Robot-assisted MRI/US fusion transperineal prostate biopsy using the Biobot system: a single-centre experience

Abstract

Treatment decisions for prostate cancer (PCa) still rely on histological confirmation from a biopsy [1]. In today's precision medicine era, cutting-edge technologies are revolutionising clinical practice. Although the potential of robotic surgery in urology is widely acknowledged, the possibility of robot-assisted prostate biopsies (RA-PBx) remains largely unexplored [2].

Newly available RA-PBx systems, such as the Biobot Mona Lisa (Biobot Surgical, Singapore), combine robotic precision with the transperineal approach, offering accurate PCa mapping, efficient site storage, and potential benefits for focal treatments [3, 4]. Moreover, they promise lower complication and infective rates, as well as improved patient comfort by enabling a minimally invasive sampling process that requires only two puncture sites [5-7].

This study aims to demonstrate the RA-PBx process using the Biobot platform and to evaluate its feasibility and safety.

The study included 44 patients with a median (IQR) age of 64.5 (58.7–70) years and a median (IQR) PSA level of 8.35 (5.57–10.97) ng/mL. Of these, 22 patients were biopsy-naïve, six underwent biopsy due to persistent clinical suspicion, nine had confirmatory biopsies following previous random sampling and seven were biopsied within an active surveillance setting.

Preoperative mpMRI indicated suspicious areas in 37 patients, was negative in four patients and was not conducted in three patients due to the presence of MRI-incompatible implants.

Targeted biopsies diagnosed PCa in 21 patients. Additionally, PCa was identified in five patients with initially negative targeted biopsies through randomised core biopsies. Of these five patients, four had International Society of Urological Pathology (ISUP) grade 1 PCa with less than 20% core involvement, and one had ISUP grade 2 tumours with 30% core involvement. In the seven patients who underwent systematic biopsy only, three cases of ISUP grade 1 and two cases of ISUP grade 2 were detected.

Pathology revealed normal prostatic tissue in 10 patients and high-grade prostatic intraepithelial neoplasia in three patients. PCa was found in 31 patients, with most cases being ISUP grade 1 (12/31) and ISUP grade 2 (9/31).

The median procedure time per patient was 31 min, including 3 min for ultrasound prostate scanning, 5 min for prostate modelling on the ultrasound scan, 7 min for biopsy planning and 16 min for biopsy execution. Procedure time progressively decreased with increased experience. No technical issues were encountered during the 44 procedures.

No intra-operative complications were recorded, but one postoperative case of acute urinary retention associated with a UTI was observed. This Clavien–Dindo grade 2 complication was successfully treated with catheterisation and antibiotic therapy.

This study has several limitations. First, the sample size was small, and the lack of a control group limits direct comparisons with other biopsy techniques. Second, while the Biobot system demonstrated high reliability and effectiveness in this preliminary study, its performance relative to state-of-the-art non-robotic MRI fusion platforms remains to be fully evaluated.

Concerns may arise regarding the cost implications and time efficiency of the procedure compared to standard techniques. Although the median procedure time was 31 min, future studies should assess whether the learning curve and robotic assistance justify potential additional costs.

It is also worth noting that the system currently lacks the capability for automatic prostate segmentation, and any patient movement requires manual repositioning of the device.

In conclusion, although preliminary, these data highlight the effectiveness and safety of the Biobot robotic system in assisting urologists with prostate biopsies. The system's high detection rate for clinically significant PCa and the absence of major technical issues underscores its reliability. Additionally, the precise PCa mapping and the ability to store and quickly revisit biopsied sites suggest potential benefits for focal treatments. Further research is warranted to compare this biopsy technique to more established ones and to better define its role in the current prostate biopsy armamentarium.

Srinivas Vourganti has received a training grant from Biobot Surgical, which supports educational or research activities related to training in the use of their technology. Additionally, he is a consultant for the development of the Biobot system for use in focal therapy procedures. There are no conflicts of interest for any of the other authors.