Impact of the type of ultrasound probe on prostate cancer detection rate and characterization in patients undergoing MRI-targeted prostate biopsies using cognitive fusion.

ABSTRACT

PURPOSE: To assess the impact of ultrasound probe (end fire vs. side fire) during MRI-targeted prostate biopsy using cognitive fusion. METHODS: Inclusion criteria were as follows consecutive patients undergoing prostate biopsies after multiparametric MRI; no PSA above 10 ng/ml; no clinical bulking disease; MRI areas suspicious for malignancy. From January 2011 to December 2012, 91 patients were included. A standard 10 TRUS-guided biopsy protocol plus 2 targeted biopsies at any MRI lesion was used. Patient's characteristics, MRI findings, and pathology evaluations were compared between the two groups. RESULTS: Mean patient age and PSA were 63 years and 5.95 ng/ml, respectively. The median number of MRI lesions was 2, and the mean volume of the index lesion was 0.64 cc. The overall PCa detection rate was 58.2 %. The MRI scoring system was significantly predictive for PCa detection and aggressiveness (p < 0.001). There was a not statistically significant trend toward greater PCa detection rate (+23 %) in the end-fire cohort (p = 0.235). The PCa detection rate is significantly improved by 1.7-fold in case of MRI score 4-5 lesion as compared to MRI score 3 lesion (p = 0.031) when using the end-fire probe. Conversely, the MRI score does not significantly influence the detection rate in the side-fire group (p = 0.250). The improvement in the PCa detection rate by the end-fire probe was predominantly reported in anterior and of apical peripheral MRI lesions. CONCLUSION: In case of high MRI score lesions, the PCa detection rate is significantly improved when using end-firing, particularly in case of anterior and apical peripheral lesions.