Assessment of the Accuracy of Biparametric MRI/TRUS Fusion-Guided Biopsy for Index Tumor Evaluation using Postoperative Pathology Specimens

Abstract

Abstract Background Multiparametric MRI (mpMRI) is widely used for prostate cancer diagnosis, surveillance, and staging; however, it has some limitations, including higher cost, longer examination time, and the use of gadolinium-based contrast agents. This study aimed to investigate the accuracy of index tumor (IT) assessed preoperatively using biparametric MRI (bpMRI)/transrectal ultrasound (TRUS) fusion prostate biopsy with radical prostatectomy (RP) specimens. Methods We included 69 patients diagnosed with prostate cancer through bpMRI/TRUS fusion-guided biopsy of lesions with Prostate Imaging Reporting & Data System (PI-RADS) category ≥ 3 and underwent robot-assisted laparoscopic radical prostatectomy (RARP) at our institution between July 2017 and December 2021. The localization of preoperative and postoperative IT, highest Gleason score (GS), and tumor diameter were examined in these patients. Results The preoperative cT stage matched the postoperative pT stage in 34 cases (48%), while 20 cases (30%) were upstaged, and 15 cases (22%) were downstaged (Weighted Kappa = 0.236). The preoperative and postoperative IT localization were consistent in 59 cases (85.5%). The concordance rate between Gleason groups in targeted biopsy and RP specimens was 48%, with an upgrade in 17 cases (24%) and a downgrade in 29 cases (28%) (Weighted Kappa = 0.424). The IT maximum diameter and maximum cancer core length on biopsy were correlated with RP tumor maximum diameter (p = 0.007, p = 0.008). Conclusion In conclusion, the diagnostic accuracy of bpMRI/TRUS fusion biopsy is comparable to that of previous reports using mpMRI. The findings suggest that bpMRI/TRUS fusion biopsy can be a cost-effective and time-saving alternative.