Toxicity after three-dimensional radiotherapy for prostate cancer with RTOG 9406 dose level IV

This is the first report of the toxicity outcomes using dose level IV (74 Gy) on Radiation Therapy Oncology Group (RTOG) study 9406 for Stage T1-T2 prostate adenocarcinoma. A total of 262 patients were entered in this cooperative group, Phase I-II, dose-escalation trial of three-dimensional conformal radiotherapy for localized prostate carcinoma treated to a dose of 74 Gy (Level IV); 256 patients were analyzable for toxicity. A minimal dose of 2 Gy/fraction was prescribed to the planning target volume (PTV). Patients were stratified according to the risk of seminal vesicle invasion on the basis of the Gleason score and presenting prostate-specific antigen level. Group 1 patients had clinical Stage T1-T2 tumors with a seminal vesicle invasion risk of