Background and Aims: To evaluate the efficacy and safety of stereotactic body radiation therapy (SBRT) in patients with the portal vein invasion (≤5 cm) and explore the association between pretreatment platelet count and out-field recurrence and radiation-induced liver disease (RILD).
Methods: A total of 490 HCC patients whose single lesion with the portal vein invasion (≤5 cm) treated with SBRT were included in our study. 334 patients were retrospectively enrolled and 156 patients were prospectively included in our investigation respectively.
Results: The 1-, 3- and 5-year overall survival (OS) rates were 96.7%, 80.6% and 72.3%, respectively. The 1-, 3- and 5-year progression free survival (PFS) rates were 80.5%, 58.4% and 45.1%, respectively. The 1-, 3- and 5-year distant metastasis-free survival (DMFS) rates were 82.2%, 61.8% and 48.3%, respectively. The 1-, 3- and 5-year local control (LC) rates were 98.2%, 95.1% and 93.5%, respectively. A lower pretreatment PLT count was found to be associated with worse OS rates (HR 0.990, 95% CI 0.985-0.996, p=0.001*), PFS rates (HR 0.995, 95% CI 0.993-0.998, p=0.001*) and higher occurrence rates of RILD (HR 0.978, 95% CI 0.965-0.991, p=0.001*).
Conclusions: SBRT was a safe and effective option in patients with the portal vein invasion (≤5 cm), which had shown good LC, OS rates and low toxicity. The platelet count could predict out-field recurrence and RILD.