Design: Multi-institutional analysis of prospective databases
Population: 1,587 men having combined MRI-targeted and systematic transperineal biopsy at 5 institutions
Primary outcome: Actionable intelligence metric and reduction metric
Effect: AIM 27.4%; ReM 83.3%; up to 17% of significant cancers missed without systematic cores

This study, published in June, analysed 1,587 men in prospective databases at five institutions who had both MRI-targeted and systematic transperineal prostate biopsy. Half had Grade Group 2 or higher cancer.

Two metrics were used. Targeted cores detected a higher grade than systematic cores alone in 27.4% of men, showing the value of targeting. Systematic cores could have been omitted without loss in 83.3%, meaning they changed the result in the remainder: up to 17% of clinically significant cancers would have been missed with targeted biopsy alone. These figures held across PI-RADS scores and prior biopsy status. PI-RADS 5 lesions were more often upgraded by systematic cores, and men with a previous negative biopsy less often.

Performance differed between institutions, which suggests technique and MRI quality matter.

The practical point is that dropping systematic cores is a trade-off, not a free gain. Where a targeted-only approach is considered, it should be discussed with the man and his risk tolerance, and MRI and biopsy quality should be audited locally.

Combine targeted and systematic cores at transperineal biopsy unless a targeted-only approach has been discussed.
Be particularly cautious about omitting systematic cores with PI-RADS 5 lesions.
Discuss the risk of a missed significant cancer if systematic cores are omitted.
Audit local MRI and biopsy performance, as results varied between centres.
Consider targeted-only sampling more readily after a previous negative biopsy.

Why it matters

The move to targeted-only biopsy is gathering pace, and this puts a number on what it costs.

The statistics, in plain English

The 27.4% is the share in whom targeting found something more important than systematic sampling; the 83.3% is the share in whom systematic sampling added nothing. The authors estimate that omitting systematic cores would have missed up to about one in six clinically significant cancers.