Rectal endosonography: just how good are we at its interpretation?

Abstract

Endorectal ultrasound (ERUS) has become an integral part of the assessment of rectal tumors. It provides information about the depth of invasion and lymph node status which in turn is used in devising a management plan. It is important therefore that accurate interpretation of these studies is achieved. The aim of this study was to assess how accurately we interpret ERUS. A collection of 26 ERUS images were compiled and confirmed by two experienced colorectal sonographers. The survey was sent to 100 ASCRS members practicing at institutions with residency programs in colorectal surgery in USA and Canada. Two separate mailings were sent. Participants were asked to allocate a T and N stage to each of the images. Their responses were compared with pathology results. Twenty five surveys were returned, 23 were completed. Thirteen respondents reported performing ERUS themselves, on average performing three examinations per month (range, 1-8). The mean duration of practice was 11.2 years (range, 0-26). The mean number of rectal cancer cases managed over a 12-month period was 25 (range, 10-75). T stage was accurately reported in 38-69%. If we continue to rely on ERUS as an important step in staging rectal cancer further education may be needed to improve overall interpretation.