Fractionated stereotactic radiotherapy in patients with primary hepatocellular carcinoma

Role of Stereotactic Body Radiation Therapy in Hepatocellular Carcinoma

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

Current Understanding of Ablative Radiation Therapy in Hepatocellular Carcinoma

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

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

PURPOSE

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

MATERIAL AND METHODS

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

RESULTS

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

CONCLUSION

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

Comparison of Combination Stereotactic Body Radiotherapy Plus High-Intensity Focused Ultrasound Ablation Versus Stereotactic Body Radiotherapy Alone for Massive Hepatocellular Carcinoma

Background

Thermal high-intensity focused ultrasound ablation is a non-invasive treatment of massive hepatocellular carcinomas. In stereotactic body radiotherapy, ablative radiotherapy is administered to tumors in targeted, limited doses to minimize damage to nearby tissues. We evaluated the outcomes and survival of patients receiving stereotactic body radiotherapy (singular therapy) versus those receiving combination thermal high-intensity focused ultrasound ablation plus stereotactic body radiotherapy (combination therapy).

Material/Methods

We compared data of 160 patients with massive hepatocellular carcinomas (12.5–18 cm) who were treated with combination therapy to those treated with singular therapy between January 2009 and February 2016.

Results

Eighty-four patients were treated with single therapy while 76 were treated with combination therapy. Comparison of short-term outcomes and long-term survival between the groups revealed no significant differences in adverse events. In the combination group, the proportions of patients with complete response, partial response, stable disease, and progressive disease were 52.6%, 21.1%, 21.1%, and 5.3%, respectively; in the single therapy group, the corresponding rates were 0%, 23.8%, 50%, and 26.2%, respectively (P<0.0001). The 1-year, 3-year, and 5-year survival rates in the combination group were 33%, 20%, and 13%, respectively, while those in the single therapy group were 21%, 14%, and 1%, respectively. These data indicated no differences in complications between the groups except for a significantly higher level of skin edema in the combination group (P=0.015).

Conclusions

Combination therapy is more effective than single therapy for the treatment of massive hepatocellular carcinomas, although rates of most complications appear to be similar.

Strategic application of radiotherapy for hepatocellular carcinoma

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

Stereotactic body radiation therapy for hepatocellular carcinoma: Experience from a tertiary cancer care center in India

AIM

The aim of this retrospective study is to assess the toxicity and tumor response of stereotactic body radiation therapy (SBRT) protocol for hepatocellular carcinoma (HCC) in our institution.

BACKGROUND

Hepatocellular cancer is one of the leading cancers among men in India. In recent years, SBRT has emerged as a promising tool in the treatment of HCC.

MATERIALS AND METHODS

Ten patients diagnosed as HCC with Barcelona Clinic Liver Cancer Stage B and C, treated with SBRT technique from January 2013 to December 2016, were included in this study. SBRT was delivered using 6 MV photons with volumetric modulated arc therapy. Acute and late toxicities were graded, and tumor response was assessed using response evaluation criteria in solid tumors criteria. Kaplan-Meier curves were generated for progression-free survival (PFS) and overall survival (OS).

RESULTS

The median age was 61.5 (52-69) years. The radiation dose ranged from 35 Gy to 60 Gy. All patients obtained partial response during assessment at 3 months after completion of treatment. The median PFS is 8 months (95% confidence interval [CI] - 5.22-10.77 months). The median OS is 51 months (95% CI - 17.64-65.10 months). The OS at 1 and 2 years is 75% and 57%, respectively.

CONCLUSIONS

SBRT is well tolerated by our patients. The 1- and 2-year OS of 75% and 57% is consistent with other prospective and retrospective SBRT studies from the literature.

Asia-Pacific clinical practice guidelines on the management of hepatocellular carcinoma: a 2017 update

There is great geographical variation in the distribution of hepatocellular carcinoma (HCC), with the majority of all cases worldwide found in the Asia-Pacific region, where HCC is one of the leading public health problems. Since the "Toward Revision of the Asian Pacific Association for the Study of the Liver (APASL) HCC Guidelines" meeting held at the 25th annual conference of the APASL in Tokyo, the newest guidelines for the treatment of HCC published by the APASL has been discussed. This latest guidelines recommend evidence-based management of HCC and are considered suitable for universal use in the Asia-Pacific region, which has a diversity of medical environments.

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

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

Radiotherapy for liver cancer

In recent years, radiotherapy for liver cancer has accomplished much technical progress. The history of radiotherapy for liver cancer shows an endeavor to overcome the problem of how to raise the irradiation dose to lesions while suppressing the unnecessary irradiation dose to normal liver tissue. With the appearance of treatment using X‐ray radiotherapy represented by three‐dimensional conformal radiotherapy, stereotactic body radiotherapy and particle beam therapy using proton beams and carbon ion beams, radiotherapy has become a safe and effective treatment option for liver cancers.

Reirradiation of Pediatric Tumors Using Hypofractionated Stereotactic Radiotherapy

BACKGROUND

This study aimed to evaluate the efficacy and safety of hypofractionated stereotactic radiotherapy for reirradiation of recurrent pediatric tumors.

METHODS AND MATERIALS

The study included 23 pediatric patients who were reirradiated using hypofractionated stereotactic radiotherapy in the radiation oncology department between January 2008 and November 2013. In total, 33 tumors were treated-27 (82%) cranial and 6 (18%) extracranial. Hypofractionated stereotactic radiotherapy was administered due to recurrent disease in 31 (94%) tumors and residual disease in 2 (6%) tumors. The median total dose was 25 Gy (range: 15-40 Gy), and the median follow-up was 20 months (range: 2-68 months).

RESULTS

The 1-year and 2-year local control rates in the entire study population were 42% and 31%, respectively. The median local control time was 11 months (range: 0-54 months) following hypofractionated stereotactic radiotherapy. The patients with tumor response after hypofractionated stereotactic radiotherapy had significantly longer local control than the patients with post-hypofractionated stereotactic radiotherapy tumor progression (21 vs 3 months, P < .001). Tumor volume <1.58 cm3 was correlated (not significantly) with better local control (23 vs 7 months, P = .064).

CONCLUSION

Reirradiation of pediatric tumors using hypofractionated stereotactic radiotherapy is a safe and effective therapeutic approach. This treatment modality should be considered as a treatment option in selected pediatric patients.

Stereotactic Body Radiotherapy for Inoperable Liver Tumors: Results of a Single Institutional Experience

OBJECTIVES

Stereotactic body radiation therapy (SBRT) is an emerging treatment option for liver tumors unsuitable for ablation or surgery. We report our experience with SBRT in the treatment of liver tumors.

MATERIALS AND METHODS

Patients with primary or secondary liver cancer were identified in our local SBRT database. Patients were included irrespective of prior liver-directed therapies. The primary endpoint of our review was in-field local control (LC). Secondary endpoints were progression-free survival (PFS), overall survival (OS), and toxicity.

RESULTS

From 2009 to 2015, a total of 71 liver lesions in 68 patients were treated with SBRT (three patients had two liver lesions treated). The median age was 71 years (27-89 years). Hepatocellular carcinoma (HCC) was the diagnosis in 23 patients (34%), with the grade of Child-Pugh A (52%), B (39%), or C (nine percent) cirrhosis. Six patients (nine percent) had intrahepatic cholangiocarcinoma (IHC). The remaining 39 patients (57%) had metastatic liver lesions. Colorectal adenocarcinoma was the most common primary tumor type (81%). The median size for HCC, IHC, and metastatic lesions was 5 cm (2-9 cm), 3.6 cm (2-4.9 cm), and 4 cm (1-8 cm), respectively. The median prescribed dose was 45 Gy (16-50 Gy). Median follow-up was 11.5 months (1-45 months). Actuarial one-year in-field LC for HCC and metastatic lesions was 85% and 64% respectively (p= 0.66). At one year, the actuarial rate of new liver lesions was 40% and 26%, respectively, (p=0.58) for HCC and metastases. Only six patients with IHC were treated with SBRT in this study - in these patients, one-year LC was 78% with new liver lesions in 53%. The SBRT treatments were well tolerated. The side effects included common criteria for adverse events (CTCAE) v4 grade 1 acute gastrointestinal toxicity in three patients, grade 3 nausea in one patient, and grade 3 acute dermatitis in another patient. Two patients had grade 5 toxicity. Radiation pneumonitis was observed in one patient two months post-SBRT treatment, and another patient was suspected to have had radio-induced liver disease (RILD) two months after SBRT. No late toxicity was seen.

CONCLUSION

SBRT is a well-tolerated and effective alternative treatment option for selected patients with primary and metastatic liver tumors.

Radiotherapy for Hepatocellular Carcinoma: New Indications and Directions for Future Study

Hepatocellular carcinoma (HCC) is a leading cause of cancer death worldwide; its incidence is increasing in the United States. Depending on disease extent and underlying liver status, patients may be treated with local, locoregional, and/or systemic therapy. Recent data indicates that radiotherapy (RT) can play a meaningful role in the management of HCC. Here, we review published experiences using RT for HCC, including the use of radiosensitizers and stereotactic RT. We discuss methods for performing preclinical studies of RT for HCC and biomarkers of response. As a part of the HCC Working Group, an informal committee of the National Cancer Institute's Radiation Research Program, we suggest how RT should be implemented in the management of HCC and identify future directions for the study of RT in HCC.

How to Improve Therapeutic Ratio in Radiotherapy of HCC

BACKGROUND

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

SUMMARY

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

KEY MESSAGE

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

Therapeutic usability of two different fiducial gold markers for robotic stereotactic radiosurgery of liver malignancies: A pilot study

AIM: To assess how the application of different types of markers affects the tracking accuracy of CyberKnife’s.

METHODS: Fifteen patients were recruited and subjected to the ultrasound-guided placement of markers. Two different type of needles 25 gauge (G) and 17 G containing two different fiducial marker, gold notched flexible anchor wire 0.28 mm × 10 mm (25 G needle) and gold cylindrical grain 1 mm × 4 mm (17 G), were used. Seven days after the procedure, a CyberKnife planning computed tomography (CT) for the simulation of radiation treatment was performed on all patients. A binary CT score was assigned to the fiducial markers visualization. Also, the CT number was calculated for each fiducial and the values compared with a specific threshold.

RESULTS: For each patient from 1 to 5, intra-hepatic markers were placed (one in 2 patients, three in 8 patients, four in 3 patients, and five in 2 patients). A total of 48 needles were used (thirty-two 17 G and sixteen 25 G) and 48 gold markers were placed (32 Grain shaped markers and 16 Gold Anchor). The result showed that the CT visualization of the grain markers was better than the anchor markers (P = 5 × 10^-9). Furthermore, the grain markers were shown to present minor late complications (P = 3 × 10^-6), and the best CT threshold number (P = 0.0005).

CONCLUSION: The study revealed that the Gold Anchor fiducial marker is correlated with a greater number of late minor complications and low visualization by the CT.

Stereotactic body radiation therapy for hepatocellular carcinoma

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

Comparison of outcomes between SBRT, yttrium-90 radioembolization, transarterial chemoembolization, and radiofrequency ablation as bridge to transplant for hepatocellular carcinoma

PURPOSE

To evaluate and compare outcome of stereotactic body radiation therapy (SBRT), yttrium-90 radioembolization, radiofrequency ablation (RFA), or transarterial chemoembolization (TACE) as bridge to liver transplant (LT) in patients with hepatocellular carcinoma.

METHODS AND MATERIALS

We retrospectively reviewed patients treated at our institution with SBRT, TACE, RFA, or yttrium-90 as bridge to LT between 2006 and 2013. We analyzed radiologic and pathologic response and rate of failure after bridge therapy. Toxicities were reported using Common Terminology Criteria for Adverse Events, 4.0. Kaplan-Meier method was used to calculate disease-free survival (DFS) and overall survival after LT.

RESULTS

Sixty patients with a median age 57.5 years (range, 44-70) met inclusion criteria. Thirty-one patients (50.7%) had hepatitis C cirrhosis, 14 (23%) alcoholic cirrhosis, and 8 (13%) nonalcoholic steatohepatitis cirrhosis. Patients received a total of 79 bridge therapies: SBRT (n = 24), TACE (n = 37), RFA (n = 9), and Y90 (n = 9). Complete response (CR) was 25% for TACE, 8.6% for SBRT, 22% for RFA, and 33% for Y90. Grade 3 or 4 acute toxicity occurred following TACE (n = 4) and RFA (n = 2). Transplant occurred at a median of 7.4 months after bridge therapy. Pathological response among 57 patients was 100% necrosis (n = 23, 40%), >50% necrosis (n = 20, 35%), <50% necrosis (n = 9, 16%), and no necrosis (n = 5, 9%). Pathologic complete response was as follows: SBRT (28.5%), TACE (41%), RFA (60%), Y90 (75%), and multiple modalities (33%). At a median follow-up of 35 months, 7 patients had recurrence after LT. DFS was 85.8% and overall survival was 79% at 5 years.

CONCLUSION

All bridge therapies demonstrated good pathological response and DFS after LT. SBRT and Y90 demonstrated significantly less grade ≥3 acute toxicity. Choice of optimal modality depends on tumor size, pretreatment bilirubin level, Child-Pugh status, and patient preference. Such a decision is best made at a multidisciplinary tumor board as is done at our institution.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Hepatocellular carcinoma and multidrug resistance: Past, present and new challenges for therapy improvement

Hepatocellular carcinoma (HCC) is the most frequent form of liver cancer and the third most common cause of cancer-related death in the world. The main risk factor worldwide for this type of malignancy is chronic hepatitis caused by hepatitis B virus and hepatitis C virus infections. Advances in early detection and treatment have improved life expectancy of patients with HCC. However, this disorder remains as a disease with poor prognosis. In fact, epidemiological studies have revealed that there is an 8-mo median survival rate in patients, approximately 20% of whom survive one year while only 5% remain alive after three years. Additionally, HCC is particularly difficult to treat because of its high recurrence rate, and its resistance to conventional chemotherapy is due, among other mechanisms, to several members of the ATP-Binding Cassette protein family involved in drug transport being overexpressed. Fortunately, there is evidence that these patients may benefit from alternative molecular-targeted therapies. This manuscript intends to provide further insight into the etiology and molecular mechanisms related to HCC development and the latest therapeutic approaches to treat this malignancy. The development of effective delivery systems of antitumor drugs able to target the liver parenchyma is also assessed. Finally, the prospects in the development of more efficient drug therapies to overcome multidrug resistance are also examined.

Adjuvant stereotactic body radiotherapy following transarterial chemoembolization in patients with non-resectable hepatocellular carcinoma tumours of ≥ 3 cm

OBJECTIVES

The optimal locoregional treatment for non-resectable hepatocellular carcinoma (HCC) of ≥ 3 cm in diameter is unclear. Transarterial chemoembolization (TACE) is the initial intervention most commonly performed, but it rarely eradicates HCC. The purpose of this study was to measure survival in HCC patients treated with adjuvant stereotactic body radiotherapy (SBRT) following TACE.

METHODS

A retrospective study of patients with HCC of ≥ 3 cm was conducted. Outcomes in patients treated with TACE alone (n = 124) were compared with outcomes in those treated with TACE + SBRT (n = 37).

RESULTS

There were no significant baseline differences between the two groups. The pre-TACE mean number of tumours (P = 0.57), largest tumour size (P = 0.09) and total tumour diameter (P = 0.21) did not differ significantly between the groups. Necrosis of the HCC tumour, measured after the first TACE, did not differ between the groups (P = 0.69). Local recurrence was significantly decreased in the TACE + SBRT group (10.8%) in comparison with the TACE-only group (25.8%) (P = 0.04). After censoring for liver transplantation, overall survival was found to be significantly increased in the TACE + SBRT group compared with the TACE-only group (33 months and 20 months, respectively; P = 0.02).

CONCLUSIONS

This retrospective study suggests that in patients with HCC tumours of ≥ 3 cm, treatment with TACE + SBRT provides a survival advantage over treatment with only TACE. Confirmation of this observation requires that the concept be tested in a prospective, randomized clinical trial.

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

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

The tolerance of gastrointestinal organs to stereotactic body radiation therapy: what do we know so far?

As stereotactic body radiation therapy (SBRT) for gastrointestinal (GI) gains popularity, there is a need to optimize doses and fractionation to minimize GI toxicity. GI organs that have classically developed radiation-induced toxicity include the liver & biliary system, small bowel, esophagus, and rectum. While the literature quantifies dose restrictions for these organs under standard fractionation, there is limited data regarding toxicity with the ablative dose schedules used in SBRT. We conducted a review of the literature to identify prospective and retrospective studies that detail GI toxicities when SBRT was employed. Based on the literature, the median SBRT dose for abdominal and thoracic tumors ranged from 24 to 60 Gy, at 5 to 25 Gy per fraction. The respective observed frequencies of grade 3 and 4 toxicities for the liver, biliary system, small bowel, and esophagus were variable among different studies. Typically, patients who suffered grade 3 and 4 toxicities were more likely to have had some form of systemic therapy as well. The effect of dose, fractionation, timing, and volume on GI toxicities has been described in the literature but more data is necessary to develop uniform treatment guidelines for SBRT.

Role of stereotactic body radiation therapy for hepatocellular carcinoma

The integration of new technologies has raised an interest in liver tumor radiotherapy, with literature evolving to support its efficacy. These advances, particularly stereotactic body radiation therapy (SBRT), have been critical in improving local control or potential cure in liver lesions not amenable to first-line surgical resection or radiofrequency ablation. Active investigation of SBRT, particularly for hepatocellular carcinoma (HCC), has recently started, yielding promising local control rates. In addition, data suggest a possibility that SBRT can be an alternative option for HCC unfit for other local therapies. However, information on optimal treatment indications, doses, and methods remains limited. In HCC, significant differences in patient characteristics and treatment availability exist by country. In addition, the prognosis of HCC is greatly influenced by underlying liver dysfunction and treatment itself in addition to tumor stage. Since they are closely linked to treatment approach, it is important to understand these differences in interpreting outcomes from various reports. Further studies are required to validate and maximize the efficacy of SBRT by a large, multi-institutional setting.

Extracranial stereotactic body radiotherapy. Review of main SBRT features and indications in primary tumors

AIM

Review of main SBRT features and indications in primary tumors.

BACKGROUND

Stereotactic body radiotherapy has been developed in the last few years. SBRT allows the hypofractionated treatment of extra cranial tumors, using either a single or limited number of dose fractions, and resulting in the delivery of a high biological effective dose with low toxicity.

MATERIAL AND METHODS

SBRT REQUIRES A HIGH LEVEL OF ACCURACY FOR ALL PHASES OF THE TREATMENT PROCESS: effective patient immobilization, precise target localization, highly conformed dosimetry and image guided systems for treatment verification. The implementation of SBRT in routine requires a careful considering of organ motion. Gating and tracking are effective ways to do so, and less invasive technologies "fiducials free" have been developed. Due to the hypofractionated scheme, the physician must pay attention to new dosimetric constraints in organ at risk and new radiobiological models are needed to assess the optimal fractionation and dose schemes.

RESULTS

Currently, SBRT is safe and effective to treat primary tumors, which are otherwise untreatable with conventional radiotherapy or surgery. SBRT has quickly developed because of its excellent results in terms of tolerance and its high locoregional control rates. SBRT indications in primary tumors, such as lung primary tumors, have become a standard of care for inoperable patients. SBRT seems to be effective in many others indications in curative or palliative intent such as liver primary tumors, and novel indications and strategies are currently emerging in prostate cancer, head and neck tumor recurrences or pelvis reirradiations.

CONCLUSION

Currently, SBRT is mainly used when there is no other therapeutic alternative for the patient. This is due to the lack of randomized trials in these settings. However, the results shown in retrospective studies let us hope to impose SBRT as a new standard of care for many patients in the next few years.

Two-week schedule of hypofractionated radiotherapy as a local salvage treatment for small hepatocellular carcinoma

BACKGROUND AND AIM

In cases of small hepatocellular carcinoma (HCC) where established curative treatment cannot be applied, stereotactic body radiotherapy (SBRT) has been used as a non-invasive alternative treatment modality. However, short-course SBRT may not be safe if the tumor is located around a critical normal organ. Therefore, we applied hypofractionated radiotherapy for these tumors and evaluated outcomes of this treatment.

METHODS

Between December 2008 and August 2011, 26 patients (28 lesions) with HCC were treated with hypofractionated radiotherapy. Inclusion criteria were HCC not suitable for surgery or other local ablative therapy, a tumor size < 6 cm, adequate hepatic function, an HCC located within 2 cm of a critical organ, and no evidence of vascular invasion. A dose of 4-5 Gy per fraction was given, with a total dose of 40-50 Gy over 2 weeks.

RESULTS

The overall response rate was 67.9%, with seven complete responses (25.0%) and 12 partial responses (42.9%) at 3 months after radiotherapy. The overall survival rates at 1 and 2 years were 88.5% and 67.2%, respectively. The local control rate at 2 years was 87.6%. The Intrahepatic recurrence-free and distant failure-free survival rates at 2 years were 36.5% and 68.2%, respectively. Grade ≥ 3 hepatic toxicity was observed in one patient.

CONCLUSIONS

Two-week schedule of hypofractionated radiotherapy for small HCC was feasible with good local control and safety. This fractionation schedule can be used as an alternative treatment option for HCC located close to a critical normal organ if short-course SBRT is not feasible.

18F-FDG PET and combined 18F-FDG-contrast CT parameters as predictors of tumor control for hepatocellular carcinoma after stereotactic ablative radiotherapy

The application of stereotactic ablative radiotherapy (SABR) to hepatocellular carcinoma (HCC) is emerging. To identify pretreatment prognostic indicators is crucial for patient selection and optimal individual therapy. The aim of this study was to determine whether (18)F-FDG PET and a combined (18)F-FDG-contrast CT parameter could be useful tools to predict tumor control for patients with HCC treated by SABR.

METHODS

We retrospectively identified 31 patients (41 tumors) who underwent (18)F-FDG PET before SABR between November 2007 and September 2011. (18)F-FDG PET parameters were collected as prognostic indicators, including visual PET scale (+/-), maximal standardized uptake value (SUV) of the tumor (T SUV max), ratio of T SUV max to maximal normal-liver SUV, ratio of T SUV max to mean normal-liver SUV, and score combining tumor volume and T SUV max (CT/(18)F-FDG PET score). They underwent SABR with a median dose of 42 Gy (ranging from 30 to 50 Gy) in 4-5 fractions. (18)F-FDG PET parameters and clinical factors were tested as predictors of tumor control and patient survival.

RESULTS

The median follow-up time was 18 mo. Among the parameters examined, T SUV max and CT/(18)F-FDG PET score were significantly correlated with tumor control. T SUV max with a cutoff value of 3.2 was the most significant prognostic indicator. The 4-y control rate was 86.2% in tumors with a T SUV max of 3.2 or less but only 37.5% in those with a T SUV max of more than 3.2 (adjusted hazard ratio, 9.40; 95% confidence interval, 1.18-74.76; P = 0.034). CT/(18)F-FDG PET score (≤ 4 vs. >4) was also a significant predictor of tumor control after SABR. Tumors with a CT/(18)F-FDG PET score of more than 4 had a 5.23-fold risk of tumor failure. After adjustment for factors of sex, American Joint Committee on Cancer stage, Cancer of the Liver Italian Program score, and Child-Pugh classification, tumors with a score of more than 4 had a 4.96-fold risk of failure after SABR, compared with tumors with a score of 4 or less. For overall survival, none was statistically significant.

CONCLUSION

The use of (18)F FDG PET to predict tumor control is feasible. T SUV max with a cutoff value of 3.2 is the best prognostic indicator. We suggest that (18)F-FDG PET may be a reference for prognostic prediction, patient selection, and radiation dose adjustment for HCC patients treated with SABR.

Sequential phase I and II trials of stereotactic body radiotherapy for locally advanced hepatocellular carcinoma

PURPOSE

To describe outcomes of prospective trials of stereotactic body radiotherapy (SBRT) for hepatocellular carcinoma (HCC).

PATIENTS AND METHODS

Two trials of SBRT for patients with active HCC unsuitable for standard locoregional therapies were conducted from 2004 to 2010. All patients had Child-Turcotte-Pugh class A disease, with at least 700 mL of non-HCC liver. The SBRT dose range was 24 to 54 Gy in six fractions. Primary end points were toxicity and local control at 1 year (LC1y), defined as no progressive disease (PD) of irradiated HCC by RECIST (Response Evaluation Criteria in Solid Tumors).

RESULTS

A total of 102 patients were evaluable (Trial 1, 2004 to 2007: n = 50; Trial 2, 2007 to 2010: n = 52). Underlying liver disease was hepatitis B in 38% of patients, hepatitis C in 38%, alcohol related in 25%, other in 14%, and none in 7%. Fifty-two percent received prior therapies (no prior sorafenib). TNM stage was III in 66%, and 61% had multiple lesions. Median gross tumor volume was 117.0 mL (range, 1.3 to 1,913.4 mL). Tumor vascular thrombosis (TVT) was present in 55%, and extrahepatic disease was present in 12%. LC1y was 87% (95% CI, 78% to 93%). SBRT dose (hazard ratio [HR] = 0.96; P = .02) and being in Trial 2 (HR = 0.38; P = .03) were associated with LC1y on univariate analysis. Toxicity ≥ grade 3 was seen in 30% of patients. In seven patients (two with TVT PD), death was possibly related to treatment (1.1 to 7.7 months after SBRT). Median overall survival was 17.0 months (95% CI, 10.4 to 21.3 months), for which only TVT (HR = 2.47; P = .01) and being in Trial 2 (HR = 0.49; P = .01) were significant on multivariate analysis.

CONCLUSION

These results provide strong rationale for studying SBRT for HCC in a randomized trial.

Stereotactic body radiation therapy combined with transcatheter arterial chemoembolization for small hepatocellular carcinoma

BACKGROUND AND AIMS

To compare the tumor control and safety of stereotactic body radiation therapy (SBRT) combined with transcatheter arterial chemoembolization (TACE) for small, solitary, and hypervascular hepatocellular carcinoma (HCC) with TACE alone.

METHODS

Three hundred and sixty-five HCC patients who had solitary, ≤ 3 cm, and hypervascular nodule were treated with TACE. Among them, 30 patients followed by SBRT (SBRT group) and 38 patients without additional therapy and previous HCC treatment (control group) were enrolled in this retrospective cohort study. Local tumor progression, complication, and disease-free survival were compared between these groups.

RESULTS

There was no difference in clinical background between these groups. Complete response to therapy was noted in 29 (96.3%) patients of the SBRT group, and in only one (3.3%) patient of the TACE group (P < 0.001). None of the patients developed acute hematologic toxicity of more than Common Terminology Criteria for Adverse Events Grade 3 during and after the treatment. Furthermore, none of the SBRT group developed radiation-induced liver damage. Disease-free survival of the 12 patients without previous HCC treatments in SBRT group was significantly superior to that in control group (15.7 months vs 4.2 months; P = 0.029).

CONCLUSION

The results indicated that SBRT combined with TACE is a safe and effective modality for locoregional treatment of small solitary primary HCC, and could be potentially a suitable option.

Multicenter results of stereotactic body radiotherapy (SBRT) for non-resectable primary liver tumors

BACKGROUND

An excess of 100 000 individuals are diagnosed with primary liver tumors every year in USA but less than 20% of those patients are amenable to definitive surgical management due to advanced local disease or comorbidities. Local therapies to arrest tumor growth have limited response and have shown no improvement on patient survival. Stereotactic body radiotherapy (SBRT) has emerged as an alternative local ablative therapy. The purpose of this study was to evaluate the tumor response to SBRT in a combined multicenter database.

STUDY DESIGN

Patients with advanced hepatocellular carcinoma (HCC, n = 21) or intrahepatic cholangiocarcinoma (ICC, n = 11) treated with SBRT from four Academic Medical Centers were entered into a common database. Statistical analyses were performed for freedom from local progression (FFLP) and patient survival.

RESULTS

The overall FFLP for advanced HCC was 63% at a median follow-up of 12.9 months. Median tumor volume decreased from 334.2 to 135 cm(3) (p < 0.004). The median time to local progression was 6.3 months. The 1- and 2-years overall survival rates were 87% and 55%, respectively. Patients with ICC had an overall FFLP of 55.5% at a median follow-up of 7.8 months. The median time to local progression was 4.2 months and the six-month and one-year overall survival rates were 75% and 45%, respectively. The incidence of grade 1-2 toxicities, mostly nausea and fatigue, was 39.5%. Grade 3 and 4 toxicities were present in two and one patients, respectively.

CONCLUSION

Higher rates of FFLP were achieved by SBRT in the treatment of primary liver malignancies with low toxicity.

Stereotactic body radiation therapy in recurrent hepatocellular carcinoma

PURPOSE

To examine the safety and efficacy of Cyberknife stereotactic body radiation therapy (SBRT) and its effect on survival in patients of recurrent hepatocellular carcinoma (HCC).

METHODS AND MATERIALS

This was a matched-pair study. From January 2008 to December 2009, 36 patients with 42 lesions of unresectable recurrent HCC were treated with SBRT. The median prescribed dose was 37 Gy (range, 25 to 48 Gy) in 4-5 fractions over 4-5 consecutive working days. Another 138 patients in the historical control group given other or no treatments were selected for matched analyses.

RESULTS

The median follow-up time was 14 months for all patients and 20 months for those alive. The 1- and 2-year in-field failure-free rates were 87.6% and 75.1%, respectively. Out-field intrahepatic recurrence was the main cause of failure. The 2-year overall survival (OS) rate was 64.0%, and median time to progression was 8.0 months. In the multivariable analysis of all 174 patients, SBRT (yes vs. no), tumor size (≤4 cm vs. >4 cm), recurrent stage (stage IIIB/IV vs. I) and Child-Pugh classification (A vs. B/C) were independent prognostic factors for OS. Matched-pair analysis revealed that patients undergoing SBRT had better OS (2-year OS of 72.6% vs. 42.1%, respectively, p = 0.013). Acute toxicities were mild and tolerable.

CONCLUSION

SBRT is a safe and efficacious modality and appears to be well-tolerated at the dose fractionation we have used, and its use correlates with improved survival in this cohort of patients with recurrent unresectable HCC. Out-field recurrence is the major cause of failure. Further studies of combinations of SBRT and systemic therapies may be reasonable.

Stereotactic body radiotherapy for primary hepatocellular carcinoma

PURPOSE

To evaluate the safety and efficacy of stereotactic body radiotherapy (SBRT) for the treatment of primary hepatocellular carcinoma (HCC).

METHODS AND MATERIALS

From 2005 to 2009, 60 patients with liver-confined HCC were treated with SBRT at the Indiana University Simon Cancer Center: 36 Child-Turcotte-Pugh (CTP) Class A and 24 CTP Class B. The median number of fractions, dose per fraction, and total dose, was 3, 14 Gy, and 44 Gy, respectively, for those with CTP Class A cirrhosis and 5, 8 Gy, and 40 Gy, respectively, for those with CTP Class B. Treatment was delivered via 6 to 12 beams and in nearly all cases was prescribed to the 80% isodose line. The records of all patients were reviewed, and treatment response was scored according to Response Evaluation Criteria in Solid Tumors v1.1. Toxicity was graded according to the Common Terminology Criteria for Adverse Events v4.0. Local control (LC), time to progression (TTP), progression-free survival (PFS), and overall survival (OS) were calculated according to the method of Kaplan and Meier.

RESULTS

The median follow-up time was 27 months, and the median tumor diameter was 3.2 cm. The 2-year LC, PFS, and OS were 90%, 48%, and 67%, respectively, with median TTP of 47.8 months. Subsequently, 23 patients underwent transplant, with a median time to transplant of 7 months. There were no ≥Grade 3 nonhematologic toxicities. Thirteen percent of patients experienced an increase in hematologic/hepatic dysfunction greater than 1 grade, and 20% experienced progression in CTP class within 3 months of treatment.

CONCLUSIONS

SBRT is a safe, effective, noninvasive option for patients with HCC ≤6 cm. As such, SBRT should be considered when bridging to transplant or as definitive therapy for those ineligible for transplant.

Stereotactic radiation therapy and selective internal radiation therapy for hepatocellular carcinoma

Recent technological advances allow precise and safe radiation delivery in hepatocellular carcinoma. Stereotactic body radiotherapy is a conformal external beam radiation technique that uses a small number of relatively large fractions to deliver potent doses of radiation therapy to extracranial sites. It requires stringent breathing motion control and image guidance. Selective internal radiotherapy or radioembolization refers to the injection of radioisotopes, usually delivered to liver tumors via the hepatic artery. Clinical results for both treatments show that excellent local control is possible with acceptable toxicity. Most appropriate patient populations and when which type of radiation therapy should be best employed in the vast therapeutic armamentarium of hepatocellular carcinoma are still to be clarified.

[Transarterial chemoembolization and conformal radiotherapy for hepatocellular carcinoma]

Hepatocellular carcinoma is a poor prognosis tumour. The potential curative therapeutic options are orthotopic liver transplantation, surgical resection and radiofrequency ablation. Unfortunately, only a minority of patients (around 20%) are eligible for these techniques. Thus, patients can benefit from palliative options, such as transarterial chemoembolization (TACE) or sorafenib that bring only modest benefit on survival. Conformal radiotherapy allows delivering high dose radiation within a precise tumour volume while sparing the surrounding liver parenchyma. As employed in monotherapy, conformal radiotherapy is highly efficient for small size hepatocellular carcinoma (<5 cm). Above 5 cm, its efficacy is more limited but its association with TACE gives spectacular rates of complete responses. Controlled phase 2 or 3 trials are urgently warranted to define its indications in the therapeutic algorithm of hepatocellular carcinoma.

Stereotactic radiotherapy of hepatocellular carcinoma: preliminary results

Stereotactic radiotherapy (SRT) offers a treatment option for hepatocellular carcinoma (HCC) patients that are not eligible for surgery, embolization, chemotherapy, or radiofrequency ablation. We have evaluated the feasibility, tolerance and toxicity of SRT for 25 HCC patients who were not eligible for these other modalities. The patients (6 women and 19 men) were treated with CyberKnife stereotactic radiotherapy using respiratory motion tracking. All patients had liver cirrhosis with an Eastern Cooperative Oncology Group (ECOG) performance score of less than 2 and pre-treatment Child scores ranging from A5 to B9. A total dose of 45 Gy in three fractions of 15 Gy each was prescribed to the 80% isodose line (95% of the PTV received 45 Gy) and delivered to the target volume over 10 to 12 days. Overall the treatment was well tolerated with two Grade 3 acute toxicities and no acute Grade 4 toxicities. Late toxicity was minimal with all observed late toxicities occurring within the first six months of follow-up. Three hepatic recurrences at a distance from the target and one metastasis were observed. The actuarial 1- and 2-year local control rate was 95% (95% CI: 69-95%). At a median overall follow-up of 12,7 months (range, 1-24 months), six of the twenty-five (24%) patients have died. Overall actuarial survival at 1- and 2-years was 79% (95% CI: 52-92%) and 52% (95% CI: 19-78%), respectively. Our results suggest promising therapeutic efficacy and good clinical tolerance to CyberKnife SRT treatment for HCC patients not eligible for other treatment modalities.

Stereotactic body radiotherapy for patients with unresectable primary hepatocellular carcinoma: dose-volumetric parameters predicting the hepatic complication

PURPOSE

To identify the parameters that predict hepatic toxicity and deterioration of hepatic function.

MATERIALS AND METHODS

A total of 47 patients with small unresectable primary hepatocellular carcinoma received hypofractionated stereotactic body radiotherapy (SBRT) using the CyberKnife. Of those, 36 patients received no other local treatments that could influence hepatic toxicity at least for 3 months after the completion of SBRT. The gross tumor volume (GTV) was 18.3 ± 15.9 cm(3) (range, 3.0-81.3 cm(3)), and the total dose administered was 30-39 Gy (median, 36 Gy). To assess the deterioration of hepatic function, we evaluated the presence or absence of the progression of Child-Pugh class (CP class). To identify the parameters of predicting the radiation-induced hepatic toxicity and deterioration of the hepatic function, several clinical and dose-volumetric parameters were evaluated.

RESULTS

Of 36 patients, 12 (33%) developed Grade 2 or higher hepatic toxicity and 4 (11%) developed progression of CP class. The multivariate analysis showed that the only significant parameter associated with the progression of CP class was the total liver volume receiving a dose less than 18 Gy (<18 Gy).

CONCLUSIONS

The progression of CP class after SBRT limits other additional local treatments and also reflects the deterioration of hepatic function. Therefore, it would be important to note that the presence or absence of the progression of CP class is a dose-limiting factor. The total liver volume receiving <18 Gy should be greater than 800 cm(3) to reduce the risk of the deterioration of hepatic function.

[Nonsurgical management of hepatocellular carcinoma]

Most of patients with hepatocellular carcinoma (HCC) cannot benefit from surgical therapies. Among nonsurgical options, only radiofrequency can challenge surgery for small size tumours. Conformal radiotherapy is likely highly efficient on solitary tumours, but controlled studies are warranted to conclude. Other options are purely palliative. Transarterial hepatic chemoembolization is the goal-standard for multifocal hepatocellular carcinoma and sorafenib for hepatocellular carcinoma with portal vein invasion, leading to modest but significant benefit on survival rates. Yttrium-90 radioembolization is under evaluation through controlled studies, and could be of major interest for multifocal hepatocellular carcinoma with or without portal venous invasion.

Phase I feasibility trial of stereotactic body radiation therapy for primary hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is increasing in incidence and the majority of patients are not candidates for radical therapies. Therefore, interest in minimally invasive therapies in growing.

METHODS

A Phase I dose escalation trial was conducted at Indiana University to determine the feasibility and toxicity of stereotactic body radiation therapy (SBRT) for primary HCC. Eligible patients had Child-Turcotte-Pugh's Class (CTP) A or B, were not candidates for resection, had 1-3 lesions and cumulative tumour diameter less than or equal to 6 cm. Dose escalation started at 36 Gy in 3 fractions (12 Gy/fraction) with a subsequent planned escalation of 2 Gy/ fraction/level. Dose-limiting toxicity (DLT) was defined as Common Terminology Criteria for Adverse Events v3.0 grade 3 or greater toxicity.

RESULTS

Seventeen patients with 25 lesions were enrolled. Dose was escalated to 48 Gy (16 Gy/fraction) in CTP-A patients without DLT. Two patients with CPC-B disease developed grade 3 hepatic toxicity at the 42-Gy (14 Gy/fraction) level. The protocol was amended for subsequent CTP-B patients to receive a regimen of 5 fractions starting at 40 Gy (8 Gy/fraction) with one patient experiencing progressive liver failure. Four additional patients were enrolled (one died of unrelated causes after an incomplete SBRT course) without DLT. The only factor related to more than one grade 3 or greater liver toxicity or death within 6 months was the CTP score (p=0.03). Six patients underwent a liver transplant. Ten patients are alive without progression with a median FU of 24 months (10-42 months), with local control/stabilisation of the disease of 100%. One and two-year Kaplan-Meier estimates for overall survival are 75% and 60%, respectively.

CONCLUSIONS

SBRT is a non-invasive feasible and well tolerated therapy in adequately selected patients with HCC. The preliminary local control and survival are encouraging. A confirmatory Phase II trial is currently open to accrual.

Cyberknife stereotactic body radiation therapy for nonresectable tumors of the liver: preliminary results

Purpose. Stereotactic body radiation therapy (SBRT) has emerged as a treatment option for local tumor control of primary and secondary malignancies of the liver. We report on our updated experience with SBRT in patients with non-resectable tumors of the liver. Methods. Our first 17 consecutive patients (mean age 58.1 years) receiving SBRT for HCC (n = 6), IHC (n = 3), and LM (n = 8) are presented. Mean radiation dose was 34Gy delivered over 1–3 fractions. Results. Treated patients had a mean decrease in maximum pretreatment tumor diameter from 6.9 ± 4.6 cm to 5.0 ± 2.1 cm at three months after treatment (P < .05). The mean total tumor volume reduction was 44% at six months (P < .05). 82% of all patients (14/17) achieved local control with a median follow-up of 8 months. 100% of patients with HCC (n = 6) achieved local control. Patients with surgically placed fiducial markers had no complications related to marker placement. Conclusion. Our preliminary results showed that SBRT is a safe and effective local treatment modality in selected patients with liver malignancies with minimal adverse events. Further studies are needed to define its role in the management of these malignancies.

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.

Stereotactic body radiotherapy: a review

Stereotactic body radiotherapy (SBRT) combines the challenge of meeting the stringent dosimetric requirements of stereotactic radiosurgery with that of accounting for the physiological movement of tumour and normal tissue. Here we present an overview of the history and development of SBRT and discuss the radiobiological rationale upon which it is based. The published results of SBRT for lung, liver, pancreas, kidney, prostate and spinal lesions are reviewed and summarised. The current evidence base is appraised and important ongoing trials are identified.