Assessment of Prospectively Assigned Likert Scores for Targeted MR Imaging-Transrectal US Fusion Biopsies in Patients with Suspected Prostate Cancer

PURPOSE - To assess the performance of prospectively assigned MRI-based Likert scale scores for detection of clinically significant prostate cancer and to analyze the pre-biopsy imaging variables associated with increased cancer detection using targeted MRI-TRUS fusion biopsy.

MATERIALS AND METHODS - In this retrospective review of prospectively generated data including men with abnormal multiparametric prostate MRI (at least one Likert score ≥3 lesion) who underwent subsequent targeted MRI-TRUS fusion biopsy, we determined the association between different imaging variables (Likert score, lesion size, lesion location, prostate volume, radiologist experience) and targeted biopsy positivity rate. We also compared the detection of clinically significant cancer according to Likert scale scores. Tumors with high-volume (≥50% of any core) Gleason score 3+4 or any tumor with greater Gleason score were considered clinically significant. Each lesion served as the elementary unit for analysis. We used logistic regression for univariate and multivariate (stepwise selection) analysis to assess for association between targeted biopsy positivity rate and each tested variable. The relationship between Likert scale and Gleason scores was evaluated using Spearman correlation coefficient.

RESULTS - 161 men with 244 lesions met eligibility criteria. Targeted biopsies diagnosed cancer in 41% (66/161) of the men and 41% of the lesions (99/244) lesions. The Likert score was the strongest predictor of targeted biopsy positivity (OR: 3.7; p<0.0001). Other imaging findings associated with a higher targeted biopsy positivity rate included smaller prostate volume (OR: 0.7; p<0.01), larger lesion size (OR: 2.2; p<0.001), and anterior location (OR: 2.0; p=0.01). Upon multiple logistic regression analysis, Likert score, lesion size and prostate volume were significant predictors of targeted biopsy positivity. Higher Likert scores were also associated with an increased detection of clinically significant tumors (p<0.0001).

CONCLUSIONS - The Likert scale score used to convey the degree of suspicion on mpMRI is the strongest predictor of targeted biopsy positivity and of the presence of clinically significant tumor.

J Urol. 2015 Jul 17. pii: S0022-5347(15)04412-2. doi: 10.1016/j.juro.2015.07.080. [Epub ahead of print]

Costa DN1, Lotan Y2, Rofsky NM1, Roehrborn C2, Liu A1, Hornberger B2, Xi Y1, Francis F3, Pedrosa I1.

1 Department of Radiology, University of Texas Southwestern Medical Center at Dallas.
2 Department of Urology, University of Texas Southwestern Medical Center at Dallas.
3 Department of Pathology, University of Texas Southwestern Medical Center at Dallas.