Could a New PSMA PET Agent Improve Detection of Distant Metastatic Lesions in Patients with Prostate Cancer?

Conventional imaging can be limited in the detection of metastatic lesions associated with prostate cancer. Specificity rates for computed tomography (CT) are “reportedly all over the map,” ranging from 40 to 60 percent, pointed out Brian Chapin, MD, in a video interview from the recent American Society of Clinical Oncology Genitourinary Cancers (ASCO GU) symposium.

“When there is lymph node involvement … , the lymph nodes themselves can be small and the deposits within those lymph nodes can be as small as 1 to 3 mm in size sometimes so it’s really hard to identify those with a conventional imaging approach,” explained Dr. Chapin, an associate professor, director of clinical research and fellowship program director in the Department of Urology within the Division of Surgery at the University of Texas MD Anderson Cancer Center in Houston.

However, in recent research presented at the ASCO GU symposium, Dr. Chapin and colleagues found the use of the radiopharmaceutical agent 18F-rhPSMA-7.3 (Blue Earth Diagnostics/Bracco Imaging) with positron emission tomography (PET) led to verified detection of distant metastatic lesions in 10 to 15 percent of 335 patients with newly diagnosed intermediate or high-risk prostate cancer.

“One in 10 patients that we had planned to bring to the operating room with presumed localized prostate cancer indeed had metastatic disease, which is quite substantial, especially when you’re looking at a population of men who had (negative conventional imaging with CT, MRI and bone scan),” emphasized Dr. Chapin. “Those were all negative and you’re identifying metastatic disease in one in 10 patients. That is pretty substantial because that can change our clinical decision-making in how we treat patients.”

(Editor’s note: For related content, see “Study Assesses PET Agent for Detecting Pelvic Lymph Node Metastases in Patients with Prostate Cancer,” “Could an Emerging PSMA/PET Imaging Agent Improve the Detection of Recurrent Prostate Cancer?” and “Is PSMA PET/CT More Beneficial than Bone Scintigraphy in Detecting Bone Lesions in Cases of High-Risk Prostate Cancer?”)

For more insights from Dr. Chapin, watch the video below.