multi-institutional dose escalation study of 3D-CRT for men with localized prostate cancer. Patients were registered on five sequential dose levels: 68.4 Gy, 73.8 Gy, 79.2 Gy, 74 Gy, and 78 Gy with 1.8 Gy/day (levels I-III) or 2.0 Gy/day (levels IV and V). Neoadjuvant hormone therapy (NHT) from 2 to 6 months was allowed. Protocol-specific, American Society for Therapeutic Radiation Oncology (ASTRO), and Phoenix biochemical failure definitions are reported.


RESULTS
Thirty-four institutions enrolled 1,084 patients and 1,051 patients are analyzable. Median follow-up for levels I, II, III, IV, and V was 11.7, 10.4, 11.8, 10.4, and 9.2 years, respectively. Thirty-six percent of patients received NHT. The 5-year overall survival was 90%, 87%, 88%, 89%, and 88% for dose levels I-V, respectively. The 5-year clinical disease-free survival (excluding protocol prostate-specific antigen definition) for levels I-V is 84%, 78%, 81%, 82%, and 82%, respectively. By ASTRO definition, the 5-year disease-free survivals were 57%, 59%, 52%, 64% and 75% (low risk); 46%, 52%, 54%, 56%, and 63% (intermediate risk); and 50%, 34%, 46%, 34%, and 61% (high risk) for levels I-V, respectively. By the Phoenix definition, the 5-year disease-free survivals were 68%, 73%, 67%, 84%, and 80% (low risk); 70%, 62%, 70%, 74%, and 69% (intermediate risk); and 42%, 62%, 68%, 54%, and 67% (high risk) for levels I-V, respectively.


CONCLUSIONS
Dose-escalated 3D-CRT yields favorable outcomes for localized prostate cancer. This multi-institutional experience allows comparison to other experiences with modern radiation therapy.
Department of Radiation Oncology, Washington University Medical School, St. Louis, MO 63110, USA. michalski@wustl.edu
Jeff
J
Michalski
Kathryn
K
Winter
Mack
M
Roach
Arnold
A
Markoe
Howard M
HM
Sandler
Janice
J
Ryu
Matthew
M
Parliament
James A
JA
Purdy
Richard K
RK
Valicenti
James D
JD
Cox
D000230:Adenocarcinoma / Q000097:blood / Q000188:drug therapy / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D000368:Aged; D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D017430:Prostate-Specific Antigen / Q000097:blood; D011471:Prostatic Neoplasms / Q000097:blood / Q000188:drug therapy / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D011879:Radiotherapy Dosage; D020266:Radiotherapy, Conformal / Q000379:methods* / Q000401:mortality; D016019:Survival Analysis; D016896:Treatment Outcome; D047368:Tumor Burden
D018931:Antineoplastic Agents, Hormonal; D017430:Prostate-Specific Antigen