Next-Generation Imaging a ‘Gold Standard’ in Metastatic Prostate Cancer

In patients with advanced or metastatic prostate cancer, imaging is a crucial process. Specifically, with next-generation imaging, doctors can more accurately determine patients’ survival outcomes and see if changes in treatment are necessary, an expert explained.

During the CURE® Educated Patient® Prostate Cancer Summit, Dr. Jack R. Andrews, a urologic oncologist at the Mayo Clinic in Arizona, spoke to patients with prostate cancer about the use of next-generation imaging.

A biomarker helpful in diagnostics and determining the stage of localized cancer, Andrews noted, is prostate-specific membrane antigen (PSMA).

“Essentially, [PSMA is] a cell membrane protein that's highly expressed in prostate cancer cells,” he explained. “But probably more importantly is that it's minimally expressed in other tissue. And because it's minimally expressed in other tissues, we're able to leverage that and use it for both diagnostic purposes and treatment purposes, but it's important to realize that its function is fairly poorly understood into what it actually does biologically.”

PSMA Diagnostics and Staging of Prostate Cancer

Common terms when discussing imaging for prostate cancer include a PSMA positron emission tomography (PET) scan, Andrews said. A PET scan is an imaging test that helps show the metabolic or biochemical function within the body, according to the Mayo Clinic. Before PET scans, patients receive a radiotracer drug, which helps doctors better see bodily functions.

Currently, there are three PSMA PET scans approved by the Food and Drug Administration (FDA), Andrews explained. These approved PSMA PET scans include the Gallium 68 PSMA-11 PET scan approved in 2020, the Pylarify PSMA PET scan approved in 2021 and the Posluma PSMA PET scan approved in 2023.

“All three of these PSMA PET radiotracers are approved in both the initial staging setting and the PSA failure after a local treatment setting,” he said.

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He emphasized that when patients undergo these different imaging tests, it can help doctors improve their ability to detect metastasis, or potential disease spread.

“With the advent of PSMA PET and improved imaging, we can more appropriately stratify [arrange] patients that we couldn't do as well previously, and so we may see survival outcomes increase in both non-metastatic and metastatic patients without any change in treatment,” Andrews noted.

The Crucial Role of PSMA PET Scans in Prostate Cancer

Previously, before the “PSMA PET era,” Andrews said, patients with prostate cancer underwent conventional imaging and received treatments that “really weren’t that great.”

Now patients have access to PSMA PET scans that help detect metastasis earlier, he noted.

“But if we don't change how we treat patients, we won't ultimately change the patient's survival outcome,” Andrews emphasized. “And so really, the next step is utilizing PSMA PET to then change our therapy and delay death and improve patient outcomes.”

LEARN MORE: ‘Paths’ of Treatment Possibilities in Prostate Cancer

He explained that using metastasis-directed therapy without androgen deprivation therapy (ADT; a type of hormone therapy) in patients with a single recurrent metastasis after local treatment is something of interest following a PET scan.

ADT is “the mainstay treatment of metastatic prostate cancer,” Andrews said. Nonetheless, some patients with metastatic prostate cancer may die because they develop castration resistance, which stems from ADT. 

“This ultimately tells us that PET imaging in the biochemical recurrent setting can change our treatment decision and that some men with isolated early metastasis may have a durable response to metastasis-directed therapy, and some may even be cured,” Andrews said. “We may be able to delay androgen deprivation therapy with PET-directed metastasis-directed therapy in appropriate patients.

“… I think it's important to realize in the metastatic setting that PSMA PET is now the gold standard. We're truly in the PSMA PET era. PSMA PET has replaced conventional imaging, and PSMA PET can be used with [prostate-specific antigen] for the surveillance of metastatic prostate cancer patients getting treatment for prostate cancer.”

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