Clinical outcome and toxicity of radiotherapy for inferior vena cava tumor thrombus in HCC patients: A retrospective study

Exploring the Evolving Landscape of Stereotactic Body Radiation Therapy in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) carries significant morbidity and mortality. Management of the HCC requires a multidisciplinary approach. Surgical resection and liver transplantation are the gold standard options for the appropriate settings. Stereotactic body radiation therapy (SBRT) has emerged as a promising treatment modality in managing HCC; its use is more studied and well-established in advanced HCC (aHCC). Current clinical guidelines universally endorse SBRT as a viable alternative to radiofrequency ablation (RFA), transarterial chemoembolisation (TACE), and transarterial radioembolisation (TARE), a recommendation substantiated by literature demonstrating comparable efficacy among these modalities. In early-stage HCC, SBRT primarily manages unresectable tumours unsuitable for ablative procedures such as microwave ablation and RFA. SBRT has been incorporated as a modality to downstage tumours or as a bridge to transplant. In the case of intermediate or advanced HCC, SBRT offers excellent results either as a single modality or adjunct to other locoregional modalities such as TACE/TARE. Recent data from late-stage HCC patients illustrate the effectiveness of SBRT in achieving local tumour control while minimising damage to surrounding healthy liver tissue. It has promising local control of approximately 80-90% in managing HCC. Additional prospective data comparing the efficacy of SBRT with the first-line recommended therapies such as RFA, TACE, and surgery are essential. The standard of care for patients with advanced/metastatic disease is systemic therapy (immunotherapy/tyrosine kinase inhibitors). SBRT, in combination with immune-checkpoint inhibitors, has an immune-modulatory effect that results in a synergistic effect. Recent findings indicate that the combination of immunotherapy and SBRT in HCC is well-tolerated and exhibits synergistic effects. Further exploration of diverse immunotherapy and radiotherapy strategies is essential to identify the appropriate time for combination treatments and to optimise dose and fraction regimens. Prospective, randomised studies are imperative to establish SBRT as the primary treatment for HCC.

Radiotherapy with Targeted Therapy or Immune Checkpoint Inhibitors for Hepatocellular Carcinoma with Hepatic Vein and/or Inferior Vena Cava Tumor Thrombi

Purpose

This study evaluated the clinical outcomes of patients with hepatocellular carcinoma (HCC) with hepatic vein tumor thrombus (HVTT) and/or inferior vena cava tumor thrombus (IVCTT) receiving radiotherapy (RT) combined with systemic therapies.

Patients and Methods

Patients with HCC with HVTT and/or IVCTT who received RT were identified at our institution. The prescription doses were 30-65 Gy for planning target volume and 40-65 Gy for the gross tumor volume. Targeted therapy and immune checkpoint inhibitors were used concurrently if patients were at a high risk of or already had distant metastasis. After RT completion, follow-up was performed at 1, 3, 6, and 12 months, and 3 to 6 months thereafter. The objective response rate (ORR), overall survival (OS), progression-free survival (PFS) and toxicity were recorded.

Results

Thirty-four patients were retrospectively enrolled between January 2016 and September 2021. Most patients received concurrent targeted therapy (70.6%) and/or post-RT (79.4%). The in-field ORR and disease control rates were 79.4% and 97.1%, respectively. The OS rates were 77.6% at 1 year and 36.3% at 2 years (median OS, 15.8 months). The median PFS and median in-field PFS were 4.2 months and not reached, respectively. The PFS and in-field PFS rates were 24.6% and 79.2% at 1 year, 19.7% and 72.0% at 2 years, respectively. An alpha-fetoprotein level >1000 ng/mL was a significant prognostic factor for worse OS (HR, 5.674; 95% CI, 1.588-20.276; p=0.008); in-field complete/partial response was a significant prognostic factor for better OS (HR, 0.116; 95% CI, 0.027-0.499; p=0.004). The most common site of first failure was the lungs (13/34 patients, 38.2%), followed by the liver (7/34 patients, 20.6%). No patients developed radiation-induced liver disease or pulmonary embolism during follow-up.

Conclusion

Combining RT and systemic therapy was safe and effective in treating patients with HCC with HVTT and IVCTT.

The Treatment of Hepatocellular Carcinoma with Major Vascular Invasion

Vascular invasion of hepatocellular carcinoma involves tumor plugs in the main trunk of the portal vein, bile ducts, and veins, and it indicates poor prognosis. It is often associated with portal hypertension, which requires evaluation and management. Treatment includes hepatic resection, systemic pharmacotherapy, hepatic arterial infusion chemotherapy, and radiation therapy. Recurrence rates post-hepatic resection are high, and systemic drug therapy often has limited therapeutic potential in patients with a poor hepatic reserve. Single therapies are generally inadequate, necessitating combining multiple therapies with adjuvant and systemic pharmacotherapy before and after hepatectomy. This narrative review will provide an overview of the treatment of hepatocellular carcinoma with vascular invasion.

Magnetic Resonance Image-Guided Hypofractionated Ablative Radiation Therapy for Hepatocellular Carcinoma With Tumor Thrombus Extending to the Right Atrium

Hepatocellular carcinoma (HCC) presenting with tumor thrombus (TT) and inferior vena cava (IVC)/right atrium (RA) infringement point to an advanced-stage disease that is deemed inoperable. Stereotactic body radiotherapy is an emerging treatment option for this group of patients with promising outcomes in recent studies that are comparable to conventional treatment methods, namely, transarterial chemoembolization and transarterial radioembolization. Here, we report a case of HCC with RA extension through the IVC. The patient was referred to our clinic for treatment options, and he was found suitable for magnetic resonance imaging-guided radiotherapy (MRgRT). We treated the patient with MRgRT in five fractions to a total dose of 40 Gray. The tumor was tracked during the treatment sessions, and adaptive treatment planning was performed before each fraction. The patient tolerated the treatment well with no acute grade 3-4 toxicities. The last follow-up showed that the patient had a complete biochemical response and is now a candidate for an orthotopic liver transplant. To our knowledge, this report is the first to document the MRgRT treatment of an HCC with TT and RA extension. MRgRT is safe and feasible for this patient group and can be an effective bridging therapy for liver transplants.