RefleXion PET/CT Imaging Performance in Patients With Prostate Cancer

A Prospective Study of the RefleXion [18F]- DCFPyL PET-CT Subsystem Imaging Performance in Patients With Prostate Cancer

This clinical trial examines RefleXion Medical Radiotherapy System (RMRS) imaging to the standard of care (SOC) [18F]-DCFPyL positron emission tomography-computed tomography (PET-CT) imaging in patients with prostate cancer. PET is an established imaging technique that utilizes small amounts of radioactivity attached to very minimal amounts of a tracer, [18F]-DCFPyL, that binds to prostate specific membrane antigen (PSMA) on tumor cells. These PSMA tumor cells can then be identified on PET imaging. CT utilizes x-rays that traverse body from the outside. CT images provide an exact outline of organs and potential inflammatory tissue where it occurs in patient's body. The RMRS is a imaging-therapy combination system that can plan for and deliver radiation therapy as well perform [18F]-DCFPyL PET-CT imaging. Comparing the imaging from the standard of care [18F]-DCFPyL-PET-CT with the [18F]-DCFPyL imaging from RMRS may help improve the quality of the imaging captured and determine if imaging can be done on the RMRS at the same time as planning for radiation therapy, which would reduce the number of scans needed to plan for radiation for prostate cancer.

PRIMARY OBJECTIVE: I. To assess imaging performance of the fluorine F 18 piflufolastat ([18F]-DCFPyL) PET-CT subsystem on the X1 RMRS to detect lesions (primary and metastatic) in patients with prostate cancer. SECONDARY OBJECTIVE: I. To determine the feasibility of generating a biology-guided radiotherapy (BgRT) plan using X1 RMRS-acquired [18F]-DCFPyL PET data derived from the imaging-only session at the studied dose level. OUTLINE: Patients receive [18F]-DCFPyL intravenously (IV) and undergo [18F]-DCFPyL PET-CT over 30 minutes per standard of care (SOC). Patients with PET avid lesions then undergo a X1 RMRS PET-CT imaging-only session within 120 minutes of injection over 20-35 minutes. After completion of study, patients are followed up within 72 hours.

Patients receive [18F]-DCFPyL IV and undergo [18F]-DCFPyL PET-CT over 30 minutes per SOC. Patients with PET avid lesions then undergo a X1 RMRS PET-CT imaging-only session within 120 minutes of injection over 20-35 minutes.

CAT, CAT Scan, Computed Axial Tomography, Computerized Axial Tomography, Computerized Tomography, CT, CT Scan, tomography

18F-DCFPyL, Fluorine F 18 DCFPyL, Piflufolastat F 18, Piflufolastat F-18, Piflufolastat F18, Pylarify

Medical Imaging, Positron Emission Tomography, PET, PET Scan, Positron Emission Tomography Scan, Positron-Emission Tomography, proton magnetic resonance spectroscopic imaging

Comparison of imaging performance of X1 RefleXion Medical Radiotherapy System (RMRS) positron emission tomography-computed tomography (PET-CT) with the diagnostic fluorine F 18 piflufolastat ([18F]-DCFPyL) PET-CT

For the standard of care (SOC) [18F]-DCFPyL PET-CT, the maximum standardized uptake value (SUV) and the greatest dimension in centimeters will be recorded for each PET avid malignant lesion identified by the nuclear medicine radiologist. The patient's radiation oncologist will interpret the X1 PET scan for the same metrics. Any discordances will be documented, and the final disposition recorded. Graphical presentations will be provided to compare SOC positive lesions and X1 positive lesions, and SOC positive lesions and X1 negative lesions with regards to lesion size, lesion location (bone, lymph nodes, soft tissue, visceral organ) and SUV uptake. Descriptive statistics will be utilized to quantify results. Mean, standard deviation, interquartile range (IQR), and range will be reported for each continuous variable. Frequency and percentage will be reported for categorical variables. Statistical significance will be assessed at the 0.05 level, one-sided.

Percent of cases where X1 RMRS [18F]-DCFPyL PET data can be used to generate an acceptable biology-guided radiotherapy (BgRT) plan

The true positive lesions identified on the X1 PET images will be identified and used for BgRT planning. Simulated planning using the RefleXion treatment planning software will be performed, and the radiation dose to organs at risk calculated. Principal investigator will determine whether this plan is acceptable or not. The percent of cases in which RefleXion [18F]-DCFPyL PET data led to an acceptable plan will be recorded (descriptive statistics). Descriptive statistics will be utilized to quantify results. Mean, standard deviation, IQR, and range will be reported for each continuous variable. Frequency and percentage will be reported for categorical variables. Statistical significance will be assessed at the 0.05 level, one-sided.

Inclusion Criteria: Documented informed consent of the participant and/or legally authorized representative Age >= 21 years Patients undergoing SOC [18F]-DCFPyL PET-CT Patients should be scheduled for [18F]-DCFPyL PET-CT prior to study entry Exclusion Criteria: Known psychiatric or substance abuse disorder that would interfere with conduct of the study Patient weight exceeding the weight limit (450 pounds) outlined per X1 RMRS specifications sheet