Escalated focal liver radiation and concurrent hepatic artery fluorodeoxyuridine for unresectable intrahepatic malignancies

[Stereotactic body radiotherapy for liver tumors: State of the art]

Thanks to the improvement in radiotherapy physics, biology, computing and imaging, patients presenting with liver tumors can be efficiently treated by radiation. Radiotherapy has been included in liver tumors treatment guidelines at all disease stages. Liver stereotactic radiotherapy has to be preferred to standard fractionated radiotherapy whenever possible, as potentially more efficient because of higher biological equivalent dose. Liver stereotactic radiotherapy planning and delivery require extensive experience and optimal treatment quality at every step, thus limiting its availability to specialized centres. Multicentre studies are difficult to develop due to a large technical heterogeneity. Respiratory management, image guidance and immobilization are considerations as important as machine type. The use of multimodal planning imaging is compulsory to achieve expected contouring quality. Treatment efficacy is difficult to assess following liver stereotactic radiotherapy, but local control is high and toxicity unusual. As a consequence, liver stereotactic radiotherapy is part of multimodal and multidisciplinary management of liver tumors.

Efficacy and safety of ultrasound-guided implantation of fiducial markers in the liver for stereotactic body radiation therapy

Objective

Stereotactic body radiation therapy (SBRT) for the treatment of a malignancy in the liver requires the perilesional implantation of fiducial markers for lesion detection. The purpose of this study is to evaluate the efficacy and safety of ultrasound (US) -guided marker implantation for SBRT.

Methods

We retrospectively reviewed 299, US–guided, intrahepatic fiducial markers implanted in 101 patients between November 2013 and September 2014. SBRT-planning CT images were analyzed to determine the technical success of the implantation, the mean distance between the tumor margin and the marker, with the ideal location of fiducials defined as the distance between a marker and a tumor less than 3 cm and the distance between markers greater than 2 cm according to the tumor conspicuity seen on gray-scale US and the artifact obscuring tumor margins. We also evaluated procedure-related major and minor complications.

Results

Technical success was achieved in 291 (97.3%) fiducial marker implantations. The mean distance between the tumor and the marker was 3.1 cm (S.D., 2.1 cm; range, 0–9.5 cm). Of 101 patients, 72 lesions (71.3%, 2.2 ± 1.0 cm; range, 0–3.0 cm) had fiducial markers located in an ideal location. The ideal location of fiducials was more common in visible lesions than in poorly conspicuous lesions (90.2% vs. 52.0%, P < 0.001). Seventeen markers (5.8%) developed beam-hardening artifacts obscuring the tumor margins. There were no major complications, although 12 patients (11.9%) developed minor complications.

Conclusions

US-guided implantation of fiducial markers in the liver is an effective and safe procedure with only rare complications.

Decision Making: Intra-arterial Therapies for Cholangiocarcinoma-TACE and TARE

The incidence of intrahepatic cholangiocarcinoma (ICC) has been increasing in recent years and now represents the second most common primary hepatic cancer in the United States. The prognosis is dismal without surgical resection. In patients ineligible to receive curative treatments, locoregional therapies represent a diverse array of techniques that can stabilize or reverse tumor progression to improve overall survival and reduce tumor-related symptoms. Transarterial chemoembolization (TACE) and transarterial radioembolization (TARE) have been demonstrated to be efficacious methods for this patient population. Deciding between these two options is challenging. This article reviews the differences in patient selection, preprocedural evaluation, financial considerations and availability, quality of life, and rates of complications and overall survival.

Radiation therapy for hepatobiliary malignancies

Hepatobiliary malignancies represent a heterogeneous group of diseases, which often arise in a background of underlying hepatic dysfunction complicating their local management. Surgical resection continues to be the standard of care for hepatocellular carcinoma (HCC) and cholangiocarcinoma (CC); unfortunately the majority of patients are inoperable at presentation. The aggressiveness of these lesions makes locoregional control of particular importance. Historical experience with less sophisticated radiotherapy resulted in underwhelming efficacy and oftentimes prohibitive liver toxicity. However, with the advent of extremely conformal and precise radiotherapy delivery, dose escalation to the tumor with sparing of surrounding normal tissue has yielded notable improvements in efficacy for this modality of treatment. Dose escalation has come in a variety of forms most notably as stereotactic body radiation therapy (SBRT) and hypofractionated proton therapy. As radiation techniques continue to improve, their proper incorporation into the local management of hepatobiliary malignancies will be paramount in improving the prognosis of what is a grave diagnosis.

Impact of the activity calculation method used in transarterial radioembolization: a dosimetric comparison between 90Y-SIRSphere and 90Y-TheraSphere therapy

PURPOSE

Transarterial radioembolization is used to treat primary and secondary liver malignancies. Two commercially available drugs are utilized for the purpose. The aim of our study is to compare the radiation dose delivered to the tumor by these drugs.

MATERIALS AND METHODS

This study included 86 patients (M : F - 7.6 : 1, median age=50.5 years), 46 patients were treated by Y-TheraSphere and 42 patients were treated by Y-SIRSphere. Activity administered in Y-TheraSphere and Y-SIRSphere was calculated using a modified partition model and a modified body surface area model, respectively. The radiation dose delivered by two drugs was calculated and compared in our study.

RESULT

Activity administered in Y-TheraSphere was significantly higher than that of Y-SIRSphere. Hence, the radiation dose delivered to the tumor by Y-SIRSphere was significantly lower (58.4%) than that of Y-TheraSphere (P=0.000).

CONCLUSION

As the radiation dose delivered by Y-SIRSphere was lower than Y-TheraSphere, we believe that the formula for Y-SIRSphere activity calculation needs to be modified so that the optimal dose can be delivered to the tumor.

Minimum absolute lymphocyte counts during radiation are associated with a worse prognosis in patients with unresectable hepatocellular carcinoma

BACKGROUND

Peripheral blood lymphocytes play an important role in antitumour immunity. We examined the relationship between the minimum absolute lymphocyte counts (Min ALCs) during radiotherapy (RT) and clinical outcomes in patients with hepatocellular carcinoma (HCC).

METHODS

Data from a total of 69 HCC patients who had received RT were retrospectively analysed. Peripheral blood lymphocytes were measured before RT, weekly during RT and after RT. Regression and mixed-effect models were used to assess the relationships with and potential predictors of overall survival (OS). Receiver-operating characteristic (ROC) curve analysis was used to define optimal cut-off points of continuous variables for outcomes.

RESULTS

The median follow up was 30 months (range, 4-68 months). The median survival time (MST), 1-year OS rate and 2-year OS rate of the whole group were 25 months, 51% and 39%, respectively. The average circulating lymphocyte counts declined during RT (1493.19 versus 503.48 cells/µl, p < 0.001). A lower Min ALC was associated with worse OS (p = 0.001), with a cut-off value of 450 cells/µl (sensitivity and specificity, 50% and 70.6%, respectively). The MSTs, 1-year OS rates and 2-year OS rates were 15 months versus 47 months, 27% versus 78% and 4% versus 71% for patients with relatively lower (⩽450 cells/µl) and higher Min ALCs (>450 cells/µl), respectively (p < 0.001). After adjusting for potential confounders, multivariate Cox regression analysis demonstrated that Min ALC independently predicted patients' OS (HR, 0.32; 95% CI, 0.15-0.69).

CONCLUSIONS

Lower Min ALCs during RT may act as a worse prognostic factor for HCC after RT.

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.

Application of radiotherapy for hepatocellular carcinoma in current clinical practice guidelines

In oncologic practice, treatment guidelines provide appropriate treatment strategies based on evidence. Currently, many guidelines are used, including those of the European Association for the Study of the Liver and European Organization for Research and Treatment of Cancer (EASL-EORTC), National Comprehensive Cancer Network (NCCN), Asia-Pacific Primary Liver Cancer Expert (APPLE), and Korean Liver Cancer Study Group and National Cancer Centre (KLCSG-NCC). Although radiotherapy is commonly used in clinical practice, some guidelines do not accept it as a standard treatment modality. In this review, we will investigate the clinical practice guidelines currently used, and discuss the application of radiotherapy.

Superiority of helical tomotherapy on liver sparing and dose escalation in hepatocellular carcinoma: a comparison study of three-dimensional conformal radiotherapy and intensity-modulated radiotherapy

Background and purpose

To compare the difference of liver sparing and dose escalation between three-dimensional conformal radiotherapy (3DCRT), intensity-modulated radiotherapy (IMRT), and helical tomotherapy (HT) for hepatocellular carcinoma.

Patients and methods

Sixteen unresectable HCC patients were enrolled in this study. First, some evaluation factors of 3DCRT, IMRT, and HT plans were calculated with prescription dose at 50 Gy/25 fractions. Then, the doses were increased using HT or IMRT independently until either the plans reached 70 Gy or any normal tissue reached the dose limit according to quantitative analysis of normal tissue effects in the clinic criteria.

Results

The conformal index of 3DCRT was lower than that of IMRT (P<0.001) or HT (P<0.001), and the homogeneity index of 3DCRT was higher than that of IMRT (P<0.001) or HT (P<0.001). HT took the longest treatment time (P<0.001). For V_50% (fraction of normal liver treated to at least 50% of the isocenter dose) of the normal liver, there was a significant difference: 3DCRT > IMRT > HT (P<0.001). HT had a lower D_mean (mean dose) and V₂₀ (V_n, the percentage of organ volume receiving ≥n Gy) of liver compared with 3DCRT (P=0.005 and P=0.005, respectively) or IMRT (P=0.508 and P=0.007, respectively). D_mean of nontarget normal liver and V₃₀ of liver were higher for 3DCRT than IMRT (P=0.005 and P=0.005, respectively) or HT (P=0.005 and P=0.005, respectively). Seven patients in IMRT (43.75%) and nine patients in HT (56.25%) reached the isodose 70 Gy, meeting the dose limit of the organs at risk.

Conclusion

HT may provide significantly better liver sparing and allow more patients to achieve higher prescription dose in HCC radiotherapy.

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.

Solutions that enable ablative radiotherapy for large liver tumors: Fractionated dose painting, simultaneous integrated protection, motion management, and computed tomography image guidance

The emergence and success of stereotactic body radiation therapy (SBRT) for the treatment of lung cancer have led to its rapid adoption for liver cancers. SBRT can achieve excellent results for small liver tumors. However, the vast majority of physicians interpret SBRT as meaning doses of radiation (range, 4-20 Gray [Gy]) that may not be ablative but are delivered within about 1 week (ie, in 3-6 fractions). Adherence to this approach has limited the effectiveness of SBRT for large liver tumors (>7 cm) because of the need to reduce doses to meet organ constraints. The prognosis for patients who present with large liver tumors is poor, with a median survival ≤12 months, and most of these patients die from tumor-related liver failure. Herein, the authors present a comprehensive solution to achieve ablative SBRT doses for patients with large liver tumors by using a combination of classic, modern, and novel concepts of radiotherapy: fractionation, dose painting, motion management, image guidance, and simultaneous integrated protection. The authors discuss these concepts in the context of large, inoperable liver tumors and review how this approach can substantially prolong survival for patients, most of whom otherwise have a very poor prognosis and few effective treatment options. Cancer 2016;122:1974-86. © 2016 American Cancer Society.

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.

Randomized Clinical Trial Comparing Proton Beam Radiation Therapy with Transarterial Chemoembolization for Hepatocellular Carcinoma: Results of an Interim Analysis

PURPOSE

To describe results of a planned interim analysis of a prospective, randomized clinical trial developed to compare treatment outcomes among patients with newly diagnosed hepatocellular carcinoma (HCC).

METHODS AND MATERIALS

Eligible subjects had either clinical or pathologic diagnosis of HCC and met either Milan or San Francisco transplant criteria. Patients were randomly assigned to transarterial chemoembolization (TACE) or to proton beam radiation therapy. Patients randomized to TACE received at least 1 TACE with additional TACE for persistent disease. Proton beam radiation therapy was delivered to all areas of gross disease to a total dose of 70.2 Gy in 15 daily fractions over 3 weeks. The primary endpoint was progression-free survival, with secondary endpoints of overall survival, local tumor control, and treatment-related toxicities as represented by posttreatment days of hospitalization.

RESULTS

At the time of this analysis 69 subjects were available for analysis. Of these, 36 were randomized to TACE and 33 to proton. Total days of hospitalization within 30 days of TACE/proton was 166 and 24 days, respectively (P<.001). Ten TACE and 12 proton patients underwent liver transplantation after treatment. Viable tumor identified in the explanted livers after TACE/proton averaged 2.4 and 0.9 cm, respectively. Pathologic complete response after TACE/proton was 10%/25% (P=.38). The 2-year overall survival for all patients was 59%, with no difference between treatment groups. Median survival time was 30 months (95% confidence interval 20.7-39.3 months). There was a trend toward improved 2-year local tumor control (88% vs 45%, P=.06) and progression-free survival (48% vs 31%, P=.06) favoring the proton beam treatment group.

CONCLUSIONS

This interim analysis indicates similar overall survival rates for proton beam radiation therapy and TACE. There is a trend toward improved local tumor control and progression-free survival with proton beam. There are significantly fewer hospitalization days after proton treatment, which may indicate reduced toxicity with proton beam therapy.

Clinical Benefit of Hepatic Arterial Infusion Concurrent Chemoradiotherapy in Locally Advanced Hepatocellular Carcinoma: A Propensity Score Matching Analysis

PURPOSE

The aim of this study was to evaluate whether hepatic arterial infusion concurrent chemoradiotherapy (CCRT) could improve overall survival (OS) in patients with locally advanced hepatocellular carcinoma (LAHCC).

MATERIALS AND METHODS

Two databases were reviewed from Yonsei Cancer Center (YCC) and Korean Liver Cancer Study Group (KLCSG) nationwide multi-center hepatocellular carcinoma (HCC) cohort. The CCRT group included 106 patients, with stage III-IV, Child-Pugh classification A, Eastern Cooperative Oncology Group performance status 0 or 1, who underwent definitive CCRT as the initial treatment at YCC. We used propensity score matching to adjust for seven clinical factors, including age, tumor size, TNM stage by the Liver Cancer Study Group of Japan, T stage, Barcelona Clinic Liver Cancer (BCLC) staging system, etiology of HCC, and portal vein invasion, which all differed significantly in the two databases. From the KLCSG cohort enrolled at 32 institutions, 106 patients for the non-CCRT group were defined.

RESULTS

After propensity score matching, all patient characteristics were balanced between the two groups. The CCRT group had better OS (median, 11.4) than the non-CCRT group (6.6 months, p=0.02). In multivariate analyses for all patients, CCRT (hazard ratio [HR], 1.48; 95% confidence interval [CI], 1.11 to 1.97; p=0.007), tumor size (HR, 1.08; 95% CI, 1.04 to 1.12; p < 0.001), and BCLC stage (HR, 0.54; 95% CI, 0.36 to 0.8; p=0.003) were independent prognostic factors for OS.

CONCLUSION

CCRT showed better OS for LAHCC patients. In LAHCC patients with a good performance and normal liver function, CCRT could be a feasible treatment option. All of these findings need to be validated in prospective clinical trials.

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.

Minimal invasive treatments for liver malignancies

Minimal invasive therapies have proved useful in the management of primary and secondary hepatic malignancies. The most relevant aspects of all these therapies are their minimal toxicity profiles and highly effective tumor responses without affecting the normal hepatic parenchyma. These unique characteristics coupled with their minimally invasive nature provide an attractive therapeutic option for patients who previously may have had few alternatives. Combination of these therapies might extend indications to bring curative treatment to a wider selected population. The results of various ongoing combination trials of intraarterial therapies with targeted therapies are awaited to further improve survival in this patient group. This review focuses on the application of ablative and intra-arterial therapies in the management of hepatocellular carcinoma and hepatic colorectal metastasis.

Ablative Radiotherapy Doses Lead to a Substantial Prolongation of Survival in Patients With Inoperable Intrahepatic Cholangiocarcinoma: A Retrospective Dose Response Analysis

PURPOSE

Standard therapies for localized inoperable intrahepatic cholangiocarcinoma (IHCC) are ineffective. Advances in radiotherapy (RT) techniques and image guidance have enabled ablative doses to be delivered to large liver tumors. This study evaluated the effects of RT dose escalation in the treatment of IHCC.

PATIENTS AND METHODS

Seventy-nine consecutive patients with inoperable IHCC were identified and treated with definitive RT from 2002 to 2014. At diagnosis, the median tumor size was 7.9 cm (range, 2.2 to 17 cm). Seventy patients (89%) received systemic chemotherapy before RT. RT doses were 35 to 100 Gy (median, 58.05 Gy) in three to 30 fractions for a median biologic equivalent dose (BED) of 80.5 Gy (range, 43.75 to 180 Gy).

RESULTS

Median follow-up time for patients alive at time of analysis was 33 months (range, 11 to 93 months). Median overall survival (OS) time after diagnosis was 30 months; 3-year OS rate was 44%. Radiation dose was the single most important prognostic factor; higher doses correlated with an improved local control (LC) rate and OS. The 3-year OS rate for patients receiving BED greater than 80.5 Gy was 73% versus 38% for those receiving lower doses (P = .017); 3-year LC rate was significantly higher (78%) after a BED greater than 80.5 Gy than after lower doses (45%, P = .04). BED as a continuous variable significantly affected LC (P = .009) and OS (P = .004). There were no significant treatment-related toxicities.

CONCLUSION

Delivery of higher doses of RT improves LC and OS in inoperable IHCC. A BED greater than 80.5 Gy seems to be an ablative dose of RT for large IHCCs, with long-term survival rates that compare favorably with resection.

Long-term safety and efficacy of stereotactic body radiation therapy for hepatic oligometastases

PURPOSE

To evaluate long-term outcome and toxicity of stereotactic body radiation therapy (SBRT) for hepatic oligometastases from solid tumors.

METHODS AND MATERIALS

Eligible patients had 1 to 3 liver metastases, maximum sum diameter 6 cm, without extrahepatic progression. We treated 106 lesions in 81 patients; 67% with colorectal primaries. Median dose was 5400 cGy in 3 to 5 fractions.

RESULTS

At median follow-up of 33 months (2.5-70 months), overall local control was 94% (95% confidence interval, not estimable); Kaplan-Meier estimated 96% at 1 year and 91% at 2, 3, and 4 years. Partial/complete response was observed in 69% of lesions with less than 3% progressing. Median survival time was 33.6 months (95% confidence interval, 29.1-38.4); Kaplan-Meier survival estimates at 1, 2, 3, and 4 years were 89.9%, 68.6%, 44.0%, and 28.0%, respectively. Grade 3 or greater liver toxicity was 4.9%.

CONCLUSION

SBRT is effective for selected patients with hepatic oligometastases with limited toxicities. A phase 3 trial comparing SBRT with "gold-standard" surgical resection is warranted.

Local and Global Function Model of the Liver

PURPOSE

To develop a local and global function model in the liver based on regional and organ function measurements to support individualized adaptive radiation therapy (RT).

METHODS AND MATERIALS

A local and global model for liver function was developed to include both functional volume and the effect of functional variation of subunits. Adopting the assumption of parallel architecture in the liver, the global function was composed of a sum of local function probabilities of subunits, varying between 0 and 1. The model was fit to 59 datasets of liver regional and organ function measures from 23 patients obtained before, during, and 1 month after RT. The local function probabilities of subunits were modeled by a sigmoid function in relating to MRI-derived portal venous perfusion values. The global function was fitted to a logarithm of an indocyanine green retention rate at 15 minutes (an overall liver function measure). Cross-validation was performed by leave-m-out tests. The model was further evaluated by fitting to the data divided according to whether the patients had hepatocellular carcinoma (HCC) or not.

RESULTS

The liver function model showed that (1) a perfusion value of 68.6 mL/(100 g · min) yielded a local function probability of 0.5; (2) the probability reached 0.9 at a perfusion value of 98 mL/(100 g · min); and (3) at a probability of 0.03 [corresponding perfusion of 38 mL/(100 g · min)] or lower, the contribution to global function was lost. Cross-validations showed that the model parameters were stable. The model fitted to the data from the patients with HCC indicated that the same amount of portal venous perfusion was translated into less local function probability than in the patients with non-HCC tumors.

CONCLUSIONS

The developed liver function model could provide a means to better assess individual and regional dose-responses of hepatic functions, and provide guidance for individualized treatment planning of RT.

Intermediate hepatocellular carcinoma: the role of transarterial therapy

According to Barcelona Clinic Liver Cancer, the recommended first-line treatment for patients with intermediate stage of hepatocellular carcinoma (HCC) is transarterial chemoembolization. Patients with intermediate stage of HCC represent 20% with a 2-year survival of approximately 50%. Nowadays, transarterial therapies have proved precious in the treatment of hepatic malignancies. During the last years, there were important developments in practiced transarterial therapies and their efficacy is still controversial. The purpose of this review is to discuss in further details these transarterial therapies that have been used to treat cases of HCC.

Impact of intravenous contrast enhancement phase on target definition for hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (IHC): Observations from patients enrolled on a prospective phase 2 trial

BACKGROUND

The safety and efficacy of radiation therapy for hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (IHC) depend on accurate definition of gross tumor volume (GTV), but GTV often varies between phases of multiphasic computed tomography (CT) imaging.

METHODS

We contoured GTVs on arterial, portal venous, and delayed phases of multiphasic CT scans for 32 patients treated on an institutional review board-approved prospective trial of proton therapy for primary liver tumors and determined which phase provided optimal GTV visualization. We assessed agreement between individual phase GTVs to determine if GTV for each phase was encompassed in a 5-mm expansion of either the smallest or the best-visualized GTV.

RESULTS

There were 19 HCC lesions and 14 IHC lesions. HCC lesions were best identified on the arterial phase in 42% (n = 8), portal venous phase in 32% (n = 6), and delayed phase in 26% (n = 5). IHC lesions were best identified on portal venous phase in 64% (n = 9) and the arterial phase in 29% (n = 4), with 1 case equally visualized on arterial and portal venous phases. In all 33 lesions, a 5-mm expansion around the smallest GTV failed to cover GTVs defined on other available phases. A 5-mm expansion around the best-visualized GTV provided satisfactory coverage of all available phases' GTVs in 6/18 HCC cases and 2/9 IHC cases.

CONCLUSIONS

Variability between GTVs on multiphasic CT scans could not be overcome with a 5-mm expansion of either the smallest GTV or the best-visualized GTV. Assessment of all available intravenous contrast phases is essential to accurately define the GTV.

Ablative and catheter-directed therapies for colorectal liver and lung metastases

Increasing data on treatment of liver metastases with locoregional therapies have solidified the expanding role of interventional radiologists (IRs) in the treatment of liver metastases from colorectal cancer. Ablative approaches such as radiofrequency ablation and microwave ablation have shown durable eradication of tumors. Catheter-directed therapies such as transarterial chemoembolization, drug-eluting beads, yttrium-90 radioembolization, and intra-arterial chemotherapy ports represent potential techniques for managing patients with unresectable liver metastases. Understanding the timing and role of these techniques in multidisciplinary care of patients is crucial. Implementation of IRs for consultation enables better integration of these therapies into patients' overall care.

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.

Advances in SPECT for Optimizing the Liver Tumors Radioembolization Using Yttrium-90 Microspheres

Radioembolization (RE) with Yttrium-90 ((90)Y) microspheres is an effective treatment for unresectable liver tumors. The activity of the microspheres to be administered should be calculated based on the type of microspheres. Technetium-99m macroaggregated albumin ((99m)Tc-MAA) single photon emission computed tomography/computed tomography (SPECT/CT) is a reliable assessment before RE to ensure the safe delivery of microspheres into the target. (90)Y bremsstrahlung SPECT imaging as a posttherapeutic assessment approach enables the reliable determination of absorbed dose, which is indispensable for the verification of treatment efficacy. This article intends to provide a review of the methods of optimizing (90)Y bremsstrahlung SPECT imaging to improve the treatment efficacy of liver tumor RE using (90)Y microspheres.

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.

Radioembolization with Yttrium-90 microspheres in hepatocellular carcinoma: Role and perspectives

Transarterial radioembolization (TARE) is a form of brachytherapy in which intra-arterially injected yttrium-90-loaded microspheres serve as a source for internal radiation purposes. On the average, it produces disease control rates exceeding 80% and it is a consolidated therapy for hepatocellular carcinoma (HCC); however, current data are all based on retrospective series or non-controlled prospective studies since randomized controlled trials comparing it with the other liver-directed therapies for intermediate and locally advanced stage HCC are still underway. The data available show that TARE provides similar or even better survival rates when compared to transarterial chemoembolization (TACE). First-line TARE is best indicated for both intermediate-stage patients (staged according to the barcelona clinic liver cancer staging classification) who have lesions which respond poorly to TACE due to multiple tumors or a large tumor burden, and for locally advanced-stage patients with solitary tumors, and segmental or lobar portal vein tumor thrombosis. In addition, emerging data have suggested the use of TARE in patients who are classified slightly beyond the Milan criteria regarding radical treatment for downstaging purposes. As a second-line treatment, TARE can also be applied in patients progressing to TACE or sorafenib; a large number of phase II/III trials are ongoing with the purpose of evaluating the best association with systemic therapies. Transarterial radioembolization is very well tolerated and has a low rate of complications which are mainly related to unintended non-target tissue irradiation, including the surrounding liver parenchyma. The complications can be additionally reduced by accurate patient selection and a strict pre-treatment evaluation including dosimetry and assessment of the vascular anatomy. Since a correct treatment algorithm for potential TARE candidates is not clear and standardized, this comprehensive review analyzes the best selection criteria for patients who really benefit from TARE and also the new advances of this therapy, which can be a very important weapon against HCC.

Radioembolization with Yttrium-90 microspheres in hepatocellular carcinoma: Role and perspectives

Transarterial radioembolization (TARE) is a form of brachytherapy in which intra-arterially injected yttrium-90-loaded microspheres serve as a source for internal radiation purposes. On the average, it produces disease control rates exceeding 80% and it is a consolidated therapy for hepatocellular carcinoma (HCC); however, current data are all based on retrospective series or non-controlled prospective studies since randomized controlled trials comparing it with the other liver-directed therapies for intermediate and locally advanced stage HCC are still underway. The data available show that TARE provides similar or even better survival rates when compared to transarterial chemoembolization (TACE). First-line TARE is best indicated for both intermediate-stage patients (staged according to the barcelona clinic liver cancer staging classification) who have lesions which respond poorly to TACE due to multiple tumors or a large tumor burden, and for locally advanced-stage patients with solitary tumors, and segmental or lobar portal vein tumor thrombosis. In addition, emerging data have suggested the use of TARE in patients who are classified slightly beyond the Milan criteria regarding radical treatment for downstaging purposes. As a second-line treatment, TARE can also be applied in patients progressing to TACE or sorafenib; a large number of phase II/III trials are ongoing with the purpose of evaluating the best association with systemic therapies. Transarterial radioembolization is very well tolerated and has a low rate of complications which are mainly related to unintended non-target tissue irradiation, including the surrounding liver parenchyma. The complications can be additionally reduced by accurate patient selection and a strict pre-treatment evaluation including dosimetry and assessment of the vascular anatomy. Since a correct treatment algorithm for potential TARE candidates is not clear and standardized, this comprehensive review analyzes the best selection criteria for patients who really benefit from TARE and also the new advances of this therapy, which can be a very important weapon against HCC.

Treatment variables related to liver toxicity in patients with hepatocellular carcinoma, Child-Pugh class A and B enrolled in a phase 1-2 trial of stereotactic body radiation therapy

PURPOSE

An analysis was performed on patients enrolled in a phase 1-2 trial using stereotactic body radiation therapy for hepatocellular carcinoma evaluating variables influencing liver toxicity.

METHODS AND MATERIALS

Thirty-eight Child-Pugh class A (CPC-A) (39 lesions) and 21 CPC-B patients (26 lesions) were followed for ≥6 months. Six months local control using modified Response Evaluation Criteria in Solid Tumors criteria, progression-free survival, overall survival, and grade III/IV treatment-related toxicity at 3 months were analyzed.

RESULTS

Median follow-up was 33.3 months (2.8-61.1 months) for CPC-A and 46.3 months (3.7-70.4 months) for CPC-B patients. Local control at 6 months was 92% for CPC-A and 93% for CPC-B. Kaplan-Meier estimated 2- and 3-year local control was 91% for CPC-A and 82% for CPC-B (P = .61). Median overall survival was 44.8 months and 17.0 months for CPC-A and CPC-B. Kaplan-Meier estimated 2- and 3-year overall survival was 72% and 61% for CPC-A and 33% and 26% for CPC-B (P = .03). Four (11%) CPC-A patients and 8 CPC-B patients (38%) experienced grade III/IV liver toxicity. Overall, CPC-A patients with ≥grade III liver toxicity had 4.59 (95% confidence interval, 1.19-17.66) times greater risk of death than those without toxicity (P = .0268). No such correlation was seen for CPC-B patients; however, 3 of these CPC-B patients underwent orthotopic liver transplant. CPC-B patients experiencing grade III/IV liver toxicity had significantly higher mean liver dose, higher dose to one-third normal liver, and larger volumes of liver receiving doses <2.5 to 15 Gy in 2.5-Gy increments. For CPC-A patients, there was no critical liver dose or volume constraint correlated with toxicity.

CONCLUSIONS

In our experience, liver stereotactic body radiation therapy is a safe therapy for patients with hepatocellular carcinoma in the context of liver cirrhosis; however, for CPC-B patients, careful attention should be paid to low-dose volumes that could potentially result in increased liver toxicity.

GEP-NETS update: Interventional radiology: role in the treatment of liver metastases from GEP-NETs

Neuroendocrine tumors from gastro-pancreatic origin (GEP-NET) can be responsible for liver metastases. Such metastases can be the dominant part of the disease as well due to the tumor burden itself or the symptoms related to such liver metastases. Intra-arterial therapies are commonly used in liver only or liver-dominant disease and encompass trans-arterial chemoembolization (TACE), trans-arterial embolization (TAE), and radioembolization (RE). TACE performed with drug emulsified in Lipiodol has been used for the past 20 years with reported overall survival in the range of 3-4 years, with objective response up to 75%. Response to TACE is higher when treatment is used as a first-line therapy and degree of liver involvement is lower. Benefit of TACE over TAE is unproven in randomized study, but reported in retrospective studies namely in pancreatic NETs. RE provides early interesting results that need to be further evaluated in terms of benefit and toxicity. Radiofrequency ablation allows control of small size and numbered liver metastases, with low invasiveness. Ideal metastases to target are one metastasis <5 cm, or three metastases <3 cm, or a sum of diameter of all metastases below 8 cm. Ablation therapies can be applied in the lung or in the bones when needed, and more invasive surgery should be probably saved for large-size metastases. Even if the indication of image-guided therapy in the treatment of GEP-NET liver metastases needs to be refined, such therapies allow for manageable invasive set of treatments able to address oligometastatic patients in liver, lung, and bones. These treatments applied locally will save the benefit and the toxicity of systemic therapy for more advanced stage of the disease.

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 role of radiotherapy in the treatment of hepatocellular carcinoma with portal vein tumor thrombus

The aim of this study was to evaluate the role of radiotherapy in the treatment of hepatocellular carcinoma (HCC) with portal vein tumor thrombosis (PVT) and to determine the prognostic factors for overall survival. Altogether, 106 patients with HCC and PVT referred for radiotherapy between 2004 and 2009 were retrospectively reviewed. A total of 60 Gy in 30 daily fractions was delivered with intensity-modulated radiotherapy techniques. Patient-related and treatment-related factors were analyzed to evaluate their prognostic significance for the overall survival rate. Complete response was noted in 10 patients and partial response in 55 patients. The liver lesions had become resectable after the completion of radiotherapy in 12 patients, and surgery was subsequently performed. One or two courses of transarterial chemoembolization (TACE) were administered to 19 patients following radiotherapy. The 1-year and 2-year overall survival rates were 34.7% and 11%, respectively, and the median survival was 7 months for the entire cohort of patients. Post-radiotherapy treatment modality, response to radiotherapy and JIS score were demonstrated as independent prognostic factors for overall survival (P = 0.003, P < 0.001, P < 0.001, respectively). For patients who received surgical intervention after radiotherapy, the median survival was 30 months and the 2-year overall survival rate was 67%. Radiotherapy achieved a 61.5% objective response rate and prolonged survival in patients with PVT. The liver tumors had become resectable after radiotherapy in 11% of patients. Our results suggested that radiotherapy could offer survival benefits and should be considered as a treatment option for patients with PVT. Radiotherapy could also be considered as a preoperative treatment modality in patients with HCC and PVT.

Charged particle therapy versus photon therapy for patients with hepatocellular carcinoma: a systematic review and meta-analysis

PURPOSE

To perform a systematic review and meta-analysis to compare the clinical outcomes and toxicity of hepatocellular carcinoma (HCC) patients treated with charged particle therapy (CPT) with those of individuals receiving photon therapy.

METHODS

We identified relevant clinical studies through searching databases. Primary outcomes of interest were overall survival (OS) at 1, 3, 5 years, progression-free survival (PFS), and locoregional control (LC) at longest follow-up.

RESULTS

73 cohorts from 70 non-comparative observational studies were included. Pooled OS was significantly higher at 1, 3, 5 years for CPT than for conventional radiotherapy (CRT) [relative risk (RR) 1·68, 95% CI 1·22-2·31; p<0·001; RR 3.46, 95% CI: 1.72-3.51, p<0.001; RR 25.9, 95% CI: 1.64-408.5, p=0.02; respectively]. PFS and LC at longest follow-up was also significantly higher for CPT than for CRT (p=0·013 and p<0.001, respectively), while comparable efficacy was found between CPT and SBRT in terms of OS, PFS and LC at longest follow-up. Additionally, high-grade acute and late toxicity associated with CPT was lower than that of CRT and SBRT.

CONCLUSION

Survival rates for CPT are higher than those for CRT, but similar to SBRT in patients with HCC. Toxicity tends to be lower for CPT compared to photon radiotherapy.

A Survey of Stereotactic Body Radiotherapy in Korea

PURPOSE

The purpose of this study is to investigate the current status of stereotactic body radiotherapy (SBRT) in Korea. A nationwide survey was conducted by the Korean Stereotactic Radiosurgery Group of the Korean Society for Radiation Oncology (KROG 13-13).

MATERIALS AND METHODS

SBRT was defined as radiotherapy with delivery of a high dose of radiation to an extracranial lesion in ≤ 4 fractions. A 16-questionnaire survey was sent by e-mail to the chief of radiation oncology at 85 institutions in June 2013.

RESULTS

All institutions (100%) responded to this survey. Of these, 38 institutions (45%) have used SBRT and 47 institutions (55%) have not used SBRT. Regarding the treatment site, the lung (92%) and liver (76%) were the two most common sites. The most common schedules were 60 Gy/4 fractions for non-small cell lung cancer, 48 Gy/4 fractions for lung metastases, 60 Gy/3 fractions for hepatocellular carcinoma, and 45 Gy/3 fractions or 40 Gy/4 fractions for liver metastases. Four-dimensional computed tomography (CT) was the most common method for planning CT (74%). During planning CT, the most common method of immobilization was the use of an alpha cradle/vacuum-lock (42%).

CONCLUSION

Based on this survey, conduct of further prospective studies will be needed in order to determine the appropriate prescribed doses and to standardize the practice of SBRT.

Transarterial radioembolization using yttrium-90 microspheres in the treatment of hepatocellular carcinoma: a review on clinical utility and developments

A selective intra-arterial liver injection using yttrium-90-loaded microspheres as sources for internal radiation therapy is a form of transarterial radioembolization (TARE). Current data from the literature suggest that TARE is effective in hepatocellular carcinoma (HCC) and is associated with a low rate of adverse events; however, they are all based on retrospective series or non-controlled prospective studies, since randomized controlled trials comparing the other liver-directed therapies for intermediate and locally advanced stages HCC are still ongoing. The available data show that TARE provides similar or even better survival rates. TARE is very well tolerated and has a low rate of complications; these complications do not result from the embolic effects but mainly from the unintended irradiation to non-target tissue, including the liver parenchyma. The complications can be further reduced by accurate patient selection and a strict pre-treatment evaluation, including dosimetry and assessment of the vascular anatomy. First-line TARE is best indicated for intermediate-stage patients (according to the Barcelona Clinic Liver Cancer [BCLC] staging classification) who are poor candidates for transarterial chemoembolization or patients having locally advanced disease with segmental or lobar branch portal vein thrombosis. Moreover, data are emerging regarding the use of TARE in patients classified slightly above the criteria for liver transplantation with the purpose of downstaging them. TARE can also be applied as a second-line treatment in patients progressing to transarterial chemoembolization or sorafenib; a large number of Phase II/III trials are in progress in order to evaluate the best association with systemic therapies. Given the complexity of a correct treatment algorithm for potential TARE candidates and the need for clinical guidance, a comprehensive review was carried out analyzing both the best selection criteria of patients who really benefit from TARE and the new advances of this therapy which add significant value to the therapeutic weaponry against HCC.

Concurrent chemoradiotherapy shows long-term survival after conversion from locally advanced to resectable hepatocellular carcinoma

PURPOSE

For locally unresectable hepatocellular carcinoma (HCC) patients, concurrent chemoradiotherapy (CCRT) has been applied as a loco-regional treatment. After shrinkage of tumors in selected patients, surgical resection is performed. The aim of this study was to evaluate prognostic factors and long-term survivors in such patients.

MATERIALS AND METHODS

From January 2000 to January 2009, 264 patients with HCC were treated with CCRT (45 Gy with fractional dose of 1.8 Gy), and intra-arterial chemotherapy was administered during radiotherapy. Eighteen of these patients (6.8%) underwent hepatic resection after showing a response to CCRT. Cases were considered resectable when tumor-free margins and sufficient remnant volumes were obtained without extrahepatic metastasis. Prior to operation, there were six patients with complete remission, 11 with partial remission, and six with stable disease according to modified Response Evaluation Criteria in Solid Tumors.

RESULTS

In pathologic review, four patients (22.2%) showed total necrosis and seven patients (38.9%) showed 70-99% necrosis. A high level of necrosis (≥80%) was correlated with low risk for extrahepatic metastasis and long-term survival. In univariate analyses, vessel invasion and capsular infiltration were significantly correlated with disease free survival (DFS) (p=0.017 and 0.013, respectively), and vessel invasion was significantly correlated with overall survival (OS) (p=0.013). In multivariate analyses, capsule infiltration was a significant factor for DFS (p=0.016) and vessel invasion was significant for OS (p=0.015).

CONCLUSION

CCRT showed favorable responses and locally advanced HCC converted into resectable tumor after CCRT in selected patients. Long-term survivors showed the pathological features of near total necrosis, as well as negative capsule and vessel invasion.

Conventional fractionated helical tomotherapy for patients with small to medium hepatocellular carcinomas without portal vein tumor thrombosis

Background

The purpose of this study was to evaluate clinical outcomes of conventional fractionated helical tomotherapy in patients with small to medium hepatocellular carcinomas (HCCs) without portal vein tumor thrombosis.

Methods

Patients with up to four HCC lesions not treatable by surgery or percutaneous ablative therapies, <10 cm in the longest diameter, and no evidence of major vascular invasion were included. From January 2008 to January 2013, 20 patients with 33 tumors met the eligibility criteria and received definitive or salvage helical tomotherapy. The most commonly prescribed dose fractionation schedule was a total dose of 50 Gy with a daily dose of 2.5 Gy. Treatment response, survival, and radiation-induced toxicities were retrospectively reviewed.

Results

The median follow-up period after radiotherapy for all patients was 24.9 (range 7.8–79.2) months. Objective responses (complete response or partial response) occurred in 30 of 33 lesions (90.9%). Eight (24.2%) lesions showed local recurrence and the actuarial local control rate at 2 years was 69.5%. Intrahepatic recurrence-free survival and overall survival rates at 2 years were 45.7% and 71.1%, respectively. Age, Child–Pugh class, tumor response, local recurrence status, and intrahepatic recurrence status were significantly associated with overall survival on univariate analysis. Among these parameters, only local recurrence status showed marginal statistical significance on multivariate analysis (P=0.068). The overall survival rate at 2 years was 50% for patients who experienced local recurrence, but 87.5% for those who did not. No patient experienced grade 2 or greater general or gastrointestinal toxicity. There were no cases of radiation-induced liver disease.

Conclusion

Conventional fractionated helical tomotherapy for patients with less than four small to medium HCCs without portal vein tumor thrombosis yielded favorable local control and overall survival without severe complications.

Nonsurgical treatment for localized hepatocellular carcinoma

The most common non-surgical approaches for the treatment of localized hepatocellular carcinoma remain hepatic artery-delivered particles laden with chemotherapy (TACE), or radioactive microparticles (TARE). External beam radiotherapy has been an effective option in many parts of the world for selected HCC patients, but now has an expanded role with stereotactic and proton beam technologies. This review focuses on existing evidence and current guidance for utilizing these modalities for localized, but unresectable, non-transplantable HCC patients.x.

SIR-Spheres yttrium-90 radioembolization for the treatment of unresectable liver cancers

Transarterial radioembolization with yttrium-90 resin microspheres (SIR-Spheres; Sirtex Medical Limited, Sydney, Australia) is a liver-directed therapy that is gaining recognition as a treatment option for liver-dominant primary and metastatic cancers. The incidence of complications is low and can be further reduced by patient selection and rigorous pretreatment assessment. Ideal candidates for radioembolization have preserved liver function without ascites or encephalopathy, Child-Pugh score <7 and limited lung shunting. Phase III randomized controlled trials (RCTs) against other liver-directed therapies are lacking for intermediate-stage hepatocellular carcinoma. However, preliminary data from a recent RCT has suggested that radioembolization has a similar time-to-progression and comparable toxicity to selective chemoembolization. Phase II/III RCTs are now ongoing to evaluate the combination of radioembolization with systemic therapies in advanced-stage hepatocellular carcinoma and metastatic liver-dominant colorectal cancer in order to expand the treatment opportunities for patients with cancers in the liver.

Bone marrow-derived stromal cell therapy in cirrhosis: clinical evidence, cellular mechanisms, and implications for the treatment of hepatocellular carcinoma

Current treatment options for hepatocellular carcinoma (HCC) are often limited by the presence of underlying liver disease. In patients with liver cirrhosis, surgery, chemotherapy, and radiation therapy all carry a high risk of hepatic complications, ranging from ascites to fulminant liver failure. For patients receiving radiation therapy, cirrhosis dramatically reduces the already limited radiation tolerance of the liver and represents the most important clinical risk factor for the development of radiation-induced liver disease. Although improvements in conformal radiation delivery techniques have improved our ability to safely irradiate confined areas of the liver to increasingly higher doses with excellent local disease control, patients with moderate-to-severe liver cirrhosis continue to face a shortage of treatment options for HCC. In recent years, evidence has emerged supporting the use of bone marrow-derived stromal cells (BMSCs) as a promising treatment for liver cirrhosis, with several clinical studies demonstrating sustained improvement in clinical parameters of liver function after autologous BMSC infusion. Three predominant populations of BMSCs, namely hematopoietic stem cells, mesenchymal stem cells, and endothelial progenitor cells, seem to have therapeutic potential in liver injury and cirrhosis. Preclinical studies of BMSC transplantation have identified a range of mechanisms through which these cells mediate their therapeutic effects, including hepatocyte transdifferentiation and fusion, paracrine stimulation of hepatocyte proliferation, inhibition of activated hepatic stellate cells, enhancement of fibrolytic matrix metalloproteinase activity, and neovascularization of regenerating liver. By bolstering liver function in patients with underlying Child's B or C cirrhosis, autologous BMSC infusion holds great promise as a therapy to improve the safety, efficacy, and utility of surgery, chemotherapy, and hepatic radiation therapy in the treatment of HCC.

Interobserver variability in target definition for hepatocellular carcinoma with and without portal vein thrombus: radiation therapy oncology group consensus guidelines

PURPOSE

Defining hepatocellular carcinoma (HCC) gross tumor volume (GTV) requires multimodal imaging, acquired in different perfusion phases. The purposes of this study were to evaluate the variability in contouring and to establish guidelines and educational recommendations for reproducible HCC contouring for treatment planning.

METHODS AND MATERIALS

Anonymous, multiphasic planning computed tomography scans obtained from 3 patients with HCC were identified and distributed to a panel of 11 gastrointestinal radiation oncologists. Panelists were asked the number of HCC cases they treated in the past year. Case 1 had no vascular involvement, case 2 had extensive portal vein involvement, and case 3 had minor branched portal vein involvement. The agreement between the contoured total GTVs (primary + vascular GTV) was assessed using the generalized kappa statistic. Agreement interpretation was evaluated using Landis and Koch's interpretation of strength of agreement. The S95 contour, defined using the simultaneous truth and performance level estimation (STAPLE) algorithm consensus at the 95% confidence level, was created for each case.

RESULTS

Of the 11 panelists, 3 had treated >25 cases in the past year, 2 had treated 10 to 25 cases, 2 had treated 5 to 10 cases, 2 had treated 1 to 5 cases, 1 had treated 0 cases, and 1 did not respond. Near perfect agreement was seen for case 1, and substantial agreement was seen for cases 2 and 3. For case 2, there was significant heterogeneity in the volume identified as tumor thrombus (range 0.58-40.45 cc). For case 3, 2 panelists did not include the branched portal vein thrombus, and 7 panelists contoured thrombus separately from the primary tumor, also showing significant heterogeneity in volume of tumor thrombus (range 4.52-34.27 cc).

CONCLUSIONS

In a group of experts, excellent agreement was seen in contouring total GTV. Heterogeneity exists in the definition of portal vein thrombus that may impact treatment planning, especially if differential dosing is contemplated. Guidelines for HCC GTV contouring are recommended.

Role of external beam radiation therapy in management of hepatocellular carcinoma

Diagnosis at advanced disease stage and early vascular invasion are the bane of majority of patients with hepatocellular carcinoma (HCC) in India. The currently standardized curative and palliative treatment modalities [surgery, ablative techniques, trans-catheter chemotherapy, systemic chemotherapy] are suboptimal for a significant proportion of disease stages. Interest in radiotherapy for hepatocellular carcinoma has seen a resurgence with revolutionary improvements in targeting radiation doses safely. Encouraging results have been reported with a host of radiation techniques from conformal radiotherapy, stereotactic whole body radiation therapy to charged particle based therapies. The dissemination of this knowledge has been slow across other specialties involved in care of patients with HCC. However the increasing availability of radiotherapy services predicts a hopeful future for wider evaluation of radiotherapy in HCC.