Aim: We aimed to evaluate the role of 18F-FDG PET/CT in the TNM staging of esophageal cancer in comparison with contrast-enhancement computed-tomography (CECT). Futhermore we set out to determine the role of semiquantitative PET parameters.
Methods: 55 patients performed 18F-FDG PET/CT and CECT. Values of Sensitivity (Se), specificity (Sp), accuracy and predictability (PPV and NPV) were evaluated. McNemar test was applied for comparison. Cohen's K was calculated to measure the agreement. 18F-FDG PET/CT semiquantitative parameters (SUVmax, SUVmean, MTV and TLG) in relation to site and histotype, were assessed by ANOVA test and post-hoc test.
Results: About T parameter, Se, Sp, accuracy, PPV and NPV of CECT and 18F-FDG PET/CT were respectively 82.35%, 94.48%, 85.00%, 93.33% and 76% for both the tecniques; the agreement resulted substantial. There were no statistically significant relationships between 18F-FDG PET/CT parameters and sites; MTV value differs in histotypes. About N parameter, Se, Sp, accuracy, PPV and NPV of CECT were respectively 82.35%, 57.89%, 65.00%, 46.67%, 88%; for 18F-FDG PET/CT were 88.23%, 60.53%, 61%, 50% and 92%; the agreement resulted fair. About M parameter, Se, Sp, accuracy, PPV and NPV PET/CT were equal for both techniques: 76.92%, 52.38%, 58.33%, 33%, 88%; the agreement resulted moderate. No statistical difference was observed in any comparison.
Conclusion: 18F-FDG PET/CT is a useful tool for whole-body evaluation of patients with esophageal cancer, allowing an effective clinical TNM staging. In particular 18F-FDG PET/CT's ability in detecting distant metastases suggest its routinary performance as a second level of investigation.