Transperineal targeted prostate biopsy comparable to transrectal fusion-guided approach

Transperineal targeted biopsy with electromagnetic-tracking fusion technology is low risk and detects clinically significant prostate cancer as well as the transrectal fusion-guided approach, Icahn School of Medicine at Mount Sinai investigators reported in a study published in Urology.¹ “This is of particular importance in the context of rising rates of bacterial resistance, greater calls for antibiotic stewardship, and cumulative infectious risks for patients on active surveillance or focal therapy protocols undergoing multiple repeat biopsies,” the investigators wrote.

The study helps to dispel the dogma suggesting the transperineal approach is better for anterior tumors when using a fusion biopsy approach, according to the study’s senior author, Art R. Rastinehad, DO, associate professor of urology and radiology at the Donald and Barbara Zucker School of Medicine at Hofstra/Northwell in East Garden City, New York, and vice chairman of urology at Lenox Hill Hospital, and system director for prostate cancer at Northwell Health, both in New York, New York.

“We found no difference in the biopsy techniques, even in subgroup analyses stratifying for lesion suspicion, size, and location with magnetic resonance ultrasound fusion biopsy, whether using transrectal or the transperineal approach,” Rastinehad said. “But [the paper] does support the dogma that standard transrectal ultrasound biopsy approach does undersample the anterior of the prostate compared with a standard transperineal biopsy.”

The current gold-standard technique for diagnosing prostate cancer in at-risk men, systematic 10- to 12-core prostate biopsy using transrectal ultrasound has a 20% to 30% false-negative rate and lacks specificity for detecting clinically significant disease, according to the paper. Advances in multiparametric magnetic resonance imaging (mpMRI) and magnetic resonance ultrasound have improved clinicians’ ability to visualize and target suspicious lesions. But there is no consensus about the optimal targeted prostate biopsy approach or platform.

The investigators conducted a prospective nonrandomized single-surgeon series of magnetic resonance ultrasound comparing transperineal and transrectal prostate biopsy, using the same electromagnetic tracking platform, UroNav.

“I believe this is the first paper to compare the transrectal approach or transperineal approach using the same fusion biopsy platform, allowing for a direct comparison of the transrectal versus transperineal approaches with respect to the targeted and nontargeted biopsy cores,” Rastinehad said.

The investigators studied 379 men considered at risk of prostate cancer because of a higher than 2.5-ng/mL prostate-specific antigen (PSA) level or abnormal digital rectal exam result. Among those patients, 168 underwent transperineal systematic 12-core biopsy and transperineal targeted prostate biopsy with electromagnetic tracking. The investigators compared those results with those of 211 patients who had a similar procedure with a transrectal approach.

They found the rate of clinically significant disease detection was 59% by transperineal targeted biopsy versus 54% for transrectal targeted prostate biopsy.

They also found no significant difference in the likelihood of detecting prostate cancer or clinically significant disease when they adjusted for PSA level, previous biopsy status, prostate volume, Prostate Imaging Reporting and Data System version 2 score, lesion volume, and lesion location.

The investigators reported no serious complications post biopsy in both the transperineal and transrectal groups. Six patients in the transperineal group had urinary retention compared with 1 patient in the transrectal group. One patient in the transrectal group developed sepsis that resolved with intravenous and oral antibiotics.

“We found that regardless of fusion biopsy approach, you are able to adequately sample the suspicious area detected on mpMRI,” Rastinehad said. “The urologic dogma that the transperineal approach helps sample the anterior of the prostate is only applicable to the nontargeted approach. The fusion biopsy targeting is the great equalizer between the transperineal and transrectal approaches, and if you can see it on mpMRI, you can sample it adequately regardless of the approach.”

This is good news as urologists move toward a transperineal approach, in part because of rising rates of infectious complications associated with transrectal biopsies, according to Rastinehad.

“This study does demonstrate that the transition to a transperineal from a transrectal approach will not decrease the diagnostic accuracy of your patients with an elevated PSA [level] and a suspicious mpMRI [finding],” he said.

Disclosures: Philips Healthcare funded the study, and Rastinehad is a consultant for Philips Healthcare.

Reference

1. Winoker JS, Wajswol E, Falagario U, et al. Transperineal versus transrectal targeted biopsy with use of electromagnetically tracked MR/US fusion guidance platform for the detection of clinically significant prostate cancer. Urology. Published online September 18, 2020. doi:10.1016/j.urology.2020.07.072