Transrectal ultrasound-guided targeted biopsy of transition zone prostate cancer under cognitive registration with prebiopsy MRI and sonographic findings.

AIM: To evaluate retrospectively the diagnostic usefulness of transrectal ultrasound (TRUS)-guided targeted biopsy (TB) for transition zone (TZ) prostate cancer (PCa) in patients with prebiopsy magnetic resonance imaging (MRI). MATERIALS AND METHODS: A consecutive series of 38 patients who underwent TRUS-guided TB of TZ lesions were evaluated. TB (mean core number, 2.4±0.6; range, 2-4) was performed by a single experienced radiologist under cognitive registration between prebiopsy MRI and TRUS. Tumour echogenicity on TRUS and Prostate Imaging-Reporting and Data System version 2 (PI-RADSv2) scoring on MRI for targeted TZ lesions were assessed. The interrupted midline sign was defined as a focal lesion traversing the midline of the TZ leading to discontinuity of the midline on both MRI and TRUS. TZ PCa with a Gleason score of 7 or greater was defined as clinically significant PCa (csPCa). RESULTS: The cancer detection rate of TRUS-guided TB for TZ lesions was 78.9% (30/38) for any PCa and 42.1% (16/38) for csPCa. Echogenicity of TZ PCa on TRUS was various and half did not show low echogenicity (low, 50%; intermediate, 26.7%; and high, 23.3%). The interrupted midline sign was identified in 50% (19/38) of patients, which was highly predictive of TZ PCa (94.7%, 18/19). CONCLUSION: TRUS-guided TB under cognitive registration based on prebiopsy MRI findings is useful to detect TZ PCa. Knowledge of the sonographic features of TZ PCa may help to target TZ PCa accurately under cognitive registration.