Compensatory enlargement of the liver after treatment of hepatocellular carcinoma with carbon ion radiotherapy - relation to prognosis and liver function

Analysis and prediction of liver volume change maps derived from computational tomography scans acquired pre- and post-radiation therapy

External beam radiation therapy (EBRT) of liver cancers can cause local liver atrophy as a result of tissue damage or hypertrophy as a result of liver regeneration. Predicting those volumetric changes would enable new strategies for liver function preservation during treatment planning. However, understanding of the spatial dose/volume relationship is still limited. This study leverages the use of deep learning-based segmentation and biomechanical deformable image registration (DIR) to analyze and predict this relationship. Pre- and Post-EBRT imaging data were collected for 100 patients treated for hepatocellular carcinomas, cholangiocarcinoma or CRC with intensity-modulated radiotherapy (IMRT) with prescription doses ranging from 50 to 100 Gy delivered in 10-28 fractions. For each patient, DIR between the portal and venous (PV) phase of a diagnostic computed tomography (CT) scan acquired before radiation therapy (RT) planning, and a PV phase of a diagnostic CT scan acquired after the end of RT (on average 147 ± 36 d) was performed to calculate Jacobian maps representing volume changes in the liver. These volume change maps were used: (i): to analyze the dose/volume relationship in the whole liver and individual Couinaud's segments; and (ii): to investigate the use of deep-learning to predict a Jacobian map solely based on the pre-RT diagnostic CT and planned dose distribution. Moderate correlations between mean equivalent dose in 2 Gy fractions (EQD2) and volume change was observed for all liver sub-regions analyzed individually with Pearson correlationrranging from -0.36 to -067. The predicted volume change maps showed a significantly stronger voxel-wise correlation with the DIR-based volume change maps than when considering the original EQD2 distribution (0.63 ± 0.24 versus 0.55 ± 23, respectively), demonstrating the ability of the proposed approach to establish complex relationships between planned dose and liver volume response months after treatment, which represents a promising prediction tool for the development of future adaptive and personalized liver radiation therapy strategies.

Carbon Ion Radiotherapy in the Treatment of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a highly lethal cancer with limited treatment options and poor prognosis. Carbon ion radiotherapy (CIRT) has emerged as a promising treatment modality for HCC due to its unique physical and biological properties. CIRT uses carbon ions to target and destroy cancer cells with a high precision and efficacy. The Bragg Peak phenomenon allows precise dose delivery to the tumor while minimizing damage to healthy tissues. In addition, the high relative biological effectiveness of carbon ions can be shown against radioresistant and hypoxic tumor areas. CIRT also offers a shorter treatment schedule than conventional radiotherapy, which increases patient convenience and compliance. The clinical outcomes of CIRT for HCC have shown excellent local control rates with minimal side effects. Considering its physical and biological properties, CIRT may be a viable option for complex clinical scenarios such as patients with poor liver function, large tumors, re-irradiation cases, and tumors close to critical organs. Further research and larger studies are needed to establish definitive indications for CIRT and to compare its efficacy with that of other treatment modalities. Nevertheless, CIRT offers a potential breakthrough in HCC management, providing hope for improved therapeutic outcomes and reduced treatment-related toxicities.

Carbon Ion Radiotherapy Acts as the Optimal Treatment Strategy for Unresectable Liver Cancer During the Coronavirus Disease 2019 Crisis

The coronavirus disease 2019 (COVID-19) pandemic has greatly disrupted the normal treatment of patients with liver cancer and increased their risk of death. The weight of therapeutic safety was significantly amplified for decision-making to minimize the risk of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Herein, the safety and effectiveness of carbon ion radiotherapy (CIRT) for unresectable liver cancer (ULC) were evaluated, and Chinese experiences were shared to solve the predicament of ULC treatment caused by SARS-CoV-2. Worldwide studies were collected to evaluate CIRT for ULC as the world has become a community due to the COVID-19 pandemic. We not only searched five international databases including the Cochrane Library, Web of Science, PubMed, Embase, and Scopus but also performed supplementary retrieval with other sources. Chinese experiences of fighting against COVID-19 were introduced based on the advancements of CIRT in China and a prospective clinical trial of CIRT for treating ULC. A total of 19 studies involving 813 patients with ULC were included in the systematic review. The qualitative synthetic evaluation showed that compared with transarterial chemoembolization (TACE), CIRT could achieve superior overall survival, local control, and relative hepatic protection. The systematic results indicated that non-invasive CIRT could significantly minimize harms to patients with ULC and concurrently obtain superior anti-cancer effectiveness. According to the Chinese experience, CIRT allows telemedicine within the hospital (TMIH) to keep a sufficient person-to-person physical distance in the whole process of treatment for ULC, which is significant for cutting off the transmission route of SARS-CoV-2. Additionally, CIRT could maximize the utilization rate of hospitalization and outpatient care (UHO). Collectively, CIRT for ULC patients not only allows TMIH and the maximized UHO but also has the compatible advantages of safety and effectiveness. Therefore, CIRT should be identified as the optimal strategy for treating appropriate ULC when we need to minimize the risk of SARS-CoV-2 infection and to improve the capacity of medical service in the context of the unprecedented COVID-19 crisis.

Evaluation of Threshold Dose of Damaged Hepatic Tissue After Carbon-Ion Radiation Therapy Using Gd-EOB-DTPA-Enhanced Magnetic Resonance Imaging

Purpose

To evaluate the threshold dose and associated factors using signal-intensity changes in the irradiated area after carbon-ion radiation therapy (C-ion RT) for patients with liver cancer.

Methods and Materials

Patients treated for the first time with C-ion RT for malignant liver tumors and followed up with 3-Tesla gadoxetic acid (Gd-EOB-DTPA)–enhanced magnetic resonance imaging (MRI) 3 months after treatment completion were retrospectively enrolled. The volume of focal liver reaction (FLR), a low-intensity area in the hepatobiliary phase of Gd-EOB-DTPA after treatment, was measured. Corrected FLR (cFLR) volume, defined as FLR corrected for changes in tumor volume from before to after treatment, was calculated, and the threshold dose was determined by applying the cFLR volume in the dose-volume histogram. To evaluate potential mismatch in fusion images of planning computed tomography and follow-up MRI, the concordance coefficient (CC) was measured, and patients with a CC < 0.7 were excluded. Sixty patients were included. Multiple regression analysis was performed with the threshold dose as the objective variable and the age, dose, number of fractionations, Child-Pugh score, pretreatment liver volume, and pretreatment tumor volume as explanatory variables. The Student t test or Mann-Whitney U test was used as required.

Results

The median threshold doses for each number of dose fractionations (4 fractions, 12 fractions, and overall) were 51.6, 51.9, and 51.8 Gy (relative biological effectiveness [RBE]), respectively, in patients categorized as Child-Pugh class A and 27.0, 28.8, and 27.0 Gy (RBE), respectively, in patients categorized as Child-Pugh class B. In the multiple-regression analysis, only the Child-Pugh score was significant (P < .001). The number of dose fractionations was not statistically significant.

Conclusions

Although few patients in the study had decreased liver function, baseline liver function was the only factor significantly associated with the median threshold dose. These findings facilitate appropriate patient selection to receive C-ion RT for malignant hepatic tumors.

Carbon Ion Radiotherapy in the Management of Hepatocellular Carcinoma

Localized hepatocellular carcinoma (HCC) that is unresectable and non-transplantable can be treated by several liver-directed therapies. External beam radiation therapy (EBRT) is an increasingly accepted and widely utilized treatment modality in this setting. Accelerated charged particles such as proton beam therapy (PBT) and carbon ion radiation therapy (CIRT) offer technological advancements over conventional photon radiotherapy. In this review, we summarize the distinct advantages of CIRT use for HCC treatment, focusing on physical and biological attributes, and outline dosimetric and treatment planning caveats. Based on these considerations, we posit that HCC may be among the best indications for use of CIRT, as it allows for maximizing tumoricidal doses to the target volume while minimizing the dose to the organs at risk.

Appraisal of Long-Term Outcomes of Liver-Directed Concurrent Chemoradiotherapy for Hepatocellular Carcinoma with Major Portal Vein Invasion

Backgrounds and Aims

Molecular-targeted agents are acceptable standards to treat advanced-stage hepatocellular carcinoma (HCC), however, their therapeutic benefit, ie, sorafenib, was significantly offset in case of major vessel invasion. Liver-directed concurrent chemo-radiotherapy (LD-CCRT) provided favorable outcomes in terms of survivals and tumor shrinkage, so, we appraised its long-term therapeutic efficacy.

Patients and Methods

Advanced HCC patients with portal vein invasion (main trunk or the 1st order branch) were enrolled. During a 5-week radiotherapy course, concurrent hepatic arterial infusion chemotherapy (HAIC) with 5-fluorouracil and leucovorin was administered through an implanted port on the first and last 5 days. Four weeks after LD-CCRT, a maintenance HAIC using 5-fluorouracil and cisplatin was administered every 4 weeks.

Results

Among 152 patients, the objective response rates as the best response by modified Response Evaluation Criteria In Solid Tumors were 48.0% after LD-CCRT and 55.3% during subsequent HAIC maintenance. After LD-CCRT, biological responses in alpha-fetoprotein and protein induced by the absence of vitamin K or antagonist-II levels were achieved in 46.2% and 52.6%, respectively. Sixteen patients (10.5%) underwent curative resection or liver transplantation after down-staging. Median overall survival and progression-free survival were 13.5 and 6.9 months, respectively.

Conclusion

LD-CCRT followed by maintenance HAIC yielded favorable survival outcomes in advanced HCC patients with major portal vein invasion. Through initial tumor reduction, LD-CCRT induced down-staging with subsequent curative treatment feasible in 10.5% of patients, resulting in long-term survival. Further prospective trials are warranted to confirm these results.

Long-Term Results of High-Dose 2-Fraction Carbon Ion Radiation Therapy for Hepatocellular Carcinoma

Purpose

Carbon ion beams have several physical and biological advantages compared with conventional radiation for cancer therapy. The objective of this study is to evaluate the safety and effectiveness of 2-fraction carbon ion radiation therapy (CIRT) in patients with hepatocellular carcinoma (HCC).

Methods and Materials

Between December 2008 and March 2013, 57 patients with localized HCC were treated with CIRT at a total dose of 45 Gy (relative biological effectiveness) in 2 fractions and retrospectively analyzed after long-term observation. The main endpoints of this study were treatment-related toxicity and local tumor control. Toxicity was assessed using the National Cancer Institute Common Terminology Criteria for Adverse Events, version 4.0. Changes in the Child-Pugh score from before to after CIRT were also examined to evaluate hepatic toxicity. Local control was defined as no progression of the irradiated lesion according to the modified Response Evaluation Criteria in Solid Tumors.

Results

The median age of the patients was 75 years (range, 49-89 years). Of these patients, 41 had a newly diagnosed lesion, and 16 had residual or recurrent lesions after previous treatments. The median follow-up duration was 54 months (range, 7-103 months). All surviving patients were followed for more than 51 months. Two patients experienced grade 3 acute skin reactions, but no other grade 3 or higher toxicities were observed in any organ. No patient exhibited an increase in the Child-Pugh score of 2 or more points after CIRT. The local tumor control rates at 1, 3, and 5 years were 98%, 91%, and 91% after CIRT, respectively. All lesions that failed to respond to previous treatments were successfully controlled by CIRT. The 1-, 3-, and 5-year overall survival rates were 97%, 67%, and 45%, respectively.

Conclusions

Two-fraction CIRT was a well-tolerated and effective treatment for patients with HCC.

Protons versus Photons for Unresectable Hepatocellular Carcinoma: Liver Decompensation and Overall Survival

PURPOSE

Ablative radiation therapy is increasingly being used for hepatocellular carcinoma (HCC) resulting in excellent local control rates; however, patients without evidence of disease progression often die from liver failure. The clinical benefit of proton- over photon-based radiation therapy is unclear. We therefore sought to compare clinical outcomes of proton versus photon ablative radiation therapy in patients with unresectable HCC.

METHODS AND MATERIALS

This is a single-institution retrospective study of patients treated during 2008 to 2017 with nonmetastatic, unresectable HCC not previously treated with liver-directed radiation therapy and who did not receive further liver-directed radiation therapy within 12 months after completion of index treatment. The primary outcome, overall survival (OS), was assessed using Cox regression. Secondary endpoints included incidence of non-classic radiation-induced liver disease (defined as increase in baseline Child-Pugh score by ≥2 points at 3 months posttreatment), assessed using logistic regression, and locoregional recurrence, assessed using Fine-Gray regression for competing risks. All outcomes were measured from radiation start date.

RESULTS

The median follow-up was 14 months. Of 133 patients with median age 68 years and 75% male, 49 (37%) were treated with proton radiation therapy. Proton radiation therapy was associated with improved OS (adjusted hazard ratio, 0.47; P = .008; 95% confidence interval [CI], 0.27-0.82). The median OS for proton and photon patients was 31 and 14 months, respectively, and the 24-month OS for proton and photon patients was 59.1% and 28.6%, respectively. Proton radiation therapy was also associated with a decreased risk of non-classic radiation-induced liver disease (odds ratio, 0.26; P = .03; 95% CI, 0.08-0.86). Development of nonclassic RILD at 3 months was associated with worse OS (adjusted hazard ratio, 3.83; P < .001; 95% CI, 2.12-6.92). There was no difference in locoregional recurrence, including local failure, between protons and photons.

CONCLUSIONS

Proton radiation therapy was associated with improved survival, which may be driven by decreased incidence of posttreatment liver decompensation. Our findings support prospective investigations comparing proton versus photon ablative radiation therapy for HCC.

Transient increases in serum α fetoprotein and protein induced by vitamin K antagonist II levels following proton therapy does not necessarily indicate progression of hepatocellular carcinoma

Transient increases in α-fetoprotein (AFP) and protein induced by vitamin K antagonist II (PIVKA-II), so-called flares, are frequently observed after treatment of hepatocellular carcinoma (HCC). In the present study, changes in AFP and PIVKA-II levels after proton therapy (PT), and the relationship between the flare phenomenon and clinical response were investigated. In 82 patients with stage I/II HCC (59 with no recurrence and 23 with out-of-field recurrence within 1 year), serum AFP and PIVKA-II levels were measured at 1, 3, 6, 9 and 12 months post-PT. AFP and PIVKA-II flares were defined as a >20% increase from the preceding serum level above 20 ng/ml (AFP) or 40 mAU/ml (PIVKA-II), followed by a >20% drop. Among the 59 patients with no recurrence, 3 (5.1%) had an AFP flare, while 23 (39%) had a PIVKA-II flare. The median time to AFP and PIVKA-II flare peaks was 1 and 6 months, respectively. In 4 patients, PIVKA-II flares were observed twice during follow-up. In 1 patient, AFP and PIVKA-II flares were observed simultaneously at 1 month post-PT. The PIVKA-II level pre-PT was significantly higher in the PIVKA-II flare-positive group compared with that in the flare-negative group (P=0.015, odds ratio 4.3, 95% confidence interval, 1.3-14.0). In the 23 patients with out-of-field recurrence, the median increase rate of PIVKA-II (203%) was higher than that in the PIVKA-II-flare-positive group (111%, P=0.035) and the time to recurrence (median, 9 months) was longer than the time to peak AFP level (1 month) in the AFP-flare-positive group (P=0.033). There was no significant association between flares and clinical response. Increases in AFP and PIVKA-II levels following PT should be assessed with caution to avoid misinterpretation of therapeutic outcome.

Compensatory hypertrophy of the liver after external beam radiotherapy for primary liver cancer

PURPOSE

We investigated whether external beam radiotherapy (EBRT) could induce compensatory liver hypertrophy in liver cancers and assessed related clinical factors.

METHODS

A total of 82 consecutive patients receiving EBRT for hepatocellular carcinoma (n = 77) or cholangiocarcinoma (n = 5) from April 2012 to June 2014 were recruited and divided into two subgroups according to tumor location in the right or left lobe. The left lateral and right lobes were considered as unirradiated volumes accordingly. Total liver volume (TLV), nontumor liver volume (NLV), left and right lobe whole volume (LLWV and RLWV, respectively), volume of liver irradiated < 30 Gy (V_< 30 Gy), Child-Pugh (CPS) score, future liver remnant (FLR) ratio, and percentage of FLR hypertrophy from baseline (%FLR) were assessed.

RESULTS

In the right lobe group, %FLR hypertrophy and LLWV increased significantly at all follow-ups (p < 0.001). %FLR hypertrophy steadily increased until the fourth follow-up. Multivariate analysis showed that the factor associated with maximum %FLR hypertrophy was tumor extent (upper or lower lobe vs. both lobes; p = 0.022). Post-RT treatments including transarterial chemoembolization or hepatic arterial infusion chemotherapy were associated with a CPS increase ≥ 2 (p = 0.002). Analysis of the RT only subgroup also showed a significant increase of %FLR until the fourth follow-up (p < 0.001). In the left lobe group, %FLR hypertrophy and RLWV showed no significant changes during follow-up.

CONCLUSION

Significant compensatory hypertrophy of the liver was observed, with a steady increase of %FLR hypertrophy until the fourth follow-up (median: 396 days). Locally advanced tumors extending across the upper and lower right lobe were a significant factor for compensating hypertrophy after EBRT.

Surgical findings and technical knacks to performing living donor liver transplantation for hepatocellular carcinoma recurrence after carbon ion radiotherapy

Although carbon-ion radiotherapy (CIRT) has been reported to achieve good local control of hepatocellular carcinoma (HCC), liver transplantation is still required in patients with tumor recurrence. However, few cases of living donor liver transplantation (LDLT) after curative CIRT for HCC has been reported. It would be of great interest to ascertain the true situation of the irradiated region as well as to clarify the surgical points. We herein report the surgical findings and our experience along with technical difficulties and knacks concerning two cases of LDLT for HCC after CIRT. Both patients suffered tumor recurrence after curative CIRT for HCC. Severe adhesions were found between the irradiated region and the surrounding tissues, which resulted in surgical difficulties. Histological findings showed severe tissue fibrosis in the CIRT area. We should pay attention to adhesions in the irradiated area caused by CIRT including the vascular reconstruction during surgery.

Metformin enhances the radiosensitivity of human liver cancer cells to γ-rays and carbon ion beams

The purpose of this study was to investigate the effect of metformin on the responses of hepatocellular carcinoma (HCC) cells to γ-rays (low-linear energy transfer (LET) radiation) and carbon-ion beams (high-LET radiation). HCC cells were pretreated with metformin and exposed to a single dose of γ-rays or carbon ion beams. Metformin treatment increased radiation-induced clonogenic cell death, DNA damage, and apoptosis. Carbon ion beams combined with metformin were more effective than carbon ion beams or γ-rays alone at inducing subG1 and decreasing G2/M arrest, reducing the expression of vimentin, enhancing phospho-AMPK expression, and suppressing phospho-mTOR and phospho-Akt. Thus, metformin effectively enhanced the therapeutic effect of radiation with a wide range of LET, in particular carbon ion beams and it may be useful for increasing the clinical efficacy of carbon ion beams.

Implementing Radiation Dose-Volume Liver Response in Biomechanical Deformable Image Registration

PURPOSE

Understanding anatomic and functional changes in the liver resulting from radiation therapy is fundamental to the improvement of normal tissue complication probability models needed to advance personalized medicine. The ability to link pretreatment and posttreatment imaging is often compromised by significant dose-dependent volumetric changes within the liver that are currently not accounted for in deformable image registration (DIR) techniques. This study investigated using delivered dose, in combination with other patient factors, to biomechanically model longitudinal changes in liver anatomy for follow-up care and re-treatment planning.

METHODS AND MATERIALS

Population models describing the relationship between dose and hepatic volume response were produced using retrospective data from 33 patients treated with focal radiation therapy. A DIR technique was improved by implementing additional boundary conditions associated with the dose-volume response in series with a previously developed biomechanical DIR algorithm. Evaluation of this DIR technique was performed on computed tomography imaging from 7 patients by comparing the model-predicted volumetric change within the liver with the observed change, tracking vessel bifurcations within the liver through the deformation process, and then determining target registration error between the predicted and identified posttreatment bifurcation points.

RESULTS

Evaluation of the proposed DIR technique showed that all lobes were volumetrically deformed to within the respective contour variability of each lobe. The average target registration error achieved was 7.3 mm (2.8 mm left-right and anterior-posterior and 5.1 mm superior-inferior), with the superior-inferior component within the average limiting slice thickness (6.0 mm). This represented a significant improvement (P<.01, Wilcoxon test) over the application of the previously published biomechanical DIR algorithm (10.9 mm).

CONCLUSIONS

This study demonstrates the feasibility of implementing dose-driven volumetric response in deformable registration, enabling improved accuracy of modeling liver anatomy changes, which could allow for improved dose accumulation, particularly for patients who require additional liver radiation therapy.

Evaluation of Focal Liver Reaction after Proton Beam Therapy for Hepatocellular Carcinoma Examined Using Gd-EOB-DTPA Enhanced Hepatic Magnetic Resonance Imaging

BACKGROUND

Proton beam therapy (PBT) achieves good local control for hepatocellular carcinoma (HCC), and toxicity tends to be lower than for photon radiotherapy. Focal liver parenchymal damage in radiotherapy is described as the focal liver reaction (FLR); the threshold doses (TDs) for FLR in the background liver have been analyzed in stereotactic ablative body radiotherapy and brachytherapy. To develop a safer approach for PBT, both TD and liver volume changes are considered clinically important in predicting the extent of damage before treatment, and subsequently in reducing background liver damage. We investigated appearance time, TDs and volume changes regarding FLR after PBT for HCC.

MATERIAL AND METHODS

Patients who were treated using PBT and were followed up using gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging (Gd-EOB-DTPA MRI) after PBT were enrolled. Sixty-eight lesions in 58 patients were eligible for analysis. MRI was acquired at the end of treatment, and at 1, 2, 3 and 6 months after PBT. We defined the FLR as a clearly depicted hypointense area on the hepatobiliary phase of Gd-EOB-DTPA MRI, and we monitored TDs and volume changes in the FLR area and the residual liver outside of the FLR area.

RESULTS

FLR was depicted in all lesions at 3 months after PBT. In FLR expressed as the 2-Gy equivalent dose (α/β = 3 Gy), TDs did not differ significantly (27.0±6.4 CGE [10 fractions [Fr] vs. 30.5±7.3 CGE [20 Fr]). There were also no correlations between the TDs and clinical factors, and no significant differences between Child-Pugh A and B scores. The volume of the FLR area decreased and the residual liver volume increased, particularly during the initial 3 months.

CONCLUSION

This study established the FLR dose for liver with HCC, which might be useful in the prediction of remnant liver volume for PBT.

Current management of patients with hepatocellular carcinoma

The current management therapies for hepatocellular carcinoma (HCC) patients are discussed in this review. Despite the development of new therapies, HCC remains a “difficult to treat” cancer because HCC typically occurs in advanced liver disease or hepatic cirrhosis. The progression of multistep and multicentric HCC hampers the prevention of the recurrence of HCC. Many HCC patients are treated with surgical resection and radiofrequency ablation (RFA), although these modalities should be considered in only selected cases with a certain HCC number and size. Although there is a shortage of grafts, liver transplantation has the highest survival rates for HCC. Several modalities are salvage treatments; however, intensive care in combination with other modalities or in combination with surgical resection or RFA might offer a better prognosis. Sorafenib is useful for patients with advanced HCC. In the near future, HCC treatment will include stronger molecular targeted drugs, which will have greater potency and fewer adverse events. Further studies will be ongoing.

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

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

Surgical resection after down-staging of locally advanced hepatocellular carcinoma by localized concurrent chemoradiotherapy

BACKGROUND

This study evaluated the down-staging efficacy and impact on resectability of concurrent chemoradiotherapy (CCRT) followed by hepatic arterial infusion chemotherapy (HAIC) in locally advanced hepatocellular carcinoma, and identified prognostic factors of disease-free survival (DFS) and overall survival (OS) after curative resection.

METHODS

DFS and OS were investigated using clinicopathologic variables. Functional residual liver volume (FRLV) was assessed before CCRT and again before surgery in patients with major hepatectomy. Tumor marker response was defined as elevated tumor marker levels at diagnosis but levels below cutoff values before surgery (α-fetoprotein < 20 ng/mL, protein induced by vitamin K absence or antagonist-II < 40 mAU/mL).

RESULTS

Of 243 patients who received CCRT followed by HAIC between 2005 and 2011, 41 (16.9 %) underwent curative resection. Tumor down-staging was demonstrated in 32 (78 %) of the resected patients. FRLV significantly increased from 47.5 to 69.9 % before surgery in patients who underwent major hepatectomy. In addition, the OS of the curative resection group was significantly higher than the OS of the CCRT followed by HAIC alone group (49.6 vs. 9.8 % at 5-year survival; p < 0.001). By multivariate analysis, the poor prognostic factors for DFS after curative resection were tumor marker non-response and the presence of a satellite nodule; however, tumor marker non-response was the only independent poor prognostic factor of OS.

CONCLUSIONS

CCRT followed by HAIC increased resectability by down-staging tumors and increasing FRLV. Curative resection may provide good long-term survival in tumor marker responders who undergo CCRT followed by HAIC.

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.

Dose volume histogram analysis of focal liver reaction in follow-up multiphasic CT following stereotactic body radiotherapy for small hepatocellular carcinoma

PURPOSE

To investigate threshold dose (TD) of focal liver reaction (FLR) following stereotactic body radiotherapy (SBRT) for patients with hepatocellular carcinoma (HCC) and liver cirrhosis.

MATERIALS AND METHODS

In consecutive 50 patients receiving SBRT for small HCC, 38 patients receiving SBRT and follow up >6 months, FLR on follow-up CT had been previously studied. Patients with good concordance between FLR and highly irradiated area were eligible. Dose volume histogram (DVH) was used to identify TDs for FLR. Clinical factors were analyzed for correlation with TDs.

RESULTS

Of 24 eligible patients, 23 had Child-Pugh score A and 1 scored B. Presence of FLR peaked at a median of 6 (range; 3-12) months. The median and 95% confidential intervals of TDs of pre-contrast and portal-venous phase CT were 32.4 Gy (30.3-35.4) and 34.4 Gy (31.9-36.0), respectively. Each median coefficient representing the concordance was 74.9% (range; 55.8-98.0%) and 80.5% (range; 70.8-92.4%), respectively. No clinical factors significantly correlated with the TDs.

CONCLUSION

We proposed 30 Gy/5 fractions as TD of FLRs following SBRT for patients with HCC and liver cirrhosis. This TD will enable us to predict injured liver volume and to avoid complication beforehand from toxicity. Further pathological and clinical studies, in addition to more practical and precise data of DVH, are needed to clarify the significance of FLRs.