Can an Integrated Approach with PSMA PET/CT and Prostate MRI Enhance Detection of Extraprostatic Extension?

Emerging research suggests that an integrated approach to combining data from prostate magnetic resonance imaging (MRI) and prostate-specific membrane antigen positron emission tomography/computed tomography (PSMA PET/CT) may offer improved utility in detecting extraprostatic extension (EPE) in patients with prostate cancer (PCa).

For the study, recently presented at the Radiological Society of North America (RSNA) conference, researchers compared three different approaches for integrating data from PSMA PET/CT and prostate MRI in 67 men (median age of 66). The study authors noted that 76.1 percent of the cohort (51 patients) had EPE.

The evaluated approaches included: an integrated Likert scale model, which indicated EPE if there were positive findings on either MRI or PSMA PET/CT; a combination of PI-RADS and PRIMARY scoring; and a combination of capsular contact length (LCC) data from prostate MRI and maximum standardized uptake value (SUVmax) from PSMA PET/CT, according to the study.

While the Likert scale model offered an 80.4 percent sensitivity rate for EPE detection, the researchers noted low specificity at 31.4 percent. The combination of PI-RADS and PRIMARY scoring provided an 87.5 percent specificity rate but only a 31.3 percent sensitivity rate, according to the study authors. In contrast, the researchers found that the approach of combining MRI-based LCC data with the SUVmax from PSMA PET/CT provided an 80.4 percent sensitivity rate and an 81.2 percent specificity rate.

(Editor’s note: For additional coverage of the recent RSNA conference, click here.)

The study authors noted that employing thresholds of LCC < 1.7 cm and an SUVmax > 12 led to upgraded EPE suspicion in eight patients with pathological EPE confirmed in seven of these patients.

“The results of this study show that combining morphological information from MRI and PSMA expression on PET/CT can be a simple and pragmatic solution for performing integrated EPE assessment,” added lead study author Sungmin Woo, M.D., Ph.D., an assistant professor of radiology at the New York University (NYU) Grossman School of Medicine in New York City, and colleagues.

(Editor’s note: For related content, see “Should PSMA PET/CT Supplant MRI for Staging of Patients with High-Risk PCa?,” “Could a Specificity Emphasis for MRI-Based T-Staging Reinvent Staging for Prostate Cancer?” and “Can AI Enhance PET/MRI Assessment for Extraprostatic Tumor Extension in Patients with PCa?”)

Reference

1. Woo S, Freedman D, Becker AS, et al. Evaluating extraprostatic extension of prostate cancer: pragmatic integration of MRI and PSMA PET/CT. Presented at the Radiological Society of North America (RSNA) conference, Nov. 30-Dec. 4, 2025, Chicago.