Functional Dose-Volume Analysis Based on a Novel Image Biomarker Derived From Dynamic Contrast-Enhanced Magnetic Resonance Imaging for Predicting Poststereotactic Body Radiation Therapy Liver Function Preservation in Patients With Hepatocellular Carcinoma.

[PURPOSE] The purpose of this study is to identify functional dose-volume parameters based on image biomarker derived from dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) for predicting poststereotactic body radiation therapy (SBRT) liver function deterioration (LFD) in patients with hepatocellular carcinoma.

[METHODS AND MATERIALS] Forty-eight patients treated with SBRT were retrospectively included. All patients underwent gadoxetate-enhanced DCE-MRI before treatment. Equivalent uniform dose, absolute dose-volume parameters including Dxcc and VxGy(cc) were calculated in 3 liver volumes: the anatomic volume (AV), the high-functional volumes (HFV) defined based on DCE-MRI derived function map, and the low-functional volume (LFV = AV - HFV). The primary endpoint of this study was the LFD as indicated by ∆albumin-bilirubin ≥ 0.5 at 1-month post-SBRT. Dose-volume parameters in patients with and without LFD were compared. Univariate logistic regression models were built to assess the ability of dose-volume parameters to distinguish between LFD and non-LFD cases.

[RESULTS] Of the 48 patients, 12 (25%) had LFD (∆albumin-bilirubin ≥ 0.5). The dose-volume parameters in the AV and LFV were not statistically different in patients with and without LFD ( > .005), while D300cc, D400cc, and V10Gy(cc) of the HFV were significantly higher in patients with LFD than in the non-LFD group ( < .005). For distinguishing LFD and non-LFD cases, the mean area under curves (AUCs) for D300cc of AV, LFV, and HFV are 0.60, 0.50, and 0.78, respectively. The mean AUCs for D400cc of AV, LFV, and HFV are 0.62, 0.50, and 0.78, respectively. The mean AUCs for V10Gy of AV, LFV, and HFV are 0.63, 0.48, and 0.77, respectively.

[CONCLUSIONS] The dose-volume parameters derived from HFV were linked to the risk of post-SBRT LFD. These functional parameters derived based on DCE-MRI could be useful to guide more personalized SBRT planning to protect liver function.