Leaflet manual of external beam radiation therapy for hepatocellular carcinoma: a review of the indications, evidences, and clinical trials

Radioprotective effect of mistletoe extract on intestinal toxicity: in vivo study using adult zebrafish

PURPOSE

The intestine is a dose-limiting organ in the treatment of intra-abdominal cancer. We previously reported that the extract of mistletoe parasites on Quercus had a more potent radioprotective effect than amifostine in reducing the developmental toxicities of zebrafish embryos. In this study, radioprotection against intestinal toxicity was investigated in adult zebrafish.

METHODS

Wild-type adult AB zebrafish were exposed to 45-50 Gy of photon beam irradiation and/or treated with mistletoe extract orally 1 h before. The main endpoints of the study were survival and degree of deformation of the intestinal villi.

RESULTS

The median follow-up period was 10 d post-irradiation (range: 7-11 d). A total of 105 zebrafish were used, including 42 in the radiation alone, 42 in the radiation and mistletoe arms, and 21 control subjects (mistletoe alone, mock-irradiated arm). The rate of both significant deformity and death was 53% in the radiation-alone arm, whereas the corresponding rate was 30% in the radiation and mistletoe arms. Significant deformity-free survival rates at 10 d post-irradiation in the radiation alone, and radiation and mistletoe arms were 44.7% (95% confidence interval [CI]:20-54.3) and 68.4% (95% CI:53.8-86.8), respectively (p=.046). The radiation and mistletoe arms showed decreased expression of two of three inflammatory genes (IL-1β and IL-6) compared to the radiation alone group (p<.05).

CONCLUSION

The radioprotective effect against intestinal toxicity was successfully shown in an adult zebrafish model. This result suggests the possibility of clinical use of mistletoe extract for the treatment of abdominal cancers.

Comparison of radiofrequency ablation and ablative external radiotherapy for the treatment of intrahepatic malignancies: A hybrid meta-analysis

Background & Aims

Radiofrequency ablation (RFA) and ablative external beam radiotherapy (ablative RT) are commonly used to treat small intrahepatic malignancies. We meta-analysed oncologic outcomes and systematically reviewed the clinical consideration of tumour location and size.

Methods

PubMed, Medline, Embase, and Cochrane Library databases were searched on February 24, 2022. Studies comparing RFA and ablative RT, providing one of the endpoints (local control or survival), and encompassing ≥5 patients in each arm were included.

Results

Twenty-one studies involving 4,638 patients were included. Regarding survival, the odds ratio (OR) was 1.204 (p = 0.194, favouring RFA, not statistically significant) among all studies, 1.253 (p = 0.153) among hepatocellular carcinoma (HCC) studies, and 1.002 (p = 0.996) among colorectal cancer metastasis studies. Regarding local control, the OR was 0.458 (p <0.001, favouring ablative RT) among all studies, 0.452 (p <0.001) among HCC studies, favouring the ablative RT arm, and 0.649 (p = 0.484) among colorectal cancer metastasis studies. Pooled 1- and 2-year survival rates for HCC studies were 91.8% and 77.7% after RFA, and 89.0% and 76.0% after ablative RT, respectively; and for metastasis studies were 88.2% and 66.4% after RFA and 82.7% and 60.6% after RT, respectively. Literature analysis suggests that ablative RT can be more effective than RFA for tumours larger than 2-3 cm or for specific sublocations in the liver (e.g. subphrenic or perivascular sites), with moderate quality of evidence (reference to the grading system of the American Society for Radiation Oncology Primary Liver Cancer Clinical Guidelines). The pooled grade ≥3 complication rates were 2.9% and 2.8% in the RFA and ablative RT arms, respectively (p = 0.952).

Conclusions

Our study shows that ablative RT can yield oncologic outcomes similar to RFA, and suggests that it can be more effective for the treatment of tumours in locations where RFA is difficult to perform or for large-sized tumours.

Systematic Review Registration

This study was registered with PROSPERO (Protocol No: CRD42022332997).

Impact and implications

Radiofrequency ablation (RFA) and ablative radiotherapy (RT) are non-surgical modalities for the treatment of small intrahepatic malignancies. Ablative RT showed oncologic outcomes at least similar to those of RFA, and was more effective at specific locations (e.g. perivascular or subphrenic locations).

Radiotherapy for bone metastases of hepatocellular carcinoma: a hybrid systematic review with meta-analyses

INTRODUCTION

External beam radiation therapy (EBRT) is commonly used as a palliative treatment for bone metastases of hepatocellular carcinoma (HCC). We planned a hybrid systematic review that meta-analyzed the efficacy and feasibility of EBRT and reviewed the literature to answer specific clinical questions.

METHODS

The PubMed, Medline, Embase, and Cochrane Library databases were searched through 1 December 2021. Primary endpoints were overall survival (OS) and response rate (RR). Secondary endpoints were comparative data, including treatment response and survival related to dose escalation, number of metastases, and fractionation scheme. Formal pooled analyses were performed on the primary endpoints, and the secondary endpoints were systematically reviewed. Complications were also reviewed.

RESULTS

Nineteen studies involving 1613 patients with HCC and bone metastases were included. The median OS was 6 months (range: 3-13 months). The pooled one-year OS was 23.1% (95% confidence interval [CI]: 18.4-28.6); pooled pain RR was 81.5% (95% CI: 76.4-85.7) and of pain complete remission was 26.5% (95% CI: 21.7-32.0). Pain response might be related to dose escalation, considering the moderate consistency of results and plausibility, with a low-quality grade of evidence^†. Considering the indeterminate results, we cannot suggest that dose escalation is correlated with OS. The oligometastasis status might be related to better OS, considering the high consistency of results and plausibility with low to moderate quality of evidence. Hypofractionated EBRT might yield comparable efficacy to conventional EBRT, with a low-quality grade of evidence. There were few complications of grade ≥3, except for hematologic complications, which ranged from 11.5to 34%.

CONCLUSION

EBRT is an efficient and feasible palliative option. Clinical consideration of hematologic complications is necessary. Future studies are needed to increase the quality of evidence for actual clinical questions. ^†Reference to a system of the American Society for Radiation Oncology primary liver cancer clinical guidelines.

Will the collaboration of surgery and external radiotherapy open new avenues for hepatocellular carcinoma with portal vein thrombosis?

Portal invasion of hepatocellular carcinoma (HCC) occurs in 12.5%-40% of patients diagnosed with cancer and yields poor clinical outcomes. Since it is a common cause of inoperability, sorafenib was regarded as the standard treatment for HCC in the Barcelona Clinic of Liver Cancer guidelines. However, the median survival of the Asian population was only approximately 6 mo, and the tumor response rate was less than moderate (< 5%). Various locoregional modalities were performed, including external beam radiotherapy (EBRT), transarterial chemoembolization, hepatic arterial infusion chemotherapy, and surgery, alone or in combination. Among them, EBRT is a noninvasive method and can safely treat tumors involving the major vessels. Palliative EBRT has been commonly performed, especially in East Asian countries, where locally invasive HCC is highly prevalent. Although surgery is not commonly indicated, pioneering studies have demonstrated encouraging results in recent decades. Furthermore, the combination of neo- or adjuvant EBRT and surgery has been recently used and has significantly improved the outcomes of HCC patients, as reported in a few randomized studies. Regarding systemic modality, a combination of novel immunotherapy and vascular endothelial growth factor inhibitor showed results superior to that of sorafenib as a first-line agent. Future clinical trials investigating the combined use of these novel agents, surgery, and EBRT are expected to improve the prognosis of HCC with portal invasion.

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.

Efficacy and safety of various primary treatment strategies for very early and early hepatocellular carcinoma: a network meta-analysis

BACKGROUND

Several treatments are available for treatment of early and very early-stage Hepatocellular Carcinoma, also known as small Hepatocellular Carcinoma (SHCC). However, there is no consensus with regards to the efficacies of these methods. We aimed at identifying the most effective initial treatment strategy for SHCC through Bayesian network meta-analyses.

METHODS

Studies published between January, 2010, and February, 2021 were searched in EMBASE, Cochrane Library, PubMed and Web of science databases, and conference proceedings for trials. The included studies reported the survival outcomes of very early and early Hepatocellular Carcinoma patients subjected to radiofrequency ablation (RFA), microwave ablation (MWA), surgical resection (SR), transarterial chemoembolization (TACE), percutaneous ethanol injection (PEI), minimally invasive liver surgery (MIS), stereotactic body radiotherapy (SBRT) and cryoablation (CA). Then, data were extracted from studies that met the inclusion criteria. Patient survival data were retrieved from the published Kaplan-Meier curves and pooled. A Bayesian random-effects model was used to combine direct and indirect evidence.

RESULTS

A total of 2058 articles were retrieved and screened, from which 45 studies assessing the efficacies of 8 different treatments in 11,364 patients were selected. The included studies had high methodological quality. Recurrence free survival* (progression/recurrence/relapse/disease/tumor-free survival were combined and redefined as RFS*) and overall survival (OS) outcomes were highest in MIS-treated patients (HR 0·57, 95% confidence intervals [CI] 0·38-0·85; HR 0.48,95% CI 0.36-0.64, respectively), followed by SR-treated patients (HR 0.60, 95% CI 0.50-0.74; HR 0.62, 95% CI 0.55-0.72, respectively). TACE was highly efficacious (58.9%) at decreasing the rates of major complications. Similar findings were obtained through sensitivity analysis, and in most of the prognostic subgroups.

CONCLUSIONS

MIS and SR exhibited the highest clinical efficacies, however, they were associated with higher rates of complications. Ablation is effective in small tumors, whereas SBRT is a relatively promising treatment option for SHCC. More well-designed, large-scale randomized controlled trials should be performed to validate our findings.

Salvage External Beam Radiotherapy after Incomplete Transarterial Chemoembolization for Hepatocellular Carcinoma: A Meta-Analysis and Systematic Review

Background and objective: Although transarterial chemoembolization (TACE) has been the commonest local modality for hepatocellular carcinoma (HCC), incomplete repsonse occurs especially for tumors with a large size or difficult tumor accessment. The present meta-analysis assessed the efficacy and feasibility of external beam radiotherapy (EBRT) as a salvage modality after incomplete TACE. Materials and Methods: We systematically searched the PubMed, Embase, Medline, and Cochrane databases. The primary endpoint was overall survival (OS), and the secondary endpoints included the response ratem toxicity of grade 3, and local control. Results: Twelve studies involving 757 patients were included; the median of portal vein thrombosis rate was 25%, and the pooled median of tumor size was 5.8 cm. The median prescribed dose ranged from 37.3 to 150 Gy (pooled median: 54 Gy in *EQD2). The pooled one- and two-year OS rates were 72.3% (95% confidence interval (CI): 60.2-81.9%) and 50.5% (95% CI: 35.6-65.4%), respectively; the pooled response and local control rates were 72.2% (95% CI: 65.4-78.1%) and 86.6 (95% CI: 80.1-91.2%) respectively. The pooled rates of grade ≥3 gastrointestinal toxicity, radiation-induced liver disease, hepatotoxicity, and hematotoxicity were 4.1%, 3.5%, 5.7%, and 4.9%, respectively. Local control was not correlated with intrahepatic (p = 0.6341) or extrahepatic recurrences (p = 0.8529) on meta-regression analyses. Conclusion: EBRT was feasible and efficient in regard to tumor response and control; after incomplete TACE. Out-field recurrence, despite favorable local control, necessitates the combination of EBRT with systemic treatments. *Equivalent dose in 2 Gy per fraction scheme.

Differences in radiotherapy application according to regional disease characteristics of hepatocellular carcinoma

There are differences in opinion regarding the application of external beam radiotherapy in the treatment of hepatocellular carcinoma. Some major guidelines state that external beam radiotherapy is yet to attain a sufficient level of evidence. However, caution should be exercised when attempting to understand the clinical need for external beam radiotherapy solely based on the level of evidence. Previously, external beam radiotherapy had low applicability in the treatment of hepatocellular carcinoma before computed tomography-based planning was popularized. Modern external beam radiotherapy can selectively target tumor cells while sparing normal liver tissues. Recent technologies such as stereotactic body radiotherapy have enabled more precise treatment. The characteristics of hepatocellular carcinoma differ significantly according to the regional etiology. The main cause of hepatocellular carcinoma is the hepatitis B virus. It is commonly diagnosed as a locally advanced tumor but with relatively preserved hepatic function. The majority of these hepatocellular carcinoma cases are found in the East Asian population. Hepatocellular carcinoma caused by hepatitis C virus or other benign hepatitis tends to be diagnosed as a less locally aggressive tumor but with deteriorated liver function. The western world and Japan tend to have patients with such causes. External beam radiotherapy has been more commonly performed for the former, although the use of external beam radiotherapy in the latter might have more concerns with regard to hepatic toxicity. This review discusses the above subjects along with perspectives regarding external beam radiotherapy in recent guidelines.

Radiofrequency ablation versus stereotactic body radiotherapy for hepatocellular carcinoma: a meta-analysis

The present meta-analysis was performed to evaluate the efficacy of radiofrequency ablation (RFA) and stereotactic body radiotherapy (SBRT) in hepatocellular carcinoma (HCC) patients. A systematic literature search was conducted of online databases prior to February 21, 2021. Eleven articles involving 8429 patients were included. The pooled hazard ratio for overall survival (OS) of RFA versus SBRT was 0.79 (p < 0.001). Statistically significant differences were found in the 1-, 2-, 3-, 4- and 5-year pooled OS and freedom from local progression (FFLP) rates between the two groups, favoring the RFA arms. However, the pooled local control (LC) rates were higher in the SBRT arm. RFA provided better OS and FFLP for treating HCC, while SBRT achieved superior LC. PROSPERO registration number: CRD42020207877.

Is the Concurrent Use of Sorafenib and External Radiotherapy Feasible for Advanced Hepatocellular Carcinoma? A Meta-Analysis

We evaluate the feasibility of a concurrent application of sorafenib and external beam radiation therapy (EBRT) for advanced hepatocellular carcinoma (HCC). PubMed, Embase, Medline, and Cochrane Library were searched up to 9 April 2021. The primary endpoint was grade ≥3 complications, and the secondary endpoint was overall survival (OS). Subgroup analyses were performed for studies with the EBRT targets, intrahepatic vs. non-intrahepatic lesions (e.g., extrahepatic metastases or malignant vessel involvement only). Eleven studies involving 512 patients were included in this meta-analysis. Pooled rates of gastrointestinal, hepatologic, hematologic, and dermatologic grade ≥3 toxicities were 8.1% (95% confidence interval (CI): 4.8-13.5, I2 = ~0%), 12.9% (95% CI: 7.1-22.1, I2 = 22.4%), 9.1% (95% CI: 3.8-20.3, I2 = 51.3%), and 6.8% (95% CI: 3.8-11.7, I2 = ~0%), respectively. Pooled grade ≥3 hepatologic and hematologic toxicity rates were lower in studies targeting non-intrahepatic lesions than those targeting intrahepatic lesions (hepatologic: 3.3% vs. 17.1%, p = 0.041; hematologic: 3.3% vs. 16.0%, p = 0.078). Gastrointestinal and dermatologic grade ≥3 complications were not significantly different between the subgroups. Regarding OS, concurrent treatment was more beneficial than non-concurrent treatment (odds ratio: 3.3, 95% CI: 1.3-8.59, p = 0.015). One study reported a case of lethal toxicity due to tumor rupture and gastrointestinal bleeding. Concurrent treatment can be considered and applied to target metastatic lesions or local vessel involvement. Intrahepatic lesions should be treated cautiously by considering the target size and hepatic reserve.

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.

Role of External Beam Radiotherapy in Hepatocellular Carcinoma

External beam radiotherapy (EBRT) has improved efficacy and safety with advancements in technology and techniques. EBRT plays an important role in management of hepatocellular carcinoma (HCC). In resectable cases, EBRT serves as a bridge to transplantation or improves local control through adjuvant radiotherapy. In unresectable patients, EBRT offers high local control rates. In metastatic settings, EBRT provides effective palliation. This review presents an overview of radiotherapy treatment modalities used for HCC, current treatment guidelines for the role of EBRT in HCC, clinical outcomes between various EBRT approaches and other locoregional treatments for HCC, and the future role of EBRT for HCC.

Clinical efficacy of external beam radiotherapy complementing incomplete transarterial chemoembolization for hepatocellular carcinoma

PURPOSE

External beam radiotherapy (EBRT) has been commonly applied as salvage or a combination locoregional modality after transarterial chemoembolization (TACE) for hepatocellular carcinomas (HCCs). This study reports oncologic outcomes and feasibility after application of the two modalities in our center.

METHODS

Forty consecutive patients who underwent EBRT due to incomplete responses of TACE were evaluated. Fourteen patients (35.0%) received stereotactic body radiotherapy (SBRT) and the remaining patients received conventionally fractionated radiotherapy (RT). A majority of patients who underwent SBRT received doses of 27 to 48 Gy in 3-4 fractions [median EQD₂ (Equivalent dose in 2 Gy per fraction radiotherapy): 57.0 Gy]. Conventionally fractionated RT was performed with a median EQD₂ of 47.8 Gy.

RESULTS

The median follow-up duration was 14.4 months (range: 2.6-83.0 months). A majority (77.5%) of patients were regarded as having Child-Pugh grade A. The median tumor size was 3.4 cm (range: 0.8-20.1 cm). Ten patients (25.0%) had thrombosis at a main portal branch. The 1- and 2-year overall survival (OS) and progression-free survival (PFS) rates were 82.2% and 42.1% and 55.8% and 32.1%, respectively. The local control rates were 89.1% and 89.1% at 1 and 2 years, respectively. The albumin level was a significant factor affecting OS (p = .002), and the BCLC stage significantly affected PFS (p = .001). Intrahepatic, out-of-field recurrence was the main cause of disease progression (60.0%), and distant metastasis developed in 12 patients (30.0%) during follow-up. Non-classic radiation-induced liver disease was seen in five (12.5%) patients, and two (5%) patients experienced grade ≥3 hepatic toxicities.

CONCLUSIONS

EBRT after incomplete TACE was feasible and yielded favorable oncologic outcomes. However, disease progression related to intrahepatic failure remained a hindrance.

Effectiveness and feasibility of external beam radiotherapy for hepatocellular carcinoma with inferior vena cava and/or right atrium involvement: a multicenter trial in Korea (KROG 17-10)

Purpose: Hepatocellular carcinoma (HCC) involving the inferior vena cava (IVC) and/or right atrium (RA) can affect systemic circulation, causing fatal complications. Standard treatment is yet to be established due to its rarity and intractability. We sought to determine the clinical efficacy of external beam radiotherapy (EBRT) in HCC treatment.Patients and methods: Our group designed this multicenter trial and recruited patients with HCC and IVC and/or RA involvement. Forty-nine patients from six institutions received EBRT with median dose of 46.7 (range: 35.4-71.5) Gy during 2009-2016. The primary outcome was overall survival (OS), and relevant predictors were evaluated.Results: Median follow-up length was 9.3 (range: 1.1-119) months. Median survival, 1-, and 2- year OS rates were 10.1 months (95% confidence interval [CI]: 7.5-12.7 months), 43.5%, and 30.1%, respectively. Significant factors affecting OS were alpha-fetoprotein level ≥300 ng/mL (risk ratio [RR]: 2.34, p = .025), tumor multiplicity (RR: 2.56, p = .028), and patient volume of institutions (high- vs. middle volume centers) (RR: 3.58, p = .001). Local control rates were 88.7% and 74.5% at 1 and 2 years, respectively. The most common first failure site was the lung (21/49, 42.9%) followed by liver outside the EBRT field (17/49, 34.7%). One case of possible radiation-induced liver disease was noted, with transient alkaline phosphatase elevation.Conclusion: EBRT can yield favorable local control in HCC with IVC and/or RA involvement. Systemic treatment may be more indicated as factors reflecting tumor aggressiveness were significant, and first distant failure is common.

Indications of external radiotherapy for hepatocellular carcinoma from updated clinical guidelines: Diverse global viewpoints

The etiology and disease patterns of hepatocellular carcinoma (HCC) significantly vary among regions. Modern standard treatments commonly require multidisciplinary approaches, including applications of up-to date medicine and advanced procedures, and necessitate the support of socioeconomic systems. For these reasons, a number of clinical guidelines for HCC from different associations and regions have been presented. External beam radiation therapy was contraindicated for HCC until a few decades ago, but with the development of new technologies, its application has rapidly increased as selective irradiation for tumorous lesions became possible. Most of the guidelines had been opposed or indifferent to radiotherapy in the past, but several guidelines have introduced indications and recommendations for radiotherapy in their updated versions. This review will discuss the characteristics of important guidelines and their contents regarding radiotherapy and will also provide guidance to physicians who are considering applications of locoregional modalities that include radiotherapy.

Comparisons between radiofrequency ablation and stereotactic body radiotherapy for liver malignancies: Meta-analyses and a systematic review

INTRODUCTION

Radiofrequency ablation (RFA) is a standard ablative modality for small liver malignancies. Stereotactic body radiotherapy (SBRT) has emerged although yet suffers a lack of high-level evidence. We performed meta-analyses and a systematic review to integrate the literature and help in clinical decision-making.

METHODS

Systemic searches were performed of the PubMed, Medline, and EMBASE databases to identify controlled studies comparing RFA and SBRT.

RESULTS

Eleven studies involving 2238 patients were included. Among them, eight studies were for treating early hepatocellular carcinomas (HCCs) and three for liver metastases. Including HCCs and liver metastases studies, the pooled two-year local control (LC) rate was higher in the SBRT arm (83.8%, 95% confidence interval [CI]: 77.6-88.4) than that in the RFA arm (71.8%, 95% CI: 61.5-80.2) (p = 0.024). Among studies on liver metastases, the pooled two-year LC rate was higher in the SBRT arm (83.6% vs. 60.0%, p < 0.001). No significant difference was found between arms in HCC studies (SBRT vs. RFA: 84.5 vs. 79.5% p = 0.431). Pooled analysis of overall survival (OS) in HCC studies showed an odds ratio of 1.43 (95% CI: 1.05-1.95, p = 0.023), favoring RFA. Among the two liver metastases studies with comparative survival data, no significant difference was observed.

CONCLUSION

LC was equivalent between RFA and SBRT for HCC and better for SBRT for the treatment of liver metastases. RFA was associated with better OS for HCC, but discrepancy between LC and OS requires further investigation, as they are local modalities having comparable efficacy.

Recent clinical applications of external beam radiotherapy for hepatocellular carcinoma according to guidelines, major trials and meta-analyses

External beam radiotherapy (EBRT) for hepatocellular carcinoma (HCC) has not been widely used due to lack of high-level evidence, despite its potent local therapeutic effect. While clinical evidence has accumulated and meta-analyses of observational studies have provided integrated information to help in clinical decision-making, a recent randomized trial demonstrated the benefit of EBRT in cases of HCC with major vessel invasion. Based on these trends, the efficacy of EBRT has been better recognized, and EBRT has been more frequently recommended in several international treatment guidelines newly updated in 2018. This review examined the key issues of EBRT in the guidelines updated in 2018 as well as recently published noteworthy randomized trials and meta-analyses. Ongoing trials to identify the trends and direction of future research on EBRT for HCC were also reviewed.

Role of Radiotherapy in the Treatment of Hepatocellular Carcinoma

The role of radiotherapy in the treatment of hepatocellular carcinoma (HCC) has evolved over the past few decades with the advancement of technology and improved imaging. Radiotherapy can offer high local control rates in unresectable HCC, including cases with major vascular involvement, and can provide a modality to help bridge patients to potentially curative resection or transplantation. In metastatic cases, radiotherapy can provide good palliation. This review focuses on the common radiotherapy treatment modalities used for HCC, provides outcome comparisons of these radiotherapy techniques to outcomes with other treatment modalities for HCC, and highlights the discrepancy of the role of radiotherapy in HCC amongst the current available treatment guidelines.

Radioprotective effects of mistletoe extract in zebrafish embryos in vivo

Introduction: Radioprotectors can enhance the efficacy of cancer radiotherapy, but their clinical use remains uncommon. The present study aimed to assess the radioprotective potential of mistletoe extract (commercial name: Abnoba Viscum), a well-known complementary cancer medicine, in zebrafish larvae. Materials and methods: Wild-type AB zebrafish embryos at 4 h-post-fertilization were exposed to 5 Gy 9-MeV electron beam irradiation after being treated for 1 h with 4 mMl/L amifostine or 0.2 mg/ml Abnoba Viscum A, F, M, or Q. Primary endpoints were abnormality-free survival and abnormality-free rates among survivors at 5 days-post-fertilization. Results: The crude abnormality-free survival rates were 33.7%, 49.0%, 38.8%, 43.9%, 38.1%, and 52.6%, whereas abnormality-free rates among survivors were 36.4%, 49.6%, 37.8%, 45.6%, 52.0%, and 62.8% for the control (with no pharmacologic treatment), amifostine, Abnoba Viscum A, F, M, and Q groups, respectively. Abnormality-free survival rates in the amifostine and Abnoba Viscum Q groups were significantly different from those in the control (p = .040 and .012, respectively), with an odds ratio (OR) of 1.90 [95% confidence interval (CI): 1.03-3.51] and 2.20 (95% CI: 1.19-4.08), respectively. Abnormality-free rates among survivors in the amifostine and Abnoba Viscum M and Q groups were significantly different from those in the control group (p = .048, .042, and <.001, respectively), with an OR of 1.79 (95% CI: 1.00-3.20), 1.82 (95% CI: 1.02-3.26), and 2.98 (1.67-5.33), respectively. Conclusion: Abnoba Viscum Q has at least a similar radioprotective effect to that of amifostine. Mistletoe extracts have been clinically applied for a long time and their effectiveness and feasibility have been verified. Abnoba Viscum Q might be a new candidate radioprotectant to enhance cancer radiotherapy efficacy.

Role of local treatment including radiotherapy in Barcelona Clinic of Liver Cancer stage C patients: a nationwide cohort analysis in South Korea

Purpose

Sorafenib is recommended as the standard treatment for hepatocellular carcinoma (HCC) of Barcelona Clinic of Liver Cancer stage C (BCLC C). However, local treatment including radiation therapy (LRT) is also widely administered in practice. The aim of our study was to define the role of LRT among BCLC C patients.

Patients and methods

Of the patients with HCC enrolled the Korean Central Cancer Registry from 2008 to 2014, the Korean Liver Cancer Study Group randomly extracted 10,580 patient data from ~50 hospitals nationwide. Among them, 3,401 patients were categorized to have BCLC C HCC. Among them, patients with information on initial treatments, defined as the first and secondary treatment within 60 days after the first treatment, were selected and classified into three initial treatment groups: LRT, sorafenib, and no treatment.

Results

Among 3,401 BCLC C HCC patients, 1,486 were included in the study and the remaining patients were excluded as they did not meet the criteria (eg, underwent local treatments without radiotherapy [RT] or received chemotherapy other than sorafenib). Of these, 266 were assigned to LRT (17.9%), 316 to sorafenib (21.3%), and 904 to no treatment group (60.8%). Median survival time of the sorafenib group was shorter than that of the LRT group (3.8 vs 7.6 months, P<0.001). In multivariable analysis, sorafenib group showed significantly higher risk related to mortality compared to LRT group, not only among all patients (HR: 1.50, 95% CI: 1.23-1.84) but also between subgroup cohorts with portal invasions (1.55, 1.23-1.84), with lymph node metastases (2.42, 1.53-3.83), without distant metastases (1.43, 1.10-1.87), and with distant metastases (1.57, 1.13-2.19). Additionally, no treatment group showed the worst survival among the three treatment groups not only in all patients, but also in all subgroups of patients (P<0.001 in all).

Conclusion

LRT as an initial treatment showed survival benefit as compared to sorafenib in HCC patients of BCLC C.

Radiation-Induced Reactions in The Liver - Modulation of Radiation Effects by Lifestyle-Related Factors

Radiation has a wide variety of effects on the liver. Fibrosis is a concern in medical fields as one of the acute effects of high-dose irradiation, such as with cancer radiotherapies. Cancer is also an important concern following exposure to radiation. The liver has an active metabolism and reacts to radiations. In addition, effects are modulated by many environmental factors, such as high-calorie foods or alcohol beverages. Adaptations to other environmental conditions could also influence the effects of radiation. Reactions to radiation may not be optimally regulated under conditions modulated by the environment, possibly leading to dysregulation, disease or cancer. Here, we introduce some reactions to ionizing radiation in the liver, as demonstrated primarily in animal experiments. In addition, modulation of radiation-induced effects in the liver due to factors such as obesity, alcohol drinking, or supplements derived from foods are reviewed. Perspectives on medical applications by modulations of radiation effects are also discussed.

MicroRNA-140-3p enhances the sensitivity of hepatocellular carcinoma cells to sorafenib by targeting pregnenolone X receptor

Background

Pregnane X receptor (PXR), which is a member of the nuclear receptor protein family (nuclear receptor subfamily 1 group I member 2 [NR 1I2]), mediates the drug-resistance in the hepatocellular carcinoma (HCC) via enhancing the expression of drug-resistance-related genes which accelerate the clearance of antitumor drugs, eg, sorafenib. However, there are few reports on miRNA targeting PXR participating in the epigenetic regulation of PXR in HCC cells.

Materials and methods

TargetScan 7.2, an online method, was used to predict the miRNAs potentially targeting PXR. The expression of PXR and PXR downstream genes was detected by quantitative real-time PCR (qPCR) and Western blot. The clearance of sorafenib in HCC cells was monitored by liquid chromatograph-mass spectrometer/mass spectrometer (LC-MS/MS). The effects of miRNA on sorafenib’s efficacy were examined by in vitro methods, eg, MTT, and in vivo methods, eg, subcutaneous or intrahepatic tumor model.

Results

By virtual screening, we identified that miR-140-3p possibly targets PXR and then confirmed that the overexpression of miR-140-3p via lentiviral particles inhibited the expression of PXR in HCC cells. The downregulation of PXR’s expression by miR-140-3p led to the reduction of PXR downstream genes’ expression, which finally resulted in the decelerating clearance of sorafenib in HCC cells and enhanced the sensitivity of HCC cells to sorafenib. The effect of miR-140-3p could not modulate the expression of mutated PXR and the effect of miR-140-3p could also be inhibited by miR-140-3p’s inhibitor. Moreover, miR-140-3p enhanced the anti-tumor effect of sorafenib in both the subcutaneous and intrahepatic HCC tumor models.

Conclusion

Our study suggests that targeting PXR by miR-140-3p is a promising strategy for enhancing sorafenib’s efficacy during HCC treatment.