Introduction: Endoscopic ultrasonography (EUS) is the most important imaging method for diagnosis of subepithelial lesions of the gastrointestinal tract. However, it still has limits in the differentiation between Gastrointestinal Stromal Tumors (GISTs) from other malignant and benign tumors (Non-GISTs). As a result of the development of effective oncological therapy there is a high need for an imaging method to the diagnosis and follow-up of GISTs. In recent years Doppler EUS has been proposed as a method to distinguish GISTs from Non-GISTs. Therefore we initiated a prospective study to evaluate Doppler EUS criteria for the detection of a GIST.
Patients and Methods: Thirty-one patients (19 women, 12 men) with subepithelial lesions (n=32) were prospectively investigated using the EUS platform Olympus GF-UCT140 (Olympus Europe, Hamburg, Germany) and HDI 5000 (Philips Ultrasound, Bothell, USA). All Doppler EUS examinations were performed by one operator unaware of the histological results. Defined ultrasound parameters were used to determine the Doppler EUS observations. All tumors were proven histologically. The exact Chi-square Test (Fisher’s Test) was used to find significant differences between GISTs and Non-GISTs. P-values of less than 0.05 were considered to be significant. The study was conducted following the Good Clinical Practice Guidelines and according to the guidelines of the Helsinki Declaration.
Results: Vessels detected: GIST 10 present, 0 absent; Non-GIST 14 present, 8 absent (p-value 0.035),
Afferent vessel: GIST 9 present, 1 absent; Non-GIST 7 present, 15 absent (p-value 0.006),
Basket-like hypervascularization: GIST 9 present, 1 absent; Non-GIST 4 present, 18 absent (p-value 0.0002),
Significance level: p-value less than 0.05
Basket-like hypervascularization in Doppler endoscopic ultrasonography is a highly specific criterion in the differentiation between Gastrointestinal Stromal Tumors from other malignant and benign tumors (Non-GISTs).
Conclusion: The differentiation of GISTs from other malignant and benign subepithelial lesions is a major issue in the management of these tumors. With this prospective study, we have addressed the need to evaluate diagnostic criteria for Doppler EUS criteria. The results demonstrated a basket-like hypervascularization is a highly specific criterion in the detection of a GIST. In the future, the direct detection of vessels could be the most important advantage of Doppler EUS contrary to other imaging methods.
