PSMA PET/CT better detects prostate cancer spread, long-term outcomes over conventional imaging
A recently approved molecular imaging technique enhances long-term prediction capabilities for patients with potentially lethal prostate cancer, surpassing traditional approaches, researchers reported Monday in JAMA Network Open.
The U.S. Food and Drug Administration greenlight the first commercially available PSMA PET imaging agent—Gallium-68—in December 2020, with a second drug (Pylarify) approved in May. Early tests with PSMA PET/CT show it can better spot non-localized cancer compared to legacy techniques, but the hybrid method remains new and evidence is still scant.
With this in mind, UCLA researchers developed a tool that uses multiple PET/CT-based variables to predict the probability of detecting cancer spread among patients whose traditional scans don’t show additional involvement. The nomogram earned high praise, acting as a surrogate for PSMA PET/CT imaging, said Michael Xiang, MD, assistant clinical professor of radiation oncology at UCLA’s school of medicine.
“The PSMA nomogram was designed to predict the positivity of PSMA PET/CT at initial diagnosis, without regard to eventual clinical outcomes, but interestingly, this PSMA PET/CT-based tool provided better risk discrimination than existing tools that were designed specifically to predict clinical outcomes,” Xiang added Monday. “This may speak to the significance of using PSMA PET/CT findings as a marker of overall disease course, and our results contribute to a growing body of data supporting the clinical use of this technique in the initial evaluation and management of high-risk patients.”
The primary study enrolled 5,275 patients with high-risk prostate cancer who were treated via radiation or surgery across 15 centers between 1995 and 2018.
The nomogram, which models individual risk of non-localized upstaging on PSMA PET/CT, proved “significantly” predictive of all clinical endpoints, including distant disease spread, cancer mortality and overall survival.
Results were validated using two external datasets: the National Cancer Database (88,000-plus patients) and the Surveillance, Epidemiology, and End Results Program repository (24,000 patients).
In September, the National Comprehensive Cancer Network updated its guidelines for imaging prostate cancer to include new PSMA-PET strategies. The research team hopes insurers follow suit, ensuring patients see the maximum benefits.
“With insurance coverage, this game-changer technology will ultimately become part of the routine staging of prostate cancer patients,” said Jeremie Calais, MD, MSc, director of the Clinical Research Program at UCLA’s Department of Molecular and Medical Pharmacology.
Read the entire study here.
Matt joined Chicago’s TriMed team in 2018 covering all areas of health imaging after two years reporting on the hospital field. He holds a bachelor’s in English from UIC, and enjoys a good cup of coffee and an interesting documentary.