Two Fraction Prostate SBRT With DIL SIB

Inclusion Criteria:

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 informed consent

Exclusion Criteria:

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)
Men of reproductive potential may not participate unless they agree to use an effective contraceptive method