Background: The aim of this study was to investigate the value of miniaturized ultrasound catheter probes (miniprobes) for preoperative staging of esophageal and gastric cancer.
Methods: Fifty-one patients with esophageal (n = 21) and gastric cancer (n = 30) underwent endoscopic ultrasound (EUS). All examinations were carried out using mechanical miniprobes (diameter 6F, 12.5 MHz) that were introduced through the instrument channel of the endoscope.
Results: EUS with miniprobes was successfully performed in all patients, although stenotic tumors, which could not be traversed with the endoscope, were found in 6 of 21 patients (29%) with esophageal cancer. Miniprobe scanning provided high-resolution images of the gastrointestinal tract. The overall accuracy in the assessment of tumor infiltration depth for esophageal and gastric cancer was 90% and 82%, respectively. However, the value of miniprobe scanning in the assessment of advanced tumors was limited by the imaging depth of the probe (approximately 3 cm). Lymph node involvement was accurately diagnosed in 78% of the patients with esophageal cancer (sensitivity 75%, specificity 80%) and in 80% of the patients with gastric cancer (sensitivity 73%, specificity 89%).
Conclusions: EUS with miniprobes can be performed as single-step procedure during diagnostic endoscopy. The 12.5 MHz transducer provides high-resolution imaging and enables accurate staging of tumors with limited infiltration depth.