The role of the elastography in the diagnosis of prostate cancer: a retrospective study on 460 patients.

OBJECTIVE

Prostate cancer is one of the most common cancer among men in industrialized total Prostatic Specific Antigen (PSA) and PSA ratio, Trans Rectal Ultrasound Scan (TRUS) and prostate biopsy, which is the gold standard for tumoral diagnosis. The poor sensibility of TRUS, when DRE and/or PSA are abnormal, requires prostate biopsy for diagnostic confirmation. The aim of this study was to evaluate the sensibility and the specificity of real time elastography (SE) with and without the association of TRUS for cancer diagnosis.

MATERIAL AND METHODS

We retrospectively evaluated 460 patients who underwent TRUS-guided prostate biopsy. The mean age of patients was 66.4 years, the mean PSA was 7.96 ng/ml and the mean PSA ratio was 17.19%. We compared histopathological findings of prostate biopsies with the results of TRUS and elastography.

RESULTS

32.17% of all patients were positive for prostate cancer.TRUS showed a sensitivity of 76.35% with a low specificity (43.59%), a Positive Predictive Value (PPV) of 39.1% and a Negative Predictive Value (NPV) of 79.53%. SE showed a lower sensitivity (61.49%), but better specificity (75%), PPV (53.85%) and NPV (80.41%). The association of TRUS + SE showed an increase in the sensitivity (79.79%) and in the NPV (86.71%). We separately evaluated the results of the two urologists with a greater experience in the use of these diagnostic methods who got an excellent sensitivity (91.42%) and an high NPV (92.68%).

CONCLUSIONS

SE is certainly an useful diagnostic method for the detection of prostate cancer, especially in association with TRUS. A great experience of the sonographist and an adequate training are indispensable to make, in the future, elastography a "structural marker".