Radiotherapy with Multimodality Therapy for Hepatocellular Carcinoma with Hepatic Vein and/or Inferior Vena Cava Tumor Thrombus

Abstract

<h3>Purpose/Objective(s)</h3> Liver cancer is the seventh most common malignancy and second leading cause of cancer-related death worldwide. Hepatic vein and/or inferior vena cava (IVC) tumor thrombus are less common. Improvement in techniques allowed the increasing use of radiotherapy in treating tumor thrombus in hepatocellular carcinoma (HCC). Hence, the present study evaluated the treatment response and survival outcomes of HCC with hepatic vein tumor thrombus (HVTT) and/or IVC involvement receiving radiotherapy in modern RT technique combined with other multimodality therapies. <h3>Materials/Methods</h3> HCC patients with HVTT and/or IVC tumor thrombus receiving radiotherapy were identified at our institution. All patients were treated with VMAT or IMRT technique and 4D-CT was used in simulation. All thrombus and primary tumor in liver were included in the GTV unless they were far from gross primary tumor. The prescription dose to 95% of the PTV was planned at 50-65Gy in 22-28 fractions over 5-6 weeks. After the completion of RT, chest-abdominal CT and liver MRI were performed at 1, 3, 6, 12 months and then 3 to 6 months thereafter. Treatment response was defined as the best response evaluation in 3 months after RT. Overall survival (OS), progression free survival (PFS) and in-field PFS were recorded during follow-up. <h3>Results</h3> Between April 2010 and September 2021, 30 men and 4 women with a median age of 53.5 years (range 30-71 years) were retrospectively included in the cohort. 7 (20.6%) patients had lymph node metastasis and 10 (29.4%) patients had distant metastasis before radiotherapy (RT). In addition to hepatic vein/inferior vena cava (IVC) tumor thrombus, portal vein and right atrium involvement were present in 17 (50.0%) and 6 (17.6%) patients. Half of the patients received TACE and 14 (41.2%) patients received systemic treatment including target therapy and immune therapy before radiotherapy. Most patients received target therapy concurrent with (70.6%) and/or post RT (79.4%). During follow-up (median 13.0 months), the median PFS and median in-field PFS were 4.2 months and not reached, respectively. The PFS and in-field PFS rate were 24.6% and 79.2% at 1 year, 19.7% and 72.0% at 2 years. The OS rate was 77.6% at 1 year and 36.3% at 2 years with a median OS of 15.8 months. PFS and OS were not associated with portal vein involvement, IVC involvement and distant metastasis before RT. The most common first failure site was lung (13/34 patients, 38.2%), followed by liver (7/34 patients, 20.6%). Only 5 (14.7%) patients had progression in the RT field of liver during follow-up. No patients had radiation-induced liver disease or pulmonary embolism during follow-up. <h3>Conclusion</h3> Our study proved that HCC lesions and tumor thrombus were sensitive to RT even after other local therapies. Combination of RT and systemic therapy in treating HCC patients with HVTT and IVC tumor thrombus was safe and effective.