Two Fraction Prostate SBRT With DIL SIB

Who May Qualify: - Patient age greater than or equal 18 - Localized adenocarcinoma of the prostate - Biopsy-proven diagnosis of prostate adenocarcinoma - Low to intermediate risk National Comprehensive Cancer Network (NCCN) disease - TX-T2c-8th addition staging - PSA\<20 ng/ml - Grade group 3 or less - Proper rectal space replacement required as determined by the treating radiation oncologist - Prostate size less than 60cc defined at time of simulation based on MRI - Patient ability to undergo MRI and documented dominant Prostate Imaging Reporting and Data System (PI-RADS) 3 or higher lesion \-- Exception is very low risk, low risk, or favorable intermediate risk with a low to intermediate decipher score in which case an SIB is not utilized - Androgen-deprivation therapy (ADT) is left to the discretion of the treating radiation oncologist - Agreement to use effective contraceptive methods such as condoms and spermicidal foam, intrauterine device, or for their partner to use prescription birth control pills - Ability to give willing to sign a consent form Who Should NOT Join This Trial: - High risk disease - Pelvic lymph node involvement - Prophylactic lymph node irradiation requirement as determined by the treating radiation oncologist - Evidence of clinical or radiological extracapsular extension or seminal vesicle invasion - Prior radiation to the pelvis - Prior malignancies within the last 5 years - Inability to meet pre-specified 2 fraction DVH constraints - Prostate size \> 60cc as measures at treatment planning MRI - Active significant inflammatory bowel disease (IBD) or rheumatological disease - Prior prostate surgeries - Previous uro lift - Transurethral resection of the prostate (TURP) within 6 months of SBRT - "Reasonable" urinary, bowel, and erectile function as defined by the pre-treatment EPIC questionnaire (\>50 overall summary score for each domain) ...See full criteria on ClinicalTrials.gov Always talk to your doctor about whether this trial is right for you.