Controlling Major Portal Vein Invasion Progression during Lenvatinib Treatment by Carbon-Ion Radiotherapy in Patients with Advanced Hepatocellular Carcinoma

Macrovascular invasion (MVI), including portal vein tumor thrombosis (PVTT), is strongly associated with poor prognosis in patients with hepatocellular carcinoma (HCC). While recommended standard treatment for patients with advanced HCC is systemic therapy, various treatment approaches, including resection, transarterial chemoembolization, and radiation, have been empirically suggested to improve prognosis by eliminating or controlling MVI. Herein, we report our experience of a case with advanced HCC where MVI was controlled by carbon-ion radiotherapy (CIRT) while on systemic therapy, resulting in a prolonged survival. A female patient with HCC in her early 60s had multiple intrahepatic lesions (maximum 60 mm in diameter) with PVTT. The PVTT of this patient had reached the main trunk of the portal vein despite the use of lenvatinib. The other intrahepatic lesions of the patient, except PVTT, had been controlled by lenvatinib. Therefore, hoping to control PVTT, we attempted CIRT. The patient resumed lenvatinib therapy after the irradiation. During lenvatinib re-treatment, no evident progression of PVTT was observed in the patient.