Comparison between CT Net enhancement and PET/CT SUV for N staging of gastric cancer: A case series

Abstract

BackgroundThe therapeutic approach of gastric cancer strictly depends on TNM staging mainly provided by CT and PET/CT. However, the lymph node size criterion as detected by MDCT causes a poor differential diagnosis between reactive and metastatic enlarged lymph nodes with low specificity values.Our study aims to compare 320-row CT Net enhancement and fluorine-18 fluoro-2-deoxy-d-glucose positron emission tomography/computed tomography (F-FDG PET/CT) SUV for N staging of gastric cancer.Materials and methods45 patients with histologically proven gastric cancer underwent CT and F-FDG PET/CT. Two radiologists in consensus evaluated all images and calculated the CT Net enhancement and F-FDG PET/CT SUV for N staging, having the histological findings as the reference standard. CT and F-FDG PET/CT sensitivity, specificity, diagnostic accuracy, positive and negative predictive values (PPV and NPV) were evaluated and compared by using the Mc Nemar test.ResultsThe histological examination revealed nodal metastases in 29/45 cases (64%). CT Net enhancement obtained sensitivity, specificity, accuracy, PPV and NPV of 90%, 81%, 87%, 90% and 81%, respectively. F-FDG PET/CT SUV obtained sensitivity, specificity, accuracy, PPV and NPV of 66%, 88%, 73%, 90% and 58%, respectively. No statistically significant difference between the two imaging modalities was found (p = 0.1).ConclusionCT Net enhancement represents an accurate tool for N staging of gastric cancer and could be considered as the CT corresponding quantitative parameter of F-FDG PET/CT SUV. It could be applied in the clinical practice for differentiating reactive lymph nodes from metastatic ones improving accuracy and specificity of CT.

Hydro-MDCT for Gastric Adenocarcinoma Staging. A Comparative Study With Surgical and Histopathological Findings for Selecting Patients for Echo-endoscopy

“…Evaluating the data reported in the scientific literature, MDCT is considered a reliable method in determining, rather than the exact number of lymph nodes involved, the presence or absence of local or regional lymph node metastases (27). This technique gives precisely important information to the surgeon for a correct planning operation for lymph node resection that, anyhow, is routinely performed in most centers and therefore incorrect staging of the N parameter would not change the surgical protocol (28).…”

Is Accurate N – Staging for Gastric Cancer Possible?

“…Enhancement of lymph nodes during portal phase might be useful in increasing specificity: An enlarged lymph node from other cause than malignancy will not, or will at a lesser extent, enhance. Considering than enhancement is a quantitative rather than a qualitative parameter, level of enhancement can help characterize an already enlarged lymph node in an objective manner, increasing specificity ( 12 ).…”