Endorectal Ultrasound in the Preoperative Evaluation of Rectal Cancer

The efficacy of endoscopic ultrasonography in local staging of rectal tumors

“…In the detection of the characteristics (malignant or benign) of lymph nodes by CT, MRI, and ERUS, structure, size and echogenicity are considered. Most investigators consider a lymph node metastatic if it has round and discrete margins, is uniformly hypoechoic, or has the same echoic pattern as a primary tumor (19,20). However, reactive or fibrotic lymph nodes sometimes may appear hypoechoic, leading to possible confusion between these nodes and typical metastatic lymph nodes.…”

Rectal Carcinoma: Multi-Modality Approach in Curative Local Treatment of Early Rectal Carcinoma

“…An abdominopelvic CT scan is performed on the majority of patients with clinically localised rectal cancer in order to identify any intra-abdominal metastasis prior to curative or radical resection. However, its role in preoperative staging is much more limited with accuracy of T-staging being 53% to 94% and for N-staging 54% to 70%, which are substantially lower than ERUS (Schaffzin & Wond, 2004). MRI is also less accurate than ERUS for staging rectal cancer, with an accuracy of 52% in T-stage and 68% in N-stage (Chen et al, 2000).…”

Preoperative Staging of Rectal Cancer: Role of Endorectal Ultrasound

“…Images are usually obtained using an ultrasound frequency of 10 to 16MHz, depending on which part of the rectum is being examined. Higher frequencies provide better resolution of the sphincter muscles and the rectal wall layer, whereas pararectal tissues and lymph nodes are more accurately assessed using lower frequencies (16). Complications of this technique have not been reported.…”