Early Study to Identify Markers in Prostate Cancer to Assess Treatment

Inclusion Criteria

• Histologically confirmed diagnosis of adenocarcinoma of the prostate from a prostate biopsy
• Cancer classified as high-risk or very high-risk by National Comprehensive Cancer Network (NCCN) criteria: grade group >= 4, prostate specific antigen (PSA) > 20, or primary tumor stage >= T3a
• Seminal vesicle invasion (cT3b) will be allowed, but not invasion into adjacent organs or structures (cT4)
• No evidence of distant metastatic disease on any clinical pre-treatment imaging (bone scan, pelvic MRI, or CT of the abdomen/pelvis). No evidence of regional metastatic disease on conventional imaging (MRI and/or CT). Patients with evidence of regional nodal metastases detected by PET only (i.e. the short-axis of the node(s) is < 1 cm on MRI and/or CT) will be allowed
• Men > 18 years old
• Eastern Cooperative Oncology Group (ECOG) performance status 0-1
• Patients are technically able to undergo a high dose rate (HDR) brachytherapy implant * Pre-radiation International Prostate Symptom Score (IPSS) score =< 20 with or without medical management * No prior transurethral resection of the prostate (TURP) * No large median lobe extending into the bladder (median lobe extending < 1 cm into the bladder will be allowed)
• Patients must have agreed to undergo EBRT, HDR brachytherapy boost, and 6-36 months of ADT as part of standard of care therapy prior to study enrollment. Second-generation anti-androgen therapies (e.g. abiraterone, enzalutamide, apalutamide, darolutamide) are also permitted at the treating physician’s discretion. Patients do not need to receive their standard of care EBRT and hormonal therapy at the University of Wisconsin, so long as they are agreeable to come for the HDR brachytherapy boost and all study-required visits during treatment and follow-up
• Prostate biopsy within 1 year of study enrollment

Exclusion Criteria

• Regional or distant metastases, either histologically proven or clinically diagnosed with a high degree of certainty
• Prior pelvic radiation therapy
• Presence of passive and/or active devices that are not compatible with the 3.0T PET/MR scanner environment. Any person with the following will be excluded: cardiac pacemaker, metal fragments in or around the eye, venous umbrella, permanent eyeliner or permanent artificial eyebrows. Patents with the following potentially non-MRI compatible devices will undergo screening using the standard University of Wisconsin Hospital and Clinics (UWHC) MRI screening protocol by trained UWHC personnel: cardiac pacemaker, heart valve replacement, intracranial aneurysm clips, middle ear, eye, joint, or penile implants, joint replacements, implantable hearing aids, neurostimulator devices, insulin pumps, shunts/stents, metal mesh/coil implants; metal plate/pin/screws/wires, or any other metallic implants. Also, patients with anatomical constraints limiting the feasibility of MRI will be excluded