Preliminary result of stereotactic body radiotherapy as a local salvage treatment for inoperable hepatocellular carcinoma

Role of Stereotactic Body Radiation Therapy in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC)is a common type of liver cancer with a poor prognosis, especially in patients with advanced stages or underlying liver disease. While surgical resection, liver transplantation, and ablation therapies have traditionally been the mainstay of treatment for HCC, radiation therapy has become increasingly recognized as an effective alternative, particularly for those who are not surgical candidates. Stereotactic Body Radiation Therapy (SBRT) is a highly precise form of radiation therapy that delivers very high doses of radiation to the tumor while sparing surrounding healthy tissue. Several studies have reported favorable outcomes with SBRT in HCC treatment. Moreover, SBRT can be used to treat recurrent HCC after prior treatment, offering a potentially curative approach in select cases. While SBRT has demonstrated its efficacy and safety in treating HCC, future studies are needed to further investigate the potential role of SBRT in combination with other treatments for HCC.

Transarterial Chemoembolization With Drug-Eluting Beads Versus Stereotactic Body Radiation Therapy for Hepatocellular Carcinoma: Outcomes From a Multicenter, Randomized, Phase 2 Trial (the TRENDY Trial)

PURPOSE

To compare transarterial chemoembolization delivered with drug eluting beads (TACE-DEB) with stereotactioc body radiation therapy (SBRT) in patients with hepatocellular carcinoma (HCC) in a multicenter randomized trial.

METHODS AND MATERIALS

Patients were included if they were eligible for TACE. They could also be recruited if they required treatment prior to liver transplantation. A maximum of four TACE-DEB procedures and ablation after incomplete TACE-DEB were both allowed. SBRT was delivered in six fractions of 8-9Gy. Primary end point was time to progression (TTP). Secondary endpoints were local control (LC), overall survival (OS), response rate (RR), toxicity, and quality of life (QoL). The calculated sample size was 100 patients.

RESULTS

Between May 2015 and April 2020, 30 patients were randomized to the study. Due to slow accrual the trial was closed prematurely. Two patients in the SBRT arm were considered ineligible leaving 16 patients in the TACE-DEB arm and 12 in the SBRT arm. Median follow-up was 28.1 months. Median TTP was 12 months for TACEDEB and 19 months for SBRT (p=0.15). Median LC was 12 months for TACE-DEB and >40 months (not reached) for SBRT (p=0.075). Median OS was 36.8 months for TACEDEB and 44.1 months for SBRT (p=0.36). A post-hoc analysis showed 100% for SBRT 1- and 2-year LC, and 54.4% and 43.6% for TACE-DEB (p=0.019). Both treatments resulted in RR>80%. Three episodes of possibly related toxicity grade ≥3 were observed after TACE-DEB. No episodes were observed after SBRT. QoL remained stable after both treatment arms.

CONCLUSIONS

In this trial, TTP after TACE-DEB was not significantly improved by SBRT, while SBRT showed higher local antitumoral activity than TACE-DEB, without detrimental effects on OS, toxicity and QoL. To overcome poor accrual in randomized trials that include SBRT, and to generate evidence for including SBRT in treatment guidelines, international cooperation is needed.

Predictive Model of Liver Toxicity to Aid the Personalized Selection of Proton Versus Photon Therapy in Hepatocellular Carcinoma

PURPOSE

Our objective was to develop an externally validated model for predicting liver toxicity after radiation therapy in patients with hepatocellular carcinoma (HCC) that can integrate both photon and proton dose distributions with patient-specific characteristics.

METHODS AND MATERIALS

Training data consisted of all patients with HCC treated between 2008 and 2019 at our institution (n = 117, 60%/40% photon/proton). We developed a shallow convolutional neural network (CNN) to predict posttreatment liver dysfunction from the differential dose-volume histogram (DVH) and baseline liver metrics. To reduce bias and improve robustness, we used ensemble learning (CNNE). After a preregistered study analysis plan, we evaluated stability using internal bootstrap resampling and generalizability using a data set from a different institution (n = 88). Finally, we implemented a class activation map method to characterize the critical DVH subregions and benchmarked the model against logistic regression and XGBoost. The models were evaluated using the area under the receiver operating characteristic curve and area under the precision-recall curve.

RESULTS

The CNNE model showed similar internal performance and robustness compared with the benchmarks. CNNE exceeded the benchmark models in external validation, with an area under the receiver operating characteristic curve of 0.78 versus 0.55 to 0.70, and an area under the precision-recall curve of 0.6 versus 0.43 to 0.52. The model showed improved predictive power in the photon group, excellent specificity in both modalities, and high sensitivity in the photon high-risk group. Models built solely on DVHs confirm outperformance of the CNNE and indicate that the proposed structure efficiently abstracts features from both proton and photon dose distributions. The activation map method demonstrates the importance of the low-dose bath and its interaction with low liver function at baseline.

CONCLUSIONS

We developed and externally validated a patient-specific prediction model for hepatic toxicity based on the entire DVH and clinical factors that can integrate both photon and proton therapy cohorts. This model complements the new American Society for Radiation Oncology clinical practice guidelines and could support value-driven integration of proton therapy into the management of HCC.

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.

Predictive Modeling of Survival and Toxicity in Patients With Hepatocellular Carcinoma After Radiotherapy

PURPOSE

To stratify patients and aid clinical decision making, we developed machine learning models to predict treatment failure and radiation-induced toxicities after radiotherapy (RT) in patients with hepatocellular carcinoma across institutions.

MATERIALS AND METHODS

The models were developed using linear and nonlinear algorithms, predicting survival, nonlocal failure, radiation-induced liver disease, and lymphopenia from baseline patient and treatment parameters. The models were trained on 207 patients from Massachusetts General Hospital. Performance was quantified using Harrell's c-index, area under the curve (AUC), and accuracy in high-risk populations. Models' structures were optimized in a nested cross-validation approach to prevent overfitting. A study analysis plan was registered before external validation using 143 patients from MD Anderson Cancer Center. Clinical utility was assessed using net-benefit analysis.

RESULTS

The survival model stratified high-risk versus low-risk patients well in the external validation cohort (c-index = 0.75), better than existing risk scores. Predictions of 1-year survival and nonlocal failure were excellent (external AUC = 0.74 and 0.80, respectively), especially in the high-risk group (accuracy > 90%). Cause-of-death analysis showed differential modes of treatment failure in these cohorts and indicated that these models could be used to stratify RT patients for liver-sparing treatment regimen or combination approaches with systemic agents. Predictions of liver disease and lymphopenia were good but less robust (external AUC = 0.68 and 0.7, respectively), suggesting the need for more comprehensive consideration of dosimetry and better predictive biomarkers. The liver disease model showed excellent accuracy in the high-risk group (92%) and revealed possible interactions of platelet count with initial liver function.

CONCLUSION

Machine learning approaches can provide reliable outcome predictions in patients with hepatocellular carcinoma after RT in diverse cohorts across institutions. The excellent performance, particularly in high-risk patients, suggests novel strategies for patient stratification and treatment selection.

Image-Guided Liver Stereotactic Body Radiotherapy Using VMAT and Real-Time Adaptive Tumor Gating: Evaluation of the Efficacy and Toxicity for Hepatocellular Carcinoma

Simple Summary

Although the use of stereotactic body radiation therapy (SBRT) in the management of hepatocellular carcinoma (HCC) remains unclear, it is a therapeutic option often considered in patients not eligible to or recurring after other local therapies. Liver SBRT can be delivered using a wide range of techniques and linear accelerators. We report the first evaluation for HCC of SBRT using volumetric modulated arc therapy (VMAT) and real-time adaptive tumor gating, which is a mainly completely non-invasive procedure (no fiducial markers for 65.2% of the patients). Our study showed that this SBRT technique has very favorable outcomes with optimal local control and a low toxicity rate.

Abstract

Liver SBRT is a therapeutic option for the treatment of HCC in patients not eligible for other local therapies. We retrospectively report the outcomes of a cohort of consecutive patients treated with SBRT for HCC at the Montpellier Cancer Institute. Between March 2013 and December 2018, 66 patients were treated with image-guided liver SBRT using VMAT and real-time adaptive tumor gating in our institute. The main endpoints considered in this study were local control, disease-free survival, overall survival, and toxicity. The median follow-up was 16.8 months. About 66.7% had prior liver treatment. Most patients received 50 Gy in five fractions of 10 Gy. No patient had local recurrence. Overall survival and disease-free survival were, respectively, 83.9% and 46.7% at one year. In multivariate analysis, the diameter of the lesions was a significant prognostic factor associated with disease-free survival (HR = 2.57 (1.19–5.53) p = 0.02). Regarding overall survival, the volume of PTV was associated with lower overall survival (HR = 2.84 (1.14–7.08) p = 0.025). No grade 3 toxicity was observed. One patient developed a grade 4 gastric ulcer, despite the dose constraints being respected. Image-guided liver SBRT with VMAT is an effective and safe treatment in patients with inoperable HCC, even in heavily pre-treated patients. Further prospective evaluation will help to clarify the role of SBRT in the management of HCC patients.

Stereotactic ablative radiotherapy for hepatocellular carcinoma: A systematic review and meta-analysis of local control, survival and toxicity outcomes

There is a growing body of literature supporting the use of stereotactic ablative body radiotherapy (SABR) in the management of primary hepatocellular carcinoma (HCC). This systematic review and meta-analysis of the current published evidence for SABR for HCC assessed the impact of treatment dose, fractionation and tumour size on the outcomes of local control (LC), overall survival (OS) and toxicity. A systematic search was independently performed by two authors for articles published in peer-reviewed journals between January 2005 and December 2019. A DerSimonian and Laird random effects model was used to assess pooled results. A multivariate meta-regression analysis incorporated the effect of explanatory variables (radiation dose in EQD2_[10], fractionation and tumour size) on outcomes of OS, LC and toxicity. Forty-nine cohorts involving 2846 HCC patients with 3088 lesions treated with SABR were included. Pooled 1-, 2- and 3-year LC rates were 91.1% (95% confidence interval [CI] 88.3-93.2), 86.7% (95% CI 82.7-89.8) and 84.2% (95% CI 77.9-88.9) respectively. Pooled 1-, 2- and 3-year OS rates were 78.4% (95% CI 73.4-82.6), 61.3% (55.2-66.9) and 48.3% (95% CI 39.0-57). Population-weighted median grade 3 toxicity rates were 6.5% (IQR 3.2-16) and mean grade 4/5 rates were 1.4% (IQR 0-2.1). Within EQD2_[10] ranges of 40 to 83.33 Gy corresponding to common dose-fractionation regimens of 30-50 Gy in 5 fractions, there was a multivariate association between superior LC and OS with increasing EQD2_[10] , with a proportionately smaller increase in grade 3 toxicity and no association with grade 4/5 toxicity. Stereotactic ablative body radiotherapy is a viable treatment option for HCC with high LC rates and low rates of reported grade 3/4 toxicity. Increasing EQD2_[10] was associated with improvements in LC and OS with a comparatively smaller increase in toxicity. Prospective randomised trials are warranted to define optimal patient selection and dose-fractionation regimens.

MRI-guided stereotactic radiation therapy for hepatocellular carcinoma: a feasible and safe innovative treatment approach

PURPOSE

Hepatocellular carcinoma (HCC) in early stages benefits from local ablative treatments such as radiofrequency ablation (RFA) or transarterial chemoembolization (TACE). In this context, radiotherapy (RT) has shown promising results but has not been thoroughly evaluated. Magnetic resonance-guided RT (MRgRT) may represent a paradigm shifting improvement in stereotactic body radiotherapy (SBRT) for liver tumors.

METHODS

We retrospectively evaluated HCC patients treated on a hybrid low-tesla MRgRT unit. A total biologically effective dose (BED) > 100 Gy was delivered in 5 consecutive fractions, respecting the appropriate organs-at-risk constraints. Hybrid MR scans were used for treatment planning and cine MR was used for delivery gating. Patients were followed up for toxicity and treatment-response assessment.

RESULTS

Ten patients were enrolled, with a total of 12 lesions. All the lesions were irradiated with no interruptions. Six patients had already performed previous local therapies. Median follow-up after SBRT was 6.5 months (1-25). Two cases of acute toxicity were reported (G ≤ 2 according to CTCAE v4.0). At the time of the analysis, 90% of the population presented local control. Child-Pugh before and after treatment remained unchanged in all but one patient.

CONCLUSION

MRgRT is a feasible and safe option showing favorable toxicity profile for HCC treatment.

Dosimetric Analysis and Normal-Tissue Complication Probability Modeling of Child-Pugh Score and Albumin-Bilirubin Grade Increase After Hepatic Irradiation

PURPOSE

This study aimed to develop robust normal-tissue complication probability (NTCP) models for patients with hepatocellular carcinoma treated with radiation therapy (RT) using Child-Pugh (CP) score and albumin-bilirubin (ALBI) grade increase as endpoints for hepatic toxicity.

METHODS AND MATERIALS

Data from 108 patients with hepatocellular carcinoma treated with RT between 2008 and 2017 were evaluated, of which 47 patients (44%) were treated with proton RT. Of these patients, 29 received stereotactic body RT and 79 moderately hypofractionated RT to median physical tumor doses of 43 Gy in 5 fractions and 59 Gy in 15 fractions, respectively. A generalized Lyman-Kutcher-Berman (LKB) model was used to model the NTCP using 2 clinical endpoints, both evaluated at 3 months after RT: CP score increase of ≥2 and ALBI grade increase of ≥1 from the pre-RT baseline. Confidence intervals on LKB fit parameters were determined using bootstrap resampling.

RESULTS

Compared with previous NTCP models, this study found a stronger correlation between normal liver volume receiving low doses of radiation (5-10 Gy) and a CP score or ALBI grade increase. A CP score increase exhibited a stronger correlation to normal liver volumes irradiated than an ALBI grade increase. LKB models for CP increase found values for the volume-effect parameter of a = 0.06 for all patients, and a = 0.02/0.09 when fit to photon/proton patients separately. Subset analyses for patients with superior initial liver functions showed consistent dose-volume effects (a = 0.1) and consistent dose-response relationships.

CONCLUSIONS

This study presents an update of liver NTCP models in the era of modern RT techniques using relevant endpoints of hepatic toxicity, CP score and ALBI grade increase. The results show a stronger influence of low-dose bath on hepatic toxicity than those found in previous studies, indicating that RT techniques that minimize the low-dose bath may be beneficial for patients.

An overview of stereotactic body radiation therapy for hepatocellular carcinoma

Introduction: According to several guidelines, stereotactic body radiation therapy (SBRT) for early hepatocellular carcinoma (HCC) can be considered an alternative to other modalities, such as resection, radiofrequency ablation (RFA), and transarterial chemoembolization (TACE), or when these therapies have failed or are contraindicated. This article reviews the current status of SBRT for the treatment of HCC.Areas covered: From the results of many retrospective reports, SBRT is a promising modality with an excellent local control of almost 90% at 2-3 years and acceptable toxicities. Currently there are no randomized trials to compare SBRT and other modalities, such as resection, RFA, and TACE, but many retrospective reports and propensity score matching have shown that SBRT is comparable to the different modalities. Repeated SBRT for intra-hepatic recurrent HCC also resulted in high local control with safety and satisfactory overall survival, which were comparable to those of other curative local treatments.Expert opinion: Despite the good results of SBRT, the conclusions of the comparisons of SBRT and other modalities are still controversial. Further studies, including randomized phase III studies to define that patients are more suitable for each curative local treatment, are needed.

Rethinking the Role of Radiation Therapy in the Treatment of Unresectable Hepatocellular Carcinoma: A Data Driven Treatment Algorithm for Optimizing Outcomes

Hepatocellular carcinoma (HCC) is the second most common cause of cancer death worldwide, with a majority of HCC patients not suitable for curative therapies. Approximately 70% of initially diagnosed patients cannot undergo surgical resection or transplantation due to locally advanced disease, poor liver function/underlying cirrhosis, or additional comorbidities. Local therapeutic options for patients with unresectable HCC, who are not suitable for thermal ablation, include transarterial embolization (bland, chemoembolization, radioembolization) and/or external beam radiation therapy (EBRT). Regarding EBRT specifically, technological advancements provide a means for safe and effective radiotherapy delivery in a wide spectrum of HCC patients. In multiple prospective studies, EBRT delivery in a variety of different fractionation schemes or in combination with transcatheter arterial chemoembolization (TACE) demonstrate improved outcomes, particularly with combination therapy. The Barcelona Clinic Liver Cancer classification provides a framework for treatment selection; however, given the growing complexity of treatment strategies, this classification system tends to simplify decision-making. In this review, we discuss the current literature regarding unresectable HCC and propose a modified treatment algorithm that emphasizes the role of radiation therapy for Child-Pugh score A or B patients with ≤3 nodules measuring >3 cm, multinodular disease or portal venous thrombosis.

Comparison of Stereotactic Body Radiation Therapy and Transarterial Chemoembolization for Unresectable Medium-Sized Hepatocellular Carcinoma

PURPOSE

This study compared the local control and overall survival (OS) between stereotactic body radiation therapy (SBRT) and transarterial chemoembolization (TACE) in medium-sized (3-8 cm) hepatocellular carcinoma (HCC).

METHODS AND MATERIALS

From January 2008 to October 2017, 188 patients with medium-sized HCC underwent either TACE (n = 142) or SBRT (n = 46). We adjusted for imbalances in treatment assignment using propensity score matching. Infield control (IFC) and OS were analyzed retrospectively.

RESULTS

The median follow-up time was 17.1 months for all patients and 26.6 months for surviving patients. The 3-year IFC was 63.0% for the TACE group and 73.3% for the SBRT group. Multivariable analysis identified the independent predictors for IFC as treatment modality (SBRT vs TACE), sex (female vs male), and recurrence status (recurrence vs new diagnosis). The 3-year OS was 22.9% for the TACE group and 47.4% for the SBRT group. Multivariable analysis identified the independent predictors of OS as number of tumors, treatment modality (SBRT vs TACE), albumin-bilirubin grade, tumor volume, Eastern Cooperative Oncology Group status, and recurrence status. Propensity score matching analysis revealed that the SBRT group had better IFC (3-year IFC of 77.5% vs 55.6%; P = .007) and OS (3-year OS of 55.0% vs 13.0%; P < .001) than the TACE group. For recurrent HCC, the SBRT group exhibited superior IFC (3-year IFC of 75% vs 57.5%; P = .022) and OS (3-year OS of 58.3% vs 5.9%; P < .001) compared with the TACE group. However, there was no difference in IFC or OS between TACE and SBRT for patients with newly diagnosed HCC.

CONCLUSIONS

SBRT has better IFC and OS rates than TACE in patients with medium-sized HCC, particularly for recurrent cases, which warrants prospective randomized controlled trials of TACE and SBRT.

[Stereotactic body radiation therapy for hepatocellular carcinoma: Results from a retrospective multicentre study]

PURPOSE

The purpose of this paper was to describe local control, overall survival, progression-free survival and toxicity of CyberKnife^®-based stereotactic body radiation therapy of hepatocellular carcinoma.

MATERIAL AND METHODS

Records of all the patients treated for hepatocellular carcinoma at the Eugene-Marquis cancer centre, Rennes and the Bretonneau hospital, Tours (France), between November 2010 and December 2016, were reviewed. Radiation therapy was performed as a salvage treatment, while awaiting liver transplantation or if no other treatment was possible.

RESULTS

One hundred and thirty-six patients were consecutively included in the study. The median follow-up was 13months. Median total dose prescribed, fractionation and overall treatment time were respectively 45Gy, three fractions and 5 days. Overall survival, progression-free survival and local control rates at 1year and 2years were 79.8 % and 63.5 %, 61.3 % and 39.4 %; 94.5 % and 91 %. Two grade 3 acute toxicity events and two grade 4 late toxicity events corresponding to a duodenal ulcer have been reported. Seven patients underwent classic radiation-induced hepatitis and 13 patients showed non-classical radiation-induced hepatitis. Barcelona Clinic Liver Cancer stage, World Health Organisation grade and planning target volume were correlated with overall survival in univariate Cox analysis.

CONCLUSION

Stereotactic body radiation therapy is effective and well-tolerated for inoperable hepatocellular carcinoma or as a bridge to liver transplantation. Toxicity is mainly related to cirrhotic background and requires a selection of patients and strict dose constraints.

Comparing stereotactic ablative radiotherapy (SABR) versus re-trans-catheter arterial chemoembolization (re-TACE) for hepatocellular carcinoma patients who had incomplete response after initial TACE (TASABR): a randomized controlled trial

Background

Hepatocellular carcinoma (HCC) accounts for 75–85% of primary liver cancers and is prevalent in the Asia-Pacific region. Till now, trans-arterial chemoembolization (TACE) is still one of common modalities in managing unresectable intermediate-stage HCC. However, post-TACE residual viable HCC is not uncommon, resulting in unsatisfied overall survival after TACE alone. Recently, stereotactic ablative radiotherapy (SABR) has been suggested to manage HCC curatively. However, evidence from phase-III trials is largely lacking.

Hence, the present phase III randomized trial is designed to compare clinical outcomes between SABR and re-TACE for unresectable HCC patients who had incomplete response after initial TACE.

Methods

The present study is an open-label, parallel, randomized controlled trial. A total of 120 patients will be included into two study groups, i.e., SABR and re-TACE, with a 1:1 allocation rate. A 3-year allocating period is planned. Patients with incomplete response after initial TACE will be enrolled and randomized. The primary endpoint is 1-year freedom-form-local-progression rate. Secondary endpoints are disease-progression-free survival, overall survival, local control, response rate, toxicity, and duration of response of the treated tumor.

Discussion

SABR has been reported as an effective modality in managing intermediate-stage HCC patients, but evidence from phase-III randomized trials is largely lacking. As a result, conducting randomized trials to demarcate the role of SABR in these patients is warranted, especially in the Asia-Pacific region, where HBV- and HCV-related HCCs are prevalent.

Trial registration

Before enrolling participants, the present study was registered prospectively on ClinicalTrials.gov (trial identifier, NCT02921139) on Sep. 29, 2016. This study is ongoing.

Impact of 99mTc-GSA SPECT Image-Guided Inverse Planning on Dose-Function Histogram Parameters for Stereotactic Body Radiation Therapy Planning for Patients With Hepatocellular Carcinoma: A Dosimetric Comparison Study

Purpose:

To evaluate the impact of ^99mTc-labeled diethylene triamine pentaacetate-galactosyl human serum albumin (^99mTc-GSA) single-photon emission computed tomography (SPECT) image-guided inverse planning on the dose–function histogram (DFH) parameters for stereotactic body radiation therapy planning in patients with hepatocellular carcinoma (HCC).

Methods:

Eleven patients were enrolled in this study. The functional liver structure (FLS) was derived from SPECT thresholds of 60% to 80% of the maximum pixel value. Two treatment plans optimized without FLS (plan C) and with FLS (plan F) were designed for 50 Gy to the planning target volume (PTV). The DFH parameters were calculated as follows: Fx = (sum of the counts within the liver volume receiving a dose >x Gy/sum of the counts within the whole liver volume) × 100. Other parameters for the PTV included D₉₅, mean dose, conformity index (CI), and homogeneity index (HI).

Results:

Compared with plan C, plan F significantly reduced DFH parameters of F₅ to F₄₀ (P < .05). There were no significant differences in the parameters of the PTV of D₉₅, mean dose, CI, and HI and organs at risks (stomach, duodenum, spinal cord, and kidneys) between plans C and F.

Conclusion:

DFH analyses revealed that ^99mTc-GSA SPECT image-guided inverse planning provided dosimetric benefits related to sparing of liver function and may reduce hepatic toxicities.

Stereotactic Body Radiation Therapy (SBRT) for Hepatocellular Carcinoma: High Rates of Local Control With Low Toxicity

OBJECTIVES

Stereotactic body radiotherapy (SBRT) is potentially curative treatment for small hepatocellular carcinomas (HCC), but data are limited on its efficacy and toxicity. We hypothesized that SBRT can achieve excellent local control (LC) with acceptable toxicity treating HCC lesions, even in advanced cirrhosis.

MATERIALS AND METHODS

Thirty-seven nonmetastatic HCC patients received SBRT to 43 lesions between October 2012 and April 2016. Median dose was 50 Gy/5 fractions. All Child-Pugh (CP) ≥B patients underwent a planned 1-month break after the first 3 fractions to assess hepatic toxicity. Patients were treated without separately placed fiducial markers using Linac-based SBRT with breath-hold (67%) or 4D-computed tomography with compression belt (33%) to reduce motion. Patients underwent magnetic resonance imaging q3 months post-SBRT.

RESULTS

Median age was 65 (range, 44 to 88). Pre-SBRT mean CP was 6.4 (range, A5 to C11). Nine (24%) had CP≥B8. Thirty-one of 33 patients (93%) had prior liver-directed therapy (median 2). Seventeen (40%) had solitary lesions. Median lesion diameter was 2.7 cm (range, 1.1 to 5.6). Median follow-up was 14 months (range, 2 to 45). There was 1 local failure (multifocal HCC with 3 prior transarterial chemoembolization). LC, freedom from liver progression, and overall survival at 12 months was 95%, 66%, 87% in the full cohort, and 100%, 76%, 93% for patients with solitary lesions. Four had grade 3 toxicity (ascites [n=2]/gastrointestinal bleed [n=1]/capsular pain [n=1]). Eight of 9 CP≥B8 patients had no grade ≥3 hepatic toxicity.

CONCLUSIONS

SBRT for HCC is well-tolerated even in patients with advanced cirrhosis and prior liver-directed treatment and provides excellent LC even for larger lesions that cannot be controlled with radiofrequency ablation. LC with SBRT compares favorably to other liver-directed therapies. Prospective studies comparing SBRT with other liver-directed therapies are warranted.

Effectiveness of Particle Radiotherapy in Various Stages of Hepatocellular Carcinoma: A Pilot Study

AIM

We analyzed the effectiveness of external particle radiotherapy (PRT) as an alternative therapy for various stages of hepatocellular carcinoma (HCC).

METHODS

Eighty-three patients with HCC underwent PRT in our hospital from 2007 to 2015 (proton beam radiation in 58 patients and carbon ion radiation in 25 patients), including patients with early-stage HCC (single HCC measuring ≤3 cm, Barcelona Clinic Liver Cancer [BCLC] stage 0 or A) (group A, n = 30), those with intermediate-stage HCC (HCCs measuring ≥3 cm but inoperable or multinodular and transcatheter arterial embolization [TACE]-refractory, BCLC stage B) (group B, n = 31), and those with advanced-stage HCC (HCC with portal invasion or extrahepatic metastasis) (group C, n = 22). The median radiation dose was 72.6 GyE (range 50-74) for proton beam radiation and 45.0 GyE (range 45-52.8) for carbon beam radiation. Local control ability was defined as continuous shrinkage of the tumor size without development of new lesions for ≥6 months after PRT.

RESULTS

The rates of local control of the target tumor at 6 months, 1 year, and 2 years were 91.9, 86.3, and 84.8%, respectively. The overall survival rates at 1, 2, and 3 years were 83.0, 65.6, and 55.1%, respectively. Patients in group A showed the best survival rates (100.0% at 1 year and 85.9% at 2 years). The 1-year survival rate was poor in group C (63.6%) despite a good local tumor control rate of 74.7%. The overall survival rates were significantly better in groups A and B than in group C.

CONCLUSIONS

The local control rates after PRT were sufficiently high compared to TACE or sorafenib. Thus, PRT should be adopted for patients with difficult-to-treat HCC in the early and intermediate stages.

Stereotactic Body Radiotherapy: Does It Have a Role in Management of Hepatocellular Carcinoma?

Stereotactic body radiotherapy (SBRT) is a form of radiotherapy that delivers high doses of irradiation with high precision in a small number of fractions. However, it has not frequently been performed for the liver due to the risk of radiation-induced liver toxicity. Furthermore, liver SBRT is cumbersome because it requires accurate patient repositioning, target localization, control of breathing-related motion, and confers a toxicity risk to the small bowel. Recently, with the advancement of modern technologies including intensity-modulated RT and image-guided RT, SBRT has been shown to significantly improve local control and survival outcomes for hepatocellular carcinoma (HCC), specifically those unfit for other local therapies. While it can be used as a stand-alone treatment for those patients, it can also be applied either as an alternative or as an adjunct to other HCC therapies (e.g., transarterial chemoembolization, and radiofrequency ablation). SBRT might be an effective and safe bridging therapy for patients awaiting liver transplantation. Furthermore, in recent studies, SBRT has been shown to have a potential role as an immunostimulator, supporting the novel combination strategy of immunoradiotherapy for HCC. In this review, the role of SBRT with some technical issues is discussed. In addition, future implications of SBRT as an immunostimulator are considered.

Robotic radiosurgery treatment in liver tumors: Early experience from an Indian center

Purpose:

The purpose of this study is to report CyberKnife experience in hepatocellular carcinoma (HCC) and liver metastasis (LM).

Materials and Methods:

Fifty liver lesions in 31 consecutive patients with liver lesion [mean age 54.5 years (range 32-81 years), 77% were male patient, GTV <10cc in 5 patients, 11-90cc in 18 & >90cc in 8 patients respectively. Eighty percentage (25/31) had prior treatment (chemotherapy 18 patient & TACE in 7 patients). Dosage schedule was 21-45Gy/3# (mean PTV dose 33Gy, Prescription isodose 84%, target coverage 94%). Mean CI, nCI & HI were 1.19, 1.31 & 1.18 respectively. Mean liver dose was 5.4 Gy, 800 cc liver dose 11.1 Gy;

Results:

At mean follow-up of 12.5 months (range 1.9–44.6 months), 19 patients were expired and 12 were alive (nine patient with stable disease, two local progression, and one with metastasis). Median overall survival (OS) of all patients are 9 months (1.9–44.6 months), in HCC patients 10.5 months (2.1–44.6 months) and MT 6.5 months (1.9–24.6 months) respectively. Gr-I-II GI toxicities were in 11/50 (22%) patients. OS was influenced by PS (Karnofsky Performance Status 70–80 vs. 90–100: 9.9 vs. 16.4; P = 0.024), Child-Pugh (CP A/B vs. C: 23.6 vs. 6.5; P = 0.069), cirrhosis (only fatty liver vs. diffuse cirrhosis: 17.8 vs. 10.6; P = 0.003), prior treatment (no Rx vs. prior Rx: 30.1 vs. 8.2; P = 0.08), number of lesions (single vs. multiple: 16.4 vs. 6.9; P = 0.001), and target volume (<10 cc vs. >90 cc: 24.6 vs. 11.2; P = 0.03).

Conclusion:

Stereotactic body radiation therapy is a safe and effective treatment. Patient related factors such as performance status, Child-Pugh classification, cirrhosis status, prior treatment, number of liver lesion & target volume (GTV) influence the survival functions.

Knockdown of SUMO1P3 represses tumor growth and invasion and enhances radiosensitivity in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common types of malignant tumors with high recurrence and metastasis rates. Radiotherapy represents a major therapeutic option for HCC patients. However, the efficacy of radiotherapy has been limited due to the development of intrinsic radioresistance of the tumor cells. Small ubiquitin-like modifier 1 pseudogene 3 (SUMO1P3), one member of SUMO pseudogene family, is a novel identified lncRNA that was originally identified to be upregulated in gastric cancer. However, the detailed roles of SUMO1P3 in HCC development remain to be elucidated. Here, the expression of SUMO1P3 in HCC tissues and cells was examined by qRT-PCR. Cell proliferation, colony formation ability, invasion ability, apoptosis, and radiosensitivity were detected by MTT assay, colony formation assay, cell invasion assay, flow cytometry analysis, and survival fraction assay, respectively. We found that SUMO1P3 was significantly upregulated in HCC tissues and cells. Besides, SUMO1P3 was highly expressed in HCC patients with higher TNM stage. Furthermore, SUMO1P3 knockdown markedly suppressed cell proliferation, colony formation ability, and cell invasiveness, promoted apoptosis, and enhanced radiosensitivity of HCC cells. We concluded that the knockdown of SUMO1P3 repressed tumor growth, invasion, promoted apoptosis, and enhanced radiosensitivity in HCC, providing evidence that SUMO1P3 might be a potential novel biomarker and a therapeutic target for HCC.

Strategic application of radiotherapy for hepatocellular carcinoma

With increasing clinical use, radiotherapy (RT) has been considered reliable and effective method for hepatocellular carcinoma (HCC) treatment, depending on extent of disease and patient characteristics. RT for HCC can improve therapeutic outcomes through excellent local control, downstaging, conversion from unresectable to resectable status, and treatments of unresectable HCCs with vessel invasion or multiple intrahepatic metastases. In addition, further development of modern RT technologies, including image-guided radiotherapy (IGRT), intensity-modulated radiotherapy (IMRT), and stereotactic body radiotherapy, has expanded the indication of RT. An essential feature of IGRT is that it allows image guidance therapy through in-room images obtained during radiation delivery. Compared with 3D-conformal RT, distinctions of IMRT are inverse treatment planning process and use of a large number of treatment fields or subfields, which provide high precision and exquisitely conformal dose distribution. These modern RT techniques allow more precise treatment by reducing inter- and intra-fractional errors resulting from daily changes and irradiated dose at surrounding normal tissues. More recently, particle therapy has been actively investigated to improve effectiveness of RT. This review discusses modern RT strategies for HCC, as well as optimal selection of RT in multimodal approach for HCC.

Radiofrequency Ablation Versus Stereotactic Body Radiotherapy for Localized Hepatocellular Carcinoma in Nonsurgically Managed Patients: Analysis of the National Cancer Database

Purpose Data that guide selection of optimal local ablative therapy for the management localized hepatocellular carcinoma (HCC) are lacking. Because there are limited prospective comparative data for these treatment modalities, we aimed to compare the effectiveness of radiofrequency ablation (RFA) versus stereotactic body radiotherapy (SBRT) by using the National Cancer Database. Methods We conducted an observational study to compare the effectiveness of RFA versus SBRT in nonsurgically managed patients with stage I or II HCC. Overall survival was compared by using propensity score-weighted and propensity score-matched analyses based on patient-, facility-, and tumor-level characteristics. A sensitivity analysis was performed to evaluate the effect of severe fibrosis/cirrhosis. In addition, we performed exploratory analyses to determine the effectiveness of RFA and SBRT in clinically relevant patient subsets. Results Overall, 3,684 (92.6%) and 296 (7.4%) nonsurgically managed patients with stage I or II HCC received RFA or SBRT, respectively. After propensity matching, 5-year overall survival was 29.8% (95% CI, 24.5% to 35.3%) in the RFA group versus 19.3% (95% CI, 13.5% to 25.9%) in the SBRT group ( P < .001). Inverse probability-weighted analysis yielded similar results. The benefit of RFA was consistent across all subgroups examined and was robust to the effects of severe fibrosis/cirrhosis. Conclusion Our study suggests that treatment with RFA yields superior survival compared with SBRT for nonsurgically managed patients with stage I or II HCC. Even though our results are limited by the biases related to the retrospective study design, we believe that, in the absence of a randomized clinical trial, our findings should be considered when recommending local ablative therapy for localized unresectable HCC.

MiR-20a-5p promotes radio-resistance by targeting NPAS2 in nasopharyngeal cancer cells

MicroRNAs (miRNAs) are key players of gene expression involved in diverse biological processes including the cancer radio-resistance, which hinders the effective cancer therapy. Here we found that the miR-20a-5p level is significantly up-regulated in radio-resistant nasopharyngeal cancer (NPC) cells via an RNA-seq and miR-omic analysis. Moreover, we identified that the neuronal PAS domain protein 2 (NPAS2) gene is one of the targets of miR-20a-5p. The involvement of miR-20a-5p and NPAS2 with NPC radio-resistance was further validated by either down- or up-regulation of their levels in NPC cell lines. Taken together, these results not only reveal novel insights into the NPC radio-resistance, but also provide hints for an effective therapeutic strategy to fight against NPC radio-resistance.

Quality assurance for a multicenter Phase II study of stereotactic ablative radiotherapy for hepatocellular carcinoma ≤5 cm: a planning dummy run

Objective

The Korean Radiation Oncology Group (12-02) investigated the outcome of stereotactic ablative radiotherapy for hepatocellular carcinoma ≤5 cm using 60 Gy in three fractions. To evaluate dosimetric differences and compliance in a multicenter trial, a planning dummy run procedure was performed.

Methods

All six participating institutions were provided the contours of two dummy run cases. Plans were performed following the study protocol to cover the planning target volume with a minimum of 90% of the prescription dose and to satisfy the constraints for organs at risk. We assessed the institutional variations in plans using dose-volume histograms.

Results

Different planning techniques were applied: static intensity-modulated radiotherapy in two institutions, CyberKnife in two institutions and RapidArc in two institutions. The conformity index of all 12 plans was ≤1.2. In terms of the planning target volume coverage, all participants followed our study protocol. For the second dummy run case, located in Segment 8 near the heart, the minimum dose of the planning target volume (D99%: dose covering 99% of the planning target volume) was variable because there was no mention of constraints of D99% of the planning target volume in the study protocol. As an important organ at risk, the normal liver volumes receiving <17 Gy in all 12 plans were >700 ml.

Conclusions

Dosimetric parameters showed acceptable compliance with the study protocol. However, we found the possibility of underdose to the planning target volume if the hepatocellular carcinoma lesion was located near organs at risk such as the heart. Based on this dummy run, we will conduct individual case reviews to minimize the effects of study protocol deviation.

Stereotactic body radiation therapy (SBRT) for definitive treatment and as a bridge to liver transplantation in early stage inoperable Hepatocellular carcinoma

Background and Purpose

Stereotactic body radiotherapy (SBRT) is an emerging modality for definitive treatment of Hepatocellular carcinoma (HCC).

Materials and Methods

This retrospective study included all early stage HCC patients who were not candidates for primary resection and/or local therapy, treated with SBRT between 11/2011 and 1/2016.

Results

Twenty-three patients were included. The median age was 62 years; 70% males; 30% females; 70% viral hepatitis carriers; 100% cirrhotic; 13 Child Pugh [CP]-A and 10 [CP]-B. The median tumor volume was 12.7cm³ (range, 2.2–53.6 cm³). Treatment was well tolerated. With the exception of one patient who developed RILD, no other patient had significant changes in 12 weeks of laboratory follow-up. SBRT was a bridge to transplantation in 16 patients and 11 were transplanted.. No surgical difficulties or complications were reported following SBRT, and none of the transplanted patients had local progression before transplantation. The median prescribed dose to the tumor was 54Gy (range, 30-54Gy), the median dose to the uninvolved liver was 6.0Gy(range, 1.6–12.6Gy). With a median follow-up time of 12 months, the median overall-survival for the 11 transplanted patients was not reached (range, 2.0–53.7+ months) and was 23 months for the 12 non-transplanted patients. The median progression-free survival for the transplanted patients was not reached (54+ months) and was 14.0 months for the non-transplanted patients. There was no SBRT-related mortality. Liver explant post SBRT revealed pathological complete response in 3(27.3%), pathological partial response in 6(54.5%), and pathological stable disease in 2(18.2%) tumors.

Conclusions

SBRT is safe and effective and can be used as a bridge to transplantation without comprising the surgical procedure.

放射性肝损伤的研究进展

我国是肝癌大国, 肝癌的年发病及死亡人数均占全球一半以上. 很多患者在肝癌发展的不同时期会接受放射治疗. 放射性肝损伤(radiation-induced liver damage, RILD)是由放射治疗导致的一种临床亚急性、慢性肝脏损伤, 是胸部和上腹部肿瘤放疗及骨髓移植前预处理中最严重的并发症之一. RILD极大地影响了胸腹部肿瘤, 特别是肝癌的放疗疗效. 因此, 本综述对RILD的病理、影像学特点、临床评估及防治作一归纳总结.

Excellent local control and tolerance profile after stereotactic body radiotherapy of advanced hepatocellular carcinoma

Background

To evaluate the efficacy and toxicity of stereotactic body radiotherapy (SBRT) in the treatment of advanced hepatocellular carcinoma (HCC).

Material and Methods

Patients with large HCCs (median diameter 7 cm, IQR 5-10 cm) with a Child-Turcotte-Pugh (CTP) score A (60%) or B (40%) and Barcelona-Clinic Liver Cancer (BCLC) classification stage B or C were treated with 3 to 12 fractions to allow personalized treatment according to the size of the lesions and the proximity of the lesions to the organs at risk aiming to give high biologically equivalent doses assuming an α/β ratio of 10 Gy for HCC. Primary end points were in-field local control and toxicity assessment.

Results

Forty seven patients with 64 lesions were treated with SBRT (median 45 Gy in 3–12 fractions) with a median follow up for patients alive of 19 months. The median biological effective dose was 76 Gy (IQR 62–86 Gy). Tumor vascular thrombosis was present in 28% and an underlying liver disease in 87% (hepatitis B or C in 21%, alcohol related in 51%, nonalcoholic steatohepatitis in 13% of the patients, primary biliary cirrhosis 2%). Eighty three percent received prior and in most cases multiple therapies. Local control at 1 year was 77%. The median overall survival from the start of SBRT was 9 months (95% CI 7.7–10.3). Gastrointestinal toxicities grade ≥ 2 were observed in 3 (6.4%) patients. An increase in CTP score without disease progression was observed in 5 patients, of whom one patient developed a radiation induced liver disease. One patient died due to liver failure 4 months after treatment.

Conclusion

SBRT is an effective local ablative therapy which leads to high local control rates with moderate toxicity for selected patients with large tumors.

Electronic supplementary material

The online version of this article (doi:10.1186/s13014-017-0851-7) contains supplementary material, which is available to authorized users.

Role and Future Directions of External Beam Radiotherapy for Primary Liver Cancer

The incidence of primary liver cancers continues to increase in the United States and worldwide. The majority of patients with primary liver cancer are not candidates for curative therapies such as surgical resection or orthotopic liver transplantation due to tumor size, vascular invasion, or underlying comorbidities. Therefore, while primary liver cancer is the sixth-most common cancer diagnosis worldwide, it represents the second leading cause of cancer-related deaths. Radiotherapy traditionally played a limited role in the treatment of primary liver cancer due to concerns over hepatic tolerance and the inability to deliver a tumoricidal dose of radiotherapy while still sparing normal hepatic parenchyma. However, the development of modern radiotherapy techniques has made liver-directed radiotherapy a safe and effective treatment option for both hepatocellular carcinoma and intrahepatic cholangiocarcinoma. An increasing body of literature has demonstrated the excellent local control and survival rates associated with liver-directed radiotherapy. These data include multiple radiotherapy techniques and modalities, including stereotactic body radiotherapy (SBRT), intensity modulated radiotherapy (IMRT), and charged particle therapy, including proton therapy. In this review, we discuss the development of liver-directed radiotherapy and evidence in support of its use, particularly in patients who are not candidates for resection or orthotopic liver transplantation. We also discuss future directions for its role in the management of primary liver cancers.

Prognostic value of tumor volume and radiation dose in moderate-sized hepatocellular carcinoma: A multicenter analysis in Korea (KROG 14-17)

The purpose of this study is to investigate the prognostic value of tumor volume and radiation dose for predicting treatment outcomes in moderate-sized hepatocellular carcinoma (HCC).A total of 72 patients with unresectable HCC ranging in size from 5 to 10 cm were treated with high-dose radiotherapy including hypofractionated radiotherapy (HRT) and stereotactic body radiotherapy (SBRT), in 3 institutions from 2003 to 2013. The HRT doses ranged from 33 to 60 Gy in 3 to 10 fractions. The primary endpoint was local progression-free survival (PFS); the secondary endpoints were overall PFS, overall survival (OS), and treatment toxicity.The median follow-up period after radiotherapy was 12.8 months. The local PFS rates at 1 and 2 years were 57.0% and 39.0%, respectively, with a median of 13.6 months. The OS rates at 1 and 2 years were 70.1% and 45.2%, respectively, with a median of 21.1 months. A gross tumor volume (GTV) of 214 cm and a total dose of 105 Gy10 were identified as the optimal cutoff values of radiotherapeutic factors for local PFS. Patients with GTV ≤ 214 cm and total dose >105 Gy10 had significant higher 2-year local PFS and OS than patients with GTV >214 cm and total dose ≤ 105 Gy10 (P = .020 for local PFS, P = .009 for OS).The optimal cutoff values of GTV ≤ 214 cm and total dose >105 Gy10 may be useful for predicting survival outcomes when treating moderate-sized HCC with high-dose radiotherapy.

Strategies to tackle the challenges of external beam radiotherapy for liver tumors

Primary and metastatic liver cancer is an increasingly common and difficult to control disease entity. Radiation offers a non-invasive treatment alternative for these patients who often have few options and a poor prognosis. However, the anatomy and aggressiveness of liver cancer poses significant challenges such as accurate localization at simulation and treatment, management of motion and appropriate selection of dose regimen. This article aims to review the options available and provide information for the practical implementation and/or improvement of liver cancer radiation programs within the context of stereotactic body radiotherapy and image-guided radiotherapy guidelines. Specific patient inclusion and exclusion criteria are presented given the significant toxicity found in certain sub-populations treated with radiation. Indeed, certain sub-populations, such as those with tumor thrombosis or those with larger lesions treated with transarterial chemoembolization, have been shown to have significant improvements in outcome with the addition of radiation and merit special consideration. Implementing a liver radiation program requires three primary challenges to be addressed: (1) immobilization and motion management; (2) localization; and (3) dose regimen and constraint selection. Strategies to deal with motion include simple internal target volume (ITV) expansions, non-gated ITV reduction strategies, breath hold methods, and surrogate marker methods to enable gating or tracking. Localization of the tumor and organs-at-risk are addressed using contrast infusion techniques to take advantage of different normal liver and cancer vascular anatomy, imaging modalities, and margin management. Finally, a dose response has been demonstrated and dose regimens appear to be converging. A more uniform approach to treatment in terms of technique, dose selection and patient selection will allow us to study liver radiation in larger and, hopefully, multicenter randomized studies.

Stereotactic Ablative Radiotherapy for Patients with Unresectable or Medically Inoperable Cholangiocarcinoma

Purpose

The role of stereotactic ablative radiotherapy (SABR) in patients with unresectable or medically inoperable cholangiocarcinoma remains unclear. We examined the efficacy and safety of SABR in this group of patients.

Methods

From January 2008 to December 2014, 15 patients with 17 lesions were included in this study. The lesions included 14 intrahepatic, 1 hilar, and 2 distal bile duct tumors. Three patients were classified as medically inoperable because of old age or multiple comorbidities. Tumors measured 0.8-13 cm (median, 3.6 cm). The median prescribed dose was 45 Gy delivered in 5 fractions over 5 consecutive days.

Results

The median follow-up period for surviving patients was 29.9 months. Objective responses were observed for 10 of 17 tumors (58.8%), including 3 complete responses (17.6%). The median survival duration was 12.6 months, and the 1- and 2-year overall survival rates were 50.3% and 14.4%, respectively. The 1- and 2-year in-field failure-free rates were 61.5% and 30.8%, respectively. For patients with biologically effective doses (BEDs) exceeding 75 Gy10, the 1- and 2-year overall survival rates were 58.3% and 33.3%, respectively, compared to 20.0% and 0%, respectively for those with BEDs lower than 75 Gy10. Radiation-induced liver disease did not develop in any patient. Acute toxicities were generally mild and tolerable.

Conclusions

Stereotactic ablative radiotherapy could be an alternative treatment for unresectable or medically inoperable cholangiocarcinoma. Further dose escalation may be considered to optimize local control.

MiR-20a-5p promotes radio-resistance by targeting Rab27B in nasopharyngeal cancer cells

BACKGROUND

MicroRNAs (miRNAs) was reported to be involved in cancer radio-resistance, which remains a major obstacle for effective cancer therapy.

METHODS

The differently expressed miRNAs were detected by RNA-seq experiment in nasopharyngeal cancer (NPC) cells. MiR-20a-5p was selected as our target, which was subject to finding its target gene Rab27B via bioinformatics analysis. The qRT-PCR, western blot and the luciferase reporter assays were performed to confirm Rab27B as the target of miR-20a-5p. In addition, the roles of miR-20a-5p in NPC radio-resistance were detected by transfection of either miR-20a-5p-mimic or miR-20a-5p-antagomiR. The involvement of Rab27B with NPC radio-resistance was also detected by the experiments with siRNA-mediated repression of Rab27B or over-expression of GFP-Rab27B. Wound healing and invasion assays were performed to detect the roles of both miR-20a-5p and Rab27B.

RESULTS

MiR-20a-5p promotes NPC radio-resistance. We identified that its target gene Rab27B negatively correlates with miR-20a-5p-mediated NPC radio-resistance by systematic studies of a radio-sensitive (CNE-2) and resistant (CNE-1) NPC cell lines. Repression of Rab27B by siRNA suppresses cell apoptosis and passivates CNE-2 cells, whereas over-expression of Rab27B triggered cell apoptosis and sensitizes CNE-1 cells.

CONCLUSIONS

MiR-20a-5p and its target gene Rab27B might be involved in the NPC radio-resistance. Thus the key players and regulators involved in this pathway might be the potential targets for developing effective therapeutic strategies against NPC.

External beam radiotherapy for unresectable hepatocellular carcinoma, an international multicenter phase I trial, SAKK 77/07 and SASL 26

PURPOSE

To assess feasibility and safety of conventionally fractionated radiotherapy (cfRT) in patients with hepatocellular carcinoma (HCC).

METHODS

Patients with histologically confirmed stage cT1-4, cN0-1 HCC and Child-Pugh Score (CPS) A or B disease were included in a phase I multicenter trial. Metastatic HCC were allowed if ≥90% of total tumor volume was located within the liver. Patients were enrolled onto five dose-escalation levels (54-70Gy in 2Gy fractions) based on a modified 3 + 3 design, with cohorts of five patients instead of three patients in dose levels 4 and 5. Primary trial endpoint was dose-limiting toxicity (DLT), as specifically defined for 17 clinical and nine laboratory parameters as grade ≥3 or ≥4 toxicity (CTCAE vs. 3). The threshold to declare a dose level as maximum tolerated dose (MTD) was defined as a DLT rate of ≤16.7% in dose levels 1-3, and ≤10% in dose levels 4-5. Best objective response of target liver lesions and adverse events (AE's) were assessed as secondary endpoints.

RESULTS

The trial was terminated early in DL 3 due to low accrual. Nineteen patients were recruited. Fifteen patients were evaluable for the primary and 18 for the secondary endpoints. Maximum tolerated dose was not reached. One patient in dose level 1, and one patient in dose level 2 experienced DLT (lipase > 5xULN, and neutrophils <500/μL respectively). However, dose level 3 (62Gy) was completed, with no DLTs in 3 patients. Overall, 56% of patients had a partial response and 28% showed stable disease according to RECIST. No signs of radiation induced liver disease (RILD). Two patients in dose level 3 experienced lymphocytopenia grade 4, with no clinical impact.

CONCLUSION

Conventionally fractionated radiotherapy of 58Gy to even large HCC was safe for patients with CPS A and B. 62Gy was delivered to three patients without any sign of clinically relevant increased toxicity. The maximum tolerated dose could not be determined.

TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT00777894 , registered October 21st, 2008.

Strategic overview on the best treatment option for intrahepaitc hepatocellular carcinoma recurrence

INTRODUCTION

The long-term survival after hepatectomy for HCC remains unsatisfactory because of the high incidence of recurrence. The cumulative 5-year recurrence rate ranged from 60-100% in previous studies and majority of them remains intrahepatic recurrence. The therapeutic modalities commonly used for primary tumors, including surgical resection, liver transplantation, TACE, local ablative therapy and radiotherapy have been used to treat recurrent tumors in the liver remnant and the outcomes with the heterogeneous therapeutic options are reviewed. It is important to note that the level of evidence for most therapeutic options is limited to cohort investigations with few RCTs and most were limited due to enrollment of various tumor stages and did not compare treatment modalities for specific tumor stages.

AREAS COVERED

A literature search for recurrent HCC was performed using Medline and PubMed up to May 2016. Expert commentary: The long term survival results after re-resection for recurrent HCC were favourable and aggressive management of postoperative intrahepatic recurrence remains the most important strategy in prolonging the survival of patients after resection of HCC.

Therapeutic Strategies in HCC: Radiation Modalities

Patients with hepatocellular carcinoma (HCC) comply with an advanced disease and are not eligible for radical therapy. In this distressed scenario new treatment options hold great promise; among them transarterial chemoembolization (TACE) and transarterial metabolic radiotherapy (TAMR) have shown efficacy in terms of both tumor shrinking and survival. External radiation therapy (RTx) by using novel three-dimensional conformal radiotherapy has also been used for HCC patients with encouraging results while its role had been limited in the past for the low tolerance of surrounding healthy liver. The rationale of TAMR derives from the idea of delivering exceptional radiation dose locally to the tumor, with cell killing intent, while preserving normal liver from undue exposition and minimizing systemic irradiation. Since the therapeutic efficacy of TACE is being continuously disputed, the TAMR with ¹³¹I Lipiodol or ⁹⁰Y microspheres has gained consideration providing adequate therapeutic responses regardless of few toxicities. The implementation of novel radioisotopes and technological innovations in the field of RTx constitutes an intriguing field of research with important translational aspects. Moreover, the combination of different therapeutic approaches including chemotherapy offers captivating perspectives. We present the role of the radiation-based therapies in hepatocellular carcinoma patients who are not entitled for radical treatment.

Stereotactic body radiation therapy for primary and metastatic liver tumors: From technological evolution to improved patient care

Technical developments allowed stereotactic body radiation therapy (SBRT) to deliver effective doses of irradiation with high precision in a small number of fractions. This paper reviews the role of SBRT for liver metastases, hepatocellular carcinoma and cholangiocarcinoma, paying special attention to patient eligibility and treatment outcomes regarding local control, toxicity and quality of life. As well as discussing specific issues of these different tumors, such as the presence of underlying liver cirrhosis and the impact on toxicity, it outlines the limitations of SBRT and future areas of development and research.

Clinical outcomes and prognostic factors of cyberknife stereotactic body radiation therapy for unresectable hepatocellular carcinoma

BACKGROUND

Stereotactic body radiation therapy (SBRT) has been an emerging non-invasive treatment modality for patients with hepatocellular carcinoma (HCC) when curative treatments cannot be applied. In this study, we report our clinical experience with Cyberknife SBRT for unresectable HCC and evaluate the efficacy and clinical outcomes of this highly sophisticated treatment technology.

METHODS

Between 2008 and 2012, 115 patients with unresectable HCC treated with Cyberknife SBRT were retrospectively analyzed. Doses ranged from 26 Gy to 40 Gy were given in 3 to 5 fractions for 3 to 5 consecutive days. The cumulative probability of survival was calculated according to the Kaplan-Meier method and compared using log-rank test. Univariate and multivariate analysis were performed using Cox proportional hazard models.

RESULTS

The median follow-up was 15.5 months (range, 2-60 months). Based on Response Evaluation and Criteria in Solid Tumors (RECIST). We found that 48.7 % of patients achieved a complete response and 40 % achieved a partial response. Median survival was 15 months (4-25 months). Overall survival (OS) at 1- and 2-years was 63.5 %(54-71.5 %) and 41.3 % (31.6-50.6 %), respectively, while 1- and 2- years Progression-free Survival (PFS) rates were 42.8 %(33.0-52.2 %) and 38.8 % (29.0-48.4 %). Median progression was 6 months (3-16 months). In-field recurrence free survival at 1 and 2 years was 85.3 % (76.2-91.1 %) and 81.6 % (72.2-88.6 %), respectively, while the 1- and 2-years out-field recurrence free survival were 52.5 % (41.2-60.8 %) and 49.5 %(38.9-59.2 %), respectively. Multivariate analysis revealed that Child-Pugh score (A vs. B), Portal vein tumor thrombosis (positive vs. negative), Tumor size (≤4 cm vs >4-9 cm /≥10 cm), and tumor response after SBRT (CR vs. PR/stable) were independent predictors of OS. Acute toxicity was mostly transient and tolerable.

CONCLUSIONS

Cyberknife SBRT appears to be an effective non-invasive treatment for local unresectable HCC with low risk of severe toxicity. These results suggested that Cyberknife SBRT can be a good alternative treatment for unresectable HCC unsuitable for standard treatment.

How to Improve Therapeutic Ratio in Radiotherapy of HCC

BACKGROUND

During the past two decades, external-beam radiation technology has substantially changed from traditional two-dimensional to conformal three-dimensional to intensity-modulated planning and stereotactic body radiotherapy (SBRT).

SUMMARY

Modern techniques of radiotherapy (RT) are highly focused and capable of delivering an ablative dose to targeted hepatocellular carcinoma (HCC) tumors. SBRT is an option for selected patients with limited tumor volume and non-eligibility for other invasive treatments. Moreover, RT combined with a radiation sensitizer (RS) to increase the therapeutic ratio has shown promising results in select studies, prompting further investigation of this combination. With the undetermined role of RT in treatment guidelines and variation in patterns of treatment failure after RT in patient with HCC, useful biomarkers to guide RT decision-making and selection of patients are needed and emerging.

KEY MESSAGE

The objective of this review is to summarize the current RS with SBRT schemes and biomarkers for patient selection used to maximize the effect of RT on HCC.

Liver-Directed Radiotherapy for Hepatocellular Carcinoma

BACKGROUND

The incidence of hepatocellular carcinoma (HCC) continues to increase world-wide. Many patients present with advanced disease with extensive local tumor or vascular invasion and are not candidates for traditionally curative therapies such as orthotopic liver transplantation (OLT) or resection. Radiotherapy (RT) was historically limited by its inability to deliver a tumoricidal dose; however, modern RT techniques have prompted renewed interest in the use of liver-directed RT to treat patients with primary hepatic malignancies.

SUMMARY

The aim of this review was to discuss the use of external beam RT in the treatment of HCC, with particular focus on the use of stereotactic body radiotherapy (SBRT). We review the intricacies of SBRT treatment planning and delivery. Liver-directed RT involves accurate target identification, precise and reproducible patient immobilization, and assessment of target and organ motion. We also summarize the published data on liver-directed RT, and demonstrate that it is associated with excellent local control and survival rates, particularly in patients who are not candidates for OLT or resection.

KEY MESSAGES

Modern liver-directed RT is safe and effective for the treatment of HCC, particularly in patients who are not candidates for OLT or resection. Liver-directed RT, including SBRT, depends on accurate target identification, precise and reproducible patient immobilization, and assessment of target and organ motion. Further prospective studies are needed to fully delineate the role of liver-directed RT in the treatment of HCC.

CyberKnife Radiosurgery - Value as an Adjunct to Surgical Treatment of HCC?

INTRODUCTION

CyberKnife radiosurgery (CK) is an effective tool for the treatment of malignancies. Its greatest potential is in high-dose radiosurgery delivered to targets in organs that move with respiration, e.g., liver tumors. For hepatocellular carcinoma (HCC), however, surgical treatment (resection, transplantation) is most likely to produce long-term survival; for non-resectable tumors, therapies other than radiosurgery are typically recommended. This study evaluated the long-lasting anti-tumor effects of CK combined with surgery in patients with HCC. MATERIALS AND METHODS : Eighteen patients (three women, 15 men) were included in this prospective observational study. They received 21 single-fraction CK treatments (26 Gy). Patient characteristics, treatment effects, tumor response (according to the Response Evaluation Criteria In Solid Tumors (RECIST) grading) and survival were measured for a median period of 29 months.

RESULTS

Local tumor control was achieved in 15 patients, with complete and partial remission observed in 10 and five patients, respectively. One patient was treated for two separate lesions in one session, and one received three treatments each separated by two-year intervals; both patients are tumor-free. Two patients showed minimal response, and in one patient local tumor viability could not be excluded by MRI. Nine patients had HCC recurrence, all distant to the treated site. Nine patients died during follow-up, including two with clear relation to tumor progress. Tumor-free survival was 79.4% after one year and 29.8% after three years, and the corresponding overall survival was 84.8% and 66%. CONCLUSION : This study shows the high effectiveness of single-session frameless CyberKnife radiosurgery for treatment of hepatocellular carcinoma and reconfirms previous results of fractioned radiotherapy of HCC. It also demonstrates the potential of radiosurgery to be combined with surgical concepts.

Stereotactic body radiation therapy for hepatocellular carcinoma

Stereotactic body radiotherapy (SBRT), in which highly conformal potent radiation doses are delivered in fewer fractions than traditional radiation therapy (RT), is an increasingly popular treatment for hepatocellular carcinoma (HCC). The great majority of HCCs smaller than 6 cm and with Child-Pugh A liver function are controlled with SBRT with limited toxicity. Long-term local control is reduced in larger tumors, and toxicity is increased in patients with Child-Pugh B or C liver function. SBRT is an effective treatment for tumor vascular thrombi and can lead to sustained vascular recanalization. The first site of recurrence following SBRT is most often within the liver, away from the high dose volume, providing rationale for combining SBRT with regional or systemic therapies. Randomized trials of SBRT are warranted.

Optimal Selection of Radiotherapy as Part of a Multimodal Approach for Hepatocellular Carcinoma

A multimodal approach to treatment is a basic oncologic principle with proven survival benefits for most cancer types. However, existing guidelines recommend single modalities for treating each stage of hepatocellular carcinoma (HCC). Nonetheless, multimodal approaches can be considered for HCC, depending on the characteristics of the disease in individual cases. Radiotherapy (RT), an effective local modality, is a critical element of most multimodal approaches. Improved RTtechnology and increased understanding of the tolerance of the liver to radiation have contributed to the popularity of RT for treating liver tumors in clinical practice. Consequently, numerous reports have described the effects of RT on liver cancer, despite a lack of stringent evidence for its benefits. RT can be delivered using various technologies and approaches, which may be the source of some confusion. For example, high-dose ablative RT can be curative on its own, or high-dose ablative or conventional RT can complement other treatments such as radiofrequency ablation and transarterial chemoembolization. Combinations of systemic agents and RT can also be applied. This review discusses the optimal selection of RT as part of a multimodal approach for HCC.

Comparative analysis of current guidelines for the treatment of hepatocellular carcinoma

Hepatocellular carcinoma is one of the most common malignancies and represents a unique challenge for physicians and patients. Treatment patterns are not uniform between areas despite efforts to promote a common protocol. Even if most hepatologists worldwide adopt the Barcelona Clinic Liver Cancer staging system, Asian and North American physicians are also independently making an effort to expand the indications of each treatment, combining therapies for better outcomes. Also, new therapeutic techniques have emerged and an increasing number of studies are trying to include these paradigm shifts into newer treatment guidelines. Controversial and diverging points in the current international guidelines are emphasized and discussed. Unanswered questions are also analyzed to identify the most needed and promising future perspectives.

Benefits of stereotactic ablative radiotherapy combined with incomplete transcatheter arterial chemoembolization in hepatocellular carcinoma

BACKGROUND

This study aimed to evaluate the effect of stereotactic ablative radiotherapy (SABR) after incomplete transcatheter arterial chemoembolization (TACE) in hepatocellular carcinoma (HCC) patients.

METHODS

The study enrolled 178 HCC patients initially treated with TACE between 2006 and 2011. Patients were included if they had Barcelona Clinic Liver Cancer stage 0 or A, ≤3 nodules with a total sum of longest diameter ≤10 cm, Child-Turcotte-Pugh score of ≤7, no major vessel invasion, and no extra-hepatic metastases.

RESULTS

Twenty-four patients achieved a complete response to TACE (group 1). Among those with incomplete response, 47 patients received other curative treatments (group 2), 37 received SABR (group 3), and 70 received non-curative treatments (group 4). The 2-year overall survival (OS) rates for groups 1, 2, 3, and 4 were 88 %, 81 %, 73 %, and 54 %, respectively. The corresponding 5-year OS rates were 50 %, 58 %, 53 %, and 28 %, respectively.

CONCLUSIONS

Patients treated with SABR after incomplete TACE had similar survival outcomes to those achieving complete response to TACE or receiving curative treatments. However, patients receiving non-curative treatments had significantly lower survival rates than the other groups. Therefore, if SABR was indicated at the initial diagnosis, it might be recommended after TACE failure.

Practical patterns for stereotactic body radiotherapy to hepatocellular carcinoma in Korea: a survey of the Korean Stereotactic Radiosurgery Group

OBJECTIVE

To investigate practical patterns for stereotactic body radiotherapy to hepatocellular carcinoma in Korea.

METHODS

In June 2013, the Korean Stereotactic Radiosurgery Group of the Korean Society for Radiation Oncology conducted a national patterns-of-care survey about stereotactic body radiotherapy to the liver lesion in hepatocellular carcinoma, consisting of 19 questions and 2 clinical scenarios.

RESULTS

All 208 radiation oncologists (100%), who are regular members of Korean Society for Radiation Oncology, responded to this survey. Among these, 95 radiation oncologists were specialists for hepatology; 64 physicians did not use stereotactic body radiotherapy for hepatocellular carcinoma, and 31 physicians used stereotactic body radiotherapy. Most physicians (52%) performed stereotactic body radiotherapy to hepatocellular carcinoma in ≤5 cases per year. Physicians applied stereotactic body radiotherapy according to tumour size and baseline Child-Pugh class. All physicians agreed the use of stereotactic body radiotherapy to 2.8-cm hepatocellular carcinoma with Child-Pugh class of A, while 23 physicians (74%) selected stereotactic body radiotherapy for Child-Pugh class of B. Nineteen physicians (61%) selected stereotactic body radiotherapy to 5-cm hepatocellular carcinoma with Child-Pugh class of A, and only 14 physicians (45%) selected stereotactic body radiotherapy for Child-Pugh class of B. On the other hand, the preferred dose scheme was same as 60 Gy in three fractions.

CONCLUSIONS

Among radiation oncologists in Korea, there was diversity in the practice for stereotactic body radiotherapy to the liver lesion in hepatocellular carcinoma. Additional prospective studies are necessary to standardize the practice and establish Korea-specific practice guidelines for hepatocellular carcinoma stereotactic body radiotherapy.

Cyberknife treatment for advanced or terminal stage hepatocellular carcinoma

AIM: To investigate the safety and efficacy of the Cyberknife treatment for patients with advanced or terminal stage hepatocellular carcinoma (HCC).

METHODS: Patients with HCC with extrahepatic metastasis or vascular or bile duct invasion were enrolled between May 2011 and June 2015. The Cyberknife was used to treat each lesion. Treatment response scores were based on Response Evaluation Criteria in Solid Tumors v1.1. The trends of tumor markers, including alpha fetoprotein (AFP) and proteins induced by vitamin K absence II (PIVKA II) were assessed. Prognostic factors for tumor response and tumor markers were evaluated with Fisher’s exact test and a logistic regression model. Survival was evaluated with the Kaplan-Meier method and multivariate analysis was performed using the Cox proportional hazards model.

RESULTS: Sixty-five patients with 95 lesions were enrolled. Based on the Barcelona Clinic Liver Cancer classification, all patients were either in the advanced or terminal stage of the disease. The target lesions were as follows: 52 were bone metastasis; 9, lung metastasis; 7, brain metastasis; 9, portal vein invasion; 4, hepatic vein invasion; 4, bile duct invasion; and 10 other lesion types. The response rate and disease control rate were 34% and 53%, respectively. None of the clinical factors correlated significantly with tumor response. Fiducial marker implantation was associated with better control of both AFP (HR = 0.152; 95%CI: 0.026-0.887; P = 0.036) and PIVKA II (HR = 0.035; 95%CI: 0.003-0.342; P = 0.004). The median survival time was 9 mo (95%CI: 5-15 mo). Terminal stage disease (HR = 9.809; 95%CI: 2.589-37.17, P < 0.001) and an AFP of more than 400 ng/mL (HR = 2.548; 95%CI: 1.070-6.068, P = 0.035) were associated with worse survival. A radiation dose higher than 30 Gy (HR = 0.274; 95%CI: 0.093-0.7541, P = 0.012) was associated with better survival. In the 52 cases of bone metastasis, 36 patients (69%) achieved pain relief. One patient had cerebral bleeding and another patient had an esophageal ulcer after treatment.

CONCLUSION: The Cyberknife can be safely administered to patients with advanced or terminal stage HCC. High AFP levels were associated with worse survival, but a higher radiation dose improved the survival.