Endoscopic ultrasonography of superficial esophageal cancers using a thin ultrasound probe system equipped with switchable radial and linear scanning modes.

BACKGROUND: Detailed information on the depth of invasion of superficial esophageal cancer is required for endoscopic mucosal resection. As a pretherapeutic diagnostic procedure, endoscopic ultrasonography using conventional 7.5 MHz systems has been ineffective at providing sufficient details. A newly developed, thin ultrasound probe system provides both radial and linear scanning for evaluation of superficial esophageal cancer.
METHODS: Endoscopic ultrasonography was performed in 16 patients using a switchable probe driven at 20 MHz. Seventeen lesions of superficial esophageal cancer were evaluated for depth of invasion to discriminate mucosal from submucosal penetration.
RESULTS: The overall accuracy of staging was 64.7%. In all six errors, mucosal cancers were overstaged as submucosal invasion. The diagnostic accuracy was 80% when the muscularis mucosae was visualized.
CONCLUSION: A 20 MHz linear-radial switchable probe is a useful new method in the staging of superficial esophageal cancer.