The value and limitations of contrast-enhanced ultrasound in detection of prostate cancer.

UNLABELLED The aim of our study was to evaluate the diagnostic value of contrast-enhanced ultrasonography (CEUS) in comparision to morphological examinations of radical prostatectomy specimens and to study factors limiting the visibility of malignant lesions. PATIENTS AND METHODS Fifty patients with proven prostate cancer (PV) were examined transrectally using, grey-scale, power Doppler (PD) and CEUS (pulse-inversion mode, low mechanical index) shortly before prostatectomy. The results were compared with morphological findings. The influence of tumour size, localization and grade on tumour visibility was studied. RESULTS A total of 72 prostate cancer foci were found at pathologic evaluation. Grey-scale imaging demonstrated 34 (47.2%), power Doppler 37 (51.4%) and CEUS 44 (61.1%) of these foci. No lesion less than 1 cm in size was detected. Statistically significant correlation was established between the visibility of of tumour in CEUS and the size of a focus (r=0.610, p=0.001). Sensitivity of CEUS in detection of peripheral gland tumours was 63.3%, of lesions invading both peripheral and central gland 83.3%, and of centrally located tumours 27.8%. In comparision, sensitivity of grey-scale imaging was 53.3%, 70.8% and 5.6%, respectively. CEUS detected 35.5% of low-grade and 80% of intermediate-grade tumours; the corresponding results of grey-scale imaging were 16.1% and 70%, respectively. Statistically significant correlation was detected (r=0.459: p=0.001) between visualization capabilities of CEUS and the malignant grade of prostate cancer. CONCLUSION CEUS improves prostate cancer detection. Sensitivity of CEUS is lower in cases of small low-grade tumours, centrally located lesions and large infiltrating prostate tumours.