Hypofractionated Radiation Therapy for the Treatment of Prostate Cancer

Inclusion Criteria

• Histologically proven prostate adenocarcinoma * Gleason score 2-7 * Biopsy within one year of date of randomization
• Clinical stage =< T2 based on digital rectal exam (DRE) and/or =< T3a based on magnetic resonance imaging (MRI) (if done); N0-Nx; M0-Mx (American Joint Committee on Cancer [AJCC] 7th edition) * T-stage and N-stage determined by physical exam and available imaging studies (computed tomography [CT], and/or MRI of the pelvis). For MRI, questionable extracapsular extension is permitted. To distinguish blood from tumor the ideal study would be to acquire T2, T1 non-contrast and T1 dynamic contrast enhanced sequence, although this is not required. A small amount of extracapsular extension is permitted as long as it can be included in the clinical target volume (CTV) and the constraints are met * M-stage determined by physical exam, CT or MRI. Bone scan not required unless clinical findings suggest possible osseous metastases
• Prostate specific antigen (PSA) < 20 ng/ml, obtained no greater than 3 months prior to randomization
• Patients belonging in one of the following risk groups: * Low: Clinical stage T1-T2; Gleason =< 6, PSA =< 10 and < 50% biopsy cores positive ** Clinical stage is based on digital rectal exam (DRE). Seminal vesicle invasion on MRI is not eligible. T1a should be permitted is subsequent peripheral zone biopsies show tumor * Clinical stage T2b-T2c; Gleason =< 6, PSA =< 10 and < 50% biopsy cores positive * Clinical stage T1-T2; Gleason =< 6, PSA =< 10 and >= 50% biopsy cores positive * Clinical stage T1-T2; Gleason = 7, PSA =< 10 and < 50% biopsy cores positive or T1-T2; Gleason =< 6 and PSA > 10 and < 20 and 50% biopsy cores positive * MRI stage T3a with evidence of extraprostatic extension is allowed
• Prostate volume: =< 80 cc * Measured from CT or MRI =< 90 days prior to randomization
• Zubrod performance status 0-1 or equivalent
• No prior total prostatectomy or cryotherapy of the prostate * Prior suprapubic prostatectomy, transurethral resection and laser ablation are permitted
• No prior radiotherapy to the prostate or lower pelvis
• No implanted hardware or other material that would prohibit appropriate treatment planning or treatment delivery, in the investigator's opinion
• No chemotherapy for a malignancy in the last 5 years
• No history of an invasive malignancy (other than this prostate cancer, or non-metastatic basal, squamous skin cancers, or non-metastatic curatively treated papillary thyroid carcinoma) in the last 3 years
• 4-6 months of androgen deprivation therapy (ADT) are allowed for intermediate risk patients (pts). This must be declared prior randomization. This may not have been started more than 2 months prior to randomization
• Patient must be able to have gold fiducial markers placed in the prostate or, if patient already has fiducial markers placed, they must be in accordance with the protocol specification. Note: If a method of intrafraction prostate tracking is available which does not require fiducial markers, this will be adequate for this trial (i.e 4 dimensional [D] transperitoneal ultrasound, onboard MRI guidance [Viewray])
• Ability to understand and the willingness to sign a written informed consent document
• Willingness to fill out quality of life/psychosocial forms
• Age ≥ 35 and ≤ 85 years
• International Prognostic Scoring System (IPSS) (American Urological Association [AUA]) score =< 12

Exclusion Criteria

• Does not have a diagnosis of prostate adenocarcinoma
• Patient has clinical T3a or any evidence of T3b disease
• Patient has stage N1 or M1 disease
• Patient has a PSA of >= 20 ng/ml obtained no greater than 3 months prior to randomization
• Patient does not meet any of the risk groups
• Prostate volume greater than 80 cc
• Zubrod performance status 2 or greater
• Prior total prostatectomy or cryotherapy of the prostate
• Prior radiation therapy to the prostate or lower pelvis
• Implanted hardware which limits treatment planning or delivery (determined by the investigator)
• Chemotherapy within the past 5 years
• Diagnosis of an invasive malignancy within 3 years (other than current prostate cancer or non-metastatic basal, squamous skin cancers, or non-metastatic curatively treated papillary thyroid carcinoma)
• The use of more than 2 months of androgen deprivation therapy (ADT) prior to randomization or plans for ADT to be continued for greater than 6 months
• Inability to have gold fiducial markers placed in the prostate, or fiducial markers already placed, that are not in accordance with protocol * Note: If a method of intrafraction prostate tracking is available which does not require fiducial markers, this will be adequate for this trial (i.e. 4D transperitoneal ultrasound, onboard MRI guidance [Viewray])
• Unwilling or inability to give informed consent
• IPSS score > 12