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

The efficacy of stereotactic body radiation therapy on huge hepatocellular carcinoma unsuitable for other local modalities

Background and aim

To evaluate the safety and efficacy of Cyberknife stereotactic body radiation therapy (SBRT) and its effect on survival in patients with unresectable huge hepatocellular carcinoma (HCC) unsuitable of other standard treatment option.

Methods

Between 2009 and 2011, 22 patients with unresectable huge HCC (≧10 cm) were treated with SBRT. dose ranged from 26 Gy to 40 Gy in five fractions. Overall survival (OS) and disease-progression free survival (DPFS) were determined by Kaplan-Meier analysis. Tumor response and toxicities were also assessed.

Results

After a median follow-up of 11.5 month (range 2–46 months). The objective response rate was achieved in 86.3% (complete response (CR): 22.7% and partial response (PR): 63.6%). The 1-yr. local control rate was 55.56%. The 1-year OS was 50% and median survival was 11 months (range 2–46 months). In univariate analysis, Child-Pugh stage (p = 0.0056) and SBRT dose (p = 0.0017) were significant factors for survival. However, in multivariate analysis, SBRT dose (p = 0.0072) was the most significant factor, while Child-Pugh stage of borderline significance. (p = 0.0514). Acute toxicities were mild and well tolerated.

Conclusion

This study showed that SBRT can be delivered safely to huge HCC and achieved a substantial tumor regression and survival. The results suggest this technique should be considered a salvage treatment. However, local and regional recurrence remain the major cause of failure. Further studies of combination of SBRT and other treatment modalities may be reasonable.

New advances in local therapy for colorectal cancer metastases to the liver

SUMMARY 

The liver is the most common site of metastasis from primary colorectal cancer (CRC), and liver metastasis represents a major cause of morbidity and mortality for patients with primary CRC. Of patients with metastatic CRC that is confined to the liver, only a minority of patients are candidates for potentially curative surgical resection. In addition, to the very well-established modalities of surgery and thermal ablation, several newer locoregional therapies are available for the treatment of hepatic metastases, including stereotactic body radiotherapy, radioembolization and chemoembolization. Small prospective studies evaluating these treatments show promising response rates and local control in the first-line and salvage settings. Further randomized trials are required for a more rigorous assessment of the benefit and optimal setting in which these therapies should be used in patients with CRC liver metastases.

Locally targeted delivery of a micron-size radiation therapy source using temperature-sensitive hydrogel

PURPOSE

To propose a novel radiation therapy (RT) delivery modality: locally targeted delivery of micron-size RT sources by using temperature-sensitive hydrogel (RT-GEL) as an injectable vehicle.

METHODS AND MATERIALS

Hydrogel is a water-like liquid at room temperature but gels at body temperature. Two US Food and Drug Administration-approved polymers were synthesized. Indium-111 (In-111) was used as the radioactive RT-GEL source. The release characteristics of In-111 from polymerized RT-GEL were evaluated. The injectability and efficacy of RT-GEL delivery to human breast tumor were tested using animal models with control datasets of RT-saline injection. As proof-of-concept studies, a total of 6 nude mice were tested by injecting 4 million tumor cells into their upper backs after a week of acclimatization. Three mice were injected with RT-GEL and 3 with RT-saline. Single-photon emission computed tomography (SPECT) and CT scans were performed on each mouse at 0, 24, and 48 h after injection. The efficacy of RT-GEL was determined by comparison with that of the control datasets by measuring kidney In-111 accumulation (mean nCi/cc), representing the distant diffusion of In-111.

RESULTS

RT-GEL was successfully injected into the tumor by using a 30-gauge needle. No difficulties due to polymerization of hydrogel during injection and intratumoral pressure were observed during RT-GEL injection. No back flow occurred for either RT-GEL or RT-saline. The residual tumor activities of In-111 were 49% at 24 h (44% at 48 h, respectively) for RT-GEL and 29% (22%, respectively) for RT-saline. Fused SPECT-CT images of RT-saline showed considerable kidney accumulation of In-111 (2886%, 261%, and 262% of RT-GEL at 0, 24, and 48 h, respectively).

CONCLUSIONS

RT-GEL was successfully injected and showed much higher residual tumor activity: 170% (200%, respectively), than that of RT-saline at 24 h (48 h, respectively) after injection with a minimal accumulation of In-111 to the kidneys. Preliminary data of RT-GEL as a delivery modality of a radiation source to a local tumor are promising.

Tumor response on CT following hypofractionated stereotactic ablative body radiotherapy for small hypervascular hepatocellular carcinoma with cirrhosis

OBJECTIVE

The purpose of this study is to evaluate the CT appearances of tumor responses following hypofractionated stereotactic ablative body radiotherapy for small hypervascular hepatocellular carcinomas (HCCs) and to assess the relationship between tumor responses and local control.

MATERIALS AND METHODS

Among 277 HCC tumors treated with stereotactic ablative body radiotherapy (35 or 40 Gy per five fractions), we selected enhanced lesions on arterial phase CT performed before stereotactic ablative body radiotherapy. Radiographic findings after stereotactic ablative body radiotherapy were evaluated during a 2-year follow-up period with the modified Response Evaluation Criteria in Solid Tumors. Local control and survival rates were calculated with the Kaplan-Meier method.

RESULTS

Forty-two tumors with a median size of 2.1 cm (range, 1.0-3.8 cm) were selected with a median follow-up of 23.3 months (range, 9-56 months). Local recurrence was observed in two tumors after achieving a complete response (CR). The 2-year local control rate was 97%, and the overall survival rate was 81%. CR increased from 10 (24%) to 28 (67%) to 30 (71%) tumors at 3, 6, and 12 months after stereotactic ablative body radiotherapy. Overall CR at maximum follow-up was 39 tumors (93%), yet three enhanced tumors persisted for more than 2 years. The median time to achieve CR was 5.9 months (range, 1.2-34.2 months).

CONCLUSION

The CR rate in hypervascular HCCs after hypofractionated stereotactic ablative body radiotherapy increased during the 2-year follow-up period. Cautious and continuous observation until tumor regrowth is considered relevant to evaluate a true effect of this treatment. Further studies for the optimal evaluation of treatment outcome after stereotactic ablative body radiotherapy are warranted.

Radiosensitization by combining an aurora kinase inhibitor with radiotherapy in hepatocellular carcinoma through cell cycle interruption

Radiotherapy has been integrated into the multimodal treatment of hepatocellular carcinoma (HCC), especially of localized hepatic tumor(s) refractory to conventional treatment. However, tumor control remains unsatisfactory mainly because of insufficient dose, and sublethally irradiated tumor may associate with metastasis. Our aim was to assess the effect of combining a molecularly targeted Aurora kinase inhibitor, VE-465, with radiotherapy in in vitro and in vivo models of human HCC. Human HCC cell lines (Huh7 and PLC-5) were used to evaluate the in vitro synergism of combining VE-465 with irradiation. Flow cytometry analyzed the cell cycle changes, while western blot investigated the protein expressions after the combined treatment. Severe combined immunodeficient (SCID) mice bearing ectopic and orthotopic HCC xenografts were treated with VE-465 and/or radiotherapy for the in vivo response. VE-465 significantly enhanced radiation-induced death in HCC cells by a mechanism involving the enhanced inhibition of histone H3 phosphorylation and interruption of cell cycle change. In SCID, mice bearing ectopic HCC xenografts, pretreatment with VE-465 (20 mg/kg/day × 9 days) significantly enhanced the tumor-suppressive effect of radiotherapy (5 Gy/day × 5 days) by 54.0%. A similar combinatorial effect of VE-465 and radiotherapy was observed in an orthotopic model of Huh7 tumor growth by 17.2%. In the orthotopic Huh7 xenografts, VE-465 significantly enhanced radiation-induced tumor growth suppression by a mechanism involving the increased apoptosis. VE-465 is a potent inhibitor of Aurora kinase with therapeutic value as a radiosensitizer of HCC.

Transarterial therapy: an evolving treatment modality of hepatocellular carcinoma

Liver cancer is the fifth most common cancer in men, the seventh most common in women, and the third most common cause of death from cancer worldwide. Only 30-40% of liver cancer patients present early enough to undergo curative treatments such as surgery or liver transplantation. Local treatment with radiofrequency ablation or ethanol injection is often reserved for non-surgical candidates with early stages of disease. Transarterial embolization has become a widely accepted treatment for asymptomatic patients with unresectable lesions. This review discusses in details the three major forms of transarterial therapies: Bland embolization, chemoembolization, and radioembolization.

Rationale for ablation of oligometastatic disease and the role of stereotactic body radiation therapy for hepatic metastases

Management paradigms for metastatic solid tumors are evolving. Once regarded as uniformly incurable, today there is recognition of an intermediate oligometastatic state, where ablation of metastatic foci may improve disease control and prolong survival. In the setting of limited colorectal liver metastases, hepatic resection has resulted in favorable long-term outcomes, but is technically unsuitable for most patients. Stereotactic body radiation therapy represents an effective, noninvasive means of tumor ablation, supported by a large body of prospective evidence specific to hepatic metastases. This review examines the current rationale for ablation of oligometastatic disease, including various objectives beyond indefinite disease-free survival. The role of stereotactic body radiation therapy for ablation of hepatic metastases is then comprehensively reviewed.

Diffusion and perfusion MRI prediction of progression-free survival in patients with hepatocellular carcinoma treated with concurrent chemoradiotherapy

PURPOSE

To assess whether MR perfusion and diffusion parameters taken before concurrent chemoradiotherapy (CCRT) are useful imaging biomarkers for predicting progression-free survival (PFS) in patients with hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

Twenty patients with locally advanced HCC who had no treatment before CCRT underwent dynamic contrast-enhanced (DCE) and diffusion-weighted MRI. Mean values of the volume transfer constant (K(trans) ), reflex constant (Kep ), extravascular extracellular volume fraction (Ve ) and the apparent diffusion coefficient (ADC) were estimated on a region of interest. The best cutoff value for each factor was assessed to differentiate between patients who had PFS shorter or longer than the median PFS. Patients were dichotomized in terms of the cutoff value. The survival outcome of the two groups and the predictive ability of each factor on PFS were evaluated.

RESULTS

Median time to PFS was 179 days. The best cutoff values for ADC, K(trans) , Kep , and Ve was 1.008 × 10(-3) mm(2) s(-1) , 0.108 min(-1) , 0.570 min(-1) , and 0.298%. Patients with higher ADC had significantly longer PFS than those with lower ADC(P < 0.0001).

CONCLUSION

The ADC of HCC acquired before CCRT correlated with PFS and was valuable in the prediction of the clinical outcome of HCC treated with CCRT.

A prospective feasibility study of respiratory-gated proton beam therapy for liver tumors

PURPOSE

To evaluate the feasibility of a respiratory-gated proton beam therapy for liver tumors.

METHODS AND MATERIALS

Fifteen patients were enrolled in a prospective institutional review board-approved protocol. Eligibility criteria included Childs-Pugh A/B cirrhosis, unresectable biopsy- proven hepatocellular carcinoma (HCC), intrahepatic cholangiocarcinoma (ICC), or metastatic disease (solid tumors only), 1-3 lesions, and tumor size of ≤6 cm. Patients received 15 fractions to a total dose of 45-75 GyE [gray equivalent] using respiratory-gated proton beam therapy. Gating was performed with an external respiratory position monitoring based system.

RESULTS

Of the 15 patients enrolled in this clinical trial, 11 had HCC, 3 had ICC, and 1 had metastasis from another primary. Ten patients had a single lesion, 3 patients had 2 lesions, and 2 patients had 3 lesions. Toxicities were grade 3 bilirubinemia-2, grade 3 gastrointestinal bleed-1, and grade 5 stomach perforation-1. One patient had a marginal recurrence, 3 had hepatic recurrences elsewhere in the liver, and 2 had extrahepatic recurrence. With a median follow-up for survivors of 69 months, 1-, 2-, and 3-year overall survivals are 53%, 40%, and 33%, respectively. Progression-free survivals are 40%, 33%, and 27% at 1, 2, and 3 years, respectively.

CONCLUSIONS

Respiratory-gated proton beam therapy for liver tumors is feasible. Phase 2 studies for primary liver tumors and metastatic tumors are underway.

Clinical factors related to recurrence after hepatic arterial concurrent chemoradiotherapy for advanced but liver-confined hepatocellular carcinoma

Before the sorafenib era, advanced but liver-confined hepatocellular carcinoma (HCC) was treated by liver-directed therapy. Hepatic arterial concurrent chemoradiotherapy (CCRT) has been performed in our group, giving substantial local control but frequent failure. The aim of this study was to analyze patterns of failure and find out predictive clinical factors in HCC treated with a liver-directed therapy, CCRT. A retrospective analysis was done for 138 HCC patients treated with CCRT between May 2001 and November 2009. Protocol-based CCRT was performed with local radiotherapy (RT) and concurrent 5-fluorouracil (5-FU) hepatic arterial infusion chemotherapy (HAIC), followed by monthly HAIC (5-FU and cisplatin). Patterns of failure were categorized into three groups: infield, intrahepatic-outfield and extrahepatic failure. Treatment failure occurred in 34.0% of patients at 3 months after RT. Infield, intrahepatic-outfield and extrahepatic failure were observed in 12 (8.6%), 26 (18.7%) and 27 (19.6%) patients, respectively. Median progression-free survival for infield, outfield and extrahepatic failure was 22.4, 18 and 21.5 months, respectively. For infield failure, a history of pre-CCRT treatment was a significant factor (P = 0.020). Pre-CCRT levels of alpha-fetoprotein and prothrombin induced by vitamin K absence or antagonist-II were significant factors for extrahepatic failure (P = 0.029). Treatment failures after CCRT were frequent in HCC patients, and were more commonly intrahepatic-outfield and extrahepatic failures than infield failure. A history of pre-CCRT treatment and levels of pre-CCRT tumor markers were identified as risk factors that could predict treatment failure. More intensified treatment is required for patients presenting risk factors.

High-dose stereotactic body radiotherapy correlates increased local control and overall survival in patients with inoperable hepatocellular carcinoma

BACKGROUND

Recent studies using stereotactic body radiotherapy (SBRT) for hepatocellular carcinoma (HCC) have reported high tumor response and local control. However, the optimal SBRT dose remains unknown, and it is still not clear whether a dose response relationship for local control (LC) and overall survival (OS) exist or not. We performed this study to determine whether a dose response relationship for LC and OS is observed in SBRT for inoperable HCC.

METHODS

Between 2003 and 2011, 108 patients with HCC were treated with SBRT. All patients were unsuitable for surgery or local ablation and had incomplete response to transarterial chemoembolization. Eighty-two patients with a longest tumor diameter (LD) less than or equal to 7.0 cm who were treated with 3-fraction SBRT and were analyzed. This cohort comprised 74 Child-Turcotte-Pugh (CTP) class A patients and 8 CTP class B7 patients. The median LD was 3.0 cm (range, 1.0-7.0 cm), and the median dose was 51 Gy (range, 33-60 Gy).

RESULTS

LC and OS rates at 2 years after SBRT were 87% and 63%, respectively, with a median follow-up duration of 30 months for all patients. The 2-year LC/OS rates for patients treated with doses of > 54, 45-54, and < 45 Gy were 100/71, 78/64, and 64%/30%, respectively (p = .009/p < .001). Multivariate analysis revealed that the SBRT dose (p = .005) and Barcelona Clinic Liver Cancer stage (p = .015) were significant prognostic factors for OS. Correlation analysis revealed a positive linear relationship between the SBRT dose and LC (p = .006, R = .899)/OS (p = .002, R = .940) at 2 years. Based on the tumor-control probability model, a dose of 54.8 Gy provides 2-year LC with a 90% probability. Five patients experienced grade 3 or higher gastrointestinal toxicity, and 6 had deteriorating of CTP score by greater than or equal to 2 within 3 months of SBRT.

CONCLUSIONS

This study demonstrated a dose response relationship for LC and OS with SBRT for HCC. Higher LC rates resulting from an increased dose may translate into survival benefits for patients with HCC.

Phase II trial of palliative radiotherapy for hepatocellular carcinoma and liver metastases

PURPOSE

To evaluate the feasibility and response of liver radiotherapy (RT) in improving symptoms and quality of life in patients with hepatocellular carcinoma (HCC) or liver metastases (LM).

PATIENTS AND METHODS

Eligible patients had HCC or LM, unsuitable for or refractory to standard therapies, with an index symptom of pain, abdominal discomfort, nausea, or fatigue. The Brief Pain Inventory (BPI), Functional Assessment of Cancer Therapy-Hepatobiliary (FACT-Hep), and European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire C30 (EORTC QLQ-C30) were completed by patients at baseline and each follow-up. The primary outcome was the percentage of patients with a clinically significant change at 1 month in the BPI subscale of symptom on average in the past 24 hours. Secondary outcomes were improvement in other BPI subscales and at other time points, FACT-Hep and EORTC QLQ-C30 at each follow-up, and toxicity at 1 week.

RESULTS

Forty-one patients (30 men and 11 women) with HCC (n = 21) or LM (n = 20) were accrued. At 1 month, 48% had an improvement in symptom on average in the past 24 hours. Fifty-two percent of patients had improvement in symptom at its worst, 37% at its least, and 33% now. Improvements in the FACT-G and hepatobiliary subscale were seen in 23% and 29% of patients, respectively, at 1 month. There were also improvements in EORTC QLQ-C30 functional (range, 11% to 21%) and symptom (range, 11% to 50%) domains. One patient developed grade 3 nausea at 1 week.

CONCLUSION

Improvements in symptoms were observed at 1 month in a substantial proportion of patients. A phase III study of palliative liver RT is planned. [Corrected]

High-dose hypofractionated X-ray radiotherapy for hepatocellular carcinoma: Tumor responses and toxicities

Hypofractionated radiotherapy (RT) has been employed to treat hepatocellular carcinoma (HCC). The present study aimed to report the treatment effects, the dose-response associations and the factors that are associated with radiation-induced liver disease (RILD) in a high-dose hypofractionated RT procedure. A total of 40 patients with non-metastatic HCC who underwent RT for local control of irradiated tumors were studied. The treatment technique was that of three-dimensional conformal or intensity-modulated radiation therapy, with a fraction size of 3 Gy and a total dose of 40–66 Gy in 14–23 fractions. The biologically-effective dose (BED) was 52.0–85.8 Gy₁₀ (median, 74.1 Gy₁₀). Tumor regression was observed in 28 patients (70.0%) with a complete response, partial response, stable disease and progressive disease status in 11 (27.5%), 17 (42.5%), five (12.5%) and seven patients (17.5%), respectively. The one-, two- and five-year overall survival (OS) and in-field control (IFC) rates were 60, 40 and 21% and 73, 62 and 56%, respectively. A positive correlation also emerged between the radiation dose and the IFC (P=0.035). Eight of the 40 patients (20%) developed non-classic RILD. A higher Cancer of the Liver Italian Program score was associated with a higher probability of non-classic RILD (P=0.02). The tumor response and IFC rate of HCC following irradiation were significantly dose-dependent. High-dose hypofractionated X-ray RT is a feasible and effective treatment for HCC in patients with good liver function and for those who meet the criteria for a curative attempt.

A dose-volume intercomparison of volumetric-modulated arc therapy, 3D static conformal, and rotational conformal techniques for portal vein tumor thrombus in hepatocellular carcinoma

We created volumetric-modulated arc therapy (VMAT) plans for portal vein tumor thrombus (PVTT) in hepatocellular carcinoma, and compared the results with those from three-dimensional conformal radiotherapy (3D-CRT) and rotational conformal radiotherapy (R-CRT) plans. CT scan data from 10 consecutive patients with PVTT treated with 3D-CRT between January 2008 and January 2010 were utilized in the analysis. We analyzed the dosimetric properties of the plans for the 10 patients using the three different techniques with three different isocenter doses of 50, 56 and 60 Gy in 2-Gy fractions. The D95, Dmean, homogeneity index and conformity index were compared for the planning target volume (PTV). The Dmean, V20 and V30 were also compared for normal livers. The monitor units (MUs) and the treatment time were also evaluated. The normal liver V30 for VMAT was significantly less than that for 3D-CRT for the prescribed doses of 56 and 60 Gy (P < 0.05). It was also found that the normal liver V30 resulting from 3D-CRT was prohibitively increased when the prescribed dose was increased in two steps. For PTV D95, we found no significant differences between the three techniques for the 50- and 56-Gy prescriptions, or between VMAT and the other techniques for the 60-Gy prescription. The differences in the MUs and treatment times were not statistically significant between VMAT and 3D-CRT. We have demonstrated that VMAT may be a more advantageous technique for dose escalation reaching 60 Gy in the treatment of PVTT due to the reduced normal liver V30.

Determination and comparison of radiotherapy dose responses for hepatocellular carcinoma and metastatic colorectal liver tumours

OBJECTIVE

The purpose of this study was to seek radiation dose responses separately for primary hepatocellular carcinoma (HCC) and metastatic (MET) colorectal liver tumours to establish tumour control probabilities (TCPs) for radiotherapy (RT) of liver tumours.

METHODS

The records of 36 HCC and 26 MET colorectal liver tumour patients were reviewed. The median dose per fraction and total dose were 4 Gy (2-10 Gy) and 52 Gy (29-83 Gy) for the HCC group and 3.6 Gy (2.0-13.0 Gy) and 55 Gy (30-80 Gy) for the MET group, respectively. Median tumour diameter was 6.6 cm (3.0-18.0 cm) and 5.0 cm (1.0-13.0 cm) for the HCC and MET groups, respectively. A logistic TCP model was fitted to the response data for each group using the maximum likelihood method.

RESULTS

50% and 90% probabilities of 6-month local control were estimated to be achievable by 2 Gy per fraction equivalent doses (α/β=10 Gy) of 53 Gy and 84 Gy for the HCC group and 70 Gy and 95 Gy for the MET group, respectively. Actuarial 1-year local control for the HCC and MET groups was 65% (45-85%) and 32% (6-58%), respectively, whereas median time to failure was 543 days (374-711 days) and 183 days (72-294 days), respectively.

CONCLUSION

Dose-response relationships were found and modelled for the HCC and MET patient groups, with a higher dose required to control MET tumours. RT offers better local control for HCC than for MET colorectal liver tumours at our institution.

ADVANCES IN KNOWLEDGE

An improved understanding of radiation dose-response relationships for primary and MET colorectal liver tumours will help inform future dose prescriptions.

Predictive models for regional hepatic function based on 99mTc-IDA SPECT and local radiation dose for physiologic adaptive radiation therapy

PURPOSE

High-dose radiation therapy (RT) for intrahepatic cancer is limited by the development of liver injury. This study investigated whether regional hepatic function assessed before and during the course of RT using 99mTc-labeled iminodiacetic acid (IDA) single photon emission computed tomography (SPECT) could predict regional liver function reserve after RT.

METHODS AND MATERIALS

Fourteen patients treated with RT for intrahepatic cancers underwent dynamic 99mTc-IDA SPECT scans before RT, during, and 1 month after completion of RT. Indocyanine green (ICG) tests, a measure of overall liver function, were performed within 1 day of each scan. Three-dimensional volumetric hepatic extraction fraction (HEF) images of the liver were estimated by deconvolution analysis. After coregistration of the CT/SPECT and the treatment planning CT, HEF dose-response functions during and after RT were generated. The volumetric mean of the HEFs in the whole liver was correlated with ICG clearance time. Three models, dose, priori, and adaptive models, were developed using multivariate linear regression to assess whether the regional HEFs measured before and during RT helped predict regional hepatic function after RT.

RESULTS

The mean of the volumetric liver HEFs was significantly correlated with ICG clearance half-life time (r=-0.80, P<.0001), for all time points. Linear correlations between local doses and regional HEFs 1 month after RT were significant in 12 patients. In the priori model, regional HEF after RT was predicted by the planned dose and regional HEF assessed before RT (R=0.71, P<.0001). In the adaptive model, regional HEF after RT was predicted by regional HEF reassessed during RT and the remaining planned local dose (R=0.83, P<.0001).

CONCLUSIONS

99mTc-IDA SPECT obtained during RT could be used to assess regional hepatic function and helped predict post-RT regional liver function reserve. This could support individualized adaptive radiation treatment strategies to maximize tumor control and minimize the risk of liver damage.

Interventional oncologic approaches to liver metastases

Metastatic liver disease is the most common cause of death in cancer patients. Complete surgical resection is currently considered the only curative treatment, with only about 25% of patients being amenable to surgery. Therefore, a variety of interventional oncologic techniques have been developed for treating secondary liver malignancies. The aim of these therapies is either to allow patients with unresectable tumors to become surgical candidates, provide curative treatment options in nonsurgical candidates, or improve survival in a palliative or even curative approach. Among these interventional therapies are transcatheter therapies such as portal vein embolization, hepatic artery infusion chemotherapy, transarterial chemoembolization, and radioembolization, as well as interstitial techniques, particularly radiofrequency ablation as the most commonly applied technique. The rationale, application and clinical results of each of these techniques are reviewed on the basis of the current literature. Future prospects such as gene therapy and immunotherapy are introduced.

Proton therapy for hepatocellular carcinoma

Proton radiotherapy has seen an increasing role in the treatment of hepatocellular carcinoma (HCC). Historically, external beam radiotherapy has played a very limited role in HCC due to a high incidence of toxicity to surrounding normal structures. The ability to deliver a high dose of radiation to the tumor is a key factor in improving outcomes in HCC. Advances in photon radiotherapy have improved dose conformity and allowed dose escalation to the tumor. However, despite these advances there is still a large volume of normal liver that receives a considerable radiation dose during treatment. Proton beams do not have an exit dose along the beam path once they enter the body. The inherent physical attributes of proton radiotherapy offer a way to maximize tumor control via dose escalation while avoiding excessive radiation to the remaining liver, thus increasing biological effectiveness. In this review we discuss the physical attributes and rationale for proton radiotherapy in HCC. We also review recent literature regarding clinical outcomes of using proton radiotherapy for the treatment of HCC.

Prognostic factors affecting local control of hepatic tumors treated by Stereotactic Body Radiation Therapy

Purpose

Robotic Stereotactic Body Radiation Therapy with real-time tumor tracking has shown encouraging results for hepatic tumors with good efficacy and low toxicity. We studied the factors associated with local control of primary or secondary hepatic lesions post-SBRT.

Methods and materials

Since 2007, 153 stereotactic liver treatments were administered to 120 patients using the CyberKnife® System. Ninety-nine liver metastases (72 patients), 48 hepatocellular carcinomas (42 patients), and six cholangiocarcinomas were treated. On average, three to four sessions were delivered over 12 days. Twenty-seven to 45 Gy was prescribed to the 80% isodose line. Margins consisted of 5 to 10 mm for clinical target volume (CTV) and 3 mm for planning target volume (PTV).

Results

Median size was 33 mm (range, 5–112 mm). Median gross tumor volume (GTV) was 32.38 cm³ (range, 0.2–499.5 cm³). Median total dose was 45 Gy in three fractions. Median minimum dose was 27 Gy in three fractions. With a median follow-up of 15.0 months, local control rates at one and two years were 84% and 74.6%, respectively. The factors associated with better local control were lesion size < 50 mm (p = 0.019), GTV volume (p < 0.05), PTV volume (p < 0.01) and two treatment factors: a total dose of 45 Gy and a dose–per-fraction of 15 Gy (p = 0.019).

Conclusions

Dose, tumor diameter and volume are prognostic factors for local control when a stereotactic radiation therapy for hepatic lesions is considered. These results should be considered in order to obtain a maximum therapeutic efficacy.

Stereotactic body radiation therapy for abdominal oligometastases: a biological and clinical review

Advances in imaging and biological targeting have led to the development of stereotactic body radiation therapy (SBRT) as an alternative treatment of extracranial oligometastases. New radiobiological concepts, such as ceramide-induced endothelial apoptosis after hypofractionated high-dose SBRT, and the identification of patients with oligometastatic disease by microRNA expression may yet lead to further developments. Key factors in SBRT are delivery of a high dose per fraction, proper patient positioning, target localisation, and management of breathing-related motion. Our review addresses the radiation doses and schedules used to treat liver, abdominal lymph node (LN) and adrenal gland oligometastases and treatment outcomes. Reported local control (LC) rates for liver and abdominal LN oligometastases are high (median 2-year actuarial LC: 61 -100% for liver oligometastases; 4-year actuarial LC: 68% in a study of abdominal LN oligometastases). Early toxicity is low-to-moderate; late adverse effects are rare. SBRT of adrenal gland oligometastases shows promising results in the case of isolated lesions. In conclusion, properly conducted SBRT procedures are a safe and effective treatment option for abdominal oligometastases.

A phase I clinical and pharmacology study using amifostine as a radioprotector in dose-escalated whole liver radiation therapy

PURPOSE

Diffuse intrahepatic tumors are difficult to control. Whole-liver radiotherapy has been limited by toxicity, most notably radiation-induced liver disease. Amifostine is a prodrug free-radical scavenger that selectively protects normal tissues and, in a preclinical model of intrahepatic cancer, systemic amifostine reduced normal liver radiation damage without compromising tumor effect. We hypothesized that amifostine would permit escalation of whole-liver radiation dose to potentially control microscopic disease. We also aimed to characterize the pharmacokinetics of amifostine and its active metabolite WR-1065 to optimize timing of radiotherapy.

METHODS AND MATERIALS

We conducted a radiation dose-escalation trial for patients with diffuse, intrahepatic cancer treated with whole-liver radiation and intravenous amifostine. Radiation dose was assigned using the time-to-event continual reassessment method. A companion pharmacokinetic study was performed.

RESULTS

Twenty-three patients were treated, with a maximum dose of 40 Gy. Using a logistical regression model, compared with our previously treated patients, amifostine increased liver tolerance by 3.3 ± 1.1 Gy (p = 0.007) (approximately 10%) with similar response rates. Peak concentrations of WR-1065 were 25 μM with an elimination half-life of 1.5 h; these levels are consistent with radioprotective effects of amifostine in patients.

CONCLUSION

These findings demonstrate for the first time that amifostine is a normal liver radioprotector. They further suggest that it may be useful to combine amifostine with fractionated or stereotactic body radiation therapy for patients with focal intrahepatic cancer.

Radiotherapy for liver metastases: a review of evidence

Over the past decade, there has been an increasing use of radiotherapy (RT) for the treatment of liver metastases. Most often, ablative doses are delivered to focal liver metastases with the goal of local control and ultimately improving survival. In contrast, low-dose whole-liver RT may be used for the palliation of symptomatic diffuse metastases. This review examines the available clinical data for both approaches. The review found that RT is effective both for local ablation of focal liver metastases and for palliation of patients with symptomatic liver metastases. However, there is a lack of a high level of evidence from randomized clinical trials.

Arterial therapies of colorectal cancer metastases to the liver

Intra-arterial therapies directed to the liver take advantage that liver tumors are fed by the hepatic artery while the liver vascularization is 30% arterial. Most common techniques of intra-arterial therapies for colorectal cancer liver metastases (CRLM) include intra-arterial hepatic chemotherapy (IAHC), transarterial chemoembolization (TACE), and radioembolization. Such treatments are used as salvage therapies because they provide response when systemic therapies are inefficient. They are also used as a first line therapy to produce maximal response in order to convert the patient from non-surgical to surgical. IAHC with FUDR or oxaliplatinum allow 90% response rate and conversion to surgery of 40% to 50% of initially inoperable patients. TACE is used in CRLM with promising response rate, namely due to the use of drug eluting beads that can be loaded with irinotecan which can elute the drug they contain after embolization in liver tumor. Radioembolization is a unique way of delivering a high tumoricidal dose of radiation (>100 Gy) to liver tumor without harming the healthy liver, and provided interesting results in salvage therapy, enough to be evaluated today in a randomized control trial in first line therapy where FOLFOX is proposed with and without additional radioembolization.

Stereotactic body radiation therapy for liver metastases from colorectal cancer: analysis of safety, feasibility, and early outcomes

INTRODUCTION

Colorectal cancer (CRC) is the third leading cause of cancer-related death in the U.S. Many patients with CRC develop hepatic metastases as the sole site of metastases. Historical treatment options were limited to resection or conventional radiation therapy. Stereotactic body radiation therapy (SBRT) has emerged as a rational treatment approach. This study reviews our experience with SBRT for patients with liver metastases from CRC.

MATERIALS AND METHODS

Fourteen histologically confirmed hepatic CRC metastases in 11 consecutive patients were identified between November, 2004 and June, 2009 at Georgetown University. All patients underwent CT-based treatment planning; a few also had MRI or PET/CT. All patients had fiducial markers placed under CT guidance and were treated using the CyberKnife system. Treatment response and toxicities were examined; survival and local control were evaluated.

RESULTS

Most patients were treated to a single hepatic lesion (n = 8), with a few treated to two lesions (n = 3). Median treatment volume was 99.7 cm(3), and lesions were treated to a median BED(10) of 49.7 Gy (range: 28-100.8 Gy). Median follow-up was 21 months; median survival was 16.1 months, with 2 year actuarial survival of 25.7%. One year local control was 72%. Among patients with post-treatment imaging, eight had stable disease (80%) and two had progressive disease (20%) at first follow-up. The most common grade 1-2 acute toxicities included nausea and alterations in liver function tests; there was one grade 3 toxicity (elevated bilirubin), and no grade 4-5 toxicities.

DISCUSSION

SBRT is safe and feasible for the treatment of limited hepatic metastases from CRC. Our results compare favorably with outcomes from previous studies of SBRT. Further studies are needed to better define patient eligibility, study the role of combined modality treatment, optimize treatment parameters, and characterize quality of life after treatment.

Radiation therapy for liver metastases

Liver metastases are a common source of cancer morbidity and mortality and are often the only site of metastases. In the last 2 decades, major technological advancements in radiation treatment planning and delivery have resulted in resurgence in the use of radiation therapy (RT) as a treatment for liver tumors. With the advent of 3-dimensional conformal radiation treatment (CRT), partial liver irradiation became possible. Stereotactic body radiation therapy (SBRT) is a further enhancement, defined as highly focused, stereotactically localized and administered, high-dose RT delivered in a hypofractionated course. There is now more than a decade of experience with CRT and SBRT for the treatment of liver metastases. In selected patients, very high local control rates have been observed, with minimal toxicity. Patients most likely to benefit from RT are those with liver confined disease, focal distribution of metastases, and metastases more than 1.5 cm from luminal gastrointestinal organs. There is growing evidence that strategies using aggressive or ablative local therapies as an adjunct to systemic therapy might achieve improvements in overall outcome as long as they are administered safely.

Radiation therapy for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common malignancy worldwide, and its incidence is on the rise. The primary therapy is resection or liver transplant, but only a minority of patients present with resectable disease. Historically, radiotherapy has not played a significant role in the treatment of liver malignancies because of the low tolerance of the whole liver to radiation. With improvements in 3-dimensional conformal radiotherapy and intensity-modulated radiotherapy, higher doses of radiation can be delivered to target lesions with low doses to the noninvolved liver; thus, experience in the use of radiation for the treatment of focal HCC has increased. At the same time, our understanding of the relationships between radiation dose and volume and the risk of classic radiation-induced liver disease and other toxicities more likely to occur in HCC patients has improved considerably. These developments have led to a body of evidence that now supports the careful use of radiotherapy for unresectable HCC. The rationale for studying radiotherapy in a randomized trial is strong.

[Stereotactic body radiation therapy for liver primary and metastases: the Lille experience]

PURPOSE

The CyberKnife(®) system is a recent radiation therapy technique that allows treatment of liver lesions with real-time tracking. Because of its high precision, the dose administered to the tumor can be increased. We report Oscar-Lambret Cancer Centre experience in the treatment of primary and secondary liver lesions.

PATIENTS AND METHODS

It is a retrospective study analyzing all the patients who have been treated for their liver lesions since July 2007. A hundred and twenty patients have been treated: 42 for hepatocellular carcinoma, 72 for liver metastases and six for cholangiocarcinoma. Gold seeds need to be implanted before the treatment and are used as markers to follow the movement of the lesion due to respiration. On average, the treatment is administered in three to four sessions over 12 days. A total dose of 40 to 45 Gy at the 80% isodose is delivered. Local control and overall survival analysis with Log-rank is performed for each type of lesion.

RESULTS

Treatment tolerance is good. The most common toxicities are of digestive type, pain and asthenia. Six gastro-duodenal ulcers and two radiation-induced liver disease (RILD) were observed. At a median follow-up of 15 months, the local control rate is respectively of 80.4% and 72.5% at 1 and 2 years. Overall survival is 84.6 and 58.3% at 1 and 2 years. The local control is significantly better for the hepatocellular carcinoma and overall survival is significantly better for liver metastases (P<0.05). The local control rate and overall survival at 1 year for cholangiocarcinoma is 100%.

CONCLUSION

CyberKnife(®) is a promising technique, well tolerated, with tumoral local control rates comparable to other techniques. Its advantage is that it is very minimally invasive delivered as an outpatient procedure in a frail population of patient (disease, age).

Radiotherapeutic strategies in the management of hepatocellular carcinoma

Although potentially curative therapies for hepatocellular carcinoma (HCC) are well established, they are offered only to a limited number of patients. For advanced HCC, sorafenib is now the treatment of choice. Radiotherapy technology has evolved remarkably during the past decade and can be precisely delivered, thereby permitting higher doses to the tumor and reduced doses to surrounding normal tissues. According to the Korean Liver Cancer Study Group (KLCSG) practice guidelines, radiation therapy is considered appropriate for unresectable, locally advanced HCC without extrahepatic metastasis, Child-Pugh class A or B, and tumors occupying less than two thirds of the liver with level II evidence. In this review, we discuss the radiotherapeutic strategies for each clinical setting in patients with HCC.

Evaluation of response after stereotactic body radiotherapy for hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is increasing in incidence due to hepatitis C. Stereotactic body radiotherapy (SBRT) is a noninvasive, effective therapy in the management of liver malignancies. The authors evaluated radiological response in 26 patients with HCC treated with SBRT at Indiana University.

METHODS

Between March 2005 and June 2008, 26 patients with HCC who were not surgical candidates were enrolled in a phase 1 to 2 trial. Eligibility criteria included solitary tumors ≤ 6 cm or up to 3 lesions with sum diameters ≤ 6 cm, and well-compensated cirrhosis. All patients had imaging before, at 1 to 3 months, and every 3 to 6 months after SBRT.

RESULTS

Patients received 3 to 5 fractions of SBRT. Median SBRT dose was 42 Gray (Gy) (range: 24-48 Gy). Median follow-up was 13 months. Per Response Evaluation Criteria in Solid Tumors (RECIST), 4 patients had a complete response (CR), 15 had a partial response (PR), and 7 achieved stable disease (SD) at 12 months. One patient with SD experienced progression marginal to the treated area. The overall best response rate (CR + PR) was 73%. In comparison, by European Association for the Study of the Liver (EASL) criteria, 18 of 26 patients had ≥ 50% nonenhancement at 12 months. Thirteen of 18 demonstrated 100% nonenhancement, being > 50% in 5 patients. Kaplan-Meier 1- and 2-year survival estimates were 77% and 60%, respectively.

CONCLUSIONS

SBRT is effective therapy for patients with HCC with an overall best response rate (CR + PR) of 73%. Nonenhancement on imaging, a surrogate for ablation, may be a more useful indicator than size reduction in evaluating HCC response to SBRT in the first 6 to 12 months, supporting EASL criteria.

Charged-particle therapy for hepatocellular carcinoma

Historically, the use of external-beam radiotherapy for hepatocellular carcinoma (HCC) has been limited by toxicity to the uninvolved liver and surrounding structures. Advances in photon radiotherapy have improved dose conformality to the tumor and facilitated dose escalation, a key contributor to improved HCC radiation treatment outcomes. However, despite these advances in photon radiotherapy, significant volumes of liver still receive low doses of radiation that can preclude dose escalation, particularly in patients with limited functional liver reserves. By capitalizing on the lack of exit dose along the beam path beyond the tumor and higher biological effectiveness, charged-particle therapy offers the promise of maximizing tumor control via dose escalation without excessive liver toxicity. In this review, we discuss the distinctive biophysical attributes of both proton and carbon ion radiotherapy, particularly as they pertain to treatment of HCC. We also review the available literature regarding clinical outcomes and the toxicity of using charged particles for the treatment of HCC.

Early experience of helical tomotherapy for hepatobiliary radiotherapy

Helical tomotherapy (HT), an image-guided, intensity-modulated, radiation therapy technique, allows for precise targeting while sparing normal tissues. We retrospectively assessed the feasibility and tolerance of the hepatobiliary HT in 9 patients. A total dose of 54 to 60 Gy was prescribed (1.8 or 2 Gy per fraction) with concurrent capecitabine for 7 patients. There were 1 hepatocarcinoma, 3 cholangiocarcinoma, 4 liver metastatic patients, and 1 pancreatic adenocarcinoma. All but one patient received previous therapies (chemotherapy, liver radiofrequency, and/or surgery). The median doses delivered to the normal liver and to the right kidney were 15.7 Gy and 4.4 Gy, respectively, below the recommended limits for all patients. Most of the treatment-related adverse events were transient and mild in severity. With a median followup of 12 months, no significant late toxicity was noted. Our results suggested that HT could be safely incorporated into the multidisciplinary treatment of hepatobiliary or pancreatic malignant disease.

Hepatic proliferation after partial liver irradiation in Sprague-Dawley rats

The liver has powerful capability to proliferate in response to various injuries, but little is known as to liver proliferation after irradiation (IR) injury. This study investigated whether liver proliferation could be stimulated in low-dose irradiated liver by partial liver IR injury with high dose radiation. Sprague-Dawley rats were irradiated by 6-MV X-ray with single dose of 25 Gy to the right-half liver, while the left-half liver was shielded (0.7 Gy) or irradiated with single doses of 3.2, 5.6, and 8.0 Gy, respectively. Hepatic proliferation in the shielded and low-dose irradiated left-half liver was evaluated by serum hepatic growth factor (HGF), proliferating cell nuclei antigen (PCNA), liver proliferation index (PI), hepatocyte mitosis index (MI). The observation time was 0 day (before IR), 30, 60, 90, and 120 days after IR. Our results showed that serum HGF and hepatocyte HGF mRNA increased after IR with HGF mRNA peak on day 30 in the shielded and low-dose irradiated left-half livers, and their values increased as the dose increased to the left-half liver. Liver PI and PCNA mRNA peaked on day 60 with stronger expressions in higher doses-irradiated livers. MI increased after IR, with the peak noted on day 60 in the shielded and on day 90 in the low-dose irradiated left-half livers. There was a 30 day delay between MI peaks in the shielded and low-dose irradiated livers. In conclusion, 25 Gy partial liver IR injury could stimulate the shielded liver and low-dose irradiated liver to proliferate. In the livers receiving a dose range of 3.2-8.0 Gy, the proliferation was stronger in higher doses-irradiated liver than the low-dose irradiated. However, IR delayed hepatocyte mitosis.

Volumetric intensity-modulated Arc (RapidArc) therapy for primary hepatocellular carcinoma: comparison with intensity-modulated radiotherapy and 3-D conformal radiotherapy

Background

To compare the RapidArc plan for primary hepatocellular carcinoma (HCC) with 3-D conformal radiotherapy (3DCRT) and intensity-modulated radiotherapy (IMRT) plans using dosimetric analysis.

Methods

Nine patients with unresectable HCC were enrolled in this study. Dosimetric values for RapidArc, IMRT, and 3DCRT were calculated for total doses of 45~50.4 Gy using 1.8 Gy/day. The parameters included the conformal index (CI), homogeneity index (HI), and hot spot (V_107%) for the planned target volume (PTV) as well as the monitor units (MUs) for plan efficiency, the mean dose (D_mean) for the organs at risk (OAR) and the maximal dose at 1% volume (D_1%) for the spinal cord. The percentage of the normal liver volume receiving ≥ 40, > 30, > 20, and > 10 Gy (V_{40 Gy}, V_{30 Gy}, V_{20 Gy}, and V_{10 Gy}) and the normal tissue complication probability (NTCP) were also evaluated to determine liver toxicity.

Results

All three methods achieved comparable homogeneity for the PTV. RapidArc achieved significantly better CI and V_107% values than IMRT or 3DCRT (p < 0.05). The MUs were significantly lower for RapidArc (323.8 ± 60.7) and 3DCRT (322.3 ± 28.6) than for IMRT (1165.4 ± 170.7) (p < 0.001). IMRT achieved a significantly lower D_mean of the normal liver than did 3DCRT or RapidArc (p = 0.001). 3DCRT had higher V_{40 Gy} and V_{30 Gy} values for the normal liver than did RapidArc or IMRT. Although the V_{10 Gy} to the normal liver was higher with RapidArc (75.8 ± 13.1%) than with 3DCRT or IMRT (60.5 ± 10.2% and 57.2 ± 10.0%, respectively; p < 0.01), the NTCP did not differ significantly between RapidArc (4.38 ± 2.69) and IMRT (3.98 ± 3.00) and both were better than 3DCRT (7.57 ± 4.36) (p = 0.02).

Conclusions

RapidArc provided favorable tumor coverage compared with IMRT or 3DCRT, but RapidArc is not superior to IMRT in terms of liver protection. Further studies are needed to establish treatment outcome differences between the three approaches.

Transcatheter intraarterial therapies: rationale and overview

Transcatheter intraarterial therapies have proved valuable in the battle against primary and secondary hepatic malignancies. The unique aspects of all such therapies are their reduced toxicity profiles and highly effective tumor responses. These unique characteristics coupled with their minimally invasive nature provide an attractive therapeutic option in patients who may have previously had few alternatives. The concept of all catheter-based intraarterial therapies is to selectively deliver anticancer treatment to tumor(s). These therapies, which include transarterial embolization, intraarterial chemoinfusion, transarterial chemoembolization with or without drug-eluting beads, and radioembolization with use of yttrium 90, inflict lethal insult to tumors while preserving normal hepatic parenchyma. This is possible because hepatic neoplasms preferentially derive their blood supply from an arterial source while the majority of noncancerous liver is supplied by the portal vein. As part of the interventional oncology review series, in this article we describe the rationale behind each of these transcatheter therapies and provide a review of the existing medical literature.

Usefulness of positron emission tomography with fluorine-18-fluorodeoxyglucose in predicting treatment response in unresectable hepatocellular carcinoma patients treated with external beam radiotherapy

PURPOSE

To assess the significance of the ratio between standardized uptake values (SUV) of tumor and normal liver tissue obtained from positron emission tomography with fluorine-18-fluorodeoxyglucose (FDG-PET) in predicting the response of hepatocellular carcinoma (HCC) patients treated with external beam radiotherapy (EBRT).

METHODS AND MATERIALS

We retrospectively analyzed 35 HCC patients who were treated with EBRT between January 2004 and June 2007. All patients underwent FDG-PET in which SUV values were obtained from tumor and normal liver tissues and were used to calculate the ratios (SUV(Tumor)/SUV(Liver)). After FDG-PET, patients received liver treatment including concurrent chemoradiation, transarterial chemoembolization plus RT, or intraarterial chemotherapy plus RT. Using three-dimensional conformal RT, median dose of 45 Gy was delivered in conventional fractions. Patients underwent abdominal/pelvic CT 1 month after RT, and treatment responses were evaluated according to the Response Evaluation Criteria in Solid Tumors criteria.

RESULTS

Patients were divided into high-SUV ratio group (n = 20) and low-SUV ratio group (n = 15) according to SUV ratio at a cutoff value of 2.5. Objective responses consisting of either complete response (CR) or partial response (PR) were observed in 16 and 6 patients (46% vs. 17%, p = 0.015), respectively; median survivals after RT were 8 months and 5 months (p = 0.41) for the high-SUV ratio group and the low-SUV ratio group, respectively. Rates of intrahepatic metastases (9% vs. 11%, p = 0.39) and distant metastases (32% vs. 32%, p = 0.27) showed no significant difference between two groups.

CONCLUSIONS

External beam RT for HCC patients with higher SUV ratios resulted in higher response rates than for patients with lower SUV ratios. Treatment of HCC with higher SUV ratios did not result in increased survival; high rates of intrahepatic and distant metastases in both SUV groups may have affected patient survival. SUV ratios from pre-RT FDG-PET may be beneficial for selecting patients who are likely to respond to EBRT for unresectable HCC.

Phase i study evaluating the treatment of patients with hepatocellular carcinoma (HCC) with carbon ion radiotherapy: the PROMETHEUS-01 trial

Background

Treatment options for patients with advanced hepatocellular carcinoma (HCC) are often limited. In most cases, they are not amenable to local therapies including surgery or radiofrequency ablation. The multi-kinase inhibitor sorafenib has shown to increase overall survival in this patient group for about 3 months.

Radiation therapy is a treatment alternative, however, high local doses are required for long-term local control. However, due to the relatively low radiation tolerance of liver normal tissue, even using stereotactic techniques, delivery of sufficient doses for successful local tumor control has not be achieved to date.

Carbon ions offer physical and biological characteristics. Due to their inverted dose profile and the high local dose deposition within the Bragg peak precise dose application and sparing of normal tissue is possible. Moreover, in comparison to photons, carbon ions offer an increased relative biological effectiveness (RBE), which can be calculated between 2 and 3 depending on the HCC cell line as well as the endpoint analyzed.

Japanese Data on the evaluation of carbon ion radiation therapy showed promising results for patients with HCC.

Methods/Design

In the current Phase I-PROMETHEUS-01-Study, carbon ion radiotherapy will be evaluated for patients with advanced HCC. The study will be performed as a dose-escalation study evaluating the optimal carbon ion dose with respect to toxicity and tumor control.

Primary endpoint is toxicity, secondary endpoint is progression-free survival and response.

Discussion

The Prometheus-01 trial ist the first trial evaluating carbon ion radiotherapy delivered by intensity-modulated rasterscanning for the treatment of HCC. Within this Phase I dose escalation study, the optimal dose of carbon ion radiotherapy will be determined.

Trial registration

NCT 01167374