Histopathologic validation of lymph node staging with FDG-PET scan in cancer of the esophagus and gastroesophageal junction - A prospective study based on primary surgery with extensive lymphadenectomy

Objective To assess the Value of positron emission tomography with (18)fluorodeoxyglu cose (FDG-PET) for preoperative lymph node staging of patients with primary cancer of the esophagus and gastroesophageal junction. Summary Background Data FDG-PET appears to be a promising tool in the preoperative staging of cance r of the esophagus and gastroesophageal junction. Recent reports indicate a higher sensitivity and specificity for detection of stage IV disease and a higher specificity for diagnosis of lymph node involvement compared with t he standard use of computed tomography and endoscopic ultrasound. Methods Forty-two patients entered the prospective study. All underwent attenuation -corrected FDG-PET imaging of the neck, thorax, and upper abdomen, a spiral computed tomography scan, and an endoscopic ultrasound. The gold standard consisted exclusively of the histology of sampled nodes obtained by extensi ve two-field or three-field lymphadenectomies (n = 39) or from guided biops ies of suspicious distant nodes indicated by imaging (n = 3). Results The FDG-PET scan had lower accuracy for the diagnosis of locoregional nodes (N1-2) than combined computed tomography and endoscopic ultrasound (48% vs . 69%) because of a significant lack of sensitivity (22% vs. 83%). The accu racy for distant nodal metastasis (M+Ly), however, was significantly higher for FDG-PET than the combined use of computed tomography and endoscopic ul trasound (86% vs. 62%). Sensitivity was not significantly different, but sp ecificity was greater (90% vs. 69%). The FDG-PET scan correctly up-staged f ive patients (12%) from N1-2 stage to M+Ly stage. One patient was falsely d ownstaged by FDG-PET scanning. Conclusions FDG-PET scanning improves the clinical staging of lymph node involvement ba sed on the increased detection of distant nodal metastases and on the super ior specificity compared with conventional imaging modalities.