18F-FDG PET/CT characteristics of IASLC grade 3 invasive adenocarcinoma and the value of 18F-FDG PET/CT for preoperative prediction: a new prognostication model

Abstract

Objective This study is performed to investigate the imaging characteristics of the International Association for the Study of Lung Cancer grade 3 invasive adenocarcinoma (IAC) on PET/CT and the value of PET/CT for preoperative predicting this tumor. Materials and methods We retrospectively enrolled patients with IAC from August 2015 to September 2022. The clinical characteristics, serum tumor markers, and PET/CT features were analyzed. T test, Mann–Whitney U test, χ2 test, Logistic regression analysis, and receiver operating characteristic analysis were used to predict grade 3 tumor and evaluate the prediction effectiveness. Results Grade 3 tumors had a significantly higher maximum standardized uptake value (SUVmax) and consolidation-tumor-ratio (CTR) (P < 0.001), while Grade 1 - 2 tumors were prone to present with air bronchogram sign or vacuole sign (P < 0.001). A stepwise logistic regression analysis revealed that smoking history, CEA, SUVmax, air bronchogram sign or vacuole sign and CTR were useful predictors for Grade 3 tumors. The established prediction model based on the above 5 parameters generated a high AUC (0.869) and negative predictive value (0.919), respectively. Conclusion Our study demonstrates that grade 3 IAC has a unique PET/CT imaging feature. The prognostication model established with smoking history, CEA, SUVmax, air bronchogram sign or vacuole sign and CTR can effectively predict grade 3 tumors before the operation.