The Ultrasonic Tactile Sensor: In Vivo Clinical Application for Evaluation of Depth of Invasion in Esophageal Squamous Cell Carcinomas

Introduction

The depth of invasion of esophageal cancer is usually evaluated using radiographic examination (barium study), normal endoscopy, chromoendoscopy, endoscopic ultrasonography (EUS) [1] [2], computed tomography (CT), or magnetic resonance imaging (MRI). These examinations are based on the morphology of the tumors. Evaluations of this type, while useful, can be prone to errors because of their subjective nature. An accurate evaluation of invasion is needed to distinguish between mucosal and submucosal cancer. This differentiation is critically important as the surgical treatments for the different stages, namely, endoscopic mucosal resection (EMR) [3] or conventional open esophagectomy with regional lymph node dissections, involve very different degrees of operative stress for the patient.

We have previously carried out an experimental study [4] of tumor tissue using an ultrasonic tactile sensor (UTS) [5] [6]. The UTS is considered to have the potential to objectively measure the stiffness of materials. Surgically resected specimens of esophageal cancers were examined using UTS and a significant difference between mucosal and submucosal cancers was demonstrated. In the present study, patients were examined using a newly designed, thin UTS probe, to measure the tissue stiffness of the lesions preoperatively, in vivo. By means of these data, the usefulness of UTS in assessing the depth of invasion of clinical esophageal cancers was evaluated.

References

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