Vascular Optimized Radiotherapy Tuned to Critical Structures for Erectile Function Using High-Precision X-Ray Treatment

Inclusion Criteria: 1. Age ≥ 18. 2. Histologically confirmed, clinically localized adenocarcinoma of the prostate. 3. Staging workup as recommended by the National Comprehensive Cancer Network (NCCN) on the basis of risk grouping. a. Advanced imaging studies (i.e. prostate-specific membrane antigen \[PSMA\] positron emission tomography \[PET\]/CT and fluciclovine PET/CT scan) can supplant a bone scan if performed first. 4. No evidence of metastatic disease in lymph nodes above the bifurcation of the renal arteries, or in bones or visceral organs (nodal disease identified on a PSMA PET/CT scan below the bifurcation of the renal arteries is allowable). 5. Eastern Cooperative Oncology Group (ECOG) performance status ≤2. 6. Ability to undergo magnetic resonance angiography (MRA) of the pelvis. 7. No indication for urgent or emergent radiation. 8. Written informed consent obtained from participant or participant's legal representative and ability for participant to comply with the requirements of the study. Exclusion Criteria: 1. Patients with neuroendocrine or small cell carcinoma of the prostate. 2. Patients with any evidence of distant metastases except that evidence of lymphadenopathy below the level of the renal arteries can be deemed locoregional per the discretion of the investigator. 3. Evidence of intraprostatic lesion by biopsy, MRI, or PSMA PET/CT within the middle third, or both lateral thirds of the prostate gland. 4. History of whole-gland cryosurgery, high-intensity focused ultrasound (HIFU), brachytherapy, or other ablative treatments of the whole prostate. 5. Prior pelvic radiotherapy. 6. History of Crohn's disease, ulcerative colitis, or ataxia telangiectasia. 7. Penile prosthesis or implant present prior to treatment.