Microenvironmental Factors in Oral Cavity Squamous Cell Carcinoma Undergoing Surgery: Correlation with Diffusion Kurtosis Imaging and Dynamic Contrast-Enhanced MRI

SIMPLE SUMMARY: Although the potential role of imaging-based parameters or pathological factors as useful cancer biomarkers has been reported in several studies, only a few investigations have been conducted to assess the associations between them. We hypothesized that the imaging features of OSCC, derived from perfusion- and diffusion-weighted techniques, may reflect not only the characteristics of cancer but also the microenvironment composition. We found that a number of pathological factors affected the imaging parameters, i.e., the inflammatory infiltrate, tumor grading and desmoplastic reaction. Evident relationships emerged between the DKI parameters and tumor-infiltrating lymphocytes. Significant differences in a few DCE-MRI parameters were also found according to the tumor grading. These findings may be helpful for a more comprehensive biological characterization of OSCC and could be used in future investigations for diagnostic and prognostic purposes. ABSTRACT: Background: In this prospective study, we hypothesized that magnetic resonance imaging (MRI) may represent not only the tumor but also the microenvironment, reflecting the heterogeneity and microstructural complexity of neoplasms. We investigated the correlation between both diffusion kurtosis imaging (DKI) and dynamic contrast-enhanced (DCE)-MRI with the pathological factors in oral cavity squamous cell carcinomas (OSCCs). Methods: A total of 37 patients with newly diagnosed OSCCs underwent an MR examination on a 3T system. The diffusion coefficient (D), the kurtosis parameter (K), the transfer constants K(trans) and K(ep) and the volume of extravascular extracellular space v(e) were quantified. A histogram-based approach was proposed to investigate the associations between the imaging and the pathological factors based on the histology and immunochemistry. Results: Significant differences in the DCE-MRI and DKI parameters were found in relation to the inflammatory infiltrate, tumor grading, keratinization and desmoplastic reaction. Relevant relationships emerged between tumor-infiltrating lymphocytes (TILs) and DKI, with lower D and higher K values being associated with increased TILs. Conclusion: Although a further investigation is needed, these findings provide a more comprehensive biological characterization of OSCCs and may contribute to a better understanding of DKI-derived parameters, whose biophysical meaning is still not well-defined.