Imaging and Genomic Biomarkers to Predict Response in Prostate Cancer

Pilot Study to Identify Radiogenomic Biomarkers to Predict Early Treatment Response to Androgen Deprivation Therapy and Radiation Therapy in High Risk Prostate Cancer

The purpose of this study is to evaluate the imaging and gene expression biomarkers in prostate cancer. Participants have high-risk prostate cancer and have indicated they will undergo external beam radiation therapy, brachytherapy, and androgen deprivation therapy (EBRT+BTX+ADT). Participants can expect to be in this study for up to 5 years.

This is a pilot study to prospectively investigate potential predictive imaging and genomic biomarkers for patients with high-risk prostate cancer treated with standard of care EBRT + BTX + ADT. The primary imaging modalities that will be evaluated will be PSMA positron emission tomography (PET) and multi-parametric magnetic resonance imaging (MRI). Pre-treatment PET/MRI scans will also be obtained as part of standard of care prior to study enrollment. Response will be assessed on a mid-treatment PET/MRI scan obtained for research purposes after completion of EBRT but prior to brachytherapy boost. PET/CT (computerized tomography) may be used instead if PET/MRI is not technically possible. Imaging response will be compared to pathology from image-directed prostate biopsies taken at the time of the brachytherapy boost. The primary genomic marker that will be evaluated is a clinically available gene-expression array, Decipher, that will be obtained as part of standard of care prior to study enrollment.

Inclusion Criteria:

• Age ≥ 18
• Histologically confirmed adenocarcinoma of the prostate
• Cancer classified as high-risk or very high-risk by National Comprehensive Cancer Network (NCCN) criteria: Grade group ≥4, PSA >20, or primary tumor stage ≥T3a
• ECOG performance status 0-1
• Agreed to undergo EBRT, high dose rate (HDR) brachytherapy boost, and 6-36 months of ADT as part of standard of care therapy prior to study enrollment
• Able to undergo a HDR brachytherapy implant: Pre-radiation IPSS score ≤20 with or without medical management; prostate ≤60 cc as measured by MRI or ultrasound; no prior trans-urethral resection of prostate (TURP); and, median lobe extending into the bladder <1 cm
• No prior or concurrent malignancy unless disease-free for at least 5 years

Exclusion Criteria:

• Evidence of regional or distant metastatic disease on pre-treatment bone scan, pelvic MRI, and/or CT of the abdomen/pelvis
• Prior pelvic radiation therapy