High-dose proton beam radiotherapy of hepatocellular carcinoma: preliminary results of a phase II trial

The effectiveness of particle radiotherapy for hepatocellular carcinoma associated with inferior vena cava tumor thrombus

BACKGROUND

The prognosis of patients who have hepatocellular carcinoma (HCC) associated with inferior vena cava tumor thrombus (IVCTT) is very poor, and effective treatment modalities are extremely limited. The objective of this study was to determine the therapeutic efficacy of particle radiotherapy for HCC with IVCTT.

METHODS

Between June 2001 and January 2009, 16 evaluable patients who had HCC with IVCTT were treated with particle radiotherapy. They were divided into 2 groups: 6 were treated with curative intent; 10 with palliative intent. The local tumor control rates, overall survival rates, and toxicities were evaluated.

RESULTS

All tumors treated with particle radiotherapy remained controlled without local recurrence at the last follow-up. The overall survival rates for the 16 patients at 1 and 3 years were 61.1 and 36.7%, respectively. We observed a significant difference in the survival rates according to treatment policy. The median survival time was 25.4 months for patients treated with curative intent and 7.7 months for those treated with palliative intent. The one-year survival rates were 100.0 and 33.3%, respectively. No Grade 3 or higher treatment-related toxicities were observed.

CONCLUSIONS

Particle radiotherapy is thought to be potentially effective and safe for HCC with IVCTT. Considering the current lack of effective and less-invasive local therapy for HCC with IVCTT, particle radiotherapy may therefore be an attractive new therapeutic approach for this type of HCC.

Clinical results and risk factors of proton and carbon ion therapy for hepatocellular carcinoma

BACKGROUND

The objective of this study was to evaluate the clinical outcome of proton and carbon ion therapy for hepatocellular carcinoma (HCC).

METHODS

In total, 343 consecutive patients with 386 tumors, including 242 patients (with 278 tumors) who received proton therapy and 101 patients (with 108 tumors) who received carbon ion therapy, were treated on 8 different protocols of proton therapy (52.8-84.0 gray equivalents [GyE] in 4-38 fractions) and on 4 different protocols of carbon ion therapy (52.8-76.0 GyE in 4-20 fractions).

RESULTS

The 5-year local control and overall survival rates for all patients were 90.8% and 38.2%, respectively. Regarding proton and carbon ion therapy, the 5-year local control rates were 90.2% and 93%, respectively, and the 5-year overall survival rates were 38% and 36.3%, respectively. These rates did not differ significantly between the 2 therapies. Univariate analysis identified tumor size as an independent risk factor for local recurrence in proton therapy, carbon ion therapy, and in all patients. Multivariate analysis identified tumor size as the only independent risk factor for local recurrence in proton therapy and in all patients. Child-Pugh classification was the only independent risk factor for overall survival in proton therapy, in carbon ion therapy, and in all patients according to both univariate and multivariate analyses. No patients died of treatment-related toxicities.

CONCLUSIONS

Proton and carbon ion therapies for HCC were comparable in terms of local control and overall survival rates. These therapies may represent innovative alternatives to conventional local therapies for HCC.

Review of clinical experience with ion beam radiotherapy

The article describes both the early development of oncology as a core discipline at the University of Heidelberg Hospital and the first steps towards ion beam treatment, from the pilot project carried out in co-operation with the Gesellschaft für Schwerionenforschung Darmstadt to the initial start-up of clinical service at the Heidelberg Heavy Ion Centre (HIT). We present an overview, based on data published in the literature, of the available clinical evidence relating the use of ion beam therapy to treat major indications in active particle centres. A rationale for the use of particle therapy in each of these indications is given. In view of the limited availability of data, we discuss the necessity to conduct clinical trials. We also look forward towards the next activities to be undertaken at the HIT.

The safety and efficacy of high-dose proton beam radiotherapy for hepatocellular carcinoma: a phase 2 prospective trial

BACKGROUND

Proton beam therapy (PBT) may provide useful local-regional treatment for hepatocellular carcinoma (HCC). The purpose of this study was to evaluate the safety and efficacy of PBT for HCC.

METHODS

Patients with cirrhosis who had radiological features or biopsy-proven HCC were included in the study. Patients without cirrhosis and patients with extrahepatic metastasis were excluded. The mean age was 62.7 years. The mean tumor size was 5.5 cm. Eleven patients had multiple tumors, and 46% were within the Milan criteria. Patients received 63 Gy delivered over a 3-week period with PBT.

RESULTS

Seventy-six patients were treated and followed prospectively for treatment outcomes at Loma Linda University Medical Center. Acute toxicity was minimal; all patients completed the full course of treatment. Radiation-induced liver disease was evaluated using liver enzyme, bilirubin, and albumin levels; no significant change supervened 6 months posttreatment. Median progression-free survival for the entire group was 36 months, with a 60% 3-year progression-free survival rate for patients within the Milan criteria. Eighteen patients subsequently underwent liver transplantation; 6 (33%) explants showed pathological complete response and 7 (39%) showed only microscopic residual.

CONCLUSIONS

PBT was found to be a safe and effective local-regional therapy for inoperable HCC. A randomized controlled trial to compare its efficacy to a standard therapy has been initiated. Cancer 2011. © 2011 American Cancer Society.

Risk factors for survival and local recurrence after particle radiotherapy for single small hepatocellular carcinoma

BACKGROUND

Particle radiotherapy is a novel treatment for malignant tumours. The present study aimed to evaluate risk factors for overall survival and local control after particle radiotherapy of single small hepatocellular carcinoma (HCC), and to identify suitable candidates for this treatment.

METHODS

All patients with a single HCC smaller than 5 cm in diameter treated by particle radiotherapy between 2001 and 2008 were identified retrospectively from a prospectively collected database. Clinical outcomes and prognostic factors were analysed.

RESULTS

A total of 150 patients were included. Five-year overall survival and local control rates were 50.9 and 92.3 per cent respectively. Multivariable analysis revealed that several factors, including age and Child-Pugh classification, significantly influenced overall survival. Proximity to the digestive tract and Child-Pugh classification were independent risk factors for local recurrence. Other tumour factors including size, gross classification, previous treatment, macroscopic vascular invasion, and tumour location in relation to the diaphragm and large vessels did not influence local control rate.

CONCLUSION

Particle radiotherapy seems safe and effective, and may be a novel treatment for small HCC. Recurrences are more frequent when the tumour is located close to the gut.

Proton beam therapy for hepatocellular carcinoma: a comparison of three treatment protocols

BACKGROUND

Our previous results for treatment of hepatocellular carcinoma (HCC) with proton beam therapy revealed excellent local control with low toxicity. Three protocols were used to avoid late complications such as gastrointestinal ulceration and bile duct stenosis. In this study, we examined the efficacy of these protocols.

METHODS AND MATERIALS

The subjects were 266 patients (273 HCCs) treated by proton beam therapy at the University of Tsukuba between January 2001 and December 2007. Three treatment protocols (A, 66 GyE in 10 fractions; B, 72.6 GyE in 22 fractions; and C, 77 GyE in 35 fractions) were used, depending on the tumor location.

RESULTS

Of the 266 patients, 104, 95, and 60 patients were treated with protocols A, B, and C, respectively. Seven patients with double lesions underwent two different protocols. The overall survival rates after 1, 3 and 5 years were 87%, 61%, and 48%, respectively (median survival, 4.2 years). Multivariate analysis showed that better liver function, small clinical target volume, and no prior treatment (outside the irradiated field) were associated with good survival. The local control rates after 1, 3, and 5 years were 98%, 87%, and 81%, respectively. Multivariate analysis did not identify any factors associated with good local control.

CONCLUSIONS

This study showed that proton beam therapy achieved good local control for HCC using each of three treatment protocols. This suggests that selection of treatment schedules based on tumor location may be used to reduce the risk of late toxicity and maintain good treatment efficacy.

The clinical experience with particle therapy in adults

Radiation therapy with charged particles, such as protons and heavier ions, provides physical selectivity and therefore allows for favorable dose distributions in comparison with conventional photon radiotherapy. Carbon ions furthermore exhibit biologic advantages related to their high linear energy transfer properties in a number of tumors known to be relatively insensitive to low-linear energy transfer radiation therapy. Over the last 2 decades, major developments in the fields of accelerator technology, diagnostic techniques, and beam delivery methods have been made. These developments formed the basis for the application of particle beams in clinical surroundings. Many clinical centers are already considering the introduction of radiation therapy with charged particles. This article reviews the clinical experience with particle therapy in adults available so far.

Current clinical evidence for proton therapy

Proton beam therapy provides the opportunity for more localized delivery of ionizing radiation with the potential for improved normal tissue avoidance to reduce treatment related morbidity and to allow for dose escalation to improve disease control and survival without increased toxicity. However, a systematic review of published peer-reviewed literature reported previously and updated here is devoid of any clinical data demonstrating benefit in terms of survival, tumor control, or toxicity in comparison with best conventional treatment for any of the tumors so far treated including skull base and ocular tumors, prostate cancer and childhood malignancies. The current lack of evidence for benefit of protons should provide a stimulus for continued research. Well designed in silico clinical trials using validated normal tissue complication probability-models are important to predict the magnitude of benefit for individual tumor sites but the future use of protons should be guided by clear evidence of benefit demonstrated in well-designed prospective studies, away from commercial influence, and this is likely to require international collaboration. Any complex and expensive technology, including proton therapy, should not be employed on the basis of belief alone and requires testing to avoid inappropriate use of potential detriment to future patients.

Dose-volume histogram analysis of the safety of proton beam therapy for unresectable hepatocellular carcinoma

PURPOSE

To evaluate the safety and efficacy of radiotherapy using proton beam (PRT) for unresectable hepatocellular carcinoma.

METHODS AND MATERIALS

Sixty consecutive patients who underwent PRT between May 1999 and July 2007 were analyzed. There were 42 males and 18 females, with a median age of 70 years (48-92 years). All but 1 patient had a single lesion with a median diameter of 45 mm (20-100 mm). Total PRT dose/fractionation was 76-cobalt Gray equivalent (CGE)/20 fractions in 46 patients, 65 CGE/26 fractions in 11 patients, and 60 CGE/10 fractions in 3 patients. The risk of developing proton-induced hepatic insufficiency (PHI) was estimated using dose-volume histograms and an indocyanine-green retention rate at 15 minutes (ICG R15).

RESULTS

None of the 20 patients with ICG R15 of less than 20% developed PHI, whereas 6 of 8 patients with ICG R15 values of 50% or higher developed PHI. Among 32 patients whose ICG R15 ranged from 20% to 49.9%, PHI was observed only in patients who had received 30 CGE (V30) to more than 25% of the noncancerous parts of the liver (n = 5) Local progression-free and overall survival rates at 3 years were 90% (95% confidence interval [CI], 80-99%) and 56% (95% CI, 43-69%), respectively. A gastrointestinal toxicity of Grade ≥2 was observed in 3 patients.

CONCLUSIONS

ICG R15 and V30 are recommended as useful predictors for the risk of developing PHI, which should be incorporated into multidisciplinary treatment plans for patients with this disease.

Nonoperative therapies for combined modality treatment of hepatocellular cancer: expert consensus statement

Although surgical resection and liver transplantation are the only treatment modalities that enable prolonged survival in patients with hepatocellular carcinoma (HCC), the majority of HCC patients presents with advanced disease and do not undergo resective or ablative therapy. Transarterial chemoembolization (TACE) is indicated in intermediate/advanced stage unresectable HCC even in the setting of portal vein involvement (excluding main portal vein). Sorafenib has been shown to improve survival of patients with advanced HCC in two controlled randomized trials. Yttrium 90 is a safe microembolization treatment that can be used as an alternative to TACE in patients with advanced liver only disease or in case of portal vein thrombosis. External beam radiation can be helpful to provide local control in selected unresectable HCC. These different treatment modalities may be combined in the treatment strategy of HCC and also used as a bridge to resection or liver transplantation. Patients should undergo formal multidisciplinary evaluation prior to initiating any such treatment in order to individualize the best available options.

[Practice guidelines for management of hepatocellular carcinoma 2009]

Hepatocellular carcinoma (HCC) is a major cancer in Korea, typically has a poor prognosis, and constitutes the majority of primary hepatic malignancies. It is the number one cause of death among people in their 50s in Korea. The five-year survival rate of liver cancer is poor; at 18.9%. Efforts to increase the survival rate through early diagnosis of HCC and optimal treatments are keenly needed. Western guideline for the management of HCC were developed, but these guidelines are somewhat unsuitable for Korean patients. Thus, the Korean Liver Cancer Study Group (KLCSG) and the National Cancer Center (NCC), Korea jointly produced the Clinical Practice Guidelines for HCC for the first time in Korea in 2003. Owing to medical advances over the following six years, diagnosis and treatment of HCC has changed considerably. As more national and foreign data are accumulated, KLCSG and NCC, Korea recently revised the Clinical Practice Guidelines for HCC. Forty or more specialists in the field of hepatology, general surgery, radiology and radiation oncology participated, and meticulously reviewed national and foreign papers, and collected opinions through advisory committee conferences. These multidisciplinary, evidence-based guidelines summarized diagnosis, surgical resection, liver transplantation, local treatments, transarterial chemoembolization, radiation therapy, chemotherapy, preemptive antiviral treatments, and response evaluation of HCC. These Korean guidelines are expected to be useful for clinical management of and research on HCC.

Do we have enough evidence to implement particle therapy as standard treatment in lung cancer? A systematic literature review

BACKGROUND

The societal burden of lung cancer is high because of its high incidence and high lethality. From a theoretical point of view, radiotherapy with beams of protons and heavier charged particles, for example, carbon ions (C-ions), should lead to superior results, compared with photon beams. In this review, we searched for clinical evidence to justify implementation of particle therapy as standard treatment in lung cancer.

METHODS

A systematic literature review based on an earlier published comprehensive review was performed and updated through November 2009.

RESULTS

Eleven fully published studies, all dealing with non-small cell lung cancer (NSCLC), mainly stage I, were identified. No phase III trials were found. For proton therapy, 2- to 5-year local tumor control rates varied in the range of 57%-87%. The 2- and 5-year overall survival (OS) and 2- and 5-year cause-specific survival (CSS) rates were 31%-74% and 23% and 58%-86% and 46%, respectively. Radiation-induced pneumonitis was observed in about 10% of patients. For C-ion therapy, the overall local tumor control rate was 77%, but it was 95% when using a hypofractionated radiation schedule. The 5-year OS and CSS rates were 42% and 60%, respectively. Slightly better results were reported when using hypofractionation, 50% and 76%, respectively.

CONCLUSION

The present results with protons and heavier charged particles are promising. However, the current lack of evidence on the clinical (cost-)effectiveness of particle therapy emphasizes the need to investigate the efficiency of particle therapy in an adequate manner. Until these results are available for lung cancer, charged particle therapy should be considered experimental.

Ion beam radiobiology and cancer: time to update ourselves

High-energy protons and carbon ions exhibit an inverse dose profile allowing for increased energy deposition with penetration depth. Additionally, heavier ions like carbon beams have the advantage of a markedly increased biological effectiveness characterized by enhanced ionization density in the individual tracks of the heavy particles, where DNA damage becomes clustered and therefore more difficult to repair, but is restricted to the end of their range. These superior biophysical and biological profiles of particle beams over conventional radiotherapy permit more precise dose localization and make them highly attractive for treating anatomically complex and radioresistant malignant tumors but without increasing the severe side effects in the normal tissue. More than half a century since Wilson proposed their use in cancer therapy, the effects of particle beams have been extensively investigated and the biological complexity of particle beam irradiation begins to unfold itself. The goal of this review is to provide an as comprehensive and up-to-date summary as possible of the different radiobiological aspects of particle beams for effective application in cancer treatment.

DNA damage by low-energy ions

Ion-beam irradiation provides a promising treatment for some types of cancer. This promise is due mainly to the selective deposition of energy into a relatively small volume (the Bragg peak), thus reducing damage to healthy tissue. Recent observations that electrons with energies below the ionization potential of DNA can cause covalent damage to the bases and backbone have led to investigations into the ability of low-energy (<1 keV·Da−1) ion beams to damage double-stranded DNA. It has been clearly demonstrated that these low-energy ions induce a mixture of single- and double-strand breaks to dried DNA in vacuo. These effects depend upon the number of ions incident upon the DNA, the kinetic energy of the ions and on their charge state. This DNA damage may be important, as all radiotherapies will result in the production of low-energy secondary ions as radiation passes through tissues. Currently, their effects are neglected in treatment planning, and thus more work is required to quantify and understand DNA damage by low-energy ions.

Sequential evaluation of hepatic functional reserve by 99mTechnetium-galactosyl human serum albumin scintigraphy after proton beam therapy: a report of three cases and a review of the literatures

The treatment strategy for malignant liver tumors should be appropriately determined because post-treatment quality of life greatly depends on the patients' residual hepatic function. In this report, we present three patients with malignant liver tumors treated by proton beam therapy in whom pre- and post-therapeutic hepatic functional reserves were evaluated sequentially for more than a year by 99mTechnetium-galactosyl human serum albumin (99mTc-GSA) scintigraphy. All three patients exhibited the distinctive time course of 99mTc-GSA uptake efficiency, which suggested a transient decline in the ratio of liver activity to heart and liver activity at 15 minutes (LHL15) 3-6 months after proton beam therapy. This change was not in parallel with that expected from a functioning normal liver tissue volume. In a year after proton beam therapy, LHL15 recovered nearly to the pre-treatment level in all three patients. Our observations may be related to the up-regulation of receptor-mediated 99mTc-GSA uptake during hepatic regeneration after proton beam therapy.

Radiation techniques in neuro-oncology

Radiation therapy plays a critical role in the management of tumors of the brain. A variety of radiotherapy techniques have been used to treat these tumors. This review describes both classic and more recent and advanced techniques available to manage these tumors. Included is a discussion of standard two- and three-dimensional radiation, as well as intensity-modulated radiotherapy, image-guided radiation therapy, stereotactic radiosurgery, and heavy particles.

Modern diagnosis and management of hepatocellular carcinoma

The incidence of hepatocellular carcinoma (HCC) is rising, and the number of patients with HCC is expected to more than double over the next 1 to 2 decades. HCC meets the criteria for establishment of a surveillance program. Patients with cirrhosis, regardless of the cause, are at the highest risk for developing HCC and this is the population in which surveillance should be performed. (Alpha-fetoprotein and hepatic ultrasonography are the currently recommended surveillance tests. If a surveillance test is abnormal, there is a need for a recall test for diagnostic evaluation of HCC. Triple-phase imaging is recommended for evaluation at recall, with MRI being more sensitive and specific. Novel genetic markers can improve the histologic diagnosis of early HCC. The Barcelona staging classification is the best system for determining the prognosis of patients and it is linked to an evidence-based treatment algorithm. Resection, transplantation, and percutaneous ablation are considered curative interventions and are currently applied to about 30% of all patients with HCC.

Synergistic effect of radiation and interleukin-6 on hepatitis B virus reactivation in liver through STAT3 signaling pathway

PURPOSE

Hepatitis B virus (HBV) reactivation can occur after radiotherapy (RT) for hepatobiliary malignancies. Our previous in vitro culture study identified interleukin-6 (IL-6) as the main bystander mediator of RT-induced HBV replication. We attempted to examine the molecular mechanism in HBV-transgenic mice.

METHODS AND MATERIALS

HBV transgenic mice were treated with whole liver RT (4 Gy daily for 5 days) with or without administration of IL-6 (400 ng twice daily for 15 days). The serum level of HBV DNA was measured using real-time polymerase chain reaction, and the IL-6 concentration was measured using enzyme-linked immunosorbent assay. The intensity of immunostaining with antibodies to HBV core protein and phosphorylated signal transducer and activator of transcription (STAT)3 in the mouse liver was qualitatively analyzed. HepG2.2.15 cells (a human hepatoblastoma cell line that persistently produces HBV DNA) were used to investigate the molecular role of IL-6 plus RT in HBV reactivation.

RESULTS

HBV reactivation was induced in vivo with IL-6 plus RT (5.58-fold) compared with RT alone (1.31-fold, p = .005), IL-6 alone (1.31-fold, p = .005), or sham treatment (1.22-fold, p = .004). HBV core protein staining confirmed augmentation of intrahepatic HBV replication. IL-6 plus RT-induced HBV DNA replication in HepG2.2.15 cells was suppressed by the STAT3 inhibitor AG490 and by transfection with dominant-negative STAT3 plasmid. Phosphorylated STAT3 staining was strongest in liver tissue from mice treated with IL-6 plus RT. The mobility shift assay demonstrated that reactivation was mediated through the interaction of phosphorylated STAT3/hepatocyte nuclear factor-3 complex with HBV enhancer 1.

CONCLUSION

RT to the liver and longer sustained IL-6 induced HBV reactivation through the STAT3 signal transduction pathway.

A prospective study of hypofractionated proton beam therapy for patients with hepatocellular carcinoma

PURPOSE

To evaluate the efficacy and safety of hypofractionated proton beam therapy for patients with hepatocellular carcinoma (HCC).

METHODS AND MATERIALS

Between September 2001 and August 2004, 51 patients with HCC greater than 2 cm away from the porta hepatis or gastrointestinal tract were treated with proton beam therapy to 66 Gy-equivalents (GyE) in 10 fractions.

RESULTS

Overall survival rates were 49.2 and 38.7% at 3 and 5 years after treatment. Local control rates were 94.5 and 87.8% at 3 and 5 years after treatment. Posttreatment serum alpha-fetoprotein values were significantly reduced when compared with pretreatment values (p < 0.0001). Patients experienced only minor acute reactions of Grade 1 or less, and 3 patients experienced late sequelae of Grade 2 or higher. However, there were no treatment-related deaths.

CONCLUSIONS

Hypofractionated proton beam therapy is safe and well-tolerated by patients with HCC located greater than 2 cm away from the porta hepatis or gastrointestinal tract and may be effective alternative to other modalities.

Proton radiotherapy for liver tumors: dosimetric advantages over photon plans

The purpose of the study is to dosimetrically investigate the advantages of proton radiotherapy over photon radiotherapy for liver tumors. The proton plan and the photon plan were designed using commercial treatment planning systems. The treatment target dose conformity and heterogeneity and dose-volume analyses of normal structures were compared between proton and photon radiotherapy for 9 patients with liver tumors. Proton radiotherapy delivered a more conformal target dose with slightly less homogeneity when compared with photon radiotherapy. Protons significantly reduced the fractional volume of liver receiving dose greater or equal to 30 Gy (V(30)) and the mean liver dose. The stomach and duodenal V(45) were significantly lower with the use of proton radiotherapy. The V(40) and V(50) of the heart and the maximum spinal cord dose were also significantly lower with the use of proton radiotherapy. Protons were better able to spare one kidney completely and deliver less dose to one (generally the left) kidney than photons. The mean dose to the total body and most critical structures was significantly decreased using protons when compared to corresponding photon plans. In conclusion, our study suggests the dosimetric benefits of proton radiotherapy over photon radiotherapy. These dosimetric advantages of proton plans may permit further dose escalation with lower risk of complications.

Hepatocellular carcinoma: radiation therapy

Although whole liver tolerance to radiation therapy (RT) is low, hepatocellular carcinoma (HCC) can be treated with focal high-dose RT, using a variety of advanced and specialized treatment strategies. Technical advancements in external beam RT that facilitate the safe delivery of RT to a wide spectrum of patients include conformal RT planning, breathing motion management, and image-guided RT. A variety of doses and RT fractionation schemes have been used safely alone or in combination with other therapies such as transarterial chemoembolization. Charged particles, produced from very specialized treatment units, are associated with particularly desirable dose distributions allowing tumoricidal doses to be delivered with sustained tumor control and little toxicity, even in the presence of Child-Pugh class B or C cirrhosis. Another strategy to deliver RT to HCC is hepatic arterial delivery of radioisotopes, such as microspheres tagged with yttrium-90. Liver toxicity is more likely in patients with reduced liver reserve and/or tumors infiltrating the majority of the liver. Phase II studies and a small phase III trial have demonstrated activity of hepatic arterial radioisotopes in HCC, providing rationale for large confirmatory randomized trials. Recurrences after RT occur most often within the liver, outside the high-dose irradiated volume, and outcomes after RT to very large and/or diffuse HCC are poor, providing rationale for combining RT with other therapies or novel radiation sensitizers. Given the vascular properties of HCC, there is rationale for investigating RT with anti-vascular endothelial growth factor-targeted agents.

Conformal radiotherapy for hepatocellular carcinoma

Technical advancements in radiation therapy (RT) have facilitated the safe delivery of conformal, dose-escalated radiation to a wide spectrum of hepatocellular carcinoma (HCC) patients. A variety of doses and RT fractionation schemes have been used, and RT has been used in combination with transarterial chemoembolization (TACE). Compared to untreated historical controls or those treated with TACE alone, outcomes following RT alone or TACE and RT are better. Despite advances in RT delivery, liver toxicity following RT remains a dose-limiting factor, and investigations to better understand the pathophysiology of RT-induced liver toxicity are warranted. For most tumors, RT can provide sustained local control. However, HCC tends to recur within the liver away from the irradiated volume, providing rationale for combining RT with systemic or regional therapies. There is a particular interest in combining RT with anti-VEGF-targeted agents for their independent activity in HCC as well as their radiation sensitization properties. Randomized trials of RT are warranted.

The evolving role of radiation therapy in hepatocellular carcinoma

Technical advancements in imaging, in radiation therapy (RT) planning and RT delivery, have facilitated the safe delivery of conformal radiation therapy to patients with unresectable hepatocellular carcinoma (HCC). Although experience in liver cancer RT is limited, the RT technologies and tools to deliver RT safely are being disseminated rapidly. A variety of doses and RT fractionations have been used to treat HCC, and RT has been used in combination with other therapies including transarterial hepatic chemoembolization (TACE). Outcomes following RT alone or RT and TACE appear better than outcomes following similar historical controls of TACE alone, however, randomized trials of RT are needed. The first site of recurrence following RT is most often within the liver, away from the high dose volume, providing rationale for combining RT with regional or systemic therapies. Given the vascular properties of HCC, the combination of RT with anti-VEGF targeted agents may improve outcomes further.

Proton beam therapy for hepatocellular carcinoma adjacent to the porta hepatis

PURPOSE

To evaluate the efficacy and safety of proton beam therapy (PBT) for patients with hepatocellular carcinoma (HCC) located adjacent to the porta hepatis.

METHODS AND MATERIALS

Subjects of the study were 53 patients with HCC located within 2 cm of the main portal vein. All patients had tumor confined to the radiation field with no evidence of metastatic disease. All patients had hepatic function levels of a Child-Pugh score of 10 or less, Eastern Cooperative Oncology Group performance status of 2 or less, and no uncontrolled ascites. Patients underwent PBT of 72.6 GyE in 22 fractions from Sept 2001 to Dec 2004.

RESULTS

After 3 years, the actuarial survival rate was 45.1% and local control rate was 86.0%. Prognostic factors for survival included Child-Pugh score, number of tumors, and alpha-fetoprotein levels. No late treatment-related toxicity of Grade 2 or higher was observed.

CONCLUSIONS

The PBT delivering 72.6 GyE in 22 fractions appears to be effective and safe for HCC adjacent to the porta hepatis.

Particle therapy in lung cancer: where do we stand?

BACKGROUND

From a theoretical point of view, charged particles should lead to superior results compared to photons. In this review, we searched for clinical evidence that protons or C-ions are really beneficial to patients with lung cancer.

METHODS

A systematic literature review based on an earlier published comprehensive review was performed and updated until November 1st 2007.

RESULTS

Ten fully published series, all dealing with non-small cell lung cancer (NSCLC), mainly stage I, were identified. No phase III trials were found. On proton therapy, 2-5 year local tumor control rates varied between 87% and 57%. The 2 year/5 year overall survival and 2 year/5 year cause specific survival varied between 31-74%/23% and 58-86%/46%, respectively. Late side effects were observed in about 10% of the patients. For C-ion therapy, the local tumor control rate was 77%, while 95% when using a hypofractionated radiation schedule. The 5 year overall survival and cause specific survival rates were 42% and 60%, respectively. Slightly better results were reported when using hypofractionation, 50% and 76%, respectively. The reported late side effects for C-ions were 4%.

CONCLUSION

The results with charged particles, at least for stage I disease, seem to be promising. A gain can be expected in reduction of late side effects, especially after treatment with C-ions. Available data demonstrate that particle therapy in general is a safe and feasible treatment modality. Although current results are promising, more evidence is required before particle therapy can become internationally the standard treatment for (subsets of) lung cancer patients.

[Regional therapy of liver tumors]

Malignant liver tumors are either originating from the liver, such as the primary liver tumors hepatocellular carcinoma and the cholangiocellular carcinoma, or metastases from extrahepatic malignancies. Apart from surgical procedures (resection, liver transplantation) percutaneous local-ablative (ethanol injection, radiofrequency thermal ablation as well as radiation therapy) and transarterial interventions are non-surgical therapeutic options. While these regional therapies have been shown in randomised controlled studies to be effective for hepatocellular carcinoma, their therapeutic efficacy in cholangiocellular carcinoma and liver metastases has not been shown. In the following we will summarize the regional therapeutic options in primary and secondary liver tumors.

Development and operation of the Loma Linda University Medical Center proton facility

The Proton Treatment Center at Loma Linda University Medical Center, the world's first hospital-based proton facility, opened in 1990 after two decades of development. Its early years were marked by a deliberately cautious approach in clinical utilization of protons, with intent to establish hospital-based proton therapy on a scientific basis. The facility was designed to be upgradeable, and development since 1990 has proceeded in three distinct phases of upgrades, both in technology and clinical applications. Upgrades continue, all of them based on an underlying program of basic and clinical research; future new applications of proton radiation therapy are expected to follow.

A systematic literature review of the clinical and cost-effectiveness of hadron therapy in cancer

BACKGROUND

In view of the continued increase in the number of hadron (i.e. neutron, proton and light or heavy ion) therapy (HT) centres we performed a systematic literature review to identify reports of the efficacy of HT.

METHODS

Eleven databases were searched systematically. No limit was applied to language or study design. Established experts were contacted for unpublished data. Data on outcomes were extracted and summarised in tabular form.

RESULTS

Seven hundred and seventy three papers were identified. For proton and heavy ion therapy, the number of RCTs was too small to draw firm conclusions. Based on prospective and retrospective studies, proton irradiation emerges as the treatment of choice for some ocular and skull base tumours. For prostate cancer, the results were comparable with those from the best photon therapy series. Heavy ion therapy is still in an experimental phase.

CONCLUSION

Existing data do not suggest that the rapid expansion of HT as a major treatment modality would be appropriate. Further research into the clinical and cost-effectiveness of HT is needed. The formation of a European Hadron Therapy Register would offer a straightforward way of accelerating the rate at which we obtain high-quality evidence that could be used in assessing the role of HT in the management of cancer.

Particle radiation therapy using proton and heavier ion beams

Particle beams like protons and heavier ions offer improved dose distributions compared with photon (also called x-ray) beams and thus enable dose escalation within the tumor while sparing normal tissues. Although protons have a biologic effectiveness comparable to photons, ions, because they are heavier than protons, provide a higher biologic effectiveness. Recent technologic developments in the fields of accelerator engineering, treatment planning, beam delivery, and tumor visualization have stimulated the process of transferring particle radiation therapy (RT) from physics laboratories to the clinic. This review describes the physical, biologic, and technologic aspects of particle beam therapy. Clinical trials investigating proton and carbon ion RT will be summarized and discussed in the context of their relevance to recent concepts of treatment with RT.

Radiation therapy for hepatocellular carcinoma: from palliation to cure

Technologic advances have provided the means to deliver tumoricidal doses of radiation therapy (RT) to patients with unresectable hepatocellular carcinoma (HCC) while avoiding critical normal tissues, providing the opportunity to use RT for curative intent treatment of HCC. For the current report, the expanded role of external beam RT in the setting of HCC from palliation to cure was reviewed. A systematic literature search was undertaken using the MEDLINE data base and secondary references to identify peer-reviewed, English-language articles that reported clinical outcomes after external beam RT alone or in combination with other treatments for HCC. Abstracts from the 2005 American Society of Clinical Oncology, American Society for Therapeutic Radiology and Oncology, American Gastrointestinal Association, and Society of Surgical Oncology Gastrointestinal Cancer Symposium also were included in the search. More than 60 articles reporting on clinical outcomes among patients who received RT for HCC have been published since 1990, including 20 articles that described unique sets of at least 15 patients. RT was used for palliation, to improve local control, and with curative intent in a wide spectrum of patients who most often were unsuitable for surgery and other treatments. Pain reduction following RT was noted in approximately 75% of patients with bone metastases from HCC who received RT. For patients with liver-confined disease treated with conformal RT, proton beam RT, and/or image guided RT with or without transarterial chemoembolization (TACE), local control response rates ranged from 40% to 90%, and the median survival ranges from 10 months to 25 months. For patients with HCC who had portal vein thrombus, the median survival after RT to treat the thrombus and/or the hepatic tumor with or without TACE ranged from 5.3 months to 9.7 months. Although outcomes after high-dose conformal RT for liver-confined HCC were excellent, the potential survival benefit of RT should be tested in randomized controlled trials that require international collaboration.

Fractionated stereotactic radiotherapy in patients with primary hepatocellular carcinoma

OBJECTIVE

The purpose of our study was to evaluate the feasibility and treatment outcomes of fractionated stereotactic radiotherapy (SRT) for primary hepatocellular carcinoma (HCC).

METHODS

We enrolled 20 patients who had been histologically diagnosed as HCC patients and treated by fractionated SRT. Tumor size was 2-6.5 cm (average: 3.8 cm). We prescribed 50 Gy in 5 or 10 fractions at the 85-90% isodose line of the planning target volume for 2 weeks. The follow-up period was 3-55 months (median: 23 months).

RESULTS

The overall response rate was 80%, with 4 patients showing complete response (20%), 14 patients showing partial response (60%) and 4 patients showing stable disease (20%). The 1-year and 2-year survival rates were 70.0 and 43.1%, respectively (median: 20 months). The 1-year and 2-year disease-free survival rates were 65.0 and 32.5%, respectively (median: 19 months). The fractionated SRT was well tolerated, because grade 3 or grade 4 toxicity was not observed.

CONCLUSION

These results suggest that fractionated SRT is a relatively safe and effective method for treating small primary HCC. Thus, fractionated SRT may be suggested as a local treatment of choice for small HCC when the patients are inoperable or when the patients refuse operation.

Hepatocellular carcinoma: therapy and prevention

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors worldwide. The major etiologies and risk factors for the development of HCC are well defined and some of the multiple steps involved in hepatocarcinogenesis have been elucidated in recent years. Despite these scientific advances and the implementation of measures for the early detection of HCC in patients at risk, patient survival has not improved during the last three decades. This is due to the advanced stage of the disease at the time of clinical presentation and limited therapeutic options. The therapeutic options fall into five main categories: surgical interventions including tumor resection and liver transplantation, percutaneous interventions including ethanol injection and radiofrequency thermal ablation, transarterial interventions including embolization and chemoembolization, radiation therapy and drugs as well as gene and immune therapies. These therapeutic strategies have been evaluated in part in randomized controlled clinical trials that are the basis for therapeutic recommendations. Though surgery, percutaneous and transarterial interventions are effective in patients with limited disease (1-3 lesions, <5 cm in diameter) and compensated underlying liver disease (cirrhosis Child A), at the time of diagnosis more than 80% patients present with multicentric HCC and advanced liver disease or comorbidities that restrict the therapeutic measures to best supportive care. In order to reduce the morbidity and mortality of HCC, early diagnosis and the development of novel systemic therapies for advanced disease, including drugs, gene and immune therapies as well as primary HCC prevention are of paramount importance. Furthermore, secondary HCC prevention after successful therapeutic interventions needs to be improved in order to make an impact on the survival of patients with HCC. New technologies, including gene expression profiling and proteomic analyses, should allow to further elucidate the molecular events underlying HCC development and to identify novel diagnostic markers as well as therapeutic and preventive targets.