This is a phase 2 randomized study for High risk localized prostate cancer (T3 to T4 disease and/or PSA > 20 and/or Gleason score ≥ 8) without evidence of distant and nodal metastasis.

Patient will be randomized to:Arm 1

• Conventional IMRT RapidArc IMRT to prostate and pelvic nodes. 76Gy to prostate, 70Gy to proximal 2/3 of seminal vesicles, and 50Gy to pelvic nodes (up to bifurcation of common iliac nodes).
• 38 fractions of daily treatment, Monday to Friday

or Arm 2

SBRT

• RapidArc IMRT to prostate and pelvic nodes. 40Gy to prostate, 36.25Gy to proximal 2/3 of seminal vesicles, and 25Gy to pelvic nodes (up to bifurcation of common iliac nodes)
• 5 fractions of weekly treatment. Once fraction per week. All patients will be given neoadjuvant and adjuvant androgen deprivation therapy (detail as below)

Inclusion Criteria:

• Histological confirmation of prostate adenocarcinoma
• High risk prostate cancer patients (i.e. T3 to T4 disease and/or PSA > 20 and/or Gleason score ≥ 8)
• ECOG performance score 0-1
• Age ≥ 18
• History/physical examination within 2 weeks prior to registration
• Able to sign informed-consent

Exclusion Criteria:

• Patients with active cancer other than prostate cancer and non-melanoma skin cancer.
• Evidence of distant metastases
• Regional lymph node involvement
• Previous radical surgery (prostatectomy), cryosurgery, or HIFU for prostate cancer
• Previous pelvic irradiation, prostate brachytherapy, or bilateral orchiectomy
• Previous hormonal therapy, such as LHRH agonists (e.g., goserelin, leuprolide) or LHRH antagonists (e.g., degarelix), anti-androgens (e.g., flutamide, bicalutamide), estrogens (e.g. DES), or surgical castration (orchiectomy)
• Unstable angina and/or congestive heart failure requiring hospitalization, transmural myocardial infarction within the last 6 months, acute bacterial or fungal infection requiring intravenous antibiotics, chronic obstructive pulmonary disease exacerbation or other respiratory illness requiring hospitalization or precluding study therapy at the time of registration
• Patients who have received prior chemotherapy.