Stereotactic body radiation therapy with or without transarterial chemoembolization for patients with primary hepatocellular carcinoma: preliminary analysis

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.

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.

Is hepatocellular carcinoma complicated with portal vein tumor thrombosis potentially curable by radiotherapy in the form of stereotactic body radiation therapy?

PURPOSE

The prognosis of hepatocellular carcinoma (HCC) with portal vein tumor thrombosis (PVTT) is dismal. Despite best treatment and care, the patients with this malignancy only showed 2.7-4 months of overall survival. It is debatable whether liver transplantation helps PVTT sufferers. The effectiveness of radiation therapy in treating HCC patients with PVTT should not be undervalued. By limiting the high dosage region to a small planning target volume, stereotactic radiation delivery has shifted toward hypofractionation, limiting the radiation exposure to healthy organs and tissues. Stereotactic body radiotherapy (SBRT) has a local control rate of 75-100%, depending on the treatment. The major limitation in SBRT for hepatocellular carcinoma with PVTT is the paucity of prospective evidence for longer periods beyond the first two years after treatment. More prospective studies/randomized clinical trials with a longer follow-up, larger sample size, and adequate statistical power are the dire need of the present situation to ascertain the curative effect of SBRT as primary therapy for advanced HCC with PVTT.

CONCLUSION

SBRT can improve survival, particularly for patients receiving multidisciplinary treatment. This review sums up our most current understanding of how radiation therapy, notably SBRT, can be used to treat hepatocellular carcinoma when combined with PVTT. Recent research has led us to believe that irradiation in the form of SBRT may cure hepatocellular carcinoma complicated by PVTT.

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.

Current Understanding of Ablative Radiation Therapy in Hepatocellular Carcinoma

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

Combination of yttrium-90 radioembolization with stereotactic body radiation therapy in the treatment of portal vein tumor thrombosis

PURPOSE

Portal vein tumor thrombosis (PVTT) from cancer involving the liver carries a dismal prognosis, with median overall survival (OS) ranging from 2 to 5 months. While treatment with yttrium-90 (90Y) radioembolization alone may improve outcomes, overall prognosis remains poor. We hypothesize that the combination of 90Y radioembolization to the parenchymal component of the tumor and stereotactic body radiation therapy (SBRT) to the vascular component is a safe and effective means of improving outcomes.

MATERIALS AND METHODS

A single center retrospective review identified 12 patients with cancers involving the liver who received both 90Y radioembolization and SBRT to the PVTT between May 2015 to August 2020. Primary endpoint was the 90-day toxicity rate by the Common Terminology Criteria for Adverse Events version 5.0. Secondary endpoints were the best response rate based on the Response Evaluation Criteria in Solid Tumors v1.1, local control rate, portal vein (PV) patency rate, and median OS.

RESULTS

Patients received a median 90Y dose of 104.3 Gy (range, 83.3 to 131.7 Gy) and a median 5-fraction SBRT dose of 32.5 Gy (range, 27.5 to 50 Gy). There were no late toxicities reported, and only 7 acute grade 1 toxicities reported: elevation of liver function tests (17%), nausea (17%), fatigue (17%), and esophagitis (8%). Local control was 83%. 58% of patients had a patent PV after treatment. With a median follow-up time of 28 months, 1-year OS was 55% with a median OS of 14 months.

CONCLUSION

Combination 90Y radioembolization and SBRT appears to be safe and effective in the treatment of PVTT. Larger prospective studies are warranted to better evaluate this combination treatment approach.

Improvement of image quality and assessment of respiratory motion for hepatocellular carcinoma with portal vein tumor thrombosis using contrast-enhanced four-dimensional dual-energy computed tomography

To assess the objective and subjective image quality, and respiratory motion of hepatocellular carcinoma with portal vein tumor thrombosis (PVTT) using the contrast-enhanced four-dimensional dual-energy computed tomography (CE-4D-DECT). For twelve patients, the virtual monochromatic image (VMI) derived from the CE-4D-DECT with the highest contrast to noise ratio (CNR) was determined as the optimal VMI (O-VMI). To assess the objective and subjective image quality, the CNR and five-point score of the O-VMI were compared to those of the standard VMI at 77 keV (S-VMI). The respiratory motion of the PVTT and diaphragm was measured based on the exhale and inhale phase images. The VMI at 60 keV yielded the highest CNR (4.8 ± 1.4) which was significantly higher (p = 0.02) than that in the S-VMI (3.8 ± 1.2). The overall image quality (4.0 ± 0.6 vs 3.1 ± 0.5) and tumor conspicuity (3.8 ± 0.8 vs 2.8 ± 0.6) of the O-VMI determined by three radiation oncologists was significantly higher (p < 0.01) than that of the S-VMI. The diaphragm motion in the L-R (3.3 ± 2.5 vs 1.2 ± 1.1 mm), A-P (6.7 ± 4.0 vs 1.6 ± 1.3mm) and 3D (8.8 ± 3.5 vs 13.1 ± 4.9 mm) directions were significantly larger (p < 0.05) compared to the tumor motion. The improvement of objective and subjective image quality was achieved in the O-VMI. Because the respiratory motion of the diaphragm was larger than that of the PVTT, we need to be pay attention for localizing target in radiotherapy.

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

Background: Both stereotactic body radiotherapy (SBRT) and radiofrequency ablation (RFA) are effective local treatments for hepatocellular carcinoma (HCC), but whether RFA is superior to SBRT is still controversial. Therefore, we performed a meta-analysis to compare the treatment outcomes of SBRT with RFA as curable or bridge intention. Methods: We searched online databases for studies that compared treatment outcomes for SBRT and RFA. Eligibility criteria included evaluation of local control, overall survival (OS), transplant rate, and post-transplant pathological necrosis. Results: As no randomized clinical trials met the criteria, 10 retrospective studies with a total of 2,732 patients were included. Two studies were in favor of SBRT in local control, two studies preferred RFA in OS, and others reported comparable outcomes for both. SBRT demonstrated significantly higher 1- and 3-year local control than RFA [odds ratio (OR) 0.42, 95% CI 0.24-0.74, P = 0.003; and OR 0.54, 95% CI 0.37-0.80, P = 0.002, respectively]. However, SBRT reported significantly shorter 1- and 2-year OS (OR 1.52, 95% CI 1.21-1.90, P = 0.0003; and OR 1.66, 95% CI 1.38-2.01, P < 0.00001, respectively). As bridge treatment, no significant difference was shown in transplant rate and post-transplant pathological necrosis rate (OR 0.57, 95% CI 0.32-1.03, P = 0.060; and OR 0.49, 95% CI 0.13-1.82, P = 0.290, respectively). Conclusions: This study demonstrates SBRT is able to complete a better local control for HCC than RFA, though the OS is inferior to RFA because of tumor burden or liver profiles of the enrolled studies. Well-designed, randomized, multicenter trials will be required to further investigate the conclusion.

Effectiveness of stereotactic body radiotherapy for portal vein tumor thrombosis in patients with hepatocellular carcinoma and underlying chronic liver disease

AIM

Stereotactic-body radiotherapy (SBRT) is a treatment option for portal vein tumor thrombosis (PVTT) in patients with hepatocellular carcinoma (HCC). Here, we report on our experience of treating PVTT using SBRT in patients with concomitant underlying chronic liver disease.

METHODS

This study included 24 patients. The initial prescription dose was 45 Gy in three fractions in 17 (70.8%) patients, but it was modified in the remaining seven (29.2%) patients, with the dose ranging from 39 to 42 Gy in 3-4 fractions. After SBRT, transarterial chemoembolization (TACE) was performed in 16 (66.7%) patients.

RESULTS

Of the 24 patients, 2 (8.3%) showed complete response, while 11 (45.8%) showed partial response. After a median follow-up of 8.4 months (range: 2.6-56.5 months), the 1-year overall survival (OS) and the median survival were 67.5% and 20.8 months, respectively. Both combined SBRT and TACE and grade ≥3 hepatic toxicity affected the 1-year OS (SBRT alone vs SBRT + TACE: 14.6% vs 71.4%, P < .001; presence of hepatic toxicity vs absence: 0% vs 81.1%, P = .002).

CONCLUSIONS

Overall, SBRT, especially in combination with TACE, is an effective treatment for patients with HCC and PVTT. An optimal dose schedule must be followed to reduce hepatic toxicity while maintaining tumor response.

Stereotactic ablative radiotherapy versus conventionally fractionated radiotherapy in the treatment of hepatocellular carcinoma with portal vein invasion: a retrospective analysis

BACKGROUND

This study aimed to compare the clinical outcomes of stereotactic ablative radiotherapy (SABR) and conventionally fractionated radiotherapy (CFRT) in hepatocellular carcinoma (HCC) patients with portal vein invasion (PVI).

METHODS

HCC patients with PVI treated with radiotherapy from 2007 to 2016 were analysed. CFRT was administered at a median dose of 51.5 Gy (interquartile range, 45-54 Gy) with 1.8-3 Gy per fraction. SABR was administered at a median dose of 45 Gy (interquartile range, 40-48 Gy) with 6-12.5 Gy per fraction. Treatment efficacy, toxicity, and associated predictors were assessed.

RESULTS

Among the 104 evaluable patients (45 in the SABR group and 59 in the CFRT group), the overall response rate (ORR, complete and partial response) was significantly higher in the SABR group than the CFRT group (62.2% vs. 33.8%, p = 0.003). The 1-year overall survival (OS) rate (34.9% vs. 15.3%, p = 0.012) and in-field progression-free survival (IFPS) rate (69.6% vs. 32.2%, p = 0.007) were also significantly higher in the SABR vs. CFRT group. All 3 rates remained higher in the SABR group after propensity score matching. Multivariable analysis identified SABR and a biologically effective dose ≥65 Gy as favourable predicators of OS. There was no difference between treatment groups in the incidence of radiation-induced liver disease or increase of Child-Pugh score ≥ 2 within 3 months of radiotherapy.

CONCLUSIONS

SABR was superior to CFRT in terms of ORR, OS, and IFPS. We suggest that SABR should be the preferred technique for HCC patients with PVI.

[Tolerance of hypofractionated stereotactic radiotherapy for hepatic tumours]

PURPOSE

The purpose of the study was to evaluate the outcomes of stereotactic radiation therapy for primary and secondary liver tumours in Jean-Perrin cancer centre (Clermont-Ferrand, France) in terms of efficacy and safety.

MATERIALS AND METHODS

Between December 2013 and June 2016, 25 patients were included. Treatment was performed on a linear accelerator Novalis TX^®. The prescription dose was 42 to 60Gy in three to five fractions. Local control at 1 year was evaluated with modified Response Evaluation Criteria in Solid Tumours (mRECIST) and RECIST criteria. Acute and late toxicity were evaluated with Common Terminology Criteria for Adverse Events (CTCAE) v4.0 criteria.

RESULTS

Median follow-up was 10.5 months. Treatment tolerance was good with few side effects grade 3 or above, no acute toxicity and only one late toxicity. We have highlighted that hepatic artery haemorrhage was associated with the presence of a biliary prosthesis in contact with the artery (P=0.006) and in the irradiation field. There was no correlation with the dose delivered to the artery and hepatic artery haemorrhage.

CONCLUSION

Stereotactic radiation therapy for liver tumours allows a good local control with few secondary effects. Caution should be exercised when treating patients with biliary prostheses in the vicinity of the target volume because there is a risk of haemorrhage of the hepatic artery in contact with the prosthesis.

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.

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.

Magnetic Resonance Imaging Evaluation of Hepatocellular Carcinoma Treated With Stereotactic Body Radiation Therapy: Long Term Imaging Follow-Up

PURPOSE

To determine the natural history of imaging findings seen on magnetic resonance imaging (MRI) of hepatocellular carcinoma (HCC) treated with stereotactic body radiation therapy (SBRT). Although arterial hyperenhancement is a key feature of untreated HCC, our clinical experience suggested that tumors that never progressed could still show hyperenhancement. Therefore, we undertook a systematic study to test the hypothesis that persistent arterial phase hyperenhancement (APHE) after SBRT is an expected finding that does not suggest failure of treatment.

METHODS AND MATERIALS

One hundred forty-six patients undergoing SBRT for HCC between January 1, 2007, and December 31, 2015, were screened retrospectively using an institutional review board-approved prospectively maintained registry. Inclusion criteria were (1) HCC treated with SBRT, (2) multiphasic MRI ≤3 months before SBRT, (3) up to 1 year of follow-up MRI post-SBRT, and (4) cirrhosis. The exclusion criterion was ≤3 months of locoregional therapy to the liver segment containing the SBRT-treated HCC. Pre- and post-SBRT MRI from up to 3 years were analyzed in consensus by independent pairs of subspecialty-trained radiologists to determine the temporal evolution of major features for HCC and imaging findings in off-target parenchyma.

RESULTS

Sixty-two patients with 67 HCCs (Organ Procurement and Transplantation Network imaging criteria [OPTN] 5a [n = 26], OPTN 5b [n = 28], OPTN 5x [n = 7]; Liver Imaging Reporting Data System [LI-RAD]-M [n = 4] and LiRADs-4 [n = 2]) were studied. Tumor size either decreased (66% [44 of 67]) or remained unchanged (34% [23 of 67]) within the first 12 months. Post-SBRT APHE was common (58% [39 of 67]). When graded using modified Response Evaluation Criteria in Solid Tumors at 3 to 6 months, 25% (17 of 67) met criteria for complete response and 75% (50 of 67) met criteria for stable disease.

CONCLUSIONS

SBRT is an effective locoregional treatment option for HCC. Persistent APHE is common and does not necessarily indicate viable neoplasm; thus, standard response assessment such as modified Response Evaluation Criteria should be used with caution, particularly in the early phases after SBRT therapy.

Critical appraisal of the potential role of intensity modulated proton therapy in the hypofractionated treatment of advanced hepatocellular carcinoma

PURPOSE

To investigate the role of intensity modulated proton therapy (IMPT) for advanced hepatocellular carcinoma in comparison with volumetric modulated arc therapy (VMAT).

METHODS

An in-silico planning study was performed on 20 patients. The prescription dose was 60Gy in 6 fractions. Patients were planned with abdominal compression. IMPT plans were optimized with or without the inclusion of CT calibration (3%) and isocenter positioning (2,4,6mm) uncertainties. Plan robustness was appraised comparing rubust optimized plans vs standard plans and also in terms of the worst-case scenario. VMAT plans were optimized for 10FFF photon beams using 2 partial arcs.

RESULTS

Target coverage was fully achieved by both VMAT and IMPT plans with a significant improvement in homogeneity (~25%) with IMPT. Integral dose was reduced of ~60% with IMPT while the conformality of the dose distributions was similar among techniques. The sparing of the organs at risk was strongly improved with IMPT although all clinical objectives were met for both techniques. The inclusion of the uncertainties in the optimization lead to some deterioration in the target dose homogeneity (from 40 to 80% worse with 4 or 6mm position uncertainty) while none of the coverage parameters or OAR objective was violated. The worst-case scenario analysis demonstrated the risk of a major target underdosage only in the case of the most extreme errors (6mm) with D98% in average ~12% lower than the threshold.

CONCLUSION

IMPT with the support of abdominal compression, can be considered a viable solution also for advanced hepatocellular carcinoma patients. Great care shall be put in the minimization of the residual respiration and positioning uncertainties but the dosimetric advantage for organs at risk and the relative robustness on target coverage are promising factors.

Should transarterial chemoembolization be given before or after intensity-modulated radiotherapy to treat patients with hepatocellular carcinoma with portal vein tumor thrombus? a propensity score matching study

Background and Objective

To compare the survival outcomes of patients with hepatocellular carcinoma (HCC) with portal vein tumor thrombus (PVTT) who received transarterial chemoembolization (TACE) before or after intensity-modulated radiotherapy (IMRT).

Methods

During the study period, the survival outcomes of HCC patients with PVTT who underwent TACE before (TACE-RT) or after IMRT (RT-TACE) were compared. Using propensity score matching (PSM), matched pairs of patients were compared.

Results

There were 76 patients in the TACE-RT group and 36 patients in the RT-TACE group. Using a 2:1 matching, 75 patients were included into this study after PSM: 50 patients in the TACE-RT group and 25 patients in the RT-TACE group. Before PSM, patients in the RT-TACE group showed significantly better survival when compared with the TACE-RT group (median survival, 13.2 months vs.7.4 months; P = 0.014) for patients with main trunk PVTT, and after PSM, the corresponding median survival was 13.2 months vs.7.4 months (P = 0.020). When compared with TACE-RT, RT-TACE had a significantly lower rate of worsening in liver function (9.5% vs. 33.3%, P = 0.044) for patients with main trunk PVTT.

Conclusions

For HCC patients with main trunk PVTT, IMRT followed by TACE yielded better survival outcomes and liver function when compared to TACE followed by IMRT.

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.

Stereotactic Body Radiation Therapy for Hepatocellular Carcinoma and Intrahepatic Cholangiocarcinoma

The role of external beam radiation therapy for primary liver malignancies has historically been limited due to the risk of radiation-induced liver disease. However, with the advent of stereotactic body radiotherapy (SBRT), we are able to dose escalate while safely sparing critical nearby structures. This review explores the evidence surrounding the use of SBRT for the treatment of primary liver malignancies. A review of the literature was performed. This article discusses the challenges, efficacy, and safety of SBRT for primary liver malignancies in order to conceptualize its role within a multidisciplinary framework. Prospective phase I and II trials show local control rates at 1 to 2 years ranging from 65% to 100%. Overall survival at 1 to 2 years ranged from 48% to 77%. Grade >3 toxicity ranged from 0% to 36%. Total radiotherapy doses ranged from 24 to 60 Gy delivered in 1 to 6 fractions. The SBRT offers a noninvasive therapy for patients with limited treatment options and should be considered in a multidisciplinary setting for the management of unresectable, locally advanced primary liver malignancies. Prospective randomized trials are warranted to determine the efficacy and safety of SBRT compared to and in combination with other treatment modalities.

Clinical outcomes and prognostic factors of stereotactic body radiation therapy for intrahepatic cholangiocarcinoma

Stereotactic body radiation therapy (SBRT) has been an emerging non-invasive treatment modality for patients with intrahepatic cholangiocarcinoma (ICC) when surgical treatment cannot be applied. The CyberKnife^® is a SBRT system that allows for real-time tracking of the tumor. The purpose of this study was to evaluate the clinical outcomes and prognostic factors for ICC patients receiving this treatment. Twenty-eight patients with ICC were enrolled in the present study. The median prescription dose was 45 Gy (range, 36-54 Gy), fractionated 3 to 5 times with a 70% to 92% isodose line. Local control, overall survival, progression-free survival and toxicity were studied. The median follow-up time was 16 months (3-42 months). Based on modified Response Evaluation and Criteria in Solid Tumors (mRECIST), response rate and disease control rate of SBRT in ICC were 46.4% (13/28) and 89.3% (25/28), respectively. Median overall survival was 15 months (95% CI, 7.22-22.78). 1- and 2-years survival rates were 57.1% and 32.1%, and 1- and 2- years Progression-free Survival rates were 50.0 % and 21.4 %. Multivariate analysis revealed that number of lesions (solitary vs. multiple nodules), CA19-9 levels (≤37 U/mL vs. 37-600/>600) and TNM stage (AJCC stage) were independent prognostic factors for ICC patients treated with SBRT. Toxicity was mostly transient and tolerable. No greater than grade 3 toxicity was observed. These results suggested that CyberKnife SBRT might be a good alternative treatment for unresectable ICC.

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.

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.

Target localization of 3D versus 4D cone beam computed tomography in lipiodol-guided stereotactic radiotherapy of hepatocellular carcinomas

BACKGROUND

Aim of this study was to comparatively evaluate the accuracy of respiration-correlated (4D) and uncorrelated (3D) cone beam computed tomography (CBCT) in localizing lipiodolized hepatocellular carcinomas during stereotactic body radiotherapy (SBRT).

METHODS

4D-CBCT scans of eighteen HCCs were acquired during free-breathing SBRT following trans-arterial chemo-embolization (TACE) with lipiodol. Approximately 1320 x-ray projections per 4D-CBCT were collected and phase-sorted into ten bins. A 4D registration workflow was followed to register the reconstructed time-weighted average CBCT with the planning mid-ventilation (MidV) CT by an initial bone registration of the vertebrae and then tissue registration of the lipiodol. For comparison, projections of each 4D-CBCT were combined to synthesize 3D-CBCT without phase-sorting. Using the lipiodolized tumor, uncertainties of the treatment setup estimated from the absolute and relative lipiodol position to bone were analyzed separately for 4D- and 3D-CBCT.

RESULTS

Qualitatively, 3D-CBCT showed better lipiodol contrast than 4D-CBCT primarily because of a tenfold increase of projections used for reconstruction. Motion artifact was observed to subside in 4D-CBCT compared to 3D-CBCT. Group mean, systematic and random errors estimated from 4D- and 3D-CBCT agreed to within 1 mm in the cranio-caudal (CC) and 0.5 mm in the anterior-posterior (AP) and left-right (LR) directions. Systematic and random errors are largest in the CC direction, amounting to 4.7 mm and 3.7 mm from 3D-CBCT and 5.6 mm and 3.8 mm from 4D-CBCT, respectively. Safety margin calculated from 3D-CBCT and 4D-CBCT differed by 2.1, 0.1 and 0.0 mm in the CC, AP, and LR directions.

CONCLUSIONS

3D-CBCT is an adequate alternative to 4D-CBCT when lipoid is used for localizing HCC during free-breathing SBRT. Similar margins are anticipated with 3D- and 4D-CBCT.

Advances in Stereotactic Body Radiation Therapy for Hepatocellular Carcinoma

Stereotactic Body Radiation Therapy (SBRT) is an emerging effective treatment for hepatocellular carcinoma (HCC) associated with acceptable rates of toxicity in appropriately selected patients. Despite often being reserved for patients unsuitable for other local treatments, prospective and retrospective studies have demonstrated excellent long-term control. SBRT may be used as a stand-alone treatment, or as an adjunct to other HCC therapies. Based on available data, SBRT appears to complement existing local liver therapies. Randomized and nonrandomized comparative studies are required to better determine the optimal role of SBRT in HCC treatment.

Risk-adapted simultaneous integrated boost-proton beam therapy (SIB-PBT) for advanced hepatocellular carcinoma with tumour vascular thrombosis

PURPOSE

To evaluate clinical effectiveness and safety of simultaneous integrated boost-proton beam therapy (SIB-PBT) in hepatocellular carcinoma (HCC) patients with tumour vascular thrombosis (TVT).

MATERIAL AND METHODS

Forty-one HCC patients with TVT underwent SIB-PBT using three dose-fractionation schemes: if gross tumour volume <1cm (n=27), 1-1.9cm (n=7), and ⩾2cm (n=7) from gastrointestinal structures, 50GyE (EQD2, 62.5GyE₁₀), 60Gy (EQD2, 80GyE₁₀), 66Gy (EQD2, 91.3GyE₁₀), respectively, in 10 fractions was prescribed to planning target volume 1 (PTV1), and 30GyE (EQD2, 32.5GyE₁₀) in 10 fractions was prescribed to PTV2.

RESULTS

Overall, treatment was well tolerated, with no grade toxicity ⩾3. Median overall survival (OS) was 34.4months and 2-year local progression-free survival (LPFS), relapse free survival (RFS), and OS rates were 88.1%, 25%, and 51.1%, respectively. Patients treated with EQD2 of ⩾80GyE₁₀ tended to show better TVT response (92.8% vs. 55.5%, p=0.002) 2-year LPFS (92.9% vs. 82.5%, p=0.463), RFS (28.8% vs. 19%, p=0.545), and OS (58.4% vs. 46.8%, p=0.428) rates than those with EQD2 of <80GyE₁₀. Multivariate analysis showed that TVT response and Child Pugh classification were independent prognostic factors for OS.

CONCLUSIONS

SIB-PBT is feasible and promising for HCC patients with TVT.

Comparison of intra-arterial chemoembolization with and without radiotherapy for advanced hepatocellular carcinoma with portal vein tumor thrombosis: a meta-analysis

Purpose

Numerous studies have tried to combine transarterial chemoembolization (TACE) or hepatic arterial infusion chemotherapy (HAIC) with radiotherapy (RT) for the treatment of hepatocellular carcinoma (HCC) patients with portal vein tumor thrombus (PVTT). However, the efficacy of TACE or HAIC combined with RT versus TACE or HAIC alone remains controversial. Thus, we performed a meta-analysis to compare the efficacy and safety of intra-arterial chemoembolization combined with RT versus intra-arterial chemoembolization alone for the treatment of HCC patients with PVTT.

Methods

PubMed, Embase, and Cochrane Library databases were systematically searched for eligible studies. Two authors independently reviewed the abstracts, extracted relevant data and rated the quality of studies. The major end points were objective response rate (ORR), overall survival (OS), and adverse events.

Results

Eight studies with a total of 1,760 patients were included in this meta-analysis. The pooled results showed that intra-arterial chemoembolization combined with RT significantly improved ORR of PVTT (OR, 4.22; 95% CI, 3.07–5.80; P<0.001) and OS (HR, 0.69; 95% CI, 0.57–0.83; P=0.001), but did not affect ORR of primary liver tumor (OR, 1.37; 95% CI, 0.67–2.79; P=0.390). The incidence of grade 3 or 4 leukopenia (OR, 5.80; 95% CI, 2.478–13.56; P<0.001) and thrombocytopenia (OR, 3.77; 95% CI, 1.06–13.43; P=0.041) was higher in the intra-arterial chemoembolization plus RT group than in the intra-arterial chemoembolization group.

Conclusion

Combination therapy of intra-arterial chemoembolization and RT for HCC patients with PVTT could bring higher ORR of PVTT and better survival benefits. This combination therapy was also associated with a significantly increased risk of adverse events. However, they were mostly mild to moderate and successfully treated with conservative treatment.

Efficacy of the treatment of transarterial chemoembolization combined with radiotherapy for hepatocellular carcinoma with portal vein tumor thrombus: A propensity score analysis

AIM

The survival outcome of patients with unresectable hepatocellular carcinoma (HCC) with portal vein tumor thrombus (PVTT) who received transarterial chemoembolization (TACE) combined with radiotherapy (RT) remains unclear.

METHODS

A total of 112 and 735 HCC patients with PVTT undergoing TACE combined with RT and TACE alone, respectively, were evaluated. One hundred and eight pairs of matched patients were selected from each treatment arm by using a propensity score matching (PSM) analysis.

RESULTS

Of the whole study population, TACE combined with RT showed significant survival benefits compared with TACE in all patients (median survival, 11.0 vs 4.8 months; P < 0.001), especially in patients with PVTT involving the right/left portal vein (median survival, 12.5 vs 5.2 months; P < 0.001) and main portal vein trunk (median survival, 8.9 vs 4.3 months; P < 0.001). After one-to-one PSM, 108 pairs of matched patients were selected for further analysis. In the propensity model, the median survival time was 10.9 versus 4.1 months (P < 0.001) in all patients, 12.5 versus 4.4 months (P = 0.002) in patients with PVTT involving the right/left portal vein and 8.9 versus 4.0 months (P < 0.001) in patients with PVTT involving the main portal vein trunk. The treatment, maximum lesion diameter and main trunk PVTT were the independent prognostic factors for survival at uni- and multivariate analysis.

CONCLUSION

TACE combined with RT provides a significantly better survival outcome than TACE for unresectable HCC patients with PVTT, especially for patients with PVTT involving the right/left portal vein or main trunk.

Efficacy of stereotactic body radiotherapy for hepatocellular carcinoma with portal vein tumor thrombosis/inferior vena cava tumor thrombosis: evaluation by comparison with conventional three-dimensional conformal radiotherapy

This study aimed to evaluate the efficacy of stereotactic body radiotherapy (SBRT) compared with three-dimensional conformal radiotherapy (3DCRT). Forty-three patients with portal vein tumor thrombosis (PVTT)/inferior vena cava tumor thrombosis (IVCTT) treated with SBRT (27 with CyberKnife (CK) and 16 with TrueBeam (TB)) from April 2013 to December 2014, and 54 treated with 3DCRT from June 2008 to March 2013 were evaluated. Dosimetric parameters, response to radiotherapy (RT) and survival outcomes were compared in total SBRT vs. 3DCRT, CK vs. 3DCRT and TB vs. 3DCRT, respectively. The median biologically effective dose 10 (BED₁₀) values in total SBRT, CK, TB and 3DCRT were 73.4 Gy₁₀, 75.0 Gy₁₀, 60.5 Gy₁₀ and 58.5 Gy₁₀, respectively (P < 0.001 in total SBRT vs. 3DCRT, P < 0.001 in CK vs. 3DCRT, P = 0.004 in TB vs. 3DCRT). The tumor response rates were 67%, 70%, 62% and 46%, respectively (P = 0.04, P = 0.04, P = 0.25). The 1-year overall survival rates were 49.3%, 56.7%, 38.1% and 29.3%, respectively (P = 0.02, P = 0.02, P = 0.30), and the 1-year local progression rates were 20.4%, 21.9%, 18.8% and 43.6%, respectively (P = 0.01, P = 0.04, P = 0.10). The use of SBRT made it possible to achieve a higher BED₁₀ compared with the use of 3DCRT. Improvements in local control and survival were achieved in the CK group and the total SBRT group. Our results suggest that SBRT may have the potential to be the standard RT technique for the treatment of PVTT/IVCTT.

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.

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.

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.

Management of Hepatocellular Carcinoma: Current Status and Future Directions

Hepatocellular carcinoma (HCC) is the second most common cause of cancer death worldwide. This cancer commonly arises against a background of chronic liver disease. As a result, a patient with HCC requires multidisciplinary care. Treatment options vary widely based on tumor burden and metastases. The most widely utilized staging system is the Barcelona Clinic Liver Cancer staging system, which recommends treatments based on tumor size and the underlying liver disease and functional status of the patient. Treatment options range from surgical resection or transplantation to locoregional therapies with modalities such as radiofrequency ablation and transarterial chemoembolization to systemic chemotherapies. Future care involves the development of combination therapies that afford the best tumor response, further clarification of the patients best suited for therapies and the development of new oral chemotherapeutic agents.

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.

Comparison of percutaneous radiofrequency ablation and CyberKnife® for initial solitary hepatocellular carcinoma: A pilot study

AIM: To compare therapeutic outcomes and adverse events in initial solitary hepatocellular carcinoma (HCC) treated with radiofrequency ablation (RFA) and CyberKnife^®.

METHODS: Seventy three consecutive patients with initial solitary HCC treated with RFA (38 patients; RFA group) and CyberKnife^® (35 patients; CK group) were enrolled in this study. Background factors were compared between the two groups. Local and intrahepatic distant recurrence control, and cumulative survival rates were compared between the two groups. These were determined using the Kaplan-Meier method, and the significance of differences was analyzed by log-rank test. The presence of more grade 3 on CTCAE ver. 4.0 early and late adverse events was investigated.

RESULTS: In background factors, age was significantly higher (P = 0.005) and the tumor diameter was significantly larger (P = 0.001) in the CK group. The 1-year local recurrence control rates were 97.4% and 97.1% in the RFA and CK groups, respectively (P = 0.71); the 1-year intrahepatic distant recurrence control rates were 85.6% and 86.1%, respectively (P = 0.91); and the 1-year cumulative survival rates were 100% and 95.2%, respectively (P = 0.075), showing no significant difference in any rate between the two groups. There were no late adverse event in the RFA group, but 11.4% in the CK group had late adverse events. In the CK group, the Child-Pugh score at 12 mo after treatment was significantly higher than that in the RFA group (P = 0.003) and significantly higher than the score before treatment (P = 0.034).

CONCLUSION: The occurrence of adverse events is a concern, but CyberKnife^® treatment is likely to become an important option for local treatment of early HCC.

Phase 1 Trial of Sorafenib and Stereotactic Body Radiation Therapy for Hepatocellular Carcinoma

PURPOSE

To determine the maximally tolerated dose of sorafenib delivered before, during, and after stereotactic body radiation therapy (SBRT) in hepatocellular carinoma (HCC).

METHODS AND MATERIALS

Eligible patients had locally advanced Child-Pugh class A HCC, showed Eastern Cooperative Oncology Group performance status 0-1, and were ineligible for standard local-regional therapies. Sorafenib was dose escalated in 2 strata: (1) low effective irradiated liver volume (veff) < 30% and (2) high veff 30%to 60%. Sorafenib (400 mg daily = dose level 1) was administered for 12 weeks, with 6 fractions SBRT delivered weeks 2 and 3, and escalation to full dose (400 mg twice daily) after 12 weeks as tolerated. Standard 3 + 3 cohorts with dose escalation of sorafenib were planned.

RESULTS

Sixteen patients (4 low veff, median dose 51 Gy; 12 high veff, median dose 33 Gy) were treated at 2 sorafenib dose levels. Of those patients 75% were had Barcelona Clinic Liver Cancer stage C, and 63% had main branch portal vein invasion. In the low veff stratum, no dose-limiting toxicities (DLTs) were observed in 4 patients treated with SBRT and sorafenib 400 mg. Inb the high veff stratum: 2 of 3 evaluable patients treated with sorafenib 400 mg experienced DLT (grade 3 large bowel bleed and grade 4 bowel obstruction 51 and 27 days, respectively, after SBRT). One of 6 evaluable patients at dose level -1 (200 mg once daily) experienced a grade 3 tumor rupture at week 5. Median overall survival and in-field local progression have not been reached. Worsening of Child-Pugh liver function class was seen in 6 of 12 patients in the high veff stratum.

CONCLUSIONS

Significant toxicity was observed in the high veff stratum, and concurrent SBRT with sorafenib is not recommended outside a clinical trial.

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.

Stereotactic body radiation therapy for small primary or recurrent hepatocellular carcinoma in 132 Chinese patients

AIM

To evaluate the efficacy of stereotactic body radiation therapy (SBRT) in small hepatocellular carcinoma (HCC) patients.

METHODS

From March 2009 to April 2015, we treated 132 small HCC patients with SBRT. Eligibility criteria included longest tumor diameter ≤5.0 cm; Child-Turcotte-Pugh (CTP) Class A or B; unfeasible, difficult or refusal to undergo other surgery or percutaneous ablative therapies; and tumor recurrence after other local treatment. The dose of 42-46 Gy in 3-5 fractions and 28-30 Gy in 1 fraction was prescribed.

RESULTS

Of the treated patients, 114 were classified as CTP A and 18 as CTP B. Median tumor size was range 1.1-5.0 cm. The local control rate at 1 years was 90.9%. OS at 1, 3, and 5 years was 94.1%, 73.5%, and 64.3%, respectively. PFS at 1, 3, and 5 years was 82.7%, 58.3%, and 36.4%, respectively. Hepatic toxicity grade ≥3 was observed in 11 patients. Multivariate analysis revealed that CTP B was associated with worse OS (P < 0.001) and multiple nodules were associated with worse PFS (P = 0.001).

CONCLUSIONS

SBRT is a promising alternative treatment for patients with primary or recurrent small HCC who are unsuitable for surgical resection or local ablative therapy.

Radiation oncology approaches in liver malignancies

Radiation therapy plays an increasingly important role in the treatment of hepatic malignancies. There is convincing evidence of safety and efficacy employing brachytherapy (yttrium-90), three-dimensional conformal radiotherapy, intensity-modulated radiotherapy, stereotactic body radiotherapy (SBRT), and proton beam therapy (PBT) in all stages of primary and metastatic involvement in the liver. Technologic advances in tumor imaging, real-time tracking of moving targets during radiotherapy delivery, and superb radiation dose deposition control have enabled treatment of previously unapproachable lesions. Recently completed and ongoing clinical trials are refining optimal dose fractionation schedules for SBRT as monotherapy. Radioembolization as part of first-line therapy in metastatic colorectal tumors is being tested in large international trials combined with FOLFOX6 and bevacizumab, as well as in hepatocellular carcinoma with sorafenib. PBT is becoming more available as new facilities open in many countries providing particle beam therapy, which delivers unparalleled control of radiation dose close to critical structures. A major point of research is understanding how best to safely destroy tumors in the background of often fragile hepatic function from cirrhosis or heavily pretreated chemotherapy liver parenchyma. Fortunately, serious complications from radiotherapy are rare, acute toxicities are typically Common Terminology Criteria for Adverse Events v4.0 grade 1-2, with consistent response rates of 50% to 97% in the modern era.

Identification of Biologically Effective Dose-Volumetric Parameters That Predict Radiation-Induced Hepatic Toxicity in Patients Treated With Helical Tomotherapy for Unresectable Locally Advanced Hepatocellular Carcinoma

The purpose of this study is to identify dose-volumetric parameters that predict radiation-induced hepatic toxicity (RIHT) by analyzing the relationship between the biologically effective dose (BED) delivered to the normal liver and RIHT.The clinical and dosimetric data from 123 patients with unresectable hepatocellular carcinoma (HCC) treated with helical tomotherapy were analyzed. The median radiation dose was a 50 Gy in 4.5 Gy fractions (range, 30-60 Gy in 1.8-5.0 Gy fractions) to 95% of the planning target volume. RIHT was defined as a Child-Pugh score increase of at least 2 points within 3 months of helical tomotherapy completion.RIHT developed in 60 patients (48.7%). Multivariate logistic regression analysis showed that VBED20 (percentage of nontarget normal liver volume that received more than a BED of 20 Gy) was a significant parameter (P < 0.001), and the cut-off value was 40.8% with a sensitivity and specificity of 0.833 and 0.698, respectively, according to the receiver operating characteristic curve (P < 0.001).Maintaining a VBED20 below 40.8% will reduce the risk of RIHT, and the proposed normal liver tolerance curve could be a useful guideline when treating unresectable HCC patients with various radiotherapy dose schedules.

Stereotactic body radiotherapy: an effective local treatment modality for hepatocellular carcinoma

Although liver-directed therapies such as surgery or ablation can cure hepatocellular carcinoma, few patients are eligible due to advanced disease or medical comorbidities. In advanced disease, systemic therapies have yielded only incremental survival benefits. Historically, radiotherapy for liver cancer was dismissed due to concerns over unacceptable toxicities from even moderate doses. Although implementation requires more resources than standard radiotherapy, stereotactic body radiotherapy can deliver reproducible, highly conformal ablative radiotherapy to tumors while minimizing doses to nearby critical structures. Trials of stereotactic body radiotherapy for hepatocellular carcinoma have demonstrated promising local control and survival results with low levels of toxicity in Child-Pugh class A patients. We review the published literature and make recommendations for the future of this emerging modality.

Feasibility and efficacy of helical tomotherapy in cirrhotic patients with unresectable hepatocellular carcinoma

Background

This study is to evaluate the toxicity and outcomes of helical tomotherapy (HT) in patients treated for unresectable hepatocellular carcinoma (HCC).

Methods

From March 2008 to September 2010, 38 patients with unresectable HCC were treated with HT. The median patient age was 67 years (range, 45–85). The median follow-up period was 17.2 months (range, 7–46). All patients had liver cirrhosis. Median radiation dose was 54 Gy (range, 46–71.8) delivered in 1.8 to 2.4-Gy fractions. The planning target volumes were 241.2 ± 153.1 cm³ (range, 45.8–722.4). Treatment responses were assessed in 3–6 months after HT.

Results

There was a complete response in 2 patients (5.2 %), partial response in 18 patients (47.4 %), stable disease in 13 patients (34.2 %), and progressive disease in 5 patients (13.2 %). The median overall survival was 12.6 months, and 1- and 2-year overall survival rates were 56.2 and 31.7 %, respectively. Eastern Cooperative Oncology Group (ECOG score, p = 0.008), Child-Pugh classification (p = 0.012), albumin (p = 0.046), and hemoglobin (p = 0.028) were significant parameters that predicted primary tumor response to radiotherapy in multivariate analysis. ECOG score (p = 0.012), Child-Pugh class (p = 0.026), and response to radiotherapy (p = 0.016) were independent prognostic factors for overall survival in multivariate analysis. Responders had better overall survival than non-responders (23.6 vs. 5.8 months, p < 0.001). The 1- and 2-year overall survival rates for responders were 68.3 and 57 %, respectively, while for non-responders, they were 0 %. The 1- and 2-year local control rates were 88.2 and 82.3 %, respectively. Five patients (13.2 %) had grade 3 or greater liver toxicity, and one patient (2.6 %) had a grade 3 gastric ulcer. No treatment-related liver failure or death was documented in this study.

Conclusions

Radiotherapy using HT seems to be a safe and effective treatment option for unresectable HCC patients. This study indicates that HT is a feasible treatment even in patients without good performance status and hepatic function reservation.

Stereotactic body radiation therapy as an ablative treatment for inoperable hepatocellular carcinoma

PURPOSE

To describe efficacy and safety of stereotactic body radiation therapy (SBRT) for the treatment of inoperable hepatocellular carcinoma.

METHODS

The records of 77 consecutive patients treated with SBRT for 97 liver-confined HCC were reviewed. A total dose of 45Gy in 3 fractions was prescribed to the 80% isodose line. Local control (LC), overall survival (OS), progression-free survival (PFS) and toxicity were studied.

RESULTS

The median follow-up was 12months. The median tumor diameter was 2.4cm. The LC rate was 99% at 1 and 2years. The 1 and 2-year OS were 81.8% and 56.6% respectively. The median time to progression was 9months (0-38). The rate of hepatic toxicity was 7.7% [1.6-13.7], 14.9% [5.7-23.2] and 23.1% [9.9-34.3] at 6months, 1year and 2years respectively. In multivariate analysis, female gender (HR 7.87 [3.14-19.69]), a BCLC B-C stage (HR 3.71 [1.41-9.76]), a sum of all lesion diameters ⩾2cm (HR 7.48 [2.09-26.83]) and a previous treatment (HR 0.10 [0.01-0.79]) were independent prognostic factors of overall survival.

CONCLUSION

SBRT allows high local control for inoperable hepatocellular carcinomas. It should be considered when an ablative treatment is indicated in Child A patients.

Stereotactic body radiation therapy in hepatocellular carcinoma: Optimal treatment strategies based on liver segmentation and functional hepatic reserve

AIM

To discuss current dosage for stereotactic body radiation therapy (SBRT) in hepatocellular carcinoma (HCC) patients and suggest alternative treatment strategies according to liver segmentation as defined by the Couinaud classification.

BACKGROUND

SBRT is a safe and effective alternative treatment for HCC patients who are unable to undergo liver ablation/resection. However, the SBRT fractionation schemes and treatment planning strategies are not well established.

MATERIALS AND METHODS

In this article, the latest developments and key findings from research studies exploring the efficacy of SBRT fractionation schemes for treatment of HCC are reviewed. Patients' characteristics, fractionation schemes, treatment outcomes and toxicities were compiled. Special attention was focused on SBRT fractionation approaches that take into consideration liver segmentation according to the Couinaud classification and functional hepatic reserve based on Child-Pugh (CP) liver cirrhosis classification.

RESULTS

The most common SBRT fractionation schemes for HCC were 3 × 10-20 Gy, 4-6 × 8-10 Gy, and 10 × 5-5.5 Gy. Based on previous SBRT studies, and in consideration of tumor size and CP classification, we proposed 3 × 15-25 Gy for patients with tumor size <3 cm and adequate liver reserve (CP-A score 5), 5 × 10-12 Gy for patients with tumor sizes between 3 and 5 cm or inadequate liver reserve (CP-A score 6), and 10 × 5-5.5 Gy for patients with tumor size >5 cm or CP-B score.

CONCLUSIONS

Treatment schemes in SBRT for HCC vary according to liver segmentation and functional hepatic reserve. Further prospective studies may be necessary to identify the optimal dose of SBRT for HCC.

Radiotherapy for liver tumors

Many patients with primary hepatic malignancies present with advanced disease that is not suitable for surgical resection, orthotopic liver transplantation, or radiofrequency ablation. Outcomes are particularly dismal in patients with large, unresectable tumors and/or tumor venous thrombosis. Liver-directed radiotherapy, including stereotactic body radiotherapy (SBRT), is able to treat a variety of tumor sizes and tumors with venous involvement and has demonstrated excellent safety and control outcomes. SBRT should be considered a standard option in patients with early-stage hepatocellular carcinoma who are not candidates for surgical resection, orthotopic liver transplantation or radiofrequency ablation. SBRT should be strongly considered in patients with larger tumors and/or tumors with tumor venous thrombosis who have adequate liver function. Radiotherapy should remain a focus of hepatocellular carcinoma research.

The challenge of inoperable hepatocellular carcinoma (HCC): results of a single-institutional experience on stereotactic body radiation therapy (SBRT)

OBJECTIVES

To evaluate the feasibility and efficacy of stereotactic body radiation therapy (SBRT) in the treatment of hepatocellular carcinoma (HCC) unsuitable for standard loco-regional therapies.

MATERIALS AND METHODS

Patients with 1-3 inoperable HCC lesions with diameter ≤6 cm were treated by SBRT. According to lesions size and liver function, two prescription regimens were adopted: 48-75 Gy in three fractions or 36-60 Gy in six fractions. SBRT was delivered using the volumetric modulated arc therapy technique with flattening filter-free photon beams. The primary end points of this study were in-field local control (LC) and toxicity. Secondary end points were overall survival (OS) and progression-free survival (PFS).

RESULTS

Forty-three patients with 63 HCC lesions were irradiated. All patients had Child-Turcotte-Pugh class A or B disease. Thirty lesions (48%) were treated with 48-75 Gy in three consecutive fractions, and 33 (52%) received 36-60 Gy in six fractions. Median follow-up was 8 months (range 3-43 months). Actuarial LC at 6, 12 and 24 months was 94.2 ± 3.3, 85.8 ± 5.5 and 64.4 ± 11.5%, respectively. A biological equivalent dose (BED) >100 Gy and GTV size were significant prognostic factors for LC in univariate analysis (p < 0.001 and p < 0.02). Median OS was 18.0 ± 5.8 months. Actuarial OS at 6, 12 and 24 months was 91.1 ± 4.9, 77.9 ± 8.2 and 45.3 ± 14.0%, respectively. Univariate analysis showed that OS is correlated with LC (p < 0.04), BED >100 (p < 0.05) and cumulative gross tumor volume GTV <5 cm (p < 0.04). Median PFS was 8 months, with a 1-year PFS rate of 41%. A significant (≥ grade 3) toxicity was observed in seven patients (16%) 2-6 months after the completion of the treatment. No classic radiation-induced liver disease was observed.

CONCLUSION

Stereotactic body radiation therapy is a safe and effective therapeutic option for HCC lesions unsuitable to standard loco-regional therapies, with acceptable local control rates and low treatment-related toxicity. The significant correlation between LC and higher doses and between LC and OS supports the clinical value of SBRT in these patients.

Role of radiotherapy in the management of hepatocellular carcinoma: A systematic review

Many patients with hepatocellular carcinoma (HCC) present with advanced disease, not amenable to curative therapies such as surgery, transplantation or radiofrequency ablation. Treatment options for this group of patients include transarterial chemoembolization (TACE) and radiation therapy. Especially TACE, delivering a highly concentrated dose of chemotherapy to tumor cells while minimizing systemic toxicity of chemotherapy, has given favorable results on local control and survival. Radiotherapy, as a therapeutic modality of internal radiation therapy with radioisotopes, has also achieved efficacious tumor control in advanced disease. On the contrary, the role of external beam radiotherapy for HCC has been limited in the past, due to the low tolerance of surrounding normal liver parenchyma. However, technological innovations in the field of radiotherapy treatment planning and delivery, have provided the means of delivering radical doses to the tumor, while sparing normal tissues. Advanced and highly conformal radiotherapy approaches such as stereotactic body radiotherapy and proton therapy, evaluated for efficacy and safety for HCC, report encouraging results. In this review, we present the role of radiotherapy in hepatocellular carcinoma patients not suitable for radical treatment.

Radiation therapy has been shown to be adaptable for various stages of hepatocellular carcinoma

In addition to surgical procedures, radiofrequency ablation is commonly used for the treatment of hepatocellular carcinomas (HCCs) of limited size and number. Transcatheter arterial chemoembolization (TACE), using iodized poppy seed oil, Lipiodol and anticancer drugs, has been actively performed for the treatment of unresectable HCC, particularly in Asian countries. Recently, Sorafenib become available for advanced HCCs when the liver is still sufficiently functional. Sorafenib is an oral multikinase inhibitor with antiproliferative and antiangiogenic effects. However, the effect of sorafenib seems to be inadequate to control the progression of HCC. Radiation therapy (RT) for HCC has a potential role across all stages of HCC. However, RT is generally not considered an option in HCC consensus documents or national guidelines, primarily because of insufficient supporting evidence. However, the method of RT has much improved because of advances in technology. Moreover, combined treatment of RT plus other treatments (TACE, sorafenib and chemotherapy etc.) has become one of the alternative therapies for HCC. Therefore, we should understand the various kinds of RT available for HCC. In this review, we focus on various kinds of external beam radiation therapy.