PET/MRI can improve diagnostic accuracy for prostate cancer patients and help avoid unnecessary biopsies, in response to latest research published within the April issue of The Journal of Nuclear Medicine. By applying the PRIMARY scoring system to PET/MRI results, researchers found that greater than 80 percent of unnecessary biopsies might be avoided on the expense of missing one in eight clinically significant prostate cancer cases.

The Prostate Imaging Reporting and Data System (PI-RADS) is a five-point scale used to guage suspected prostate cancer on MR images. PI-RADS category 3, which presents an unclear suggestion of clinically significant prostate cancer, stays a diagnostic challenge. Although biopsy is advisable under the present guidelines, lower than 20 percent of PI-RADS 3 lesions contain clinically significant prostate cancer.

PI-RADS 3 lesions present a dilemma to each urologists and patients because immediate biopsy might be unnecessary; nonetheless, a monitoring strategy could lead on to some missed diagnoses of clinically significant prostate cancer. Hence, specifically ruling out clinically significant prostate cancer amongst PI-RADS 3 lesions has significant clinical implications.”

Hongqian Guo, MD, urologist at Nanjing Drum Tower Hospital on the Affiliated Hospital of Nanjing University Medical School in Nanjing, China

On this study, 56 men with PI-RADS 3 lesions underwent ⁶⁸Ga-PSMA PET/MRI. The five-level PRIMARY system, which is predicated on a mix of ⁶⁸Ga-PSMA pattern, localization, and intensity information, was used to report prostate ⁶⁸Ga-PSMA PET/MRI findings. After imaging, all patients underwent prostate systematic biopsy together with targeted biopsy to find out clinically significant prostate cancer.

Among the many 56 patients, clinically significant prostate cancer was detected in eight patients (14.3 percent) by biopsy. When a PRIMARY rating of not less than 4 was used to make a biopsy decision in men with PI-RADS 3 lesions, 40 of 48 (83.3 percent) participants could have avoided unnecessary biopsies, on the expense of missing 1 in 8 (12.5 percent) of clinically significant prostate cancer cases.

“By demonstrating the additive value of ⁶⁸Ga-PSMA PET/MRI in classifying PI-RADS 3 lesions, this study provides latest insight into the clinical indication for ⁶⁸Ga-PSMA PET/MRI,” noted Guo. “In the longer term, PI-RADS 3 patients might be referred for ⁶⁸Ga-PSMA PET/MRI before prostate biopsy.”

This study was published online in March 2024.