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Using PSMA-PET / MRI to Guide Cyberknife-Delivered Stereotactic Body Radiation Therapy for Favorable Risk Prostate Cancer

Trial Status: Temporarily Closed to Accrual and Intervention

This phase II trial studies the effect of using PSMA-PET / MRI to guide cyberknife-delivered stereotactic body radiation therapy in favorable risk prostate cancer patients. Diagnostic procedures, such as PSMA-PET / MRI may help design the radiation treatment plan so that the entire prostate receives the prescribed dose of radiation and, in addition, the visible tumor as defined by the scans receives hot spots. Hot spots are areas that receive above the dose of prescription simply due to the nature of radiation therapy. The imaging techniques in this study help focus the hot spots on certain regions determined by the scans where the visible tumor is located as opposed to the current practice where hot spot regions are randomly located in the target area. PSMA-PET / MRI may help better guide stereotactic body radiotherapy and improve treatment outcomes for future patients with prostate cancer.

Inclusion Criteria

  • Written informed consent obtained to participate in the study and Health Insurance Portability and Accountability Act (HIPAA) authorization for release of personal health information
  • Histologically confirmed prostate adenocarcinoma
  • Low or favorable intermediate risk, based on the National Comprehensive Cancer Network (NCCN) criteria with appropriate staging (e.g. bone scan)
  • Subject has adequate performance status as defined by Eastern Cooperative Oncology Group (ECOG) performance status of 0-2
  • Subject is willing and able to comply with the protocol as determined by the treating investigator
  • Subject speaks English (quality of life instrument is validated in English)

Exclusion Criteria

  • Contraindications for MRI
  • Other prior or concomitant malignancies with the exception of: * Non-melanoma skin cancer * Other cancer for which the subject has been disease free for >= 5 years before the first study treatment and of low potential risk for recurrence
  • Inflammatory bowel disease
  • Previous transurethral prostatic resection (TURP) or surgery of the prostate

North Carolina

Chapel Hill
UNC Lineberger Comprehensive Cancer Center
Contact: Panayiotis Mavroidis
Phone: 984-974-8438


I. To determine the safety of using prostate-specific membrane antigen (PSMA)-positron emission tomography (PET)/magnetic resonance imaging (MRI) to define radiotherapy targets, while meeting all the current planning criteria.


I. To further describe the adverse events associated with using PSMA-PET/MRI to define radiotherapy target volumes in subjects with low and favorable intermediate risk prostate cancer.

II. To evaluate biochemical control after radiotherapy in subjects who have received PSMA-PET/MRI to define radiotherapy target volumes.

III. To measure patient-reported quality of life prior to radiation therapy and over time in subjects with prostate cancer who have received PSMA-PET/MRI to define radiotherapy target volumes.

IV. To determine the proportion of screened subjects who are enrolled on the study.


Patients receive gallium Ga 68-labeled PSMA-11 (68Ga-PSMA-11) intravenously (IV) and then undergo PET/MRI over 30 minutes and PET/CT. Patients may undergo a repeat 68Ga-PSMA PET scan if for whatever reason 68Ga-PSMA synthesis fails or the PET scans fail. Patients then undergo daily stereotactic body radiation therapy (SBRT) using cyberknife for 1 week.

After completion of study, patients are followed up at 1, 3, 6, 9, 12, 18, 24, 30, 36, 42, 48, 54, and 60 months.

Trial Phase Phase II

Trial Type Treatment

Lead Organization
UNC Lineberger Comprehensive Cancer Center

Principal Investigator
Panayiotis Mavroidis

  • Primary ID LCCC1917
  • Secondary IDs NCI-2020-08190
  • ID NCT04243941