3533 The additive role of pet scanning with eus and ct in accurately predicting surgical resectability of esophageal carcinomas.

Abstract

INTRODUCTION: Endoscopic ultrasound (EUS) has demonstrated T and N staging accuracy approaching 85% and 75%, respectively, but lacks the ability to detect distant metastases. Computed Tomography (CT) is the currently accepted modality to identify distant metastatic disease. AIM: To evaluate whether Positron Emission Tomography (PET) scanning alters pre-operative staging of distant lymph nodes (LNs) or metastases in determining curative surgical resectability of esophageal carcinomas. METHODS: All newly diagnosed cases of esophageal carcinoma who underwent pre-operative imaging before surgery were retrospectively analyzed. A total of eighteen patients from October 1998 to October 1999 without any significant co-morbidities precluding them from curative surgical intent were included. Seventeen patients were evaluated with EUS(Olympus UM-130 radial echoendoscope) and conventional CT, while 15 underwent F-18-FDG PET imaging. Imaging staging accuracy was compared to surgical histopathologic staging in 15 of 18 patients. Three patients deemed unresectable by evidence of distant LNs/metastases did not undergo surgery but were included in the analysis. RESULTS: EUS T and N staging accuracy was 79%(11/14) and 50%(7/14), respectively. Thirteen of 15 tumors were histological stage T2 or T3. EUS was 76% accurate in correctly determining curative surgical resectability as defined as stage ≤T3N1. PET scanning demonstrated increased local tumor/nodal uptake in 13 of 15(87%) patients, and revealed increased distant nodal or metastatic uptake in 4 of 4(100%) patients. One false positive reading in a patient with increased cervical LN uptake was found to have benign nodes at surgery (PPV=80%). CT nodal staging accuracy was 24%(4/17), and only correctly identified 2 of 4(50%) patients with distant LNs/metastases. Whereas combined EUS and CT accurately defined surgical resectability (≤T3N1M0) in 14 of 16(87%) patients, the addition of PET increased preoperative resectability sensitivity to 100%(14/14). PET scanning revealed surgical unresectability, as evidenced by distant metastatic disease, in an additional 2 of 15 patients, thus avoiding unnecessary surgery. CONCLUSIONS: PET scanning detects additional distant LNs/metastases which may be missed by conventional CT alone. Pre-operative PET scanning in conjunction with EUS and CT may be useful in determining curative surgical resectability of esophageal carcinomas.