Extended Systematic Versus Mri-Assisted pRostate Transperineal Biopsy

A Randomized Controlled Trial Comparing Magnetic Resonance Imaging (MRI)-Targeted Biopsy and Extended Transperineal Systematic Biopsy for Detection of Clinically Significant Prostate Cancer: the SMART Trial

This is a randomized controlled trial to evaluate the detection of clinically significant prostate cancer (csPCa) by MRI-targeted approach (MRI-arm) versus 24-core transperineal (TP) systematic biopsy (TP-arm). Clinically significant prostate cancer (csPCa) is defined as ISUP (International Society of Urogenital Pathology) Grade group ≥2 prostate cancer. Patients with elevated PSA 4-20 ng/mL with or without abnormal digital rectal examination (DRE) will be randomized in a 1:1 manner to MRI-arm or TP-arm. In the MRI-arm, multiparametric MRI prostate will be performed for each subject. MRI prostate is considered abnormal if PI-RADS (Prostate Imaging-Reporting and Data System, version 2.1) score is 3, 4 or 5. For subjects in MRI-arm with abnormal MRI, MRI-targeted biopsy will be performed, followed by 12-core systematic transperineal biopsy (sparing MRI-target). For subjects in MRI-arm with normal MRI, no biopsy is performed. For subjects in TP-arm, 24-core systematic transperineal biopsy will be performed without MRI guidance. The study flowchart is provided in Figure 1. The detection rates of csPCa will be compared between MRI-targeted biopsy plus 12-core systematic biopsy (in MRI-arm) versus TP-arm. The study hypothesis is MRI-guided prostate biopsy with 12-core systematic biopsy is superior to 24-core transperineal systematic biopsy in detection of csPCa.

The current study is a randomized controlled trial using a superiority design with the subjects randomized in 1:1 manner to either MRI-arm or TP-arm. In the MRI-arm, multiparametric MRI is performed for all subjects. If MRI is abnormal (PI-RADS score 3-5), 3-4 core targeted followed by 12-core systematic transperineal biopsies under local anaesthesia will be performed. If MRI is normal, no biopsy is performed. A 12-core systematic biopsy is also included in MRI-targeted biopsy as it has been shown in the Trio study that adding systematic biopsy increased the detection of csPCa.

In the TP-arm, no MRI will be performed, and all subjects will receive 24-core transperineal prostate biopsy under local anaesthesia. Patient will be followed up in clinic about 30 days after biopsy to review pathology result and complication.

Inclusion Criteria:

1. Men ≥18 years of age
2. Clinical suspicion of prostate cancer and indicated for prostate biopsy
3. Serum Prostate-specific antigen (PSA) 4-20 ng/mL
4. Digital rectal examination ≤ cT2 (organ confined cancer)
5. Able to provide written informed consent

Exclusion Criteria:

1. Prior prostate biopsy
2. Past or current history of prostate cancer
3. MRI prostate performed within past 5 years
4. Contraindicated to undergo MRI scan (e.g. pacemaker in-situ, claustrophobia, estimated glomerular filtration rate < 50ml/min in serum renal function test within 3 months)
5. Contraindicated to transperineal prostate biopsy: active urinary tract infection, fail insertion of transrectal ultrasound probe into rectum (abdominal perineal resection, anal stenosis), fail to be placed in lithotomy position, uncorrectable coagulopathy, antiplatelet or anticoagulant which cannot be stopped (keep aspirin before and after biopsy is permitted)