Three‐dimensional endoscopic ultrasonography for the assessment of early gastric carcinoma invasion: could it provide diagnostic innovations?

Background: This study aimed to evaluate a three-dimensional endoscopic ultrasonographic (3-D EUS) system in the assessment of the tumor invasion depth of early gastric carcinoma. Methods: Sixty-nine macroscopically early cancer lesions in 67 patients were recruited in an in vivo study. The surgically resected gastric specimens of 30 of them were re-examined in an ex vivo study. An Olympus 3-D EUS imaging system was employed in both studies. Diagnostic accuracy for tumor invasion depth was evaluated and compared with histopathological sections stained by H&E and Masson’s trichrome stain. Reconstructed surface-rendering images were evaluated and compared with the endoscopic and macroscopic findings. Results: Three-dimensional EUS allowed rapid tomographic assessment of the lesions in both the in vivo and ex vivo studies. The accuracy of 3-D EUS for the assessment of tumor invasion depth was 87% in the in vivo study. The accuracy rate was significantly lower (P = 0.03) for the cancer lesions associated with ulcer fibrosis (74%) than for those with no fibrosis (97%). In the 30 subjects who underwent both studies, the accuracy rates were higher in the ex vivo than the in vivo study (94%vs 77% for all the lesions, and 93%vs 74% for cancers associated with fibrosis), but were not statistically significant. The rates of good surface-rendering images were 64% and 94% in the in vivo and ex vivo studies, respectively. The differences were attributed to the clearer dual-plane reconstruction images obtained in the ex vivo study in absence of motion artifacts. Conclusions: Three-dimensional EUS is a promising imaging technique for the assessment of tumor invasion depth of early gastric cancer.