Comparison of real-time elastography with grey-scale ultrasonography for detection of organ-confined prostate cancer and extra capsular extension: A prospective analysis using whole mount sections after radical prostatectomy

Abstract

Study Type - Diagnostic (exploratory cohort) Level of Evidence 2b What's known on the subject? and What does the study add? Current studies evaluating real-time elastography in patients prior to radical prostatectomy reported sensitivities between 57% and 100% for detection of prostate cancer. This is the first prospective study comparing the findings of real-time elastography and conventional gray-scale ultrasound with final pathology. A significant improvement for cancer detection as well as detection of extra capsular is shown by adding the attributes of tissue elasticity to current gray-scale imaging. OBJECTIVE • To evaluate whether transrectal real-time elastography (RTE) improves the detection of intraprostatic prostate cancer (PCa) lesions and extracapsular extension (ECE) compared with conventional grey-scale ultrasonography (GSU). PATIENTS AND METHODS • In total, 229 patients with biopsy-proven PCa were prospectively screened for cancer-suspicious areas and ECE using GSU and RTE. • The largest tumour focus detected by RTE was defined as the index lesion. • The prostate gland was stratified into six sectors on GSU and RTE, which were compared with histopathological whole mount sections after radical prostatectomy. RESULTS • Histopathologically, PCa was confirmed in 894 out of 1374 (61.8%) evaluated sectors and ECE was identified in 47 (21%) patients. • Of these 894 sectors, RTE correctly detected 594 (66.4%) and GSU 215 (24.0%) cancer suspicious lesions. • Sensitivity was 51% and specificity 72% using RTE compared to 18% and 90% for GSU. • RTE identified the largest side specific tumour focus in 68% of patients. • ECE was identified with a sensitivity of 38% and specificity of 96% using RTE compared to 15% and 97% using GSU. CONCLUSIONS • Compared with GSU, RTE provides a statistically significant improvement in detection of PCa lesions and ECE. • RTE enhances GSU, although improvement is still needed to achieve a clinically meaningful sensitivity. © 2011 BJU Internationl.