Multiparametric magnetic resonance imaging/transrectal ultrasound (mpMRI/TRUS) fusion: a preliminary approach in targeted prostate biopsy

Objective To evaluate the feasibility and efficacy of multiparametric magnetic resonance imaging/transrectal ultrasound (mpMRI/TRUS) fusion guided targeted prostate biopsy. Methods From March 2014 to May 2015, 32 patients with a suspected lesion of prostate cancer (PCa) by mpMRI examinations had undergone mpMRI/TRUS fusion prostate biopsy. The age of the patients was 47~82 years (median 64 years ). Serum PSA before biopsy was 1.11~33.53 ng/ml (median 8.73 ng/ml). There were 13 cases with PSA 20ng/ml. A 12-core systematic prostate biopsy guided by TRUS was performed, followed by real-time fusion of TRUS and MRI images after import of MRI DICOM images to the ultrasound system (GE, Logiq E9). The plane for biopsy was located, and a 2- to 3-core targeted biopsy was performed for each suspected lesion. Results 21 of 32 patients (65.6%) were diagnosed with PCa. For each individual, one to two suspected lesions were located by mpMRI, with 2 to 3 cores sampled at each suspect lesion. Four cases were diagnosed by systematic biopsy only, 11 were diagnosed by both systematic and targeted biopsy, and 6 were diagnosed by targeted biopsy only. For systematic biopsies, Gleason Scores were 6-8 (mean: 7.13), in which ≤6, 7, and ≥8 recorded 20%(3/15)、46.7%(7/15)、33.3%(5/15) , respectively. For targeted biopsies, Gleason Scores were 6~10 (mean: 7.47), in which ≤6, 7, and ≥8 recorded 17.6%(3/17)、47.1%(8/17)、35.3%(6/17), respectively. For the 11 patients who were diagnosed both by systematic and targeted biopsy, three patients had a higher Gleason Score in targeted biopsy than in systematic ones. Conclusions mpMRI/TRUS fusion markedly increases positive rate in prostate biopsy and reduces misdiagnosis of PCa with a higher Gleason Score. Further application of such technique relies on a more precise imaging of PCa lesions and future development of fusion imaging technology. Key words: Prostatic neoplasms; Magnetic resonance imaging; Ultrasonography; Biopsy