Study Suggests Merits of PSMA PET/MRI for Detecting HCC in LI-RADS 3 Cases

Can prostate-specific membrane antigen (PSMA) positron emission tomography (PET)/magnetic resonance imaging (MRI) have an impact in differentiating LI-RADS 3 cases?

In a new prospective study, recently published in the Journal of Nuclear Medicine, researchers examined the use of (68Ga)Ga-PSMA-11 PET/MRI in 19 patients with cirrhosis and a total of 54 LI-RADS 3 observations from MRI.

In addition to detecting 12 out of 13 cases of hepatocellular carcinoma (HCC) for a 92 percent sensitivity rate, the study authors found that PET/MRI offered 95 percent specificity, 94 percent accuracy, an 86 percent positive predictive value (PPV) and a 97 percent negative predictive value (NPV).

Lead study author Onofrio Catalano, M.D., Ph.D., in a recent interview with Diagnostic Imaging, said the voxel-by-voxel assessment of metabolic and morphologic data as well as the advanced motion correction afforded by PET/MRI facilitates improved visualization of lesions previously characterized as LI-RADS 3 with conventional imaging.

“We had a pretty high accuracy, which is about 94 percent, (for) a subset of critical lesions that by (conventional) imaging we cannot characterize and using (PET/MRI), we can characterize 94 percent of those that are not characterized in any way without a biopsy,” maintained Dr. Catalano, an associate professor of radiology at Harvard Medical School and medical director of PET/MR at Mass General Brigham in Boston.

Dr. Catalano added that he was surprised by the effectiveness of PET/MRI in differentiating very small lesions.

“In this case, we were able to properly detect or rule out uptake even in small lesions with the site of the lesion (approximately) 12 millimeters for malignant lesion (and) 9.5 millimeters for benign lesions. So they're smaller lesions but nonetheless, the study proved useful also in this challenging situation,” noted Dr. Catalano.

(Editor’s note: For related content, see “Meta-Analysis Examines MRI-Based AI for Predicting Microvascular Invasion in Hepatocellular Carcinoma,” “Key MRI Findings Predictive of Treatment Response for Unresectable Hepatocellular Carcinoma” and “Could an Emerging PET Tracer be a Game Changer for Detecting Hepatocellular Carcinoma?”)

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