HDR Focal: Feasibility Study

Eligibility Details: Inclusion Criteria: - Age ≥ 18 years - ECOG performance status 0 - 2 - Histological evidence of prostate adenocarcinoma - Low- and favorable intermediate-risk prostate cancer - Informed consent: All patients must sign a document of informed consent indicating their understanding of the investigational nature and risks of the study before any protocol related studies are performed - No contraindications to MRI: - Absent or unifocal intraprostatic disease (<2 separate/distinct lesions), on multiparametric MRI - Prostate gland size <80cc - Baseline IPSS <18 - No TRUP within the past 6 months, nor large TURP defect - Absence of radiological evidence of regional or distant metastases (optional evaluation, at physician discretion) - No previous pelvic and/or prostate EBRT and/or brachytherapy - No contraindications to general anesthesia, or spinal/epidural anesthesia - Absence of bleeding diathesis and/or anti-coagulative therapy that cannot be temporarily ceased during brachytherapy - No contraindications to endorectal coil, surgically absent rectum, severe hemorrhoids or colorectal surgery - Negative past medical history of Ulcerative Colitis, Crohn's Disease, Ataxia Telangiectasia, or SLE - Absence of latex allergy - No other medical conditions deemed by the PI to make patient ineligible for prostate HDR brachytherapy