Diagnostic accuracy of imaging modalities in detection of histopathological extranodal extension: A systematic review and meta-analysis

Objective: To present an up to date systematic review and meta-analysis evaluating the diagnostic accuracy of the most used imaging modalities in detection of histopathological extra nodal extension (ENE) in head and neck squamous cell carcinoma. Materials and methods: Medline, Embase, and Cochrane databases were systematically searched on March 27th 2020. Screening, inclusion, quality assessment, and data extraction were done by two reviewers. Meta-analysis was conducted using the bivariate model approach after pooling the studies according to imaging modality. Heterogeneity was explored by meta-regression. Comparison was done by meta-regression and sub-group analyses. fResults: Out of 476 initial hits, 25 studies were included for analysis. Of these, 14 dealt with CT, nine with PET/ CT, four with MRI, two with ultrasound, and none with PET/MRI. Meta-analysis based on a total sample size of 3391 showed that CT had a sensitivity of 76% [67-82%] and specificity of 77% [69-83%], MRI a sensitivity of 72% [64-79%] and specificity of 78% [57-90%], and PET/CT a sensitivity of 80% [76-84%] and specificity of 83% [74-90%] in the ability to predict ENE. No meta-analysis could be done on ultrasound. There were no significant differences between modalities in overall accuracy; however, PET/CT had significantly higher sensitivity than CT and MRI. Conclusion: There was no significant difference in the ability of CT, MRI, and PET/CT to diagnose histopathological ENE, except that PET/CT had a significantly higher sensitivity than CT and MRI.