Preoperative staging of rectal carcinoma by endorectal ultrasound: is there a learning curve?

Abstract

ERUS is an accurate method for staging rectal cancer pre-operatively. Accurate assessment of tumour stage can be achieved immediately by an experienced radiologist without specific training in ERUS. Nodal staging accuracy tends to improve with experience but reaches a plateau after 30 cases.

Accuracy of transrectal ultrasonography in staging rectal tumors that are clinically eligible for transanal endoscopic microsurgery

“…Badger et al compared several studies and reported a N-stage TRUS accuracy of 59-82%. 7,19 Further investigations in our hospital will also include N-staging as indications for TEM in literature seem to expand to even T2 and T3 lesions after preoperative chemoradiotherapy.…”

“…Third, patients who have undergone radiation therapy, with resulting edema, inflammation, and necrosis, tend to be overstaged more often than patients who have not. 1,6,7,18 The only overstaged patient in our series had indeed been biopsied prior to TRUS.…”

“…[7][8][9]11,15,16 Overstaging can be explained by several reasons. First, Katsura et al reported that peritumoral inflammation can make echogenic layers become hypoechoic, resulting in overstaging of rectal lesions.…”

“…4 TRUS was examined in several unicenter studies and might be the best diagnostic option in assessing T-stage, with accuracy levels between 62 and 95%. [7][8][9][10][11][12][13][14] However, the largest series in literature reports an unacceptable 66% overall Tstage accuracy. 9 TRUS, CT, and MRI were compared in a metaanalysis including 90 studies.…”

Preoperative Staging of Rectal Cancer: Role of Endorectal Ultrasound

“…Ultrasonographic criteria for distinguishing malignant from inflammatory lymph nodes are a source of controversy. The criteria of echogenicity and border characteristics are subjective, although at least one study has shown that as many as 72% of nodes with hypoechoic patterns are metastatic (70). Nodal size as a criterion to consider a node to be metastatic is a matter of debate.…”