Roles of the apparent diffusion coefficient and tumor volume in predicting tumor grade in patients with choroid plexus tumors

To explore the utility of the apparent diffusion coefficient (ADC) and tumor volume to predict histological grade and prognosis in patients with choroid plexus tumors.

ADC and tumor volumes were retrospectively evaluated in 25 patients with choroid plexus papilloma (CPP; WHO grade 1 [n = 13]), atypical CPP (aCPP; grade 2 [n = 8]), or choroid plexus carcinoma (grade 3 [n = 4]) The prognostic roles of ADC and tumor volume were assessed.

There were significant differences in mean and minimum ADC values, and tumor volume among the WHO grades (p = 0.033, p = 0.044, and p = 0.014, respectively). Receiver-operating characteristic analysis revealed a mean cutoff ADC value ≤ 1.397 × 10⁻³ mm²/s for aCPP (sensitivity = 0.667, specificity = 0.923). Multiple linear regression analysis demonstrated that both mean ADC (β = − 0.455, p = 0.005) and tumor volume (β = 0.513, p = 0.002) were correlated with WHO grade (adjusted R² = 0.520, p = 0.005). Kaplan-Meier curve analysis identified poorer survival in patients with WHO grade 2 and 3 tumors than in those with WHO grade 1 disease (p = 0.049 and p = 0.012, respectively). A mean ADC ≤ 1.397 × 10⁻³ mm²/s (p = 0.001) and tumor volume 21.05 ml (p = 0.031) predicted significantly poorer survival.

Mean ADC and tumor volume were correlated with WHO grade of choroid plexus tumors. A lower ADC value and a larger tumor volume predicted a poorer prognosis.