Purpose

This research study is for men with intermediate- or high-risk prostate cancer who are planning to receive hormone therapy and radiation treatment. The purpose of the study is to see whether a special type of diagnostic imaging done during hormone therapy can help doctors more accurately target remaining cancer with radiation, while avoiding areas that may no longer need extra treatment. All participants will receive standard hormone therapy and radiation therapy, along with three imaging scans, over a six-month period. The information gained from this study may help make prostate cancer radiation treatment more precise and reduce side effects for future patients.

Conditions

Eligibility

Eligible Ages
Over 18 Years
Eligible Sex
Male
Accepts Healthy Volunteers
No

Inclusion Criteria

  • 18 years of age and older. - Eastern Oncology Group Status 0 to 1. - Histologic diagnosis of prostate cancer. - Prior screening MRI with at least one PI-RADS4 or PI-RADS 5 lesion, obtained within 180 days of screening. - NCCN intermediate-risk or high-risk prostate cancer (Appendix B). All patients will be staged by MRI. - Prior PSMA PET scan with at least one focal avid lesion greater than background prostate that is concordant with a lesion on MRI, obtained within 180 days of screening. - Intention for SBRT (36.25 Gy/5 fraction) with focal boost (up to 50 Gy) to one MRI/PET-concordant lesion34.

Exclusion Criteria

  • Prior imaging (CT, bone scan, MRI, PSMA-PET/CT) showing nodal or distant disease. - Intention to receive treatment intensification with secondary androgen receptor signaling inhibitors or chemotherapy. - Clinical T4 disease. - Prior ADT. - Prior pelvic RT. - Prior prostate surgery, including TURP. - International prostate symptom score > 20. - Prior urethral stricture. - Prostate volume > 80 cc on MRI. - Hip implants that cause artifacts over the prostate gland. - Inability to discontinue anti-coagulation for fiducial marker placement. - Active Crohn's disease or scleroderma.

Study Design

Phase
Phase 2
Study Type
Interventional
Allocation
N/A
Intervention Model
Single Group Assignment
Primary Purpose
Treatment
Masking
None (Open Label)

Arm Groups

ArmDescriptionAssigned Intervention
Experimental
ADT + SBRT + PSMA PET/CT Imaging
- ADT as prescribed - PSMA PET/CT imaging will be completed at baseline, 8 weeks after ADT start, and at end of treatment - SBRT is administered starting 10 weeks after ADT start
  • Diagnostic Test: PSMA PET/CT
    PSMA PET/CT is an imaging test that uses a radioactive tracer to highlight prostate cancer cells. Imaging will be performed at baseline, approximately eight weeks after starting ADT, and approximately 24 weeks after starting ADT (end of treatment). These scans are used to guide radiation treatment planning and assess treatment response.
  • Drug: Androgen Deprivation Therapy (ADT) +/- bicalutamide
    ADT is used to lower testosterone levels, which can slow or shrink prostate tumors. All participants will receive approximately six months of ADT starting before radiation therapy, using injectable or oral medications. Depending on the type of ADT, participants may also receive daily bicalutamide. Bicalutamide is categorized as an antiandrogen, which means it will block the effects of testosterone and work together with ADT to slow down or shrink prostate cancer.
  • Radiation: Stereotactic Body Radiation Therapy (SBRT) +/- focal microboost
    SBRT is a form of radiation therapy that delivers precise, high-dose radiation to the prostate over a short period of time. SBRT will be initiated 10 weeks after initiation of ADT and will be delivered in five sessions over two weeks. Based on PSMA PET/CT and MRI findings after initiation of ADT, some participants may receive an optional focal radiation microboost to areas of residual cancer. The microboost, if delivered, will be given during the same SBRT treatment sessions and will be limited by standard safety constraints.

Recruiting Locations

Dana-Farber/Brigham and Women's Cancer Center at Milford Regional Medical Center
Milford, Massachusetts 01757
Contact:
Luke Peng, MD
508-488-3800
lcpeng@bwh.harvard.edu

Dana-Farber/Brigham and Women's Cancer Center in Clinical Affiliation with South Shore Hospital
Weymouth, Massachusetts 02190
Contact:
Luke Peng
508-488-3800
lcpeng@bwh.harvard.edu

More Details

Status
Recruiting
Sponsor
Martin T. King, MD, PhD

Study Contact

Detailed Description

Prostate cancer is commonly treated with a combination of hormone therapy and radiation therapy. Hormone therapy, or androgen deprivation therapy (ADT), lowers testosterone levels and often shrinks or weakens prostate cancer before radiation begins. However, after hormone therapy starts, it can become harder for doctors to tell exactly where active cancer remains inside the prostate using standard imaging (typically an MRI). This study is being conducted to determine whether a newer imaging test can better identify which parts of the cancer are still active and may benefit from more focused radiation treatment. All participants in this study will receive six months of ADT, which is part of standard care for intermediate- and high-risk prostate cancer. In addition, participants will undergo PSMA PET/CT scans, a type of imaging that highlights prostate cancer cells, as well as MRI scans. These scans will be performed at three time-points: before hormone therapy begins, approximately eight weeks after starting hormone therapy (before radiation planning), and again at 24 weeks (at the end of all treatment) to see how the cancer has responded to treatment. Radiation therapy will begin shortly after the eight-week imaging scan. Participants will receive high-precision radiation (stereotactic body radiation therapy/SBRT) to the prostate over about two weeks. Based on the imaging results, doctors may give an extra "boost" of radiation to small areas that still show signs of active cancer. If the scans show that the cancer has responded well to hormone therapy, some patients may not need this extra boost. This approach is designed to deliver the strongest treatment where it is needed while limiting radiation to healthy tissue in order to minimize side effects. The main goal of the study is to understand whether doctors can confidently use the mid-treatment PSMA PET/CT scan to guide radiation planning. Researchers will also monitor changes in PSA blood levels, imaging findings, treatment side effects, and patient-reported quality of life, including urinary, bowel, and sexual symptoms. Additionally, doctors participating in the study will provide feedback on how easy or difficult it is to define radiation target areas using the different scans. Participation in this study lasts about 6 months, and all treatments provided are commonly used in prostate cancer care, with the incorporation of PSMA PET scans being the experimental component. While participants may or may not directly benefit, the results obtained from this study may help improve how radiation therapy is planned and delivered for future patients with prostate cancer, with the goal of maintaining treatment effectiveness while reducing side effects.

Notice

Study information shown on this site is derived from ClinicalTrials.gov (a public registry operated by the National Institutes of Health). The listing of studies provided is not certain to be all studies for which you might be eligible. Furthermore, study eligibility requirements can be difficult to understand and may change over time, so it is wise to speak with your medical care provider and individual research study teams when making decisions related to participation.