Accurate Preoperative Evaluation of the Location of Esophagogastric Junction Adenocarcinoma Using Positron Emission Tomography-Computed Tomography.

BACKGROUND The surgical procedure for esophagogastric junction (EGJ) adenocarcinoma usually depends on the location of its epicenter or proximal margin, but accurate evaluation of these positions is often difficult. The usefulness of positron emission tomography-computed tomography (PET-CT) for this purpose is unknown. METHODS Between June 2005 and February 2015, we enrolled 30 patients with cT2-4 EGJ adenocarcinoma (Siewert type I/II) who underwent surgical resection. We ascertained the sensitivity and specificity of preoperative PET-CT for identifying the primary tumor and regional lymph node metastasis, and compared PET-CT and pathological findings in terms of the distance from the EGJ to the tumor epicenter or proximal tumor margin. RESULTS PET-CT detected the primary tumor with a sensitivity of 97% (29/30), and detected lymph node metastasis with a sensitivity and specificity of 22% (4/18) and 100% (8/8), respectively. No significant association was observed between the maximal standardized uptake value and histological type, tumor size, or pT status. Regarding the accuracy of evaluating tumor location, the median differences between PET-CT and pathological measurements were .6 cm for the tumor epicenter and .5 cm for the proximal margin from the EGJ. PET-CT and pathological findings showed agreement regarding Siewert classification type (I or II) and lengths of esophageal involvement exceeding 4 cm or 2 cm in 77% (10/13), 85% (11/13), and 85% (11/13) of cases, respectively. DISCUSSION PET-CT had high sensitivity for primary EGJ adenocarcinoma. It may effectively locate the tumor epicenter and proximal margin and thus help clinicians determine the optimal surgical procedure.