The ultrasonic tactile sensor: in vivo clinical application for evaluation of depth of invasion in esophageal squamous cell carcinomas.

Background and Study Aims: We have previously demonstrated that an ultrasonic tactile sensor (UTS) could be used to distinguish between mucosal and submucosal cancer in surgically resected specimens, by providing a measurement of tissue stiffness which could be less prone to subjective errors. In the current study, we evaluated the potential of a newly developed, thin UTS to differentiate in vivo between mucosal and submucosal invasion during clinical endoscopic examination.
Patients and Methods: Between March and July 1997, 15 patients with esophageal cancer who were not receiving special treatment, underwent preoperative UTS examination during endoscopy. The thin UTS probe was inserted through the biopsy channel of the endoscope. A transparent cap was placed on the distal end of the endoscope in order to facilitate vertical placement of the probe on the tumor.
Results: Although the probe used in this study was a prototype, the results of the current in vivo study were in agreement with our previous in vitro study on surgically resected specimens. The mean delta(f) value of the mucosal cancers, which means the magnitude of the frequency shift recorded by the UTS, was -5356.23 Hz, and the corresponding value for submucosal cancers was -4126.56 Hz; this difference was significant.
Conclusion: The UTS is potentially an essential tool for preoperative evaluation of esophageal cancers. The ability to differentiate between mucosal and submucosal cancers is important because of the differences in surgical management of these tumors, i.e. endoscopic mucosal resection or conventional open esophagectomy.