Endorectal ultrasound in the diagnosis of rectal cancer: accuracy and criticies.

Introduction: Endorectal ultrasound (ERU) is used for locoregional staging of rectal cancer. Our work compares the data in the literature regarding diagnostic accuracy of the technique and results of routine use of the technique in two centers in Piedmont. Material and methods: 77 reports ultrasound with the final diagnosis of rectal cancer from the period 2008–2012 were examined. The echographies were performed by two experienced operators, using two ultrasound device with the same technical characteristics. Results: Sensitivity levels are high, with the exception of stage T3. Specificity is always high. The relationships of verisimilitude, both negative and positive, showing that the accuracy of the test is still high. The risk of overstaging is higher for pT1, while most important the risk of understaging concerns the stage T3 (23.5%); on the contrary the ERU is able to exclude infiltration of perirectal organs with a good accuracy (NPV of 99.3%). Conclusion: Although our study was a retrospective study, likewise some literature's reports, the interpretation of our analysis results shows a significant risk of downstaging T3 and N+ tumors. ERU represents in our experience a very important radiological staging methods to evaluate T1 and T2 rectal cancer.