Phase I/II Hypofractionated Radiotherapy for Prostate Cancer

Inclusion Criteria: Histologically proven adenocarcinoma of the prostate. Stage ≤ T2b disease, as defined by 1997 American Joint Committee on Cancer (AJCC) classification Predicted risk of lymph node involvement (by standard nomograms) of 15% or less (24), OR histologically negative pelvic nodes Gleason score ≤ 7 No evidence of distant metastasis Age 18+ Informed consent signed in accordance with institutional protocol Pretreatment evaluations must be completed as specified in Section 7.0. ECOG performance status 0-1 No previous or concurrent cancers, other than localized basal cell or squamous cell skin carcinoma, unless continually disease free for at least 5 years No prior pelvic irradiation, prostate brachytherapy, or bilateral orchiectomy Gonadotropin-releasing hormone agonist (GnRH-a) use permitted (maximum of 6 months duration). Anti-androgen therapy permitted concurrently with GnRH-a. No previous or concurrent cytotoxic chemotherapy No radical surgery or cryosurgery for prostate cancer The absence of any co-morbid medical condition which would constitute a contraindication for radical radiotherapy The absence of serious concurrent illness of psychological, familial, sociological, geographical or other concomitant conditions which do not permit adequate follow-up and compliance with the study protocol. No current use of anticoagulation therapy, other than aspirin.