The accuracy of transrectal ultrasonography supplemented with computer-aided ultrasonography for detecting small prostate cancers

To determine the extent to which computer-aided ultrasonography of the prostate (HistoScanning(TM), Advanced Medical Diagnostics, Waterloo, Belgium) can identify tumour foci that correspond to a volume of >= 0.50 mL. Between September 2004 and February 2006, 29 men were HistoScanned before scheduled radical prostatectomy. The three-dimensional raw (grey-scaled) data required for HistoScanning analysis were acquired by transrectal ultrasonography, and analysed using organ-specific tissue-characterization algorithms which form the core of the HistoScanning technology. The HistoScanning analysis results were compared with the histology of the whole-mounted prostate, step-sectioned sagittally at 5-mm intervals, and each slide analysed by 5 x 5 mm grid analysis. Of 29 patients, 13 had histology unknown to those evaluating the HistoScanning data. With 0.50 mL as the lower threshold for delineating and visualizing cancer volume, HistoScanning correctly predicted the presence of all 12 lesions that were subsequently confirmed to occupy >= 0.50 mL. In addition three lesions were predicted as being present and of >= 0.50 mL. These three lesions were subsequently confirmed to be present but were <= 0.50 mL on histopathological review. Thus, using the clinically accepted volume threshold of 0.50 mL, the sensitivity, specificity, positive and negative predictive value of HistoScanning were 12/12, 13/16 (82%), 12/15 (80%) and 12/12, respectively, for the cancer foci analysed. In this preliminary study, HistoScanning accurately detected cancer foci of >= 0.50 mL; these encouraging results will need to be verified in a larger group of patients.