Sensitivity and specificity of FDG PET-CT scan in detecting lymph node metastasis in operable periampullary tumours in correlation with the final histopathology after curative surgery

Abstract

18F-Fluorodeoxyglucose-positron emission tomography/computerised tomography (FDG-PET/CT) was investigated for evaluation of periampullary tumours and other gastrointestinal neoplasms. The aim of this study was to evaluate the utility of FDG-PET/CT for detection of lymph node metastasis in periampullary tumours by comparing the preoperative FDG-PET/CT scan finding with postoperative histopathology of lymph nodes. Study was done on 24 patients with diagnosis of periampullary carcinoma either proven or suspected on conventional radiology. Standard uptake value (SUV) were measured for lymph node areas with uptake in FDG-PET/CT and compared with histopathological lymph node status. For detection of lymph node metastasis, FDG-PET/CT with cutoff value SUV max ≥2.0 had a sensitivity of 71.4 % and specificity of 77.8 % and that for SUV max ≥2.5 and 2.8 were 57.1, 42.9 and 77.8, 77.8 %, respectively. The sensitivity and specificity of FDG-PET/CT at each lymph node groups were 72 and 89 % in peripancreatic area, 100 and 93 % in hepatoduodenal area and 100 and 100 % in aortocaval area at SUV max ≥2.0, respectively. At SUV max ≥2.5 the values were 57 and 89 % in peripancreatic area, 100 and 93 % in hepatoduodenal area and 100 and 93 % in aortocaval area. FDG-PET-CT has a possible role in detection of lymph node metastasis in periampullary carcinomas and may be used as a guide for possible lymphadenectomy during surgery and for prognostic purpose.