Developments in MRI-targeted prostate biopsy

Value of Incremental Biopsy Cores for Microultrasound Targeted Prostate Biopsies

OBJECTIVE

To determine the optimal number of cores needed during microultrasound-informed prostate biopsy for the detection of clinically significant prostate cancer (csPCa, defined as Gleason Grade Group ≥2).

METHODS

A retrospective review of 1011 consecutive patients between September 2021 and July 2023 at our institution were identified; 536 underwent microultrasound biopsy and 475 underwent magnetic resonance imaging (MRI)/ultrasound (US) targeted biopsy. Lesions were given a Prostate Risk Identification using Microultrasound (PRI-MUS) score, with lesions PRI-MUS ≥3 targeted. MRI lesions were scored with Prostate Imaging-Reporting and Data System (PI-RADS) and lesions PI-RADS ≥3 were targeted. The primary outcome is the detection of csPCa stratified by number of cores.

RESULTS

One hundred thirty-eight patients underwent targeted biopsies for microultrasound only lesions, 182 for microultrasound and MRI lesions and 426 underwent MRI/US for MRI lesions. The first targeted core detected 78.0% (46/59), 77.8% (63/81), and 78.8% (216/274) of csPCa for microultrasound, microultrasound+MRI, and MRI/US, respectively. Comparing first to third core, there was not a significant difference in overall detection of csPCa by microultrasound, though MRI/US was significantly different (28.4% vs 36.4% P = .12, 32.5% vs 41.8% P = .06, 42.5% vs 53.9% P < .001 for microultrasound, microultrasound+MRI, and MRI/US, respectively). PI-RADS 3 and PRI-MUS 3 lesions had lower first core detection rates compared to PI-RADS 5 and PRI-MUS 5 lesions (44.4% vs 85.4% P = .01, 65.2% vs 81.4% P = .14, 60% vs 83.1% P = .07 for microultrasound, microultrasound+MRI, and MRI/US, respectively).

CONCLUSION

A three-core targeted biopsy per microultrasound lesion improves detection rate of csPCa and should be considered to improve diagnostic accuracy.

A Matched-pair Analysis Comparing Systematic Prostate Biopsy by Conventional Transrectal Ultrasound-guidance Versus Software-based Predefined 3D-Guidance

OBJECTIVE

To compare software-based three-dimensional-guided systematic prostate biopsy (3D-GSB) with conventional transrectal ultrasound-guided systematic biopsy (TGSB) regarding prostate cancer (PCa) detection rates (CDR).

METHODS

In total, 956 patients (200 TGSB patients and 756 3D-GSB patients) without prior positive biopsies and with a prostate-specific antigen value ≤20 ng/ml were eligible for analysis. TGSB and 3D-GSB cases were matched in a 1:1 ratio using propensity score matching with age, prostate-specific antigen, prostate volume, previous biopsy status, and suspicious palpatory finding as confounders. 3D-GSB was conducted with the semi-robotic prostate fusion-biopsy system Artemis. For each patient in both groups, SB was conducted in a similar pattern with 12 cores. All cores in 3D-GSB were automatically planned and mapped on a 3D-model as well as on the real-time transrectal ultrasound imaging. Primary end points were the clinically significant (cs) and overall CDR. Secondary end point was the cancer-positive core rate.

RESULTS

After matching, the csCDR was not significantly different between the 3D-GSB and the TGSB groups (33.3% vs 28.8%, P = .385). Overall CDR was significantly higher for 3D-GSB compared to TGSB (55.6% vs 39.9%, P = .002). 3D-GSB detected significantly more non-significant PCa than TGSB (22.2% vs 11.1%, P = .004). In patients with PCa, the number of cancer-positive SB cores was significantly higher by TGSB (42% vs 25%, P < .001).

CONCLUSION

3D-GSB was associated with a higher CDR than TGSB. However, no significant difference was shown in detection of csPCa between both techniques. Therefore, currently, 3D-GSB does not appear to add value to conventional TGSB.

Feasibility and preliminary clinical tolerability of low-field MRI-guided prostate biopsy

OBJECTIVE

We evaluate the clinical feasibility of a portable, low-field magnetic resonance imaging (MRI) system for prostate cancer (PCa) biopsy.

METHODS

A retrospective analysis of men who underwent a 12-core systematic transrectal ultrasound-guided prostate biopsy (SB) and a low-field MRI guided transperineal targeted biopsy (MRI-TB). Comparison of the detection of clinically significant PCa (csPCa) (Gleason Grade [GG] ≥ 2) by SB and low field MRI-TB, stratified by Prostate Imaging Reporting & Data System (PI-RADS) score, prostate volume, and prostate serum antigen (PSA) was performed.

RESULTS

A total of 39 men underwent both the MRI-TB and SB biopsy. Median (interquartile range [IQR]) age was 69.0 (61.5-73) years, body mass index (BMI) was 28.9 kg/m² (25.3-34.3), prostate volume was 46.5 cc (32-72.7), and PSA was 9.5 ng/ml (5.5-13.2). The majority (64.4%) of patients had PI-RADS ≥ 4 lesions and 25% of lesions were anterior on pre-biopsy MRII. Cancer detection rate (CDR) was greatest when combining SB and MRI-TB (64.1%). MRI-TB detected 74.3% (29/39) cancers. Of which, 53.8% (21/39) were csPCa while SB detected 42.5% (17/39) csPCa (p = 0.21). In 32.5% (13/39) of cases, MRI-TB upstaged the final diagnosis, compared to 15% (6/39) of cases in which SB upstaged the final diagnosis (p = 0.11).

CONCLUSION

Low-field MRI-TB is clinically feasible. Although future studies on the accuracy of MRI-TB system are needed, the initial CDR is comparable to those seen with fusion-based prostate biopsies. A transperineal and targeted approach may be beneficial in patients with higher BMI and anterior lesions.

A Comparative Study of Prostate Cancer Detection Rate Between Transperineal COG-TB and Transperineal FUS-TB in Patients with PSA ≤20 ng/mL

Background: The combination of prebiopsy MRI and transperineal targeted biopsies is being increasingly used to obtain tissues from patients with suspected prostate cancer (PCa). Objective: To investigate the difference in PCa detection rate between transperineal cognitive fusion TB (COG-TB) and transperineal software fusion TB (FUS-TB). Participants: The present study included 163 male patients with suspected PCa who had not undergone prostate biopsy, had a prostate-specific antigen (PSA) level of ≤20 ng/mL, and had been examined by bi-parameter MRI and confirmed to have prostate nodules by prostate imaging reporting and data system version 2 (PI-RADS V2) scores ≥3 (from December 3, 2018 to October 7, 2019). Intervention: Seventy-one patients underwent transperineal COG-TB, and 92 patients underwent transperineal FUS-TB. The detection rate of the first four needles was compared. Results: No significant difference was found in the overall detection rate of PCa between COG-TB and FUS-TB (60.56% vs 51.08%, p = 0.228). This result was consistent even after stratifying by PI-RADS score. There was also no significant difference between COG-TB and FUS-TB in the detection rate of clinically significant PCa (p = 0.641). Moreover, COG-TB and FUS-TB showed no difference in the detection rate of PCa with different Gleason scores. Conclusions: In patients with suspected PCa with PSA ≤20 ng/mL and PI-RADS ≥3, FUS-TB was comparable to COG-TB in the detection rate of PCa.