Risk Factors of Non-Classic Radiation-Induced Liver Disease (ncRILD) After Intensity-Modulated Radiotherapy in Hepatocellular Carcinoma.

PURPOSE

This study aimed to identify independent risk factors for non-classic radiation-induced liver disease (ncRILD) in hepatocellular carcinoma (HCC) patients treated with intensity-modulated radiation therapy (IMRT) and to construct a predictive nomogram.

PATIENTS AND METHODS

We retrospectively analyzed 177 primary HCC patients treated with IMRT between 2013 and 2021. Univariate and multivariate analyses were conducted to identify risk factors for ncRILD. A nomogram was developed based on significant variables. Dosimetric parameters were also assessed across different fractionation doses.

RESULTS

Multivariate analysis identified tumor number ≥ 2, mean liver dose ≥ 1371.4 cGy, and normal liver volume < 700 mL as independent risk factors for ncRILD. A nomogram was established using logistic regression. In patients receiving ≥ 4 Gy per fraction, ncRILD was significantly associated with Vs5-Vs40 (p < 0.05), but not with V5-V40. No such associations were found for 2 Gy and 3 Gy groups.

CONCLUSION

Patients with multifocal tumor, lower normal liver volume and higher mean liver dose are at increased risk of developing radiation-induced liver injury. These findings suggest that dosimetric parameters, especially at higher fraction doses, may play a critical role in the occurrence of ncRILD.