Evaluating the Clinical Accuracy of Gallium-68 PSMA PET/CT Imaging in Patients With Biochemical Recurrence of Prostate Cancer

Phase 2

Completed

Brief Summary: This study investigates if a new drug (PSMA) makes prostate cancer easier to identify in positron-emission tomography (PET) imaging. If this works, prostate cancer treatments can be prescribed that match the location of the disease. PSMA is radiolabeled with Gallium-68 (Ga-68). This means a participant receives a small dose of radiation from the drug - less than the annual radiation limit for a medical worker.

To test this new drug, participants will receive an injection of Ga-68 PSMA and then have a PET scan. This PET scan, and the reported results, will be entered into the medical record and shared with the treating oncologists.

Detailed Description: This study evaluates PSMA-HBED-CC labelled with Gallium-68, abbreviated 68Ga PSMA. This is a radiotracer that attaches to receptors in the membrane of prostate cancer cells. The 68Ga PSMA is identified using a positron emission tomography (PET) scanner. It is believed that 68Ga PSMA will identify prostate cancer more precisely than normal imaging methods (MRI, CT, or ultrasound). Imaging is key to successful treatment - disease must be identified to be treated.

The 68Ga PSMA will be tested in men who have biochemical recurrence of prostate cancer after surgery or radiation treatment. Participants undergo the 68Ga PSMA PET scan before further treatment. Clinical information, including any MRI, CT, or ultrasound imaging and biopsy/surgery information, will be used to determine if the 68Ga PSMA PET imaging was better than the standard imaging. The study team will collect this information for about 1 year after the PSMA scan.

Depending on findings, participants may be invited back for a second 68Ga PSMA scan. This is done if the first scan showed positive lymph nodes or soft tissue metastases but a surgery or biopsy result does not.

The results from these scans will be shared with the participant. Results will also be entered into the participant's medical record and shared with the treating oncologists.

Recruitment & Eligibility

Inclusion Criteria

Ability to understand and willingness to provide informed consent.
Pathologically proven prostate adenocarcinoma.
Rising PSA after definitive therapy with a prostatectomy or radiation therapy (external beam radiation therapy or brachytherapy).
If post-radical prostatectomy, a PSA level of > 0.2 ng/mL measured more than 6 weeks post-operatively with a second confirmatory persistent PSA > 0.2 ng/mL.
If post-radiation therapy, a PSA level that is equal to, or greater than, a 2 mg/mL rise above the lowest PSA value ('nadir').
A PSA level result within the last 2 months meeting criteria above.
Not receiving any other investigational agents (i.e., unlabeled drugs or drugs under an IND for initial efficacy investigations).
No other malignancy within the past 2 years (skin basal cell or cutaneous superficial squamous cell carcinoma or superficial bladder cancer are exempt from this criterion).
Karnofsky performance status greater than or equal to 50 (ECOG/WHO 0, 1, or 2) within the last 3 months.

Exclusion Criteria

Cannot receive furosemide.
History of Stevens-Johnson syndrome.
History or diagnosis of Paget's disease.
Malignancy other than current disease under study.
Allergy to sulfa or sulfa-containing medications.
Uncontrolled intercurrent illness including, but not limited to, ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, or psychiatric illness/social situations that would limit compliance with study requirements.

Arm && Interventions

Group	Intervention	Description
68Ga PSMA PET scan	Ga-68 PSMA-HBED-CC PET	Ga-68 PSMA-HBED-CC PET/CT scan

Primary Outcome Measures

Name	Time	Method
Sensitivity of Ga 68-labeled PSMA-11 Positron Emission Tomography/Computed Tomography (PET/CT) for the Detection on a Per Patient Basis	Up to 12 months after the 68Ga PSMA PET scan	Sensitivity was defined as the proportion of subjects correctly identified as positive by Ga-68 PSMA-11 PET/CT scans compared to a reference standard. Reference standards included conventional imaging (CT, MRI), clinical follow-up within 12 months after PET, and histopathology/biopsy when available. A true positive was defined as a lesion detected by Ga-68 PSMA PET/CT and confirmed by at least one reference standard.

Secondary Outcome Measures

Name	Time	Method
Positive Predictive Value (PPV) of Ga 68-labeled PSMA-11 Positron Emission Tomography/Computed Tomography (PET/CT) for the Detection of Tumor Location on a Per Patient Basis	Up to 12 months after 68Ga PSMA PET scan	Positive predictive value will be determined on a per-subject basis of 68Ga PSMA PET scan for detection of tumor sites, confirming against imaging, clinical follow-up, and histopathology when available.
Sensitivity of Ga 68-labeled PSMA-11 (PET/CT) for Detecting Tumor Location, Confirming With Histopathology, on a Per-subject Basis.	Up to 12 months after 68Ga PSMA PET scan	Sensitivity is defined as the proportion of subjects with a positive Ga-68 PSMA-11 PET/CT scan for detection of tumor location, confirmed by histopathology, on a per-subject basis.
Determine Detection Rates on a Per-subject Basis of 68Ga PSMA-HBED-CC PET/CT When Stratified by PSA Value	Up to 12 months after 68Ga PSMA PET scan	Detection rates will be evaluated on a per-subject basis, stratified by PSA values: 0.2 - \<0.5, 0.5 - \<1.0, 1.0 \<2.0, 2.0 - \<5.0, 5.0 or greater