Three-dimensional endoscopic ultrasound for rectal cancer staging

Zeynab Yaberi mohammad,1,* Amir hasanvand,2

1. Department of Radiologic Technology, Faculty of Paramedicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
2. Department of Radiologic Technology, Faculty of Paramedicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.

Abstract

Introduction

Three-dimensional (3d) endoscopic ultrasound (eus) image reconstruction may improve the accuracy of eus and help decrease errors in staging. potential advantages of 3d reconstruction in eus include better spatial assessment of the location of tumors and their relationships with adjacent organs and blood vessels.

Methods

Publications were retrieved by a systematic search of multiple bibliographic databases, including medline, embase, scopus, cochrane library, web of science, biomed central, science direct, and google scholar. the language of search was restricted to english.

Results

Kim et al. have published significant work on the efficacy of 3d endorectal ultrasonography in rectal cancer. they studied 33 patients using both 3d and conventional eus for staging of rectal cancer. the accuracy of 3d eus was 90.9% for t2 and 84.8% for t3 tumors, whereas that of conventional eus was 84.8 and 75.8%, respectively. lymph node metastasis was accurately predicted by 3d eus in 28 patients (84.8%) and by conventional eus in 22 patients (66.7%) eus. 3d eus has shown greater accuracy then 2d eus or ct for evaluation in rectal cancer staging and lymph node metastasis. 2d eus, 3d eus, and ct scan were used to evaluate 86 consecutive rectal cancer patients undergoing curative surgery. the accuracy in t-staging was 78% for 3d eus, 69% for 2d eus, and 57% for ct (p < 0.001–0.002), whereas the accuracy in evaluating lymph node metastases was 65, 56, and 53%, respectively (p < 0.001–0.006). examiner errors were the most frequent cause of misinterpretation, occurring in 47% of 2d eus examinations and 65% of 3d eus examinations. giovannini et al. studied a software program for staging of rectal cancer by 3d eus that can be used with electronic radial or linear rectal probes in 35 patients. in 6 of 15 patients classified as having t3n0 lesions, 3d eus revealed malignant lymph nodes – a finding that was confirmed surgically in 5 of these 6 patients.

Conclusion

3d eus also made it possible to precisely assess the degree of infiltration of the mesorectum in all patients, demonstrating complete invasion of the mesorectum in 8. these findings were confirmed in all cases by surgery. 2d eus for t- and n-staging was accurate in 25 of 35 rectal tumors (71.4%), while 3d eus was accurate in 31 of 35 (88.6%). tis technology has not been utilized on a widespread basis to date.

Keywords

Endoscopic ultrasound, three-dimensional, rectal cancer.