Gallium Ga 68-labeled PSMA-11 PET/CT in Diagnosing Participants with Intermediate to High-Risk Prostate Cancer

PRIMARY OBJECTIVES:

I. Determine sensitivity, specificity, positive, and negative predictive value of gallium Ga 68-labeled prostate specific membrane antigen (PSMA)-11 (68Ga PSMA-HBED-CC) PET for detection of regional pelvic nodal metastases compared to pathology at radical prostatectomy (per patient, using nodal regional correlation).

SECONDARY OBJECTIVES:

I. Determine sensitivity, specificity, positive, and negative predictive value of 68Ga PSMA-HBED-CC PET for detection of extra-pelvic nodal metastases, visceral metastases, and osseous metastases compared to biopsy and imaging follow-up.

EXPLORATORY OBJECTIVES:

I. Determine sensitivity, specificity, positive, and negative predictive value for detection of regional nodal metastases in comparison to cross-sectional imaging performed contemporaneously with 68Ga PSMA-HBED-CC PET.

II. Compare progression free survival at one year (as measured by prostate specific antigen [PSA]) between patients with, and without, nodal metastases.

III. Correlate maximum standardized uptake value (SUVmax) from 68Ga PSMA-HBED-CC PET and short-axis diameter (of nodal disease on cross-sectional imaging) to presence of true pathology.

IV. Quantify and describe the incidence of osseous and distant metastatic lesions.

OUTLINE:

Participants receive gallium Ga 68-labeled PSMA-11 intravenously (IV) and 75 minutes later undergo PET/CT over 25 to 40 minutes. Participants with disease outside the pelvic region and no clinical imaging obtained as standard of care after the first scan may receive a second dose of gallium Ga 68-labeled PSMA-11 and undergo a second PET/CT.

After completion of study treatment, participants are followed up at 1 day and then up to 12 months.