Analysis of false positive PI-RADS 4 lesions: experience from a single nonacademic center using cognitive fusion.

BACKGROUND: We evaluated pathological findings in targeted biopsies of PI-RADS4 and PI-RADS5 lesions, and clinical data that could predict those patients with benign findings. MATERIALS AND METHODS: A retrospective study was conducted to summarize the experience from a single nonacademic center using cognitive fusion and a 1.5 or 3.0 Tesla scanner. RESULTS: We found a false positive rate of 29 and 3.7% for any cancer in PI-RADS 4 and 5 lesions, respectively. Diverse histologic patterns were observed among target biopsies. At multivariate analysis, size ≤ 6 mm and previous negative biopsy were independent predictors of false positive PI-RADS4 lesions. The small number of false PI-RADS5 lesions precluded further analyses. CONCLUSION: Benign findings are common in PI-RADS4 lesions and most of them do not show obvious glandular or stromal hypercellularity as expected in hyperplastic nodules. Size ≤ 6 mm and previous negative biopsy predict a higher probability of false positive results in patients with PI-RADS 4 lesions.

Real life data of MRI-targeted biopsy - experience from a single nonacademic centre using cognitive fusion and 1.5 tesla scanning.

OBJECTIVES: To date, it is unknown whether systematic biopsies can be safely omitted in patients with unsuspicious MRI findings or if systematic biopsies should be required when targeting focal lesions (PI-RADS 3-5). METHODS: A series of 366 patients (249 without a previous biopsy) were examined in a 1.5 Tesla MRI scanner. All patients were submitted to systematic biopsies (12-14 regions) with additional targeted biopsies (by cognitive fusion) of focal PI-RADS lesions (PI-RADS 3-5). RESULTS: In our series, patients with PI-RADS 1/2 findings had rates of adenocarcinoma of any grade, >GG1 and GG4/5 of 34%, 14% and 3%, respectively. The use of MRI prior to biopsy in our series increased the detection of clinically significant prostate cancer (CSPCa) in 28% of patients with focal lesions, and focal lesions were present in 293/366 (80%) of all patients. For CSPCa (>GG1), targeted biopsies improved the diagnosis in 28% of patients, while systematic biopsies resulted in an additional 19% of cancer cases in the series. CONCLUSION: Systematic biopsies should still be considered in patients with PI-RADS 1/2 findings. Our findings also suggest a stronger benefit of the combined strategy of targeted and systematic biopsies than the findings of previous studies concerning the detection of CSPCa in biopsy-naïve patients.