A Study of Stereotactic Body Radiation Therapy (SBRT) Without Androgen Deprivation Therapy (ADT) in People With Unfavorable Intermediate-Risk Prostate Cancer

Inclusion Criteria:

• Pathologically proven diagnosis of prostate adenocarcinoma within 12 months ofenrollment

• Unfavorable intermediate risk prostate cancer by NCCN 2021 risk stratificationguidelines, including any of the following clinicopathologic features:

• Gleason Score 4+3

• ≥ 50% biopsy cores positive

• Two or more of the following risk factors:

• Grade Group 2 or 3

• cT2b-T2c

• PSA 10 - 20 ng/mL

• Able to undergo MRI for initial staging and MR based radiation planning

• Sufficient biopsy tissue available for Decipher genomic testing

• Prostate volume < 90cc

• IPSS ≤ 20

• Age ≥ 18

• KPS ≥ or ECOG 0-2

• Estimated life expectancy >5 years

• Willing and able to provide written informed consent and Authorization for Use andRelease of Health and Research Study Information (HIPAA authorization)

Exclusion Criteria:

• Radiographic T3-T4 detected on staging mpMRI

°Must be "consistent with" (>90% probability) or suspicious for/probable/probably (75%-90% probability) ofT3-T4 disease determined by the reading radiologist.

• Evidence of distant metastases as determined by MRI, PET, or CT imaging

• Evidence of pelvic lymph node involvement as determined by MRI, PET, or CT imaging

• Prior treatment for prostate cancer including chemotherapy, surgery, or hormonaltherapy

• Prior pelvic radiation

• Active second malignancy or past history of malignancies diagnosed within the last 2years that requires active therapy and/or in remission, with the exception ofresected non-melanoma skin cancers, non-muscle invasive bladder cancer, stage I headand neck cancer, or stage I colorectal cancer

• TURP or greenlight PVP within 6 months of enrollment

• History of Crohn's Disease or Ulcerative Colitis