Association Between Tumor Multifocality on Multi-parametric MRI and Detection of Clinically-Significant Prostate Cancer in Lesions with Prostate Imaging Reporting and Data System (PI-RADS) Score 4

The Role of Secondary Lesion Biopsy in Detecting Clinically Significant Prostate Cancer

BACKGROUND

Multiparametric MRI (mpMRI) and fusion-targeted biopsy (TB) have improved the detection of clinically significant prostate cancer (csPCa); however, it remains unclear whether secondary lesions (SLs) identified on mpMRI must also be biopsied in addition to the index lesion (IL). Currently, American Urological Association and European Association of Urology guidelines suggest biopsying all lesions, but supporting data are sparse. This study examines whether including SL biopsies provides additional value in csPCa detection compared to IL biopsy alone when systematic biopsy (SB) is also performed.

METHODS

Men with multiple PI-RADS ≥ 3 lesions on mpMRI who underwent prostate biopsy were retrospectively identified. The primary analysis compared csPCa detection rates from SB and IL TB, with or without SL TB. Secondary analyses assessed the impact of prostate-specific antigen (PSA) density and SL PI-RADS scores on csPCa detection. Sensitivity analyses were performed to investigate the robustness of findings.

RESULTS

Among 73 men, csPCa detection rate was 47% with SB and IL biopsy alone and improved to 52% with SL biopsies included (p = 0.62). Secondary analyses showed no significant differences in csPCa detection based on PSA density or SL PI-RADS scores. Two of three sensitivity analyses supported the primary findings.

CONCLUSIONS

Biopsying SLs does not significantly increase csPCa detection rates compared to IL biopsy alone when SB is also performed. This supports the notion that SL biopsies can be safely omitted without compromising clinical outcomes, thereby potentially reducing patient discomfort and procedural costs, and may inform future guideline development and revisions.

Intra-practice Urologist-level Variation in Targeted Fusion Biopsy Outcomes

OBJECTIVE

To examine the extent to which the urologist performing biopsy contributes to variation in prostate cancer detection during fusion-guided prostate biopsy.

METHODS

All men in the Michigan Urological Surgery Improvement Collaborative (MUSIC) clinical registry who underwent fusion biopsy at Michigan Medicine from August 2017 to March 2019 were included. The primary outcomes were clinically significant cancer detection rate (defined as Gleason Grade ≥2) in targeted cores and clinically significant cancer detection on targeted cores stratified by PI-RADS score. Bivariate and multivariable logistic regression analyses were performed.

RESULTS

A total of 1133 fusion biopsies performed by 5 providers were included. When adjusting for patient age, PSA, race, family history, prostate volume, clinical stage, and PI-RADS score, there was no significant difference in targeted clinically significant cancer detection rates across providers (range = 38.5%-46.9%, adjusted P-value = .575). Clinically significant cancer detection rates ranged from 11.1% to 16.7% in PI-RADS 3 (unadjusted P = .838), from 24.6% to 43.4% in PI-RADS 4 (adjusted P = .003), and from 69.4% to 78.8% in PI-RADS 5 (adjusted P = .766) lesions.

CONCLUSION

There was a statistically significant difference in clinically significant prostate cancer detection in PI-RADS 4 lesions across providers. These findings suggest that even among experienced providers, variation at the urologist level may contribute to differences in clinically significant cancer detection rates within PI-RADS 4 lesions. However, the relative impact of biopsy technique, radiologist interpretation, and MR acquisition protocol requires further study.

Systematic Review and Meta-Analysis of Free-Hand and Fixed-Arm Spatial Tracking Methodologies in Software-Guided MRI-TRUS Fusion Prostate Biopsy Platforms

OBJECTIVE

To evaluate the cancer detection rate (CDR) between the 2 dominant spatial tracking methodologies in software-guided MRI-transrectal ultrasound fusion prostate biopsy (SGF-Bx) platforms: fixed-arm and free-hand.

METHODS

We conducted a systematic review and meta-analysis on published primary analyses of prospective trials and cohort studies that enrolled biopsy-naïve patients for SFG-Bx. Inclusion criteria included the use of the Prostate Imaging Reporting & Data System (PI-RADS) v2.0 or later and the targeting of lesions graded as PI-RADS 3 or higher. Random effects models were used to assess the overall prostate cancer (PCa) CDR and the clinically significant prostate cancer (csPCa) CDR for both platforms. csPCa was standardized to a definition of Gleason Grade Group 2 or higher when possible. Subgroup analysis was performed by stratifying studies into the average number of cores taken per lesion.

RESULTS

The PCa CDR was 0.674 for free-hand systems and 0.681 for fixed-arm systems. The csPCa CDR was 0.492 for free-hand systems and 0.500 for fixed-hand systems. There was no significant difference between free-hand and fixed-arm cancer detection rates for both overall PCa (P = .88) and csPCa (P = .90). Subgroup analyses revealed significant PCa CDR and csPCa CDR differences (P < .001) between free-hand and fixed-arm platforms only when 2 cores per lesion were taken, in favor of fixed-arm platforms.

CONCLUSIONS

Fixed-arm platforms performed similarly in cancer detection to free-hand platforms but show a minor benefit on fewer samples. While tracking methodology differences appear subtle, further investigation into the clinical impact of platform-specific features are warranted.