Stereotactic Body Radiotherapy vs. Radiofrequency Ablation in the Treatment of Hepatocellular Carcinoma: A Meta-Analysis

Combination treatment of HCC with SBRT and immune checkpoint inhibition

The treatment of unresectable or metastatic HCC has been significantly advanced in recent years by developments in both radiotherapy and systemic cancer therapies. Independently, both Stereotactic Ablative Body Radiotherapy (SBRT) and Immune Checkpoint Inhibitors (ICIs) are licensed for the treatment of these tumours. Building on the successes seen in other solid tumours, there is significant interest in exploring combination treatments. In this review article we briefly present the evidence base for the use of these treatments in patients with HCC. With reference to our current understanding of the immuno-oncology and radiobiology of HCCs, we demonstrate why combining these two modalities is of interest. Finally, we discuss the clinical trials that are currently underway or planned and the direction that future research may take.

Brazilian Landscape of Hepatocellular Carcinoma

The incidence of hepatocellular carcinoma (HCC) is expected to increase in the coming years, and strategies to mitigate the burden of this disease are needed in different regions. Geographic variations in epidemiology and risk factors, such as viral hepatitis and metabolic disease, pose challenges in adopting programs for early detection programs and management of patients with HCC. Brazil, like other countries, has high economic and social inequality, with heterogeneous access to health care. Viral hepatitis is the main risk factor but there is growing awareness of fatty liver disease. Risk factor monitoring and screening programs are unmet priorities because patients are often diagnosed at later stages. Advances in the management of patients with HCC have been made in recent years, including new tools for selecting patients for liver transplantation, sophisticated surgical techniques, and new systemic agents. High-volume academic centers often achieve favorable results through the adoption and application of established treatments, but this is not a reality in most regions of Brazil, because of disparities in wealth and resources. As HCC management requires a coordinated and multidisciplinary team, the role of local referral centers in decentralizing access to treatments and promoting health education in different regions should be encouraged and supported.

Local Therapies for Hepatocellular Carcinoma and Role of MRI-Guided Adaptive Radiation Therapy

Hepatocellular carcinoma (HCC) is the most common liver tumor, with a continually rising incidence. The curative treatment for HCC is surgical resection or liver transplantation; however, only a small portion of patients are eligible due to local tumor burden or underlying liver dysfunction. Most HCC patients receive nonsurgical liver-directed therapies (LDTs), including thermal ablation, transarterial chemoembolization (TACE), transarterial radioembolization (TARE), and external beam radiation therapy (EBRT). Stereotactic ablative body radiation (SABR) is a specific type of EBRT that can precisely deliver a high dose of radiation to ablate tumor cells using a small number of treatments (or fractions, typically 5 or less). With onboard MRI imaging, MRI-guided SABR can improve therapeutic dose while minimizing normal tissue exposure. In the current review, we discuss different LDTs and compare them with EBRT, specifically SABR. The emerging MRI-guided adaptive radiation therapy has been reviewed, highlighting its advantages and potential role in HCC management.

Stereotactic Body Radiation Therapy versus Surgical Resection for Stage I/II Hepatocellular Carcinoma

SBRT is an emerging locoregional treatment modality for hepatocellular carcinoma (HCC). Although local tumor control rates seem encouraging, large-scale survival data comparing SBRT to surgical resection are lacking. We identified patients with stage I/II HCC from the National Cancer Database amenable for potential surgical resection. Patients undergoing hepatectomy were matched by propensity score (1:2) with patients who underwent SBRT as primary treatment. A total of 3787 (91%) and 366 (9%) patients underwent surgical resection or SBRT between 2004 and 2015, respectively. After propensity matching, the 5-year overall survival was 24% (95% CI 19-30%) in the SBRT group versus 48% (95% CI 43-53%) in the surgery group (p < 0.001). The association of surgery with overall survival was consistent in all subgroups. In patients treated with SBRT, a biologic effective dose (BED) of ≥100 Gy (31%, 95% CI 22%-40%) compared with BED < 100 Gy (13%, 95% CI 8-22%) was associated with a higher 5-year overall survival rate (hazard ratio of mortality of 0.58, 95% CI 0.43-0.77; p < 0.001). Surgical resection may be associated with prolonged overall survival compared with SBRT in patients with stage I/II HCC.

Clinical consensus statement: Establishing the roles of locoregional and systemic therapies for the treatment of intermediate-stage hepatocellular carcinoma in Canada

BACKGROUND

Hepatocellular carcinoma (HCC) a leading cause of cancer mortality worldwide and approximately one-third of patients present with intermediate-stage disease. The treatment landscape of intermediate-stage HCC is rapidly evolving due to developments in local, locoregional and systemic therapies. Treatment recommendations focused on this heterogenous disease stage and that take into account the Canadian reality are lacking. To address this gap, a pan-Canadian group of experts in hepatology, transplant, surgery, radiation therapy, nuclear medicine, interventional radiology, and medical oncology came together to develop consensus recommendations on management of intermediate-stage HCC relevant to the Canadian context.

METHODS

A modified Delphi framework was used to develop consensus statements with strengths of recommendation and supporting levels of evidence graded using the AHA/ACC classification system. Tentative consensus statements were drafted based on a systematic search and expert input in a series of iterative feedback cycles and were then circulated via online survey to assess the level of agreement.

RESULTS & CONCLUSION

The pre-defined ratification threshold of 80 % agreement was reached for all statements in the areas of multidisciplinary treatment (n = 4), intra-arterial therapy (n = 14), biologics (n = 5), radiation therapy (n = 3), surgical resection and transplantation (n = 7), and percutaneous ablative therapy (n = 4). These generally reflected an expansion in treatment options due to developments in previously established or emergent techniques, introduction of new and more active therapies and increased therapeutic flexibility. These developments have allowed for greater treatment tailoring and personalization as well as a paradigm shift toward strategies with curative intent in a wider range of disease settings.

Stereotactic Body Radiotherapy for Hepatocellular Carcinoma: A Brief Overview

Stereotactic body radiotherapy (SBRT), a type of external beam radiotherapy, yields local control of hepatocellular carcinoma (HCC) at rates as high as 90%. SBRT has been recognized as an alternative therapy for patients for whom standard modalities such as surgery (resection or transplantation) or ablation are deemed unsuitable. SBRT has the potential to improve the prognosis of HCC, as it can be used as an adjunct to other treatment modalities. The assessment of post-SBRT images of the treated tumor and surrounding normal liver tissue requires special attention. Future research is warranted to determine how best to use SBRT versus other therapies and how to combine them.

Stereotactic body radiation therapy versus radiofrequency ablation in hepatocellular carcinoma: an up-date meta-analysis

PURPOSE

Radiofrequency ablation (RFA) and stereotactic body radiotherapy (SBRT) are available locoregional curative treatments for nonsurgical Hepatocellular carcinoma (HCC) patients. We aimed to compare the clinical efficacy and safety of SBRT versus RFA for HCC.

METHODS

A computerized bibliographic search was performed using PubMed, Embase, the Cochrane Library and Web of Science to identify comparative studies. The primary outcome was overall survival (OS), and the secondary outcomes were freedom from local progression (FFLP) and treatment-related complications.

RESULTS

In total, there were 17 trials involving 22,180 patients. Patients receiving RFA showed significantly better 1-, 2- year OS (OR 0.69, 95% CI 0.50-0.96, P = 0.141,OR 0.69, 95% CI 0.53-0.89, P = 0.082), whereas SBRT resulted in significantly better 1-, 2-, 3- year FFLP (OR 2.19, 95% CI 1.44-3.34, P = 0.303; OR 1.57, 95% CI 1.12-2.19, P = 0.268; OR 2.22, 95% CI 1.70-2.90, P = 0.470). There were no significant differences for 3-, 5- year OS in both groups (OR 0.94, 95% CI 0.65-1.38, P = 0.001; OR 0.98, 95% CI 0.68-1.34, P = 0.016). The overall treatment-related complication rate did not differ significantly between the two treatment arms, while SBRT was significantly associated with Child-Pugh worsening.

CONCLUSIONS

Though SBRT has excellent FFLP, RFA yields superior short-term survival for HCC. But the discrepancy between FFLP and OS requires further investigation.

Proton Beam Therapy and Photon-Based Magnetic Resonance Image-Guided Radiation Therapy: The Next Frontiers of Radiation Therapy for Hepatocellular Carcinoma

External beam radiation therapy (EBRT) has increasingly been utilized in the treatment of hepatocellular carcinoma (HCC) due to technological advances with positive clinical outcomes. Innovations in EBRT include improved image guidance, motion management, treatment planning, and highly conformal techniques such as intensity-modulated radiation therapy (IMRT) and stereotactic body radiation therapy (SBRT). Moreover, proton beam therapy (PBT) and magnetic resonance image-guided radiation therapy (MRgRT) have expanded the capabilities of EBRT. PBT offers the advantage of minimizing low- and moderate-dose radiation to the surrounding normal tissue, thereby preserving uninvolved liver and allowing for dose escalation. MRgRT provides the advantage of improved soft tissue delineation compared to computerized tomography (CT) guidance. Additionally, MRgRT with online adaptive therapy is particularly useful for addressing motion not otherwise managed and reducing high-dose radiation to the normal tissue such as the stomach and bowel. PBT and online adaptive MRgRT are emerging technological advancements in EBRT that may provide a significant clinical benefit for patients with HCC.

ACR Appropriateness Criteria® Management of Liver Cancer: 2022 Update

The treatment and management of hepatic malignancies can be complex because it encompasses a variety of primary and metastatic malignancies and an assortment of local and systemic treatment options. When to use each of these treatments is critical to ensure the most appropriate care for patients. Interventional radiologists have a key role to play in the delivery of a variety of liver directed treatments including percutaneous ablation, transarterial embolization with bland embolic particles alone, transarterial chemoembolization (TACE) with injection of a chemotherapeutic emulsion, and transarterial radioembolization (TARE). Based on 9 clinical variants, the appropriateness of each treatment is described in this document. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances in which peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

The Current Role of Stereotactic Body Radiation Therapy (SBRT) in Hepatocellular Carcinoma (HCC)

The role of stereotactic body radiotherapy (SBRT), which can deliver high radiation doses to focal tumors, has greatly increased in not only early-stage hepatocellular carcinoma (HCC), but also in portal vein or inferior vena cava thrombi, thus expanding this therapy to pre-transplantation and the treatment of oligometastases from HCC in combination with immune checkpoint inhibitors (ICI). In early-stage HCC, many promising prospective results of SBRT have been reported, although SBRT is not usually indicated as a first treatment potion in localized HCC according to several guidelines. In the treatment of portal vein or inferior vena cava tumor thrombi, several reports using various dose-fraction schedules have shown relatively good response rates with low toxicities and improved survival due to the rapid advancements in systemic therapy. Although SBRT is regarded as a substitute therapy when conventional bridging therapies to transplantation, such as transarterial chemoembolization (TACE) and radiofrequency ablation (RFA), are not applicable or fail in controlling tumors, SBRT may offer advantages in patients with borderline liver function who may not tolerate TACE or RFA, according to several reports. For oligometastases, the combination of SBRT with ICI could potentially induce an abscopal effect in patients with HCC, which is expected to provide the rationale for SBRT in the treatment of oligometastatic disease in the near future.

Stereotactic Body Radiation Therapy for the Management of Hepatocellular Carcinoma: Efficacy and Safety

Simple Summary

This study aimed to describe treatment efficacy and safety in patients with hepatocellular carcinoma (HCC) undergoing stereotactic body radiation therapy (SBRT). In one of the largest retrospective studies to date, we analyzed the data of 318 patients. The median follow-up period was 70.2 months. The local control rate at 24 and 60 months was 94% (91–97%) and 94% (91–97%), respectively. Relapse-free survival at 12, 24, and 60 months was 62% (55–67%), 29% (23–36%), and 13% (8–19%), respectively. OS at 12, 24, and 60 months was 72% (95%CI 67–77%), 44% (38–50%), and 11% (7–15%), respectively. The outcome is highly related to the natural evolution of the underlying cirrhosis. Child-Pugh score B-C, high BCLC score, portal thrombosis, GTV volume, and higher PTV volume reported on total hepatic volume ratio were significantly associated with OS. SBRT is efficient for the management of HCC with a favorable toxicity profile.

Abstract

This study aimed to describe patient characteristics, treatment efficacy, and safety in patients with hepatocellular carcinoma (HCC) undergoing stereotactic body radiation therapy (SBRT). We retrospectively analyzed data of 318 patients with 375 HCC treated between June 2007 and December 2018. Efficacy (overall survival [OS], relapse-free survival, and local control) and acute and late toxicities were described. The median follow-up period was 70.2 months. Most patients were treated with 45 Gy in three fractions. The median (range) PTV volume was 90.7 (2.6–1067.6) cc. The local control rate at 24 and 60 months was 94% (91–97%) and 94% (91–97%), respectively. Relapse-free survival at 12, 24, and 60 months was 62% (55–67%), 29% (23–36%), and 13% (8–19%), respectively. OS at 12, 24, and 60 months was 72% (95%CI 67–77%), 44% (38–50%), and 11% (7–15%), respectively. Approximately 51% and 38% experienced acute and late toxicity, respectively. Child-Pugh score B-C, high BCLC score, portal thrombosis, high GTV volume, and higher PTV volume reported on total hepatic volume ratio were significantly associated with OS. SBRT is efficient for the management of HCC with a favorable toxicity profile. The outcome is highly related to the natural evolution of the underlying cirrhosis.

The Significance of Systemic Inflammation Markers in Intrahepatic Recurrence of Early-Stage Hepatocellular Carcinoma after Curative Treatment

Simple Summary

This retrospective study using the prospectively collected registry data of newly diagnosed, previously untreated hepatocellular carcinoma (HCC) evaluates the significance of systemic inflammatory markers (SIMs) to intrahepatic recurrence (IHR) after curative treatment. Out of 4076 patients who met the inclusion criteria, 52.6% experienced IHR. SIMs, including pre-treatment platelet-to-lymphocyte ratio (PLR), post-treatment changes of neutrophil-to-lymphocyte ratio PLR, and lymphocyte-to-monocyte ratio were significantly associated with the prognosis of early-stage HCC patients who received initial curative treatment. The prognostic significances of SIMs were consistent for IHR-free survival, early and late IHR, and overall survival.

Abstract

Systemic inflammatory markers (SIMs) are known to be associated with carcinogenesis and prognosis of hepatocellular carcinoma (HCC). We evaluated the significance of SIMs in intrahepatic recurrence (IHR) of early-stage HCC after curative treatment. This study was performed using prospectively collected registry data of newly diagnosed, previously untreated HCC between 2005 and 2017 at a single institution. Inclusion criteria were patients with Barcelona Clinic Liver Cancer stage 0 or A, who underwent curative treatment. Pre-treatment and post-treatment values of platelet, neutrophil, lymphocyte, monocyte, neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR), and lymphocyte/monocyte ratio (LMR) were analyzed with previously well-known risk factors of HCC to identify factors associated with IHR-free survival (IHRFS), early IHR, and late IHR. Of 4076 patients, 2142 patients (52.6%) experienced IHR, with early IHR in 1018 patients (25.0%) and late IHR in 1124 patients (27.6%). Pre-treatment platelet count and PLR and post-treatment worsening of NLR, PLR, and LMR were independently associated with IHRFS. Pre-treatment platelet count and post-treatment worsening of NLR, PLR, and LMR were significantly related to both early and late IHR. Pre-treatment values and post-treatment changes in SIMs were significant factors of IHR in early-stage HCC, independent of previously well-known risk factors of HCC.

Chinese expert consensus on conversion therapy for hepatocellular carcinoma (2021 edition)

Recent advances in systemic and locoregional treatments for patients with unresectable or advanced hepatocellular carcinoma (HCC) have resulted in improved response rates. This has provided an opportunity for selected patients with initially unresectable HCC to achieve adequate tumor downstaging to undergo surgical resection, a 'conversion therapy' strategy. However, conversion therapy is a new approach to the treatment of HCC and its practice and treatment protocols are still being developed. Review the evidence for conversion therapy in HCC and develop consensus statements to guide clinical practice. Evidence review: Many research centers in China have accumulated significant experience implementing HCC conversion therapy. Preliminary findings and data have shown that conversion therapy represents an important strategy to maximize the survival of selected patients with intermediate stage to advanced HCC; however, there are still many urgent clinical and scientific challenges for this therapeutic strategy and its related fields. In order to summarize and learn from past experience and review current challenges, the Chinese Expert Consensus on Conversion Therapy for Hepatocellular Carcinoma (2021 Edition) was developed based on a review of preliminary experience and clinical data from Chinese and non-Chinese studies in this field and combined with recommendations for clinical practice. Sixteen consensus statements on the implementation of conversion therapy for HCC were developed. The statements generated in this review are based on a review of clinical evidence and real clinical experience and will help guide future progress in conversion therapy for patients with HCC.

Radiofrequency ablation vs radiation therapy vs transarterial chemoembolization vs yttrium 90 for local treatment of liver cancer - a systematic review and network meta-analysis of survival data

INTRODUCTION

The comparative effectiveness of radiofrequency ablation (RFA), radiation therapy (RT), transarterial chemoembolization (TACE) and transarterial radioembolization with Yttrium-90 (Y90) relative to one another for the treatment of hepatocellular carcinoma (HCC) is unclear. The aim of this systematic review and network meta-analysis is to compare RFA to RT to TACE to Y90 in the treatment of HCC.

METHODS

Pubmed, Embase and Cochrane CENTRAL were searched up until April 19, 2021. Observational analyses with propensity score matched (PSM) cohort analyses and randomized controlled trials (RCT) reporting on two or more treatments relative to one another with respect to overall survival (OS) and/or progression free survival (PFS) were included. Survival data were extracted from Kaplan-Meier survival curves, and meta-analyzed using a multivariate network meta-analysis.

RESULTS

After exclusions, 24 RCTs or PSM observational studies reporting on 5549 patients were included. While 1-year OS was greater for Y90 than TACE (RR 0.85, 95% CI: 0.72-0.99), all other 1-year OS comparisons across the 4 modalities yielded similar OS, and there were no differences across any modalities in 2-year and 3-year OS. TACE had a modest PFS advantage relative to RFA (RR 0.81, 95% CI: 0.68-0.95) and RT (RR 0.65, 95% CI: 0.51-0.83) at 2 years.

CONCLUSION

All modalities assessed resulted in similar OS, which explains the current heterogenous practice patterns. This conclusion may assist in decision making based on administrative and patient costs, and implementation of these modalities. Other factors such as toxicity rate specific to individual patients could not be assessed using network meta-analysis and may also play a role in selection of modality. Further studies, ideally using PSM cohort analyses or RCT study design, reporting on OS, PFS, local control, complete response and toxicity are needed prior to drawing definitive conclusions.

Comparison of clinical outcome between stereotactic body radiotherapy and radiofrequency ablation for unresectable hepatocellular carcinoma

Stereotactic body radiotherapy (SBRT) is a novel noninvasive treatment for unresectable hepatocellular carcinoma (HCC). Whether its efficacy is comparable to radiofrequency ablation (RFA), a recommended therapy for unresectable HCC, is unknown. The present study aims to compare the clinical outcome between SBRT and RFA for patients with unresectable HCC.The clinical data of 60 patients with unresectable HCC from January 2018 to January 2021 were retrospectively reviewed. There were 22 cases treated by SBRT and 38 cases by RFA. The short-term and long-term clinical outcomes were compared.There was no significant difference in the baseline demographic characteristics between two groups. The complete remission rate at 3 months was comparable between SBRT group (81.8%) and RFA group (89.4%). Local tumor control rate was also similar between two groups (90.9% vs. 94.7%). There was no severe complication (grade IIIa or above) in both groups. The 1-year and 2-year overall survival rates were 88.2% and 85.7% in SBRT group and 100% and 75% in RFA group, respectively. There was no statistical significant difference between groups (P = .576).SBRT can achieve similar short and long-term clinical outcome as RFA for unresectable HCC. Future prospective clinical study is needed to justify its role in patients with HCC.

Frontiers of therapy for hepatocellular carcinoma

The incidence of hepatocellular carcinoma continues to increase worldwide. Fortunately, there have been notable recent advances in locoregional and systemic therapy. In this current review, we will highlight these new developments and future directions of hepatocellular carcinoma treatment and address the importance of a multidisciplinary approach to treatment.

Comparison of stereotactic body radiotherapy and radiofrequency ablation for hepatocellular carcinoma: Systematic review and meta-analysis of propensity score studies

AIM

Stereotactic body radiotherapy (SBRT) is an emerging treatment for hepatocellular carcinoma (HCC) and has shown excellent local control (LC), as has radiofrequency ablation (RFA). As no randomized controlled trial has compared SBRT and RFA for HCC, data from a propensity score matched study (PSMS) are valuable. However, the results varied greatly and depended on composing factors of Barcelona Clinic Liver Cancer staging (BCLC-factors) adjusted. Therefore, we undertook a systematic review and meta-analyses of the studies focusing on BCLC-factors matching.

METHODS

We systematically searched PubMed, the Cochrane database, EMBASE, and Web of Science to identify studies comparing RFA and SBRT using propensity scores. The hazard ratios (HRs) of overall survival (OS) and LC from BCLC-factor-matched and -unmatched PSMS were pooled. Heterogeneity between the data from these studies was assessed.

RESULTS

Three BCLC-factor-matched studies were identified. Stereotactic body radiotherapy led to comparable OS (HR, 0.89; 95% CI, 0.74-1.08; p = 0.24; I²  = 0%; p for heterogeneity, 0.56) and significantly better LC (HR, 0.39; 95% CI, 0.30-0.51; p < 0.001; I²  = 0%; p for heterogeneity, 0.67). We also identified three additional BCLC-factor-unmatched studies (HR of OS, 1.41; 95% CI, 1.21-1.65; p < 0.0001; I²  = 0%; p for heterogeneity, 0.63). However, considerable heterogeneity was observed for HR of OS between BCLC-factor-matched and -unmatched studies (I²  = 92.6%; p for heterogeneity, 0.0002).

CONCLUSIONS

When BCLC-factors were properly adjusted, the results of the meta-analysis revealed equivalent OS and better LC for SBRT compared with RFA. Stereotactic body radiotherapy could be an alternative treatment option for HCC.

Current Understanding of Ablative Radiation Therapy in Hepatocellular Carcinoma

The role of ablative stereotactic body radiotherapy (SBRT) in hepatocellular carcinoma (HCC) has been evolving over the last few decades. SBRT has mostly been used in early stages of HCC, including few (≤ 3 in number) tumors, small tumours (< 3 cm in size), as well as larger tumours which are ineligible for other ablative modalities, mostly without vascular invasion. In early stage HCC, SBRT is used as a definitive treatment with curative intent or with intent to bridge to liver transplant. Retrospective and prospective institutional series document a high rate of local control (68–95% at 3 years) following SBRT. This coupled with a low risk of toxicity makes this non-invasive ablative treatment an attractive option for patients who are ineligible for other ablative treatments. Small randomized studies of ablative radiation have also shown non-inferiority of radiation as compared to radiofrequency ablation (RFA). Currently, SBRT is widely available as a safe and effective liver directed therapy, although there is a need for more studies providing higher level evidence. This review gives a brief overview of SBRT and the evidence for its use in HCC patients with ablative intent.

Early diagnosis and therapeutic strategies for hepatocellular carcinoma: From bench to bedside

Hepatocellular carcinoma (HCC) is the fourth leading cause of cancer-related deaths worldwide. The prognosis of patients with HCC remains poor largely due to the late diagnosis and lack of effective treatments. Despite being widely used, alpha-fetoprotein serology and ultrasonography have limited diagnostic performance for early-stage HCC. The emergence of omics strategies has contributed to significant advances in the development of non-invasive biomarkers for the early diagnosis of HCC including proteins, metabolites, circulating tumor deoxyribonucleic acid, and circulating non-coding ribonucleic acid. Early diagnosis is beneficial to patients as it increases the proportion who can be treated with curative treatment, thus prolonging survival outcomes. Currently, multiple clinical trials involving locoregional, systemic therapies, and combinations of these modalities are changing therapeutic strategies for different stage HCC. Success in several preclinical trials that involve immunotherapeutic innovations has created the potential to complement and enforce other treatment strategies in the future. This review summarizes the most recent advances in non-invasive early molecular detection, current therapy strategies, and potential immunotherapeutic innovations of HCC.

Stereotactic Radiotherapy for Hepatocellular Carcinoma, Radiosensitization Strategies and Radiation-Immunotherapy Combination

Simple Summary

Radiotherapy is rapidly turning into a crucial component of multidisciplinary treatment for liver cancer because many patients are not surgical treatment candidates. Thanks to technical developments, radiotherapy have achieved high precision treatments, making it possible to eliminate tumor cells without severe damage to the liver and other organs. Stereotactic Body Radiation Therapy is an advanced radiotherapy technique able to eradicate malignant tumors wherever they are located in properly selected patients. The best use of radiotherapy, the most fruitful radiotherapy strategy, and the best way to combine it with other treatments for liver cancer are largely unknown. Radiosensitizers, agents that can potentiate radiotherapy, could broaden the radiotherapeutic landscape. Radiotherapy potentiation can be achieved with diverse treatments, not only drugs but also nanoparticles. In order to clear up the performance of radiotherapy in liver cancer management in the future and the best ways to potentiate its effects, considerable medical research is needed.

Abstract

Stereotactic body radiotherapy (SBRT) is an emerging ablative modality for hepatocellular carcinoma (HCC). Most patients with HCC have advanced disease at the time of diagnosis, and therefore, are not candidates for definitive-intent therapies such as resection or transplantation. For this reason, various alternative local and regional therapies have been used to prevent disease progression, palliate symptoms, and delay liver failure. Stereotactic body radiation therapy is a non-invasive technique of delivering ablative doses of radiation to tumors while sparing normal or non-tumor hepatic tissue. Incorporation of SBRT in multidisciplinary HCC management is gradual, initially applied when other liver-directed therapies have failed or are contraindicated, and tried in combination with other locoregional or systemic therapies for more unfavorable conditions by more experienced teams. In order to improve SBRT therapeutic ratio, there has been much interest in augmenting the effect of radiation on tumors by combining it with chemotherapy, molecularly targeted therapeutics, nanoparticles, and immunotherapy. This review aims to synthesize available evidence to evaluate the clinical feasibility and efficacy of SBRT for HCC, and to explore novel radio-potentiation concepts by combining SBRT with novel therapeutics. It is expected that those approaches would result in improved therapeutic outcomes, even though many questions remain with regard to the optimal way to assemble treatments. Further trials are needed to evaluate and consolidate these promising therapies for HCC.