Abstract:
Objective To explore the predictive value and assess the effectiveness of a risk prediction model based on 18F-fluorodeoxyglucose (FDG) PET/CT metabolic parameters for lymph node staging in gastric cancer (GC).
Methods The clinical data and 18F-FDG PET/CT imaging data of 167 patients who underwent radical GC surgery at Fujian Cancer Hospital from October 2011 to September 2022 were retrospectively analyzed. The cohort included 129 males and 38 females, with a median age of 62(56, 69) years. Multiple Logistic regression analysis was used to identify independent factors that affect the lymph node staging of GC. The predictive value of individual metabolic parameters and their combinations was evaluated using receiver operating characteristic (ROC) curve analysis. A risk prediction model and nomogram were constructed, and their diagnostic performance was assessed. The calibration of the model was evaluated using the Hosmer-Lemeshow (H-L) test.
Results Multiple Logistic regression analysis show that gender, tumor infiltration depth, tumor length diameter, and total lesion glycolysis (TLG) are independent factors affecting the N0 stage of GC. The odds ratios (OR) (95%CI) are 0.217(0.060–0.784), 5.907(1.984–17.589), 0.622(0.427–0.905), and 1.010(1.004–1.017), all P<0.05. Carcinoembryonic antigen (CEA) and tumor length diameter are independent factors affecting the N3a and N3b stages of GC, respectively. Their OR (95%CI) are 1.018(1.004–1.033) and 1.258(1.074–1.473), both P<0.05. ROC curve analysis show that the area under curve (AUC) for predicting the N0 stage of GC using gender, tumor infiltration depth, tumor length diameter, and TLG are 0.565, 0.706, 0.725, and 0.652, respectively. The AUCs for CEA and tumor length diameter in predicting the N3a and N3b stages of GC are 0.648 and 0.710, respectively. The risk prediction model for predicting the N0 stage has an AUC of 0.796(95%CI: 0.716–0.876, P<0.001), with a sensitivity of 56.4%, specificity of 89.8%, positive predictive value of 62.9%, negative predictive value of 87.1%, and accuracy of 82.0%. The H-L test results indicates good calibration of the model (χ2=9.067, P=0.337).
Conclusion The risk prediction model based on 18F-FDG PET/CT metabolic parameters demonstrates good performance in predicting lymph node N0 stage in GC.