Prostate cancer

Follow-up of men with a PI-RADS 4/5 lesion after negative MRI/Ultrasound fusion biopsy

Study population

Out of a prospective database of 1546 men who underwent transrectal MRI/US TB and SB due to suspicion of prostate cancer at Charité-Universitätsmedizin Berlin between January 2012 and May 2017, we retrospectively analyzed men with a negative biopsy of PI-RADS Score ≥ 4 lesions. Follow-up data were extracted from patient files where available and by a patient questionnaire. The questions included inter alia post-biopsy patient guidance and the indication for a repeat mpMRI or biopsy. The indication was made by the treating outpatient urologist as it is the standard of care in Germany.

Patient meta-data was collected in accordance with the standards of reporting for MRI-TB studies (START) checklist in a prospective database17. Subgroups of this cohort were included in previous analyses17. All patients signed a written informed consent for the intervention, data acquisition, and data appraisal. The study was performed according to the Declaration of Helsinki and authorized by the Institutional Review Board of the Charité-Universitätsmedizin Berlin.

Multiparametric imaging control

All patients received a 3-T mpMRI (Magnetom Skyra; Siemens Medical Systems, Erlangen, Germany) at Charité-Universitätsmedizin Berlin. The MRI protocol always comprised multi- planar (axial and coronal) high spatial resolution T2-weighted turbo spin-echo sequences (T2w TSE), axial T1-weighted images, axial diffusion-weighted images (DWIs; measured b-values 0.400 and 800 s/mm2, calculated b-value of 1 400 s/mm2) and gadolinium-based dynamic contrast-enhanced (DCE) sequences. T2w imaging and DWIs were performed in all patients and DCE MRI in most patients. In compliance with the guidelines of the European Society of Urogenital Radiology (ESUR) the evaluation and validation of the mpMRI image data were performed or supervised by a team of experienced expert radiologists at Charité-Universitätsmedizin Berlin using PI-RADS version 2 (v2). Lesions initially rated using PI-RADS V1 were re-rated using V2 for the analysis. Experienced radiologists were defined by the consensus statement with a minimum number read of 1000 mpMRIs and a yearly read over 20018. Considering clinical routine, radiologists were not blinded to clinical data. For patients with multiple lesions, the maximal PI-RADS score was used for further analysis.

MRI/US fusion-guided TB and SB

In accordance with the EAU guidelines at the time of the biopsy, the transrectal interventions were performed under antibiotic prophylaxis with a fluoroquinolone (ciprofloxacin) by a team of experienced urologists. MRI/US fusion-guided TB of the prostate was performed first, using the high-end US machine HiVison Preirus (Hitachi Medical Systems, Tokyo, Japan) or Aplio 500 (Toshiba, Otawara, Japan) with endocavity endfire probes (11C3, Toshiba; EUP V53 W; Hitachi Medical Systems) or a biplane probe transrectal (EUP CC531, Hitachi Medical Systems), as described previously6. Per PI-RADS lesion 3 targeted biopsies were obtained. Subsequently, transrectal SB was performed with 10 cores from left/right apex, left/right lateral midgland, left/right base, left/right ventral and left/right paraurethral.

All cores were potted and documented separately and were examined and analyzed by a certain team of experienced pathologists at Charité-Universitätsmedizin Berlin.

Definition of clinically significant prostate cancer

Clinically significant prostate cancer was defined as Gleason score ≥ 3 + 4 = 7 (International Society of Urological Pathology [ISUP] grade 2). Gleason scoring was based on the highest grade detected on histological analysis.

Statistical analyses

Continuous variables were described using medians and interquartile ranges (IQR), whereas categorical variables were characterized using proportions. All descriptive analyses were performed using the Statistical Package for the Social Sciences (SPSS) software version 25 for Mac OS (SPSS Inc., IBM Company, Chicago, IL, USA).

Research involving human participants

Approval was obtained from the ethics committee of Charité University Medicine Berlin. The procedures used in this study adhere to the tenets of the Declaration of Helsinki.

Informed consent

Informed consent was obtained from all individual participants included in the study.

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