Stereotactic Ablative Radiotherapy (SABR) of Pelvis and Prostate Targets For High Risk Prostate Cancer

Patients will be accrued in alternating dose levels. The two distinct areas of dose escalations (pelvic lymph node and prostate lesion) will take place one at a time. Minimum waiting periods will be assigned between each dose cohort to observe toxicity. The phase I portion of the study will be completed when dose limiting toxicity is reached or when a sufficiently high dose level (i.e.,5.5 Gy per fraction to a total 27.5 Gy for pelvic lymph node region and 11Gy per fraction to a total of 55Gy to the prostate lesion), is attained to consider the therapy likely to be efficacious. All patients will be treated with a total of 24 months of androgen suppression therapy (ADT). Radiation therapy will start 8-12 weeks after initiation of ADT. No. Patients for each cohort: 7-15 Cohort 1: 9.5 Gy per fraction to prostate/SV, 10 Gy per fraction to prostate lesion, 4.5Gy per fraction to pelvic lymph node region for 5 fractions for a total of 47.5 / 50 / 22.5 Gy to Prostate+SV /Prostate lesions/Nodes Cohort 2: 9.5 Gy per fraction to prostate/SV, 10 Gy per fraction to prostate lesion, 5Gy per fraction to pelvic lymph node region for 5 fractions for a total of 47.5 / 50 / 25 Gy to Prostate+SV /Prostate lesions/Nodes Cohort 3: 9.5 Gy per fraction to prostate/SV, 10.5 Gy per fraction to prostate lesion, 5Gy per fraction to pelvic lymph node region for 5 fractions for a total of 47.5 / 52.5 / 25 Gy to Prostate+SV /Prostate lesions/Nodes Cohort 4: 9.5 Gy per fraction to prostate/SV, 10.5 Gy per fraction to prostate lesion, 5.5 Gy per fraction to pelvic lymph node region for 5 fractions for a total of 47.5 / 52.5 / 27.5 Gy to Prostate+SV /Prostate lesions/Nodes Cohort 5: 9.5 Gy per fraction to prostate/SV, 11 Gy per fraction to prostate lesion, 5.5 Gy per fraction to pelvic lymph node region for 5 fractions for a total of 47.5 / 55 / 27.5 Gy to Prostate+SV /Prostate lesions/Nodes