ASST-Spedali Civili Radiologia 1
ASST-Spedali Civili
Radiologia 1

Author of 1 Presentation

GI Tract - Rectum Poster presentation - Scientific

SE-045 - Comparison of 3D endorectal ultrasound (ERUS), CT, MRI and rectoscopy in pre-operative assessment of rectal cancer location.

Abstract

Purpose

Defining the best therapeutic approach for rectal cancer is conditioned not only by tumor staging but also by its location. Based on their distance from the ano-rectal ring (ARR), rectal cancers are classified as low (up to 5cm), middle (from >5 to 10cm) or high (from <10 to 15cm). The aim of this study is to compare the accuracy of ERUS, CT, MRI and rectoscopy in assessing rectal cancer location.

Material and methods

We retrospectively evaluated pre-operative imaging and endoscopic findings of 29 patients with rectal cancer: 18 underwent surgery as first choice treatment, 11 had neo-adjuvant chemotherapy before surgery. The real distance between tumor and ARR was measured adding up the distance between the tumor and the margin of resection on the anatomo-pathologic sample with the distance between the anastomosis and the ARR on the post-surgery rectoscopy. Accuracy was evaluated with percent error.

Results

Global percent error was 7,26% for endoscopy,18,12% for MRI, 21,57% for ERUS and 30% for CT. ERUS proved to be a reliable tool in early tumors (T1-T2) and in low rectal cancers. MRI showed a better performance than ERUS in high rectal cancer, but comparable to endoscopy. MRI was also more accurate than ERUS and CT in restaging patients who underwent neo-adjuvant chemotherapy before surgery. Overall, CT showed a poor performance with the highest percent of error.

Conclusion

Our results are consistent with literature, indicating ERUS/MRI accurate in low/high rectal tumors respectively. Overall, rectoscopy has proven to be the most accurate test to define rectal cancer location. CT performed poorly.

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