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.