What Is the Optimal MRI-Guided Biopsy Approach in Prostate Cancer?

June 13, 2019

The PAIREDCAP trial looked at different biopsy approaches to see which has the highest cancer detection rate for prostate cancer.

Among men undergoing first-time prostate biopsy, MRI-visible lesions are associated with a heightened risk of clinically significant prostate cancer, according to new research. Combining targeted and systematic biopsy approaches can offer the highest chance of detecting the cancer.

“Despite advances, the optimal method for use of MRI-guided biopsy is not yet clear,” wrote study authors led by Fuad F. Elkhoury, MD, of the David Geffen School of Medicine at UCLA. “Is sampling of only MRI-visible lesions (or regions of interest) sufficient, or should systematic sampling also be used?” Other questions include whether MRI guidance should be reserved for men undergoing repeated biopsy, and if a software-based image fusion is necessary.

The PAIREDCAP trial was a prospective, paired cohort study comparing the cancer detection rate (CDR) of systematic prostate biopsy, a cognitive fusion biopsy method, and a software fusion method. It included a total of 300 men, 248 of whom had MRI-visible lesions; these men underwent all three biopsy procedures at the same time. The results were published in JAMA Surgery.

The overall CDR for clinically significant prostate cancer was 70.2% among the men with MRI-visible lesions. When the biopsy methods were used alone, the CDR was 46.8% for cognitive targeting, 60.1% for systematic sampling, and 62.1% for either cognitive or software fusion (P = .70). This means that from 20 of 174 cases (11.5%) to 58 of 174 cases (33.3%) of clinically significant disease would have been missed with any one biopsy method. The greatest biopsy sensitivity was achieved when systematic and targeted results were combined.

In the 52 men without MRI-visible lesions, the CDR was 15%. A larger percentage of the group with MRI-visible targets had elevated prostate-specific antigen (PSA) density. Combining a negative MRI with a low PSA density resulted in only an 8% incidence of clinically significant disease.

“The present PAIREDCAP trial provides evidence in favor of a prebiopsy MRI to identify men naive for biopsy who are at increased risk,” the authors concluded. “The discordance of tumor locations between biopsy methods indicates that targeted and systematic biopsies may detect different tumors.”

In an accompanying editorial, Ahmad Shabsigh, MD, and Cheryl T. Lee, MD, both of the Ohio State University Wexner Medical Center in Columbus, wrote that the results do suggest that relying on targeted biopsy alone is suboptimal. “If the urologist does not have a fusion machine, cognitive biopsy is still essential,” they wrote. “The results reflect the reality that multiparametric MRI is better than what clinicians have had, but there is still a way to go.”