Robotic transperineal biopsy: an initial Australian experience of a novel device – the biobot Mona Lisa.

Abstract

INTRODUCTION & OBJECTIVES: There has been a rapid uptake in the use of both multiparametric MRI and transperineal biopsy in Australia recently, making prostate biopsy safer (1) and more accurate (2). Various biopsy templates as well as methods and technologies for targeting lesions exist, but the optimal approach is yet to be defined. This study aims to analyse the initial experience of a novel robotic device with MRI/US fusion capability designed specifically for transperineal biopsy. METHOD: An institution ethics committee-approved prospective database was used to record all transperineal biopsies. Data from all biopsies using the TGA/FDA/CE-approved iSR'obot Mona Lisa™ were extracted and analysed. All men underwent general anaesthetic and were given a single prophylactic IV dose of cephazolin only. The Mona Lisa™ was mounted to the operating table and the TRUS probe inserted. Targeted and template core positions were marked out on a touchscreen in 3 dimensions. The Mona Lisa™ automatically moved its needle guide sequentially for each predetermined core position. Biopsies were taken via only 2 perineal skin punctures in a biconical configuration. The number of cores taken was dependent on prostate volume and MRI status. All men had template cores taken and those with a positive MRI had targeted cores taken also. (see video in presentation). RESULTS: The first 18 cases of transperineal biopsy using the iSR'obot Mona Lisa™ were performed from July to October 2015. Mean PSA was 11.5 (range 2.7–51). Fourteen men presented for initial work-up of suspected prostate cancer, 3 for previous negative biopsy, and 1 for re-biopsy on active surveillance. Of the 17 who had a prior MRI, 13 were positive (PIRADS 4 or 5) and 4 were negative (PIRADS 2). No MRIs were reported as PIRADS 1 or 3. Of the 13 men with positive MRIs, 7 had cognitive fusion and 6 used the Mona Lisa™ MRI/US fusion software. The mean numbers of targeted and template biopsy cores were 5.3 and 23.4 respectively. There were no episodes of retention or infection. Of the 4 men with negative MRIs, 3 had no cancer on biopsy and 1 had a microfocus of Gleason 6 only. Of the 13 men with positive MRIs, 12 had significant cancer (Gleason 7–9) on biopsy. Of the 12 men with positive targeted cores, 11 had the highest Gleason score found on targeted biopsy cores. CONCLUSIONS: Using the iSR'obot Mona Lisa™ for robotic transperineal prostate biopsy was safe and feasible. Even from the start of the learning curve, when using this device for biopsy, MRI did not miss any significant cancer and there was excellent correlation of positive MRI to significant cancer on biopsy. Targeted cores hit the tumour with highest Gleason score in all but one patient. Although the Mona Lisa™ includes the option of MRI/US fusion, it can also be used with high accuracy for cognitive fusion. Further experience by multiple users is required for more meaningful results.