The accuracy of magnetic resonance imaging to measure the depth of invasion in oral tongue cancer: a systematic review and meta-analysis

The accuracy of magnetic resonance imaging (MRI)-derived depth of invasion (DOI) compared to histopathological DOI is still controversial. A meta-analysis was performed to address this controversy and further investigate the best imaging sequence to measure DOI of tongue squamous cell carcinomas (SCC). A comprehensive literature search of five electronic databases was conducted. Stata/SE was used to establish a continuous variable model to assess the consistency between MRI-derived DOI and histopathological DOI. IBM SPSS Statistics 22.0 was used to evaluate the correlation between MRI-derived DOI and histopathological DOI. The meta-analysis showed that the weighted mean difference (WMD) of DOI measured by MRI had an acceptable overestimation compared with that measured by histopathology (WMD 1.64 mm; P < 0.001). In the subgroup analyses, there was no difference between T1-weighted imaging (T1WI) and histopathological values (WMD 0.77 mm; P = 0.273), while T2-weighted imaging (T2WI) had a major overestimation (WMD 2.09 mm; P < 0.001). The overall inter-class correlation coefficient (ICC) between MRI-derived DOI and histopathological DOI was 0.869 (95% CI 0.837–0.895), and was 0.923 (95% CI 0.894–0.944) in the T1WI subgroup and 0.790 (95% CI 0.718–0.845) in the T2WI subgroup. MRI is an accurate modality for evaluating the DOI in oral tongue SCC, and T1WI showed relatively higher validity than T2WI for DOI measurements.