Outcomes of combination MRI-targeted and transperineal template biopsy in restaging low-risk prostate cancer for active surveillance

Abstract

ObjectiveActive surveillance (AS) offers a strategy to reduce overtreatment and now is a widely accepted treatment option for low-risk prostate cancer. An ideal tool for risk-stratification would detect aggressive cancers and exclude such men from taking up AS in the first place. We evaluate if a combination of transperineal template biopsy with magnetic resonance imaging (MRI)-targeted biopsy identifies significant prostate cancer amongst men initially diagnosed with low-risk prostate cancer.MethodsThis prospective, single-blinded study included men with low-risk prostate cancer (D'Amico's Criteria) diagnosed on conventional transrectal ultrasound-guided biopsy. Patients first underwent multiparametric MRI of the prostate ≥6 weeks after initial biopsy. Each suspicious lesion is mapped and assigned a Prostate Imaging Reporting and Data System (PIRADS) score. Template biopsy is first performed with the surgeon blinded to MRI findings followed by MRI-targeted biopsy using a robotic transperineal biopsy platform.ResultsThe age of the 19 men included is 65.4 ± 4.9 years (mean ± SD). Prostate specific antigen (PSA) at diagnosis and at the time of transperineal biopsy were comparable (7.3 ± 1.7 ng/mL and 7.0 ± 1.8 ng/mL, p = 0.67), so were prostate volumes (34.2 ± 8.9 mL and 32.1 ± 13.4 mL, p = 0.28). MRI-targeted biopsy had a higher percentage of cancer detection per core compared to template biopsy (11.7% vs. 6.5%, p = 0.02), this was more than 3 times superior for Gleason 7 disease (5.9% vs. 1.6%, p < 0.01). Four of 18 (22.2%) patients with MRI lesions had significant disease with MRI-targeted biopsy alone. Three of 19 patients (15.8%) had significant disease with template biopsy alone. In combination, both techniques upclassified five patients (26.3%), all of whom underwent radical prostatectomy. Whole mount histology confirmed tumour location and grade. All six patients with PIRADS 5 lesions had cancer detected (66.6% significant disease).ConclusionA combination of MRI-targeted and template biopsy may optimally risk-classify “low-risk” patients diagnosed on initial conventional transrectal ultrasonography (TRUS) prostate biopsy.

Transperineal versus transrectal prostate biopsy in the diagnosis of prostate cancer: a systematic review and meta-analysis

“…Conventional prostate biopsy does have some limitations including severe complications and high rate of false negatives. Therefore, prostate biopsy strategies including guidance technology, biopsy approaches, and number of cores have emerged to improve the diagnosis rate of PCa [6–11]. An urgent need to identify the most effective and safe way to diagnose PCa still remains.…”

Multiparametric MRI‐ultrasonography software fusion prostate biopsy: initial results using a stereotactic robotic‐assisted transperineal prostate biopsy platform comparing systematic vs targeted biopsy

“…A waiver for informed consent was granted by the institutional review board (CIRB 2009/1053/D). Our mpMRI protocol and biopsy technique were previously described [5,6].…”

“…All patients underwent a 3-Tesla MRI scan (Magnetom Skyra; Siemens, Erlangen, Germany) using a 60-channel pelvic phased-array coil. MRI protocols included high spatial resolution T2-weighted imaging in axial, sagittal and coronal planes, diffusion-weighted imaging in the axial plane (B value up to 1800 s/mm 2 ) and dynamic contrast-enhanced images (temporal resolution of 3.5-5.0 s), and were in accordance with the current international prostate MRI guidelines [6,8]. The majority of the mpMRI images were read by a senior radiologist (L.Y.M.)…”

“…Transperineal cores are usually taken via multiple separate perineal skin punctures, either freehand or with guidance of a brachytherapy grid. The iSR'obot Mona Lisa TM (Biobot Surgical, Singapore, Singapore) is currently the only commercially available stereotactic robot-assisted transperineal prostate biopsy platform that provides precise three-dimensional (3D) targeting of the biopsy needle via only two skin punctures [5,6].…”

The role of multiparametric magnetic resonance imaging and magnetic resonance-guided biopsy in active surveillance for low-risk prostate cancer: A systematic review

“…The combination scheme detected upgrading in 71% if the patients compared to 64% and 59% of MRI/ultrasound-fusion and systematic biopsies, respectively [ 30 ]. Another suggested combination scheme is the MRI-targeted and transperineal template biopsies, which detected disease upgrading in 26.3% of the patients, outperforming any of the two types alone [ 27 ].…”