Surgery versus external beam radiotherapy for hepatocellular carcinoma involving the inferior vena cava or right atrium: A systematic review and meta‐analysis

Clinical application of advances and innovation in radiation treatment of hepatocellular carcinoma

Background:

Hepatocellular carcinoma (HCC) management has evolved over the past two decades, with the development of newer treatment modalities. While various options are available, unmet needs are reflected through the mixed treatment outcome for intermediate-stage HCC. As HCC is radiosensitive, radiation therapies have a significant role in management. Radiation therapies offer local control for unresectable lesions and for patients who are not surgical candidates. Radiotherapy also provides palliation in metastatic disease, and acts as a bridge to resection and transplantation in selected patients. Advancements in radiotherapy modalities offer improved dose planning and targeted delivery, allowing for better tumor response and safer dose escalations while minimizing the risks of radiation-induced liver damage. Radiotherapy modalities are broadly classified into external beam radiation therapy and selective internal radiation therapy. With emerging modalities, radiotherapy plays a complementary role in the multidisciplinary care of HCC patients.

Aim:

We aim to provide an overview of the role and clinical application of radiation therapies in HCC management.

Relevance for Patients:

The continuous evolution of radiotherapy techniques allows for improved therapeutic outcomes while mitigating unwanted adverse effects, making it an attractive modality in HCC management. Rigorous clinical studies, quality research and comprehensive datasets will further its application in the present era of evidence-based practice in Medicine.

The inferior vena cava: anatomical variants and acquired pathologies

The inferior vena cava (IVC) is the largest vein in the body, draining blood from the abdomen, pelvis and lower extremities. This pictorial review summarises normal anatomy and embryological development of the IVC. In addition, we highlight a wide range of anatomical variants, acquired pathologies and a common pitfall in imaging of the IVC. This information is essential for clinical decision making and to reduce misdiagnosis.

Benefits of Local Treatment Including External Radiotherapy for Hepatocellular Carcinoma with Portal Invasion

We aimed to identify the oncologic benefits of local treatment including radiotherapy (LRT) in hepatocellular carcinoma (HCC) invading the portal vein. We used clinical data of patients with HCC invading the portal vein from 2008 to 2014 provided by 50 hospitals nationwide. A total of 1163 patients were included in the analysis. The LRT group was younger than the best supportive care (BSC) group (p < 0.001). The mean Child-Pugh score of the LRT group (6.1) was significantly lower than that of the BSC group (7.7) (p < 0.001). Propensity score-matched analysis generated 222 pairs. The median survival of all patients, LRT, and BSC groups were 5.0, 8.0, and 2.0 months, respectively. The overall survival (OS) rates in the LRT and BSC groups were 34.2% and 16.2% at one year, and 12.6% and 6.8% at two years, respectively (p < 0.001). Multivariate analysis showed that LRT (HR 0.41, 95% CI 0.32-0.52), age >60 years, extrahepatic metastases, tumor size ≥10 cm, and Child-Pugh class (CPC) B or C were independent predictors of higher mortality (all p < 0.05). Statistical differences in survival were maintained in all CPC-albumin-bilirubin classes (all p < 0.05). LRT was significant in patients with HCC with portal invasion, valid for patients with CPC A and B.

Efficacy of Local Treatments for Hepatocellular Carcinoma Involving the Inferior Vena Cava and/or Right Atrium

Major vessel invasion is frequently observed in locally advanced hepatocellular carcinoma (HCC). The most commonly involved major vessel is the portal vein; however, approximately 4% of patients with HCC have inferior vena cava (IVC) and/or right atrium (RA) invasion. Although these conditions have dismal prognoses, local treatments have not been regularly administered because they may affect systemic circulation. Owing to recent technological advances, various local treatments including surgery and external radiotherapy have increasingly been performed in these patients. Since irradiating tumorous lesions in the liver while preserving normal tissues is possible and major vessels are relatively resistant to radiation, external radiotherapy has been a feasible palliative modality for treating vessel-invasive HCC. In addition, systemic fatal complications that were initially a cause of concern have become rare after radiotherapy. While invasive procedures such as extracorporeal circulation or hepatic vascular exclusion may be required, pioneering surgeons have performed surgical resections in selected patients and have obtained promising results. Surgery has shown the best survival outcomes compared to other treatment options including radiotherapy, but the possibility of perioperative morbidity should be considered. In addition, a combination of local treatment and novel systemic agents, which demonstrated better survival and response rates than sorafenib, is expected to maximize therapeutic effects. In this review, we have discussed the most recent treatments for HCC with IVC and/or RA involvement and have provided information intended to guide therapeutic decisions and facilitate future research.