New Developments in PSMA PET Imaging for Prostate Cancer

Dr. Hope answers some questions about the significance of these developments and gives insight into what’s next for PSMA PET.

Thomas Hope, MD

Professor In Residence

In the 2020-21 issue of Images, we shared the story of the U.S. Food and Drug Administration’s approval of Prostate-Specific Membrane Antigen (PSMA) PET imaging, based on research conducted at UC San Francisco and UCLA. The technique uses positron emission tomography in conjunction with a PET-sensitive drug that is highly effective in detecting prostate cancer throughout the body so that it can be better and more selectively treated. The PSMA PET scan also identifies cancer that is often missed by current standard-of-care imaging techniques.

At this time, UCSF and UCLA are the only two medical centers in the U.S. that can offer PSMA PET to the public through this FDA approval. A limited number of other U.S. medical centers are currently using PSMA as an investigational technique, generally as part of a clinical trial. However, more hospitals will have the opportunity to adopt the technology in 2022 after applying for expedited FDA approval, which is now possible as a result of the initial FDA approval gained by UCLA and UCSF.

In September 2021, a team led by Thomas Hope, MD, at UCSF and Jeremie Calais, MD, at UCLA, published a paper in JAMA Oncology (doi:10.1001/ jamaoncol.2021.3771) detailing the phase 3 diagnostic efficacy trial that led to FDA approval of PSMA PET.

In addition, the National Comprehensive Cancer Network (NCCN) and the Society of Nuclear Medicine and Molecular Imaging (SNMMI) included PSMA PET in published prostate guidelines and established appropriate use criteria (AUC) for this new imaging technique.

What is the main focus of the JAMA Oncology paper?

The paper focuses on the role of 68Ga-PSMA-11 PET at time of initial staging. The goal was to compare the imaging results to nodes found at time of surgery in order to determine the sensitivity and specificity of PSMA PET. This study showed that PSMA PET has a high specificity for the detection of nodal metastases, although the sensitivity for small pelvic nodes was lower than expected.

What is the significance of NCCN including PSMA PET in their published prostate guidelines?

This is a very important development. NCCN guidelines are used by many insurance companies to determine what tests to cover. The inclusion in these guidelines will help increase the likelihood of insurance coverage of PSMA PET at time of initial staging and biochemical recurrence. Additionally, the NCCN guidelines recently convinced the FDA to include 68Ga-PSMA-11 PET at time of initial staging for patients with prostate cancer.

What are some highlights from the SNMMI’s appropriate use criteria for PSMA PET imaging?

Similar to the NCCN guidelines, the SNMMI AUC document will have an impact on insurance coverage. Through the Protecting Access to Medicare Act (PAMA), high-cost imaging studies will be required to use clinical decision support mechanisms. The AUC document will provide the required documentation to support the use of PSMA PET in the appropriate indications.

What’s next for PSMA PET imaging?

Next up is to grow the use of PSMA PET for patient selection in PSMA radioligand therapy.

Currently there are no FDA approved agents for PSMA radioligand therapy, but we expect approval of 177Lu-PSMA-617 in the coming months, and so we will start using PSMA PET in this patient population. Additionally, now that PSMA PET will be widely available, we will need to complete clinical trials in order to understand how to manage patients better based on the results of PSMA PET imaging studies. 

Learn more at https://www.ucsf.edu/news/2020/12/419196/ucsf-ucla-gain-fda-approval-prostate-cancer-imaging-technique

PSMA PET scan identifies cancer that is often missed by current standardof-care imaging techniques.

Promoting Academic Success in Radiology & Biomedical Imaging

Under the direction of the Chair, Dr. Christopher Hess, the Radiology Academic Affairs team manages the complexities of the often-opaque academic processes for all our faculty and our non-faculty academics [NFAs]. Our team have worked over the last 3 years to streamline and clarify many processes including faculty and NFA hiring, annual reviews, department committee composition, and the academic advancement processes, to promote transparency, equity, and diversity in our department. We are building on our faculty mentoring program and have revamped and created new faculty development workshops and courses. We are continually improving on systems so that we can better support and celebrate our faculty in their career pathway to success.

Recruitment

Our department has been extraordinarily busy with a much-increased clinical workload, along with strategic expansion of our radiology clinical sites – BCH Oakland, Berkeley Outpatient Center, and the development of a new Emergency Radiology section at ZSFG. This, coupled with the retirement of three beloved faculty has necessitated multiple faculty searches.

As of June 2022, our Department of Radiology has 140 faculty, with 37 Imaging Scientists and 103 Radiologists, including 8 emeritus faculty working on recall. Four of our new Radiology faculty commenced work since February 1, 2022, and 11 additional faculty joined our Department between July 1 and November 1 this calendar year. During the last 9 months we have also successfully completed five national searches for section chiefs with the appointments of Dr. Jane Wang for Abdominal Imaging, Dr. Pallav Kolli for Interventional Radiology, Dr. Vinil Shah for Neuroradiology, Dr. Jesse Courtier for

Mission Bay Pediatric Radiology, and Dr. Raymond Sze for Oakland Children’s Pediatric Radiology. It has been an extraordinary recruitment year for our department, and our academic affairs team is so appreciative of the many faculty who have been part of, or chaired, our search committees. Thank you to all faculty for attending presentations, interviews, and welcoming candidates to our campuses! While it can be such a time-consuming process, successfully expanding our teams has been highly rewarding this past year. Please see the separate introduction pages for each of our new faculty.

Faculty Mentoring Program

Our Faculty Mentoring Program, designed to create mentoring networks for each of our assistant professors, continues to guide and support the faculty through career direction decisions and research collaborations, as well as providing sponsorship opportunities. We currently have 31 MD Assistant Professors and 7 PhD Assistant Professors in the mentoring program. Sri Nagarajan, PhD, was appointed as Director of Mentoring for the Imaging Scientist PhD faculty in 2021.

It is only through the dedication of each our faculty that the mentoring program is so successful. In January 2022 we again honored and celebrated all faculty mentors during National Mentoring Month, with our custom department tote bags. This June we were thrilled to acknowledge the extraordinary mentoring work of Dr. Dan Vigneron who was the recipient of the 2022 Radiology Award for Outstanding Faculty Mentoring. Dan was previously the Director of Mentoring for our imaging scientists and has been an extraordinary mentor for imaging scientists and radiologists in our department.