Correlation of apparent diffusion coefficient with histopathological parameters of salivary gland cancer

The aim of this study was to correlate the apparent diffusion coefficient (ADC) with histopathological parameters of salivary gland cancer. A retrospective analysis of 44 patients with salivary gland cancer who underwent diffusion-weighted magnetic resonance imaging of salivary glands was performed. The ADC of salivary gland cancer was correlated with pathological tumour type and grade, stage (T stage and N stage), and morphological (perineural spread and location) prognostic parameters. There was a significant difference in ADC values between low-intermediate- and high-grade tumours (P = 0.024), lower T stages (T1, T2) versus higher T stages (T3, T4) (P = 0.001), lower N stages (N0, N1) versus higher N stages (N2, N3) (P = 0.001), and the presence versus absence of perineural spread (P = 0.001). The cut-off ADC values to predict higher-grade, higher T stage, nodal spread, and perineural spread were 0.94, 0.92, 0.94, and 0.98 × 10^-3 mm²/s, with area under the curve of 0.847, 0.858, 0.900, and 0.798 and accuracy of 75.0%, 75.0%, 75.0%, and 77.3%, respectively. The ADC value is a non-invasive imaging parameter that correlates with histopathological parameters of salivary gland cancer.