A Cohort of Transperineal Electromagnetically Tracked MR/US Fusion Guided Biopsy: Assessing the Impact of Inter-Reader Variability on Cancer Detection.

We evaluated the ability to detect clinically significant prostate cancer (CS-PCa) using a novel electromagnetically (EM) tracked transperineal MR/US fusion guided targeted biopsy (tpTBx) platform and the impact of inter-reader variability on cancer detection. We hypothesized that tpTBx would be safe and efficacious for the detection of PCa and that considerable variability in the accuracy of predicting PCa diagnosis amongst mpMRI readers would be found.

176 patients with suspicious lesions detected on multiparametric magnetic resonance imaging (mpMRI) underwent a systematic modified Barzel template biopsy (12-core) transperineal biopsy (tpSBx) and tpTBx with EM tracking (UroNav, Philips Healthcare, Best, Netherlands) in the same setting. Cancer detection rates (CDR) were stratified by PI-RADS v2 scores and compared with Fisher's exact test. Area under the curve (AUC) was calculated for prostate specific antigen (PSA), PSA density, PI-RADS score, and sub-group analysis of individual readers PIRADS scores with respect to CDR and CS PCa.

Overall CDR was 76.7% (135/176), of which 76.3% (103/135) were CS. Among the 135 patients with PCa, tpTBx detected 90.4% (122/135) of cases, either alone or in combination with tpSBx. The remaining 9.6% (13/135) of cases missed by tpTBx were diagnosed by tpSBx alone, of which 3 were CS. Conversely, tpSBx missed 14% (19/135) of cases, 14 of which were CS-PCa. Sensitivities for tpTBx and tpSBx were 90.4% and 85.9% respectively. On a per-lesion basis, PI-RADS score (AUC 0.74) outperformed both PSA (AUC 0.59) and PSA density (AUC 0.63) in discriminating CS disease from non-CS PCa on tpTBx. Although not formally statistically tested, AUC amongst different mpMRI readers appeared to display considerable variability. There were no adverse events including sepsis.

EM-tracked tpTBx of MRI visible lesions enhanced the ability of tpSBx to detect PCa with greater sensitivity for CS disease. These findings suggest tpTBx as a safe, alternative fusion platform for patients with a suspicious lesion on prostate MRI. The assessment of inter-reader variability in conjunction with prediction of CS-CaP and CDR is an important first step for quality control in implementing an MR based screening program.

BJU international. 2019 Nov 24 [Epub ahead of print]

Ethan Wajswol, Jared S Winoker, Harry Anastos, Ugo Falagario, Kennedy Okhawere, Alberto Martini, Patrick-Julien Treacy, Nicholas Voutsinas, Cynthia J Knauer, John P Sfakianos, Sara C Lewis, Bachir A Taouli, Ardeshir R Rastinehad

Department of Urology, Icahn School of Medicine at Mount Sinai, New York, NY., Department of Radiology, Icahn School of Medicine at Mount Sinai, New York, NY.