Outcomes After Stereotactic Body Radiation Therapy as a Bridging Modality to Liver Transplantation for Hepatocellular Carcinoma

Stereotactic body radiation therapy (SBRT) in patients with hepatocellular cancer-a narrative review and expert opinion

Background and Objective

Stereotactic body radiation therapy (SBRT) is a highly conformal technique of external beam radiotherapy precisely delivering high total (ablative) doses in a small number of fractions to clearly defined target volumes. Its development enabled efficient and safe radiation treatments in patients with localized hepatocellular cancer (HCC) unsuitable for other local treatment options. Moreover, it can be easily combined with several other therapy approaches. Thus, the aim of this narrative review is to outline the current role of SBRT in the multifocal treatment of HCC patients.

Methods

We searched PubMed for articles dealing with SBRT alone, in combination with other local or systemic treatments or in comparison to other local treatments in patients with HCC. This included original articles, reviews and conceptional articles dealing with the technique of SBRT. All articles were analysed for suitability by two independent reviewers.

Key Content and Findings

This review summarizes the currently available evidence for SBRT as a definitive treatment for HCC as well as its role within combination approaches including bridging to transplantation. SBRT is an effective and safe definitive treatment option in patients with localized HCC unsuitable for surgery and/or other local therapies based on retrospective and prospective series. Its combination with other local treatments yields superior results compared to single modality treatment based on non-randomized data. A growing number of prospective trials confirmed at least similar if not superior rates of local control with low toxicities compared to well established other local treatments even in non-selected patients.

Conclusions

SBRT is a promising tool in the treatment of HCC. It can be used either as definitive treatment, within combination approaches or as a bridging tool. Several phase III trials comparing SBRT with other local options are ongoing, which will further clarify its encouraging role.

SBRT for Liver Tumors: What the Interventional Radiologist Needs to Know

This review summarizes the clinical evidence supporting the utilization of stereotactic body radiotherapy (SBRT) for liver tumors, including hepatocellular carcinoma, liver metastases, and cholangiocarcinoma. Emerging prospective evidence has demonstrated the benefit and low rates of toxicity across a broad range of clinical contexts. We provide an introduction for the interventional radiologist, with a discussion of underlying themes such as tumor dose-response, mitigation of liver toxicity, and the technical considerations relevant to performing liver SBRT. Ultimately, we recommend that SBRT should be routinely included in the armamentarium of locoregional therapies for liver malignancies, alongside those liver-directed therapies offered by interventional radiology.

Cell-Free DNA as a Surveillance Tool for Hepatocellular Carcinoma Patients after Liver Transplant

The liver is the world's sixth most common primary tumor site, responsible for approximately 5% of all cancers and over 8% of cancer-related deaths. Hepatocellular carcinoma (HCC) is the predominant type of liver cancer, accounting for approximately 75% of all primary liver tumors. A major therapeutic tool for this disease is liver transplantation. Two of the most significant issues in treating HCC are tumor recurrence and graft rejection. Currently, the detection and monitoring of HCC recurrence and graft rejection mainly consist of imaging methods, tissue biopsies, and alpha-fetoprotein (AFP) follow-up. However, they have limited accuracy and precision. One of the many possible components of cfDNA is circulating tumor DNA (ctDNA), which is cfDNA derived from tumor cells. Another important component in transplantation is donor-derived cfDNA (dd-cfDNA), derived from donor tissue. All the components of cfDNA can be analyzed in blood samples as liquid biopsies. These can play a role in determining prognosis, tumor recurrence, and graft rejection, assisting in an overall manner in clinical decision-making in the treatment of HCC.

Approach to Stereotactic Body Radiotherapy for the Treatment of Advanced Hepatocellular Carcinoma in Patients with Child-Pugh B-7 Cirrhosis

OPINION STATEMENT

Patients with hepatocellular carcinoma (HCC) with underlying Child-Pugh B-7 cirrhosis benefit from management from an experienced, multidisciplinary team. In patients with localized disease who meet criteria for liver transplant, establishing care at a liver transplant center is crucial. For those awaiting transplant, local bridge therapies have emerged as a strategy to maintain priority status and eligibility. Multiple liver-directed therapies exist to provide locoregional tumor control. The careful selection of locoregional therapy is a multidisciplinary endeavor that takes into account patient factors including tumor resectability, underlying liver function, performance status, previous treatment, tumor location/size, and vascular anatomy to determine the optimal management strategy. Technological advances in external beam radiation therapy have allowed stereotactic body radiation therapy (SBRT) to emerge in recent years as a versatile and highly effective bridge therapy consisting of typically between 3 and 5 high dose, highly focused, and non-invasive radiation treatments. When treating cirrhotic patients with HCC, preserving liver function is of utmost importance to prevent clinical decline and decompensation. SBRT has been shown to be both safe and effective in carefully selected patients with Child-Pugh B cirrhosis; however, care must be taken to prevent radiation-induced liver disease. This review summarizes the evolving role of SBRT in the treatment of HCC in patients with Child-Pugh B-7 cirrhosis.

Stereotactic body radiation therapy for primary liver tumors: An effective liver-directed therapy in the toolbox

The use of radiation for primary liver cancers has historically been limited because of the risk of radiation-induced liver disease. Treatment fields have become more conformal because of several technical advances, and this has allowed for dose escalation. Stereotactic body radiation therapy (SBRT), also known as stereotactic ablative radiotherapy, is now able to safely treat liver tumors to ablative doses while sparing functional liver parenchyma by using highly conformal therapy. Several retrospective and small prospective studies have examined the use of SBRT for liver cancers; however, there is a lack of well-powered randomized studies to definitively guide management in these settings. Recent advances in systemic therapy for primary liver cancers have improved outcomes; however, the optimal selection criteria for SBRT as a local therapy remain unclear among other liver-directed options such as radiofrequency ablation, transarterial chemoembolization, and radioembolization.