Imaging-Based Tumor Margin Patterns and Primary Tumor Categories and Their Association with Adverse Histopathological Features in Oral Tongue Squamous Cell Carcinoma

Background: This retrospective study introduces imaging inner tumor margin patterns (iITMP) and evaluates their correlation with pathological Worst pattern of invasion (WPOI) in oral tongue squamous cell carcinoma (OTSCC). Associations of iITMP with pathological primary tumor category (pT), histologic grade, perineural invasion (PNI), nodal metastasis, and extranodal extension (ENE) were assessed. Correlations between imaging depth of invasion (iDOI) and pathological DOI (pDOI), and between imaging primary tumor (iT) and pT, PNI, and ENE were evaluated. Methods: Baseline magnetic resonance imaging (MRI) from January 2021 to December 2022 of 224 upfront-operated OTSCC patients was reviewed by two blinded radiologists using contrast-enhanced thin-slice. iITMP (types 1–3) were classified based on inner tumor margin morphology. iDOI was measured after excluding peritumoral hyperenhancement. Correlation between categorical and continuous variables were assessed using Kappa statistics and Spearman’s test respectively. Associations between categorical variables were analyzed using Fisher’s exact or Pearson’s chi-squared tests. Univariable and multivariable analyses were additionally performed. Results: The mean patient age was 47 ± 11 years. Substantial agreement was observed between iITMP and WPOI, and between iT and pT. iDOI strongly correlated with pDOI. iITMP was significantly associated with pT, irregular (iITMP2) and infiltrative (iITMP3) margins were associated with PNI only on univariate analysis, while iITMP was not an independent predictor on multivariable analysis. iT significantly correlated with PNI and ENE. Conclusions: iITMP strongly correlate with WPOI and is substantially associated with pT categories. iT categories show significant association with PNI and ENE. Therefore, iITMP and iT may serve as potential imaging biomarkers of adverse histopathological features in OTSCC.