Early experience with multiparametric magnetic resonance imaging-targeted biopsies under visual transrectal ultrasound guidance in patients suspicious for prostate cancer undergoing repeated biopsy

Objectives. The purpose of this study was to investigate the detection rate of prostate cancer (PCa) by multiparametric magnetic resonance imaging-targeted biopsies (mp-MRI-bx) in patients with prior negative transrectal ultrasound biopsy (TRUS-bx) sessions without previous experience of this. Material and methods. Eighty-three patients with prior negative TRUS-bx scheduled for repeated biopsies due to persistent suspicion of PCa were prospectively enrolled. mp-MRI was performed before biopsy and all lesions were scored according to the Prostate Imaging Reporting and Data System (PI-RADS) and Likert classification. All underwent repeated TRUS-bx (10 cores) and mp-MRI-bx under visual TRUS guidance of any mp-MRI-suspicious lesion not targeted by systematic TRUS-bx. Results. PCa was found in 39 out of 83 patients (47%) and mp-MRI identified at least one lesion with some degree of suspicion in all 39 patients. Both PI-RADS and Likert scoring showed a high correlation between suspicion of malignancy and biopsy results (p < 0.0001). Five patients (13%) had cancer detected only on mp-MRI-bx outside the TRUS-bx areas (p = 0.025) and another seven patients (21%) had an overall Gleason score upgrade of at least one grade based on the mp-MRI-bx. Secondary PCa lesions not visible on mp-MRI were detected by TRUS-bx in six out of 39 PCa patients. The secondary foci were all Gleason 6 (3 + 3) in 5-10% of the biopsy core. According to the Epstein criteria, 37 out of 39 cancer patients were classified as clinically significant. Conclusion. Using mp-MRI, even without previous experience, can improve the detection rate of significant PCa at repeated biopsy and allows more accurate Gleason grading.