Introduction

There exists a growing debate as to whether mp-MRI targeted biopsy alone without standard template is sufficient for evaluation of patients with suspicion of prostate cancer. We investigate and describe our experience with fusion biopsy.

Methods

We retrospectively reviewed medical charts of patients undergoing fusion transrectal US-guided biopsy from July 2014 through February 2016. Patients eligible for fusion biopsy had identifiable lesions on mp-MRI compatible to the fusion biopsy system. Each lesion was graded according to the Prostate Imaging Reporting and Data System version 2 (PIRADSv2) by a radiologist. The fusion biopsy procedure included a minimum of 2 core biopsies for each target lesion and a standard 12 core template biopsy. Clinically significant disease was defined as Gleason Score 7 or higher adenocarcinoma of the prostate.

Results

A total of 255 patients with a mp-MRI-identified lesion underwent fusion and standard template biopsy. Indications included elevated PSA without a prior biopsy (11.4%), rising PSA with a prior negative biopsy (52.4%), active surveillance for prostate cancer (33.3%) and isolated abnormal digital rectal exam (2.7%). Pathologic results from the fusion-targeted biopsy were compared to those from the concomitantly performed standard template biopsies (Table 1). Of patients with PIRADSv2 4 or 5 lesions (n=145), 40.0% had no cancer, 25.5% had Gleason 6, 25.5% had Gleason 7, and 9.0%, had Gleason 8-10 on final histopathology. Fusion Biopsy of PIRADSv2 3 lesions (n=66) revealed no cancer in 65.2%, Gleason 6 in 15.2%, Gleason 7 in 19.7% and Gleason 8-10,in 0% of patients. Of 83 patients with clinically significant cancer, 26 (31.3%) would have been missed on standard biopsy and 12 (14.5%) would have been missed using fusion biopsy alone. Concordance between both biopsy modalities was 63.1%.

Conclusions

mp-MRI targeted fusion biopsy improves the detection of clinically significant prostate cancer in select patients. However, our results demonstrate that a significant proportion of these cancers will not be detected by a targeted biopsy alone. Therefore, standard template biopsies should remain an integral component of any fusion biopsy program.

Funding

None