Siewert type I and II oesophageal adenocarcinoma: Sensitivity/specificity of computed tomography, positron emission tomography and endoscopic ultrasound for assessment of lymph node metastases in groups of thoracic and abdominal lymph node stations

Objectives: In Siewert type I/II oesophageal adenocarcinoma, the sensitivity and specificity of computed tomography (CT), positron emission tomography (PET)-CT and endoscopic ultrasound (EUS) for assessment of the N descriptor in defined groups of lymph nodes were investigated. Methods: CT, PET/CT, EUS images and the pathological data of 101 oesophageal adenocarcinomas submitted to primary resection were compared. The lymph nodes were identified as (a) right paratracheal/subcarinal/pulmonary ligament; (b) paraoesophageal; (c) paracardial; (d) left gastric artery, lesser curvature; (e) coeliac trunk, hepatic/splenic artery. Results: Of the 2451 lymph nodes identified, 273 (11.1%) were histologically positive. Overall sensitivity, specificity and negative and positive predictive value for detection of lymph nodes metastatic were respectively: CT sensitivity 39%, specificity 86%, negative 58% and positive 74% predictive value; PET/CT sensitivity 30%, specificity 98%, negative 58% and positive 93% predictive value; EUS sensitivity 50%, specificity 81%, negative 72% and positive 62% predictive value. The sensitivity of CT, PET/CT and EUS in the thoracic nodal groups (a) and (b) was, respectively, 58.3%, 7.1% and 87.5% and 33.3%, 20% and 80%. Sensitivity was below 47% for all tests in the abdominal nodal groups. In contrast, specificity (88.6-100%) was super imposable in all nodal groups. The strength of agreement among the 3 imaging techniques was poor (kappa < 0.30) for the thoracic anatomical groups of interest: (a) lower paratracheal/subcarinal/pulmonary ligament and (b) paraoesophageal; it was moderate/good (kappa >0.30) for the abdominal N groups of interest: c, d and e. Conclusions: The diagnostic performance of CT, PET and EUS for assessing the N descriptor in the paracardial and abdominal stations close to the primary tumour is not satisfactory. EUS can efficiently assess the presence/absence of nodal metastases in the thoracic stations.