PSMA-PET to Guide Prostatectomy: Can PSMA-PET Appropriately Modify Surgery, Reduce Nerve Damage and Optimize Quality-of-Life?

Project Summary/Abstract
The 68Ga-P16-093 radiopharmaceutical is an investigational agent that targets prostate specific membrane
antigen (PSMA), which is highly expressed in most prostate cancers. PSMA-PET has not been validated as a
tool for guiding surgical resection of primary prostate cancer.
The objective of this Phase II Clinical Trial is to critically test the ability of 68Ga-P16-093 PET to identify extra-
prostatic extension of prostate cancer, to guide surgical resection, and to improve the patient’s post-surgical
quality-of-life. For prostate cancer patients who require prostatectomy, we hypothesize that PSMA-PET
findings will accurately differentiate patients who can safely undergo nerve-sparing and/or muscle-sparing
surgery from those in whom more aggressive wide resection is essential for cancer control; thus, optimizing
quality-of-life outcomes. Therefore, the project has two complementary yet independent Specific Aims:
Aim 1. To measure the accuracy of both 68Ga-P16-093 PET-CT, and conventional standard-of-care
mpMRI, for presurgical detection of extra-prostatic extension.
Aim 2. To measure treatment modifications, and patient quality-of-life outcomes, that result from 68Ga-
P16-093 -PET incorporation into surgical planning.
The innovations of this project are the application of this imaging technology in pre-surgical treatment
planning for newly diagnosed disease; the definitive assessment of agent performance in a surgical randomized
controlled trial; and the detailed assessments of imaging impact on both surgical planning and subsequent
patient clinical outcome. As a control group, one-half of the enrolled subjects will receive their standard-of-care
prostatectomy with surgical planning supported only by multiparametric MRI and biopsy findings. The other
half of the subjects will be randomized to also receive pre-surgical pelvic imaging with 68Ga-P16-093 PET/CT
for independent assessment of the location and extent of disease. The radiology MRI and PET readers will be
blinded to the findings of the other modality. The surgeon will receive reports on all imaging, but must
document a standard-of-care surgical plan before receiving the PET findings. The surgeon will then document
whether, and how, the PET information modifies their prior surgical plan. For validation of imaging findings,
whole mount pathology will serve as the “gold standard” for characterization of disease. Patient outcome
measures, and cancer recurrence, will be tracked for 18-months following surgery. Our preliminary studies
indicate 68Ga-P16-093 PET-CT will show higher accuracy than mpMRI for detection of extra-prostatic
extension. And, that the PET-directed surgical modifications will frequently result in appropriate preservation
of nerves and muscle, thereby improving post-treatment quality-of-life for many patients, while also helping to
avoid positive surgical margins.

Grant Number: 5R01CA258994-05
NIH Institute/Center: NIH
Principal Investigator: Clinton Bahler