Real-time sonoelastography compared to magnetic resonance imaging using four different modalities at 3.0 T in the detection of prostate cancer: strength and weaknesses

Objective: To compare the results of RTE with four different modalities at 3.0 T using endorectal and body phased array coil in the detection of PC.

Patients and methods: Between May 2009 and July 2010, 50 patients with biopsy proven PC scheduled for radical prostatectomy (RP) were examined. All patients underwent RTE of the prostate and 3.0 T endorectal MRI. The investigators were unaware of the clinical data and of each others results.

Results: RTE detected PC in 46 (92%) and MRI in 42 (84%) of the patients. Depending on the analysis sensitivity was 44.1-58.9% for RTE and 36.7-43.1% for MRI. Specificity was 83.0-74.8% for RTE and 85.9-79.8% for MRI. Sensitivity was significantly higher for RTE (16-sectors: p=0.0348; 8-sectors: p=0.0002) and showed better results in the dorsal (RTE: 51.9%; MRT: 37.7%) and apical to middle (RTE: 66.7%-80.0%; MRI: 41.7%-60.0%) parts of the prostate. MRI showed better results in the base (MRI: 19.4%; RTE: 14.9%) and transitional zone (TZ) (MRI: 34.7%; RTE: 29.6%). Concerning capsular involvement the results were comparable with sensitivity and specificity of RTE being 79.2% and 80.0% compared to 80.8% and 70.0% of MRI.

Conclusions: Concerning sensitivity RTE showed advantages in apical and middle parts whereas MRI may provide advantages in the glands' base and TZ. Both RTE and MRI have limitations particularly in basal and ventral parts. Most of the undetected tumours were of low tumour volume and Gleason Score. Considering capsular involvement both techniques showed comparable results.