Introduction

Prostate cancer (PCa) remains the only solid organ tumor that is diagnosed by a non-targeted sampling method. Recently, multi-parametric MRI (MP-MRI) in conjunction with an MRI- ultrasound (US) fusion guided biopsy (bx) has demonstrated improved PCa detection. Unfortunately, this technology has been limited to tertiary care centers. Therefore, we sought to compare cognitive versus targeted software to assess the ability of cognitive registration to disseminate more readily into the community.

Methods

Consecutive patients underwent an MRI-US fusion prostate bx for elevated PSA, abnormal DRE, active surveillance or prior negative bx with a persistently elevated PSA. All subjects underwent pre-bx MP-MRI and lesions visible on MRI were graded using the PI-RADS version 2 classification system. The UroNav bx tracking system was used to fuse the stored MR images with real-time US generating a 3D model, which was then used to sequentially perform cognitive, targeted, and standard 12 core systematic biopsies in an office setting under local anesthesia. Descriptive statistics included patient characteristics and univariate analysis was done using logistic regression analysis to detect the associations between presence of cancer, clinically significant cancer, demographic variables, and bx method. Signed rank test was used for paired comparisons amongst bx method.

Results

44 patients (median age 66 yrs, median PSA 6.4) underwent an MRI-US fusion bx between July 2014 and October 2015 with an overall CDR of 59%. Cognitive CDR was 40.9% with 25% being clinical significant disease. The targeted CDR was 27.3% with 22.7% being clinically significant disease. Overall, the cognitive approach had a sensitivity of 69.2% (95% CI: 50%, 88%) whereas the targeted approach had sensitivity of 46.2% (95% CI: 26%, 67%). Furthermore, the targeted approach missed 8 cancers when compared to the cognitive approach, whereas, the cognitive approach missed 2 cancer when compared to the targeted approach. The difference in sensitivity is most pronounced when comparing standard and targeted methods (p=0.02) and approaches significance when comparing cognitive and targeted methods (p=0.11).

Conclusions

MRI-US fusion targeted software when compared to the cognitive platform, was not found to have higher cancer detection rate nor sensitivity. We believe this highlights the importance of the MRI itself, rather than the platform used.

Funding

None