Value of elastography by color patterns in the restaging of rectal cancer

Introduction: The qualitative elastography by endoscopic echography is a technique to examine the elastic properties of tissues that can distinguish the fibrosis of the tumor by means of color patterns. Objective: To determine the value of elastography by color patterns in the reestadification of the rectum cancer. Methods: An observational and descriptive study (serial cases) of 54 patients with rectum cancer was carried out, who were assisted in the National Center of Minimum Access Surgery, in Havana, between September, 2018 and December, 2022 to whom elastography by endoscopic echography were carried out for the reevaluation of the tumor. To determine the value of this technique the sensibility, specificity, the predictive positive and negative values, the positive and negative true ratio, as well as the index of Youden were calculated. The diagnostic consistency was established according to the kappa index and the histologic study of the sample was the reference standard. Results: The elastography consistency with the pathologic result was good (ĸ=0.84). The specificity and the index of validity were 91.7 and 94.4%, respectively; while the negative predictive value was 84.6%. The 16 patients with mixed elastographic pattern (ye3) had residual tumor located in some of the layers of the rectum wall. The Youden index reached values close to 1. Conclusions: The value of this technique resides in its diagnostic specificity and negative predictive value when differentiating fibrosis from the residual tumor in the rectal wall.