Radiation-induced liver disease in three-dimensional conformal radiation therapy for primary liver carcinoma: the risk factors and hepatic radiation tolerance

Efficacy and safety of SBRT combined with sintilimab and IBI305 in patients with advanced HCC and previously failed immunotherapy: study protocol of a phase 2 clinical trial

INTRODUCTION

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related death in China. The combination of immune checkpoint inhibitors (ICIs) and antiangiogenic drugs, such as bevacizumab and tyrosine kinase inhibitors, has been recommended as first-line treatment for advanced HCC. However, two-thirds of patients did not benefit from this form of immunotherapy. Currently, data on the subsequent regimen for patients previously treated with ICIs are lacking. Studies have shown that the combination of radiotherapy (RT) and ICIs is a potentially effective second-line therapy for HCC. This study aims to assess the efficacy and safety of combined therapy with stereotactic body RT (SBRT), sintilimab and IBI305 (a biosimilar of bevacizumab) in patients with HCC following the progression of first-line ICI therapy.

METHODS AND ANALYSIS

This study is an open-label, single-arm, single-centre, phase 2 trial of 21 patients with advanced HCC in whom previous ICI therapy has failed. Participants will receive approximately 30-40 Gy/5-8F SBRT, followed by 200 mg sintilimab and 15 mg/kg IBI305 intravenously every 3 weeks. Treatment will continue until the development of unacceptable toxicity or disease progression. We will use Simon's two-stage design, with the objective response rate (ORR) as the primary endpoint. Secondary endpoints include ORR of lesions without RT, disease control rate, progression-free survival, overall survival and safety.

ETHICS AND DISSEMINATION

The study was authorised by the Medical Ethics Committee. Dissemination of results will occur via a peer-reviewed publication and other relevant media.

TRIAL REGISTRATION NUMBER

ChiCTR2200056068.

Liver Late Effects in Childhood Cancer Survivors Treated With Radiation Therapy: A PENTEC Comprehensive Review

PURPOSE

A pediatric normal tissue effects in the clinic (PENTEC) comprehensive review of patients with childhood cancer who received radiation therapy (RT) to the liver was performed to develop models that may inform RT dose constraints for the liver and improve risk forecasting of toxicities.

METHODS AND MATERIALS

A systematic literature search was performed to identify published data on hepatic toxicities in children. Treatment and outcome data were extracted and used to generate normal tissue complication probability (NTCP) models. Complications from both whole and partial liver irradiation were considered. For whole liver irradiation, total body irradiation and non-total body irradiation treatments were considered, but it was assumed that the entire liver received the prescribed dose. For partial liver irradiation, only Wilms tumor flank field RT could be analyzed. However, a prescribed dose assumption could not be applied, and there was a paucity of analyzable liver dosimetry data. To associate the dose-volume exposures with the partial volume complication data from flank irradiation, liver dose-volume metrics were reconstructed for Wilms tumor flank RT using age-specific computational phantoms as a function of field laterality and superior extent of the field.

RESULTS

The literature search identified 2103 investigations pertaining to hepatic sinusoidal obstructive syndrome (SOS) and liver failure in pediatric patients. All abstracts were screened, and 241 articles were reviewed in full by the study team. A model was developed to calculate the risk of developing SOS after whole liver RT. RT dose (P = .006) and receipt of nonalkylating chemotherapy (P = .01) were significant. Age <20 years at time of RT was borderline significant (P = .058). The model predicted a 2% risk of SOS with zero RT dose, 6.1% following 10 Gy, and 14.5% following 20 Gy to the whole liver (modeled as the linear-quadratic equivalent dose in 2-Gy fractions [α/β = 3 Gy]). Patients with Wilms tumor treated with right flank RT had a higher observed rate of SOS than patients receiving left flank RT, but data were insufficient to generate an NTCP model for partial liver irradiation. From the phantom-based dose reconstructions, mean liver dose was estimated to be 2.16 ± 1.15 Gy and 6.54 ± 2.50 Gy for left and right flank RT, respectively, using T10-T11 as the superior field border and a prescription dose of 10.8 Gy (based on dose reconstruction). Data were sparse regarding rates of late liver injury after RT, which suggests low rates of severe toxicity after treatment for common pediatric malignancies.

CONCLUSIONS

This pediatric normal tissue effects in the clinic (PENTEC) review provides an NTCP model to estimate the risk of hepatic SOS as a function of RT dose following whole liver RT and quantifies the range of mean liver doses from typical Wilms tumor flank irradiation fields. Patients treated with right flank RT had higher rates of SOS than patients treated with left flank RT, but data were insufficient to develop a model for partial liver irradiation. Risk of SOS was estimated to be approximately ≤6% in pediatric patients receiving whole liver doses of <10 Gy.

Development and validation of a nomogram for radiation-induced hepatic toxicity after intensity modulated radiotherapy for hepatocellular carcinoma: a retrospective study

OBJECTIVE

This study aimed to construct a nomogram to predict radiation-induced hepatic toxicity in patients with hepatocellular carcinoma treated with intensity-modulated radiotherapy.

METHODS

This study reviewed the clinical characteristics and dose-volume parameters of 196 patients with hepatocellular carcinoma. Radiation-induced hepatic toxicity was defined as progression of the Child-Pugh score caused by intensity-modulated radiotherapy. Factors relevant to radiation-induced hepatic toxicity were selected using receiver operating characteristic and univariate logistic analysis. A risk assessment model was developed, and its discrimination was validated.

RESULTS

Eighty-eight (44.90%) and 28 (14.29%) patients had radiation-induced hepatic toxicity ≥ 1 (Child-Pugh ≥ 1) and radiation-induced hepatic toxicity ≥ 2 (Child-Pugh ≥ 2). Pre-treatment Child-Pugh, body mass index and dose-volume parameters were correlated with radiation-induced hepatic toxicity ≥ 1 using univariate logistic analysis. V15 had the best predictive effectiveness among the dose-volume parameters in both the training (area under the curve: 0.763, 95% confidence interval: 0.683-0.842, P < 0.001) and validation cohorts (area under the curve: 0.759, 95% confidence interval: 0.635-0.883, P < 0.001). The area under the curve values of the model that was constructed by pre-treatment Child-Pugh, body mass index and V15 for radiation-induced hepatic toxicity ≥1 were 0.799 (95% confidence interval: 0.719-0.878, P < 0.001) and 0.775 (95% confidence interval: 0.657-0.894, P < 0.001) in the training and validation cohorts, respectively. Patients with a body mass index ≤ 20.425, Barcelona clinic liver cancer = C, Hepatitis B Virus-positive, Eastern Cooperative Oncology Group = 1-2 and hepatic fibrosis require lower V15 dose limits.

CONCLUSIONS

Risk assessment model constructed from Pre-treatment Child-Pugh, V15 and body mass index can guide individualized patient selection of toxicity minimization strategies.

Microinvasion in hepatocellular carcinoma: predictive factor and application for definition of clinical target volume for radiotherapy

BACKGROUND

To investigate the correlation between microinvasion and various features of hepatocellular carcinoma (HCC), and to clarify the microinvasion distance from visible HCC lesions to subclinical lesions, so as to provide clinical basis for the expandable boundary of clinical target volume (CTV) from gross tumor volume (GTV) in the radiotherapy of HCC.

METHODS

HCC patients underwent hepatectomy of liver cancer in our hospital between July 2019 and November 2021 were enrolled. Data on various features and tumor microinvasion distance were collected. The distribution characteristics of microinvasion distance were analyzed to investigate its potential correlation with various features. Tumor size compared between radiographic and pathologic samples was analyzed to clarify the application of pathologic microinvasion to identify subclinical lesions of radiographic imaging.

RESULTS

The average microinvasion distance was 0.6 mm, with 95% patients exhibiting microinvasion distance less than 3.0 mm, and the maximum microinvasion distance was 4.0 mm. A significant correlation was found between microinvasion and liver cirrhosis (P = 0.036), serum albumin level (P = 0.049). Multivariate logistic regression analysis revealed that HCC patients with cirrhosis had a significantly lower risk of microinvasion (OR = 0.09, 95%CI = 0.02 ~ 0.50, P = 0.006). Tumor size was overestimated by 1.6 mm (95%CI=-12.8 ~ 16.0 mm) on radiographic size compared to pathologic size, with a mean %Δsize of 2.96% (95%CI=-0.57%~6.50%). The %Δsize ranged from - 29.03% to 34.78%.

CONCLUSIONS

CTV expanding by 5.4 mm from radiographic GTV could include all pathologic microinvasive lesions in the radiotherapy of HCC. Liver cirrhosis was correlated with microinvasion and were independent predictive factor of microinvasion in HCC.

Predictors of Toxicity in a Randomized Study of Consolidation Chemoradiation Versus Observation After First Line Chemotherapy in Advanced Gall Bladder Cancers

Purpose

Gall bladder cancers (GBC) usually presents in advanced stage. First-line chemotherapy (CT) is the standard of care, and there is no other option for responders than to wait for disease progression. We conducted a randomized study of consolidation chemoradiation (CTRT) versus observation in responders to first line CT (NCT05493956), which showed an improvement in overall survival by 6 months and therefore is practice changing. We are reporting the toxicity and factors predicting toxicity due to CTRT so that it informs appropriate patient selection.

Methods and Materials

Responders to first line CT (partial response, stable disease) were randomized to CTRT versus observation after 4 cycles. CTRT was delivered by 3D conformal radiotherapy (along-with concurrent capecitabine at 1250 mg/m2) to a dose of 45 Gy in 25 fractions to GBC and lymphatics followed by a boost of 9 Gy in 5 fractions to the GBC. Toxicities documented during CTRT were recorded using the Radiation Therapy Oncology Group criteria. Dose volume data were correlated with the radiation induced side effects.

Results

Among 135 patients enrolled both arms are well balanced demographically, and 58% patients had T4 tumors, 42% had N2 and 15% had paraaortic lymph node, and 27% underwent upfront stenting. Grade 3 adverse events, such as anemia, dyspepsia, hepatotoxicity (Child Pugh B), and gastrointestinal bleed due to CTRT was observed in 9%, 1.5%, 13%, and 5.8%, respectively. Age >58 years (P = .02), planning target volume (PTV) 1 volume (>919 cc, P = .02), PTV2 volume (>380 cc, P = .01), mean liver dose (>28 Gy, P = .07), and liver V40 (>50%, P = .02) predicted radiation-induced liver disease. A receiver operating curve analysis revealed a cut-off value of PTV1 volume of 800 cc (sensitivity and specificity of 75% and 54%) and PTV2 volume of 300 cc (sensitivity and specificity of 81% and 65%) for prediction of hepatotoxicity. Duodenum V45 >45% (P = .02) predicted grade 3 anemia. Numerically high V15 duodenum (98%, P = .11), large PTV2 volume >484 cc (P = .06) and prior stenting had predilection for gastrointestinal bleed.

Conclusions

Consolidation CTRT is tolerable in those with PTV1 volume less than 800 cc.

Time variation of high-risk groups for liver function deteriorations within fluctuating long-term liver function after hepatic radiotherapy in patients with hepatocellular carcinoma

PURPOSE

The purpose of this study is to find essential risk factors associated with liver function (LF) deteriorations within fluctuating long-term LF and their time-varying effects in patients with hepatocellular carcinoma (HCC) receiving hepatic radiotherapy and to identify high-risk groups for adverse LF deteriorations and their changes over time in facilitating the prevention of hepatic decompensation and the improvement of survival.

MATERIALS AND METHODS

A total of 133 HCC patients treated by hepatic radiotherapy were enrolled. A study design was conducted to convert posttreatment long-term LF with fluctuating levels over time to recurrent LF events using defined upgrades in a grading scale. The hazard ratios (HR) of pretreatment biochemical, demographic, clinical, and dosimetric factors in developing posttreatment LF events were estimated using the Cox model. Methodologies of the counting process approach, robust variance estimation, goodness-of-fit testing based on the Schoenfeld residuals, and time-dependent covariates in survival analysis were employed to handle the correlation within subjects and evaluate the time-varying effects during long-term follow-up.

RESULTS

Baseline LF score before radiotherapy and gender were significant factors. Initial HR in developing LF events was 1.17 (95% CI 1.11-1.23; P < 0.001) for each increase of baseline LF score and kept almost constant over time (HR, 1.00; 95% CI 1.00-1.01; P = 0.065). However, no difference was observed regarding initial hazards for gender (HR, 1.00; 95% CI 0.64-1.56; P = 0.994), but the hazard for women got higher monthly over time compared with men (HR, 1.04; 95% CI 1.01-1.07; P = 0.006).

CONCLUSIONS

High-risk groups for adverse LF deteriorations after hepatic radiotherapy may change over time. Patients with poor baseline LF are vulnerable from the beginning. Women require prevention strategies and careful monitoring for deteriorations at a later stage.

Stereotactic Body Radiation Therapy (SBRT) for Hepatocellular Carcinoma (HCC) With Single Photon Emission Computed Tomography (SPECT) Functional Treatment Planning in Patients With Advanced Hepatic Cirrhosis

Purpose

We report on the feasibility and outcomes of liver stereotactic body radiation therapy (SBRT) for hepatocellular carcinoma (HCC) with single-photon emission computed tomography (SPECT) functional treatment planning in patients with Child-Pugh (CP) B/C cirrhosis.

Methods and Materials

Liver SPECT with 99mTc-sulfur colloid was coregistered to treatment planning computed tomography (CT) for the guided avoidance of functional hepatic parenchyma during SBRT. Functional liver volumes (FLVs) obtained from SPECT were compared with anatomic liver volumes defined on the planning CT. Radiation dose constraints were adapted exclusively to FLV. Local control, toxicity, and survival were reported with at least 6 months of radiographic follow-up. Pre- and posttransplant outcomes were analyzed in a subset of patients who completed SBRT as a bridge to liver transplant. Model of End-Stage Liver Disease was used to score hepatic function before and after SBRT completion.

Results

With a median follow-up of 32 months, 45 patients (58 lesions) with HCC and CP-B/C cirrhosis received SBRT to a median dose of 45 Gy (3-5 fractions). FLV loss (34%, P < .001) was observed in all patients, and the functional and anatomic liver volumes matched well in a control group of noncirrhotic/non-HCC patients. Despite marked functional parenchyma retraction, the amount of FLV on SPECT exposed to the threshold irradiation was significantly less than the CT liver volumes (P < .001) because of the optimized beam placement during dosimetry planning. Twenty-three patients (51%) successfully completed orthotopic liver transplant, with a median time to transplant of 9.2 months. With 91% in-field local control, the overall 2-year survival was 65% (90% after the orthotopic liver transplant), with no incidence of radiation-induced liver disease observed within 3 to 4 months or accelerated CP class migration from B to C within the first 6 months post-SBRT. Mean Model of End-Stage Liver Disease-Na score was not significantly elevated at 3-month intervals after SBRT completion.

Conclusions

Functional treatment planning with 99mTc sulfur colloid SPECT/CT allows identification and avoidance of functional hepatic parenchyma in patients with CP-B/C cirrhosis, leading to low toxicity and satisfactory transplant outcomes.

Deep learning based automatic internal gross target volume delineation from 4D-CT of hepatocellular carcinoma patients

BACKGROUND

The location and morphology of the liver are significantly affected by respiratory motion. Therefore, delineating the gross target volume (GTV) based on 4D medical images is more accurate than regular 3D-CT with contrast. However, the 4D method is also more time-consuming and laborious. This study proposes a deep learning (DL) framework based on 4D-CT that can achieve automatic delineation of internal GTV.

METHODS

The proposed network consists of two encoding paths, one for feature extraction of adjacent slices (spatial slices) in a specific 3D-CT sequence, and one for feature extraction of slices at the same location in three adjacent phase 3D-CT sequences (temporal slices), a feature fusion module based on an attention mechanism was proposed for fusing the temporal and spatial features. Twenty-six patients' 4D-CT, each consisting of 10 respiratory phases, were used as the dataset. The Hausdorff distance (HD95), Dice similarity coefficient (DSC), and volume difference (VD) between the manual and predicted tumor contour were computed to evaluate the model's segmentation accuracy.

RESULTS

The predicted GTVs and IGTVs were compared quantitatively and visually with the ground truth. For the test dataset, the proposed method achieved a mean DSC of 0.869 ± 0.089 and an HD95 of 5.14 ± 3.34 mm for all GTVs, with under-segmented GTVs on some CT slices being compensated by GTVs on other slices, resulting in better agreement between the predicted IGTVs and the ground truth, with a mean DSC of 0.882 ± 0.085 and an HD95 of 4.88 ± 2.84 mm. The best GTV results were generally observed at the end-inspiration stage.

CONCLUSIONS

Our proposed DL framework for tumor segmentation on 4D-CT datasets shows promise for fully automated delineation in the future. The promising results of this work provide impetus for its integration into the 4DCT treatment planning workflow to improve hepatocellular carcinoma radiotherapy.

Low-dose radiotherapy combined with dual PD-L1 and VEGFA blockade elicits antitumor response in hepatocellular carcinoma mediated by activated intratumoral CD8+ exhausted-like T cells

Atezolizumab (anti-PD-L1) combined with bevacizumab (anti-VEGFA) is the first-line immunotherapy for advanced hepatocellular carcinoma (HCC), but the number of patients who benefit from this regimen remains limited. Here, we combine dual PD-L1 and VEGFA blockade (DPVB) with low-dose radiotherapy (LDRT), which rapidly inflames tumors, rendering them vulnerable to immunotherapy. The combinatorial therapy exhibits superior antitumor efficacy mediated by CD8+ T cells in various preclinical HCC models. Treatment efficacy relies upon mobilizing exhausted-like CD8+ T cells (CD8+ Tex) with effector function and cytolytic capacity. Mechanistically, LDRT sensitizes tumors to DPVB by recruiting stem-like CD8+ Tpex, the progenitor exhausted CD8+ T cells, from draining lymph nodes (dLNs) into the tumor via the CXCL10/CXCR3 axis. Together, these results further support the rationale for combining LDRT with atezolizumab and bevacizumab, and its clinical translation.

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.

Dose Volume and Liver Function Test Relationship following Radiotheraphy for Right Breast Cancer: A Multicenter Study

OBJECTIVE

The liver is a critical organ at risk during right breast radiotherapy (RT). Liver function tests (LFTs) such as alanine aminotransferase (ALT), aspartate aminotransferase (AST), and gamma-glutamyl transferase (GGT) serve as biochemical markers for hepatobiliary damage. In this multicenter cross-sectional study, the effects of liver dose-volume on changes in LFTs pre- and post-RT in patients treated for right breast cancer were evaluated.

MATERIALS AND METHODS

Between January 2019 and November 2022, data from 100 patients who underwent adjuvant right breast RT across three centers were retrospectively assessed. Target volumes and normal structures were contoured per the RTOG atlas. Patients were treated with a total dose of 50 Gy in 25 fractions to the CTV, followed by a boost to the tumor bed where indicated. The percentage change in LFT values in the first two weeks post-RT was calculated. Statistics were analyzed with SPSS version 22 software, with significance set at p < 0.05. Statistical correlation between liver doses (in cGy) and the volume receiving specific doses (Vx in cc) on the change in LFTs were analyzed using Kolmogorov-Smirnov, Mann-Whitney U test.

RESULTS

The median age among the 100 patients was 56 (range: 29-79). Breast-conserving surgery was performed on 75% of the patients. The most common T and N stages were T1 (53%) and N0 (53%), respectively. None of the patients had distant metastasis or simultaneous systemic treatment with RT. A total of 67% of the treatments utilized the IMRT technique and 33% VMAT. The median CTV volume was 802 cc (range: 214-2724 cc). A median boost dose of 10 Gy (range: 10-16 Gy) was applied to 28% of the patients with electrons and 51% with IMRT/VMAT. The median liver volume was 1423 cc (range: 825-2312 cc). Statistical analyses were conducted on a subset of 57 patients for whom all three LFT values were available both pre- and post-RT. In this group, the median values for AST, ALT, and GGT increased up to 15% post-RT compared to pre-RT, and a median liver Dmean below 208 cGy was found significant. While many factors can influence LFT values, during RT planning, attention to liver doses and subsequent regular LFT checks are crucial.

CONCLUSION

Due to factors such as anatomical positioning, planning technique, and breast posture, the liver can receive varying doses during right breast irradiation. Protecting patients from liver toxicity secondary to RT is valuable, especially in breast cancer patients with a long-life expectancy. Our study found that, even in the absence of any systemic treatment or risk factors, there was an average increase of nearly 15% in enzymes, indicating acute liver damage post-RT compared with pre-RT. Attention to liver doses during RT planning and regular follow-up with LFTs is essential.

Salvage Locoregional Therapy Following Progression After Radiotherapy for Hepatocellular Carcinoma Is Associated with Improved Outcomes

PURPOSE

To evaluate the impact of salvage locoregional therapy (salvage-LT) on survival of hepatocellular carcinoma (HCC) patients presenting with intrahepatic tumor progression following radiotherapy.

METHODS

This single-institution retrospective analysis included consecutive HCC patients having intrahepatic tumor progression following radiotherapy during 2015-2019. Overall survival (OS) was calculated from the date of intrahepatic tumor progression after initial radiotherapy by using the Kaplan-Meier method. Log-rank tests and Cox regression models were used for univariable and multivariable analyses. An inverse probability weighting was used to estimate treatment effect of salvage-LT considering confounding factors.

RESULTS

A total of 123 patients (mean age ± SD, 70 years ± 10; 97 men) were evaluated. Among those, 35 patients underwent 59 sessions of salvage-LT, including transarterial embolization/chemoembolization (n = 33), ablation (n = 11), selective internal radiotherapy (n = 7), and external beam radiotherapy (n = 8). At a median follow-up of 15.1 months (range, 3.4-54.5 months), the median OS was 23.3 months in patients who received salvage-LT and 6.6 months who did not. At multivariate analysis, ECOG performance status, Child-Pugh class, albumin-bilirubin grade, extrahepatic disease, and lack of salvage-LT were independent predictors of worse OS. After inverse probability weighting, salvage-LT was associated with a survival benefit of 8.9 months (95% CI: 1.1, 16.7 months; p = 0.03).

CONCLUSIONS

Salvage locoregional therapy is associated with increased survival in HCC patients suffering from intrahepatic tumor progression following initial radiotherapy.

Radiotherapy plus anti-PD1 versus radiotherapy for hepatic toxicity in patients with hepatocellular carcinoma

PURPOSE

In this study, we aimed to compare the radiation-induced hepatic toxicity (RIHT) outcomes of radiotherapy (RT) plus antibodies against programmed cell death protein 1 (anti-PD1) versus RT alone in patients with hepatocellular carcinoma (HCC), evaluate prognostic factors of non-classic radiation-induced liver disease (ncRILD), and establish a nomogram for predicting the probability of ncRILD.

PATIENTS AND METHODS

Patients with unresectable HCC treated with RT and anti-PD1 (RT + PD1, n = 30) or RT alone (n = 66) were enrolled retrospectively. Patients (n = 30) in each group were placed in a matched cohort using propensity score matching (PSM). Treatment-related hepatotoxicity was evaluated and analyzed before and after PSM. The prognostic factors affecting ncRILD were identified by univariable logistic analysis and Spearman's rank test in the matched cohort to generate a nomogram.

RESULTS

There were no differences in RIHT except for increased aspartate aminotransferase (AST) ≥ grade 1 and increased total bilirubin ≥ grade 1 between the two groups before PSM. After PSM, AST ≥ grade 1 occurred more frequently in the RT + PD1 group (p = 0.020), and there were no significant differences in other hepatotoxicity metrics between the two groups. In the matched cohort, V25, tumor number, age, and prothrombin time (PT) were the optimal prognostic factors for ncRILD modeling. A nomogram revealed a good predictive performance (area under the curve = 0.82).

CONCLUSIONS

The incidence of RIHT in patients with HCC treated with RT + PD1 was acceptable and similar to that of RT treatment. The nomogram based on V25, tumor number, age, and PT robustly predicted the probability of ncRILD.

Local Therapies for Hepatocellular Carcinoma and Role of MRI-Guided Adaptive Radiation Therapy

Hepatocellular carcinoma (HCC) is the most common liver tumor, with a continually rising incidence. The curative treatment for HCC is surgical resection or liver transplantation; however, only a small portion of patients are eligible due to local tumor burden or underlying liver dysfunction. Most HCC patients receive nonsurgical liver-directed therapies (LDTs), including thermal ablation, transarterial chemoembolization (TACE), transarterial radioembolization (TARE), and external beam radiation therapy (EBRT). Stereotactic ablative body radiation (SABR) is a specific type of EBRT that can precisely deliver a high dose of radiation to ablate tumor cells using a small number of treatments (or fractions, typically 5 or less). With onboard MRI imaging, MRI-guided SABR can improve therapeutic dose while minimizing normal tissue exposure. In the current review, we discuss different LDTs and compare them with EBRT, specifically SABR. The emerging MRI-guided adaptive radiation therapy has been reviewed, highlighting its advantages and potential role in HCC management.

Irradiation stent with 125 I plus TACE versus sorafenib plus TACE for hepatocellular carcinoma with major portal vein tumor thrombosis: a multicenter randomized trial

BACKGROUND AND AIM

Treatment strategy for hepatocellular carcinoma (HCC) and Vp4 [main trunk] portal vein tumor thrombosis (PVTT) remains limited due to posttreatment liver failure. We aimed to assess the efficacy of irradiation stent placement with 125 I plus transcatheter arterial chemoembolization (TACE) (ISP-TACE) compared to sorafenib plus TACE (Sora-TACE) in these patients.

METHODS

In this multicenter randomized controlled trial, participants with HCC and Vp4 PVTT without extrahepatic metastases were enrolled from November 2018 to July 2021 at 16 medical centers. The primary endpoint was overall survival (OS). The secondary endpoints were hepatic function, time to symptomatic progression, patency of portal vein, disease control rate, and treatment safety.

RESULTS

Of 105 randomized participants, 51 were assigned to the ISP-TACE group, and 54 were assigned to the Sora-TACE group. The median OS was 9.9 months versus 6.3 months (95% CI: 0.27-0.82; P =0.01). Incidence of acute hepatic decompensation was 16% (8 of 51) versus 33% (18 of 54) ( P =0.036). The time to symptomatic progression was 6.6 months versus 4.2 months (95% CI: 0.38-0.93; P =0.037). The median stent patency was 7.2 months (interquartile range, 4.7-9.3) in the ISP-TACE group. The disease control rate was 86% (44 of 51) versus 67% (36 of 54) ( P =0.018). Incidences of adverse events at least grade 3 were comparable between the safety populations of the two groups: 16 of 49 (33%) versus 18 of 50 (36%) ( P =0.73).

CONCLUSION

Irradiation stent placement plus TACE showed superior results compared with sorafenib plus TACE in prolonging OS in patients with HCC and Vp4 PVTT.

New Staging Model for Radiation-based Hepatocellular Carcinoma Treatment: A National Multicenter Study

BACKGROUND AND AIMS

The study aimed to create a new staging model for radiotherapy-based treatment for prognostic hepatocellular carcinoma (HCC) classification.

METHODS

The training cohort comprised 658 patients receiving stereotactic body radiotherapy and external validation cohort comprised 533 patients receiving three-dimensional conformal radiotherapy and intensity-modulated radiotherapy. We established a modified staging system as follows: stage I, solitary nodule without macrovascular invasion, or 2-3 nodules no more than 3.0 cm apart, and performance status (PS) 0-2 (Ia: ALBI-1 grade; Ib: ALBI-2 or 3 grade); stage II: 2-3 nodules with any one nodule more than 3.0-cm apart, or ≥4 nodules, and performance status 0-2 (IIa: ALBI-1 grade; IIb: ALBI-2 grade); stage III: macrovascular invasion, regional lymph node metastasis or distant metastasis, and performance status 0-2 (IIIa: ALBI-1 grade; IIIb: ALBI-2 grade); stage IV: performance status 3-4, or performance status 0-2 with ALBI-3 grade. We analyzed long-term overall survival based on different stages.

RESULTS

The staging model showed an excellent ability to discriminate patients according to four stages and seven substages with notably different curves in the training and validation cohort. The median survival decreased from stages I to IV with 63.0 months in stage I (not reached in Ia, and 53.0 months in Ib), 24.0 months in stage II (28.0 months in IIa, and 22.0 months in IIb), 11.0 months in stage III (18.0 months in IIIa, and 9.0 months in IIIb), and less than 9.0 months in stage IV in the training cohort.

CONCLUSIONS

The modified staging model may provide an alternative for clinical radiation oncologists.

Role of rapid arc-image-guided radiotherapy in hepatocellular carcinoma with portal vein tumor thrombosis: A study from tertiary care center in Punjab, India

Background and Objectives

Treatment of hepatocellular carcinoma (HCC) with portal vein tumor thrombus (PVTT) is very challenging with poor outcome. In this situation, radiotherapy has become an alternative treatment modality, more precisely due to advances in radiation techniques. The goal of our study is to do analysis of these patients treated with rapid arc image-guided technology (RA-IGRT) at our institution.

Materials and Methods

Thirteen patients were included in the study. As per intuition policy, patient set up, contouring, and treatment plans were generated. Radiological response assessment was done 1-month post-radiotherapy. Survival analysis curve along with Chi-square test for prognostic factors assessment was done using SPSS.

Results

With median dose of 45 Gy in 20 fractions, we were able to achieve 27.3% objective response rate with median survival of 5 months in eligible patients.

Conclusions

One-year overall survival up to 30% can be achieved in HCC with PVTT, especially in patients with objective response to radiotherapy with Japan Integrated Staging score 2, provided it is precisely hit by RA-IGRT.

Non-classic radiation-induced liver disease after intensity-modulated radiotherapy for Child-Pugh grade B patients with locally advanced hepatocellular carcinoma

BACKGROUND

The incidence of classic radiation-induced liver disease (cRILD) has been significantly reduced. However, non-classic radiation-induced liver disease (ncRILD) remains a major concern following radiotherapy in patients with hepatocellular carcinoma (HCC). This study evaluated the incidence of ncRILD following intensity-modulated radiotherapy (IMRT) for Child-Pugh grade B (CP-B) patients with locally advanced HCC and established a nomogram for predicting ncRILD probability.

METHODS

Seventy-five CP-B patients with locally advanced HCC treated with IMRT between September 2014 and July 2021 were included. The max tumor size was 8.39 cm ± 5.06, and the median prescribed dose was 53.24 Gy ± 7.26. Treatment-related hepatotoxicity was evaluated within three months of completing IMRT. A nomogram model was formulated to predict the probability of ncRILD, using univariate and multivariate analysis.

RESULTS

Among CP-B patients with locally advanced HCC, ncRILD occurred in 17 (22.7%) patients. Two patients (2.7%) exhibited a transaminase elevation of ≥ G3, fourteen (18.7%) exhibited a Child-Pugh score increase of ≥ 2, and one (1.3%) demonstrated both a transaminase elevation of ≥ G3 and a Child-Pugh score increase of ≥ 2. No cRILD cases were observed. A mean dose to the normal liver of ≥ 15.1 Gy was used as the cutoff for ncRILD. Multivariate analysis revealed that the prothrombin time before IMRT, tumour number, and mean dose to the normal liver were independent risk factors for ncRILD. The nomogram established on the basis of these risk factors displayed exceptional predictive performance (AUC = 0.800, 95% CI 0.674-0.926).

CONCLUSIONS

The incidence of ncRILD following IMRT for CP-B patients with locally advanced HCC was acceptable. A nomogram based on prothrombin time before IMRT, tumour number, and mean dose to the normal liver accurately predicted the probability of ncRILD in these patients.

Radiation-induced liver disease: beyond DNA damage

Radiation-induced liver disease (RILD), also known as radiation hepatitis, is a serious side effect of radiotherapy (RT) for hepatocellular carcinoma. The therapeutic dose of RT can damage normal liver tissue, and the toxicity that accumulates around the irradiated liver tissue is related to numerous physiological and pathological processes. RILD may restrict treatment use or eventually deteriorate into liver fibrosis. However, the research on the mechanism of radiation-induced liver injury has seen little progress compared with that on radiation injury in other tissues, and no targeted clinical pharmacological treatment for RILD exists. The DNA damage response caused by ionizing radiation plays an important role in the pathogenesis and development of RILD. Therefore, in this review, we systematically summarize the molecular and cellular mechanisms involved in RILD. Such an analysis is essential for preventing the occurrence and development of RILD and further exploring the potential treatment of this disease.

Microarray analysis identifies coding and non-coding RNA markers of liver injury in whole body irradiated mice

Radiation injury from medical, accidental, or intentional sources can induce acute and long-term hepatic dysregulation, fibrosis, and cancer. This long-term hepatic dysregulation decreases quality of life and may lead to death. Our goal in this study is to determine acute changes in biological pathways and discover potential RNA biomarkers predictive of radiation injury. We performed whole transcriptome microarray analysis of mouse liver tissue (C57BL/6 J) 48 h after whole-body irradiation with 1, 2, 4, 8, and 12 Gray to identify significant expression changes in mRNAs, lncRNAs, and miRNAs, We also validated changes in specific RNAs through qRT-PCR. We used Ingenuity Pathway Analysis (IPA) to identify pathways associated with gene expression changes. We observed significant dysregulation of multiple mRNAs across all doses. In contrast, miRNA dysregulation was observed upwards of 2 Gray. The most significantly upregulated mRNAs function as tumor suppressors: Cdkn1a, Phlda3, and Eda2r. The most significantly downregulated mRNAs were involved in hemoglobin synthesis, inflammation, and mitochondrial function including multiple members of Hbb and Hba. The most significantly upregulated miRNA included: miR-34a-5p, miR-3102-5p, and miR-3960, while miR-342-3p, miR-142a-3p, and miR-223-3p were most significantly downregulated. IPA predicted activation of cell cycle checkpoint control pathways and inhibition of pathways relevant to inflammation and erythropoietin. Clarifying expression of mRNA, miRNA and lncRNA at a short time point (48 h) offers insight into potential biomarkers, including radiation markers shared across organs and animal models. This information, once validated in human models, can aid in development of bio-dosimetry biomarkers, and furthers our understanding of acute pathway dysregulation.

Radiation therapy in the era of immune treatment for hepatocellular carcinoma

Immune checkpoint inhibitors (ICIs) have revolutionized cancer treatment in recent years and provide new opportunities to treat hepatocellular carcinoma (HCC). To date, several ICIs have been approved by the FDA for advanced HCC in first-line or second-line therapy. Downstaging conversion therapy for potentially resectable HCC to provide opportunities for surgical intervention is challenging. ICIs have become a hot spot in this field due to their high response rate. However, HCC has various etiologies and can evade the immune system through multiple mechanisms, which limit the efficacy of ICI monotherapy and demand novel combination strategies. Radiation therapy (RT) is also a candidate for conversion therapy in HCC and is currently gaining increasing attention as a good combination partner with ICIs due to its ability to modulate the tumor microenvironment. In this review, we illustrate the current indications for ICIs and RT in HCC, the rationale for their synergistic combination, and the current clinical trials in combination therapy. We also speculate on predictive biomarkers and novel future strategies to further enhance the efficacy of this combination. This review aims to provide references for future research on radiation and immunotherapy to arrive at a promising new era of HCC treatment.

Noncoplanar Volumetric Modulated Arc Therapy for Hepatocellular Carcinoma Based on a Cage-Like Radiotherapy System: A Simulation Study

BACKGROUND

The incorporation of noncoplanar beam arrangements has been proposed in liver radiotherapy modalities, which can reduce the dose in normal tissues compared to coplanar techniques. Noncoplanar radiotherapy techniques for hepatocellular carcinoma treatment based on the Linac design have a limited effective arc angle to avoid collisions.

PURPOSE

To propose a novel noncoplanar volumetric modulated arc therapy technique based on a cage-like radiotherapy system and investigate its performance in hepatocellular carcinoma patients.

METHODS

The computed tomography was deflected 90° to meet the structure of a cage-like radiotherapy system and design the noncoplanar volumetric modulated arc therapy technique based on a cage-like radiotherapy system plan in the Pinnacle3 planning system. An noncoplanar volumetric modulated arc therapy technique based on a cage-like radiotherapy system plan was customized for each of 10 included hepatocellular carcinoma patients, with 6 dual arcs ranging from -30° to 30°. Six couch angles were set with an interval of 36° and distributed along with the longest diameter of planning target volume. The dosimetric parameters of noncoplanar volumetric modulated arc therapy technique based on a cage-like radiotherapy system plan were compared with the noncoplanar volumetric modulated arc therapy and volumetric modulated arc therapy plan.

RESULTS

The 3 radiotherapy techniques regarding planning target volume were statistically different for D98%, D2%, conformity index, and homogeneity index with χ² = 9.692, 14.600, 8.600, and 12.600, and P = .008, .001, .014, and .002, respectively. Further multiple comparisons revealed that noncoplanar volumetric modulated arc therapy technique based on a cage-like radiotherapy system significantly reduced the mean dose (P = .005) and V5 (P = .005) of the normal liver, the mean dose (P = .005) of the stomach, and V30 (P = .028) of the lung compared to noncoplanar volumetric modulated arc therapy. Noncoplanar volumetric modulated arc therapy technique based on a cage-like radiotherapy system significantly reduced the mean dose (P = .005) and V5 (P = .005) of the normal liver, the mean dose (P = .017) of the spinal cord, V50 (P = .043) of the duodenum, the maximum dose (P = .007) of the esophagus, and V30 (P = .047) of the whole lung compared to volumetric modulated arc therapy. The results indicate that noncoplanar volumetric modulated arc therapy technique based on a cage-like radiotherapy system protects the normal liver, stomach, and lung better than noncoplanar volumetric modulated arc therapy and protects the normal liver, spinal cord, duodenum, esophagus, and lung better than volumetric modulated arc therapy.

CONCLUSIONS

The noncoplanar volumetric modulated arc therapy technique based on a cage-like radiotherapy system technique with the arrangement of noncoplanar arcs provided optimal dosimetric gains compared with noncoplanar volumetric modulated arc therapy and volumetric modulated arc therapy, except for the heart. Noncoplanar volumetric modulated arc therapy technique based on a cage-like radiotherapy system should be considered in more clinically challenging cases.

A human-in-the-loop based Bayesian network approach to improve imbalanced radiation outcomes prediction for hepatocellular cancer patients with stereotactic body radiotherapy

Background

Imbalanced outcome is one of common characteristics of oncology datasets. Current machine learning approaches have limitation in learning from such datasets. Here, we propose to resolve this problem by utilizing a human-in-the-loop (HITL) approach, which we hypothesize will also lead to more accurate and explainable outcome prediction models.

Methods

A total of 119 HCC patients with 163 tumors were used in the study. 81 patients with 104 tumors from the University of Michigan Hospital treated with SBRT were considered as a discovery dataset for radiation outcomes model building. The external testing dataset included 59 tumors from 38 patients with SBRT from Princess Margaret Hospital. In the discovery dataset, 100 tumors from 77 patients had local control (LC) (96% of 104 tumors) and 23 patients had at least one grade increment of ALBI (I-ALBI) during six-month follow up (28% of 81 patients). Each patient had a total of 110 features, where 15 or 20 features were identified by physicians as expert knowledge features (EKFs) for LC or I-ALBI prediction. We proposed a HITL based Bayesian network (HITL-BN) approach to enhance the capability of selecting important features from imbalanced data in terms of accuracy and explainability through humans' participation by integrating feature importance ranking and Markov blanket algorithms. A pure data-driven Bayesian network (PD-BN) method was applied to the same discovery dataset of HCC patients as a benchmark.

Results

In the training and testing phases, the areas under receiver operating characteristic curves of the HITL-BN models for LC or I-ALBI prediction during SBRT are 0.85 (95% confidence interval: 0.75-0.95) or 0.89 (0.81-0.95) and 0.77 or 0.78, respectively. They significantly outperformed the during-treatment PD-BN model in predicting LC or I-ALBI based on the discovery cross-validation and testing datasets from the Delong tests.

Conclusion

By allowing the human expert to be part of the model building process, the HITL-BN approach yielded significantly improved accuracy as well as better explainability when dealing with imbalanced outcomes in the prediction of post-SBRT treatment response of HCC patients when compared to the PD-BN method.

Is hepatocellular carcinoma complicated with portal vein tumor thrombosis potentially curable by radiotherapy in the form of stereotactic body radiation therapy?

PURPOSE

The prognosis of hepatocellular carcinoma (HCC) with portal vein tumor thrombosis (PVTT) is dismal. Despite best treatment and care, the patients with this malignancy only showed 2.7-4 months of overall survival. It is debatable whether liver transplantation helps PVTT sufferers. The effectiveness of radiation therapy in treating HCC patients with PVTT should not be undervalued. By limiting the high dosage region to a small planning target volume, stereotactic radiation delivery has shifted toward hypofractionation, limiting the radiation exposure to healthy organs and tissues. Stereotactic body radiotherapy (SBRT) has a local control rate of 75-100%, depending on the treatment. The major limitation in SBRT for hepatocellular carcinoma with PVTT is the paucity of prospective evidence for longer periods beyond the first two years after treatment. More prospective studies/randomized clinical trials with a longer follow-up, larger sample size, and adequate statistical power are the dire need of the present situation to ascertain the curative effect of SBRT as primary therapy for advanced HCC with PVTT.

CONCLUSION

SBRT can improve survival, particularly for patients receiving multidisciplinary treatment. This review sums up our most current understanding of how radiation therapy, notably SBRT, can be used to treat hepatocellular carcinoma when combined with PVTT. Recent research has led us to believe that irradiation in the form of SBRT may cure hepatocellular carcinoma complicated by PVTT.

Radiomics-Based Predictive Model of Radiation-Induced Liver Disease in Hepatocellular Carcinoma Patients Receiving Stereo-Tactic Body Radiotherapy

(1) Background: The application of stereotactic body radiation therapy (SBRT) in hepatocellular carcinoma (HCC) limited the risk of the radiation-induced liver disease (RILD) and we aimed to predict the occurrence of RILD more accurately. (2) Methods: 86 HCC patients were enrolled. We identified key predictive factors from clinical, radiomic, and dose-volumetric parameters using a multivariate analysis, sequential forward selection (SFS), and a K-nearest neighbor (KNN) algorithm. We developed a predictive model for RILD based on these factors, using the random forest or logistic regression algorithms. (3) Results: Five key predictive factors in the training set were identified, including the albumin–bilirubin grade, difference average, strength, V5, and V30. After model training, the F1 score, sensitivity, specificity, and accuracy of the final random forest model were 0.857, 100, 93.3, and 94.4% in the test set, respectively. Meanwhile, the logistic regression model yielded an F1 score, sensitivity, specificity, and accuracy of 0.8, 66.7, 100, and 94.4% in the test set, respectively. (4) Conclusions: Based on clinical, radiomic, and dose-volumetric factors, our models achieved satisfactory performance on the prediction of the occurrence of SBRT-related RILD in HCC patients. Before undergoing SBRT, the proposed models may detect patients at high risk of RILD, allowing to assist in treatment strategies accordingly.

Organs at risk radiation dose constraints

Dose constraints are essential for performing dosimetry, especially for intensity modulation and for radiotherapy under stereotaxic conditions. We present the update of the recommendations of the French society of oncological radiotherapy for the use of these doses in classical current practice but also for reirradiation.

Evaluation of Pretreatment Magnetic Resonance Elastography for the Prediction of Radiation-Induced Liver Disease

Purpose

Magnetic resonance (MR) elastography (E) is a noninvasive technique for quantifying liver stiffness (LS) for fibrosis. This study evaluates whether LS is associated with risk of developing radiation-induced liver disease (RILD) in patients receiving liver-directed radiation therapy (RT).

Methods and Materials

Based on prior studies, LS ≤3 kPa was considered normal and LS >3.0 kPa as representing fibrosis. RILD was defined as an increase in Child-Pugh (CP) score of ≥2 from baseline within 1 year of RT. Univariate and multivariate Cox models were used to assess correlation.

Results

One hundred two patients, 51 with primary liver tumors and 51 with liver metastases, were identified with sufficient follow-up. In univariate models, pre-RT LS >3.0 kPa (hazard ratio [HR] 4.9; 95% confidence interval [CI], 1.6-14; P = .004), body mass index (BMI), clinical cirrhosis, CP score, albumin-bilirubin (ALBI) grade 2, primary liver tumor, and mean liver dose were significantly associated with risk of post-RT RILD. In a multivariate analysis, LS >3.0 and mean liver dose both were significantly associated with RILD risk.

Conclusions

Elevated pre-RT LS is associated with an increased risk of RILD in patients receiving liver-directed RT.

Indications of IMRT, PRT and CIRT for HCC from comparisons of dosimetry and normal tissue complication possibility

PURPOSE

To identify the indications for hepatocellular carcinoma (HCC) irradiated by intensity-modulated photon radiotherapy (IMRT), proton radiotherapy (PRT) or carbon-ion radiotherapy (CIRT) by comparing of dosimetric parameters and incidences of classic radiation-induced liver disease (RILD).

METHODS

In all, 40 HCCs were divided into group A (tumors located > 1 cm away from gastrointestinal [GI] tract), and group B (tumors located < 1 cm away from GI tract). The prescribed curative doses were 60 Gy (relative biological effectiveness [RBE]) in 10 fractions for group A, and 67.5 Gy (RBE) in 15 fractions for group B. IMRT, PRT and CIRT plans were separately generated to reach the curative doses and coverage. Dosimetric parameters evaluated were mean dose to normal liver (MDTNL) and the volume of normal liver receiving more than 1 Gy (RBE) (V1). Lyman-Kutcher-Burman model was used to determine the incidences of classic RILD, and Power model of non-linear regression, to estimate the tumor volume that could be irradiated with the curative doses within dose constraint of MDTNL.

RESULTS

With comparable target doses, the MDTNL (Gy [RBE]) were 18.8 ± 3.7, 13.5 ± 3.1 and 12.8 ± 2.7 in group A and 24.9 ± 7.1, 18.2 ± 3.7 and 17.5 ± 3.7 in group B, respectively, for IMRT, PRT and CIRT. The classic RILD incidences (%) were 22.3 ± 30.0 in IMRT, 2.3 ± 4.9 in PRT and 1.2 ± 2.4 in CIRT. V1 (%) were 89.9 ± 8.8, 43.0 ± 10.2 and 45.9 ± 8.8, respectively, for IMRT, PRT and CIRT.

CONCLUSIONS

PRT and CIRT could spare the liver more than IMRT. IMRT could deliver the curative doses to HCC up to a diameter of 7.9 cm; PRT, up to 13.2 cm; and CIRT, up to 14.8 cm.

HDR Brachytherapy and SBRT as Bridging Therapy to Liver Transplantation in HCC Patients: A Single-Center Experience

Background

In the treatment of patients with HCC awaiting liver transplantation (LT), local ablative treatments (LAT) are available either for downstaging or as bridging treatment. We present our clinical experience with both available radiation-based techniques, brachytherapy (BT), and stereotactic body radiotherapy (SBRT).

Methods

All patients diagnosed with HCC and who were treated with BT or SBRT at our institution between 2011 and 2018 were retrospectively reviewed. The current analysis included all patients who subsequently underwent LT.

Results

A total of 14 patients (male=9; female=5) were evaluated. Seven underwent BT for bridging before LT, and seven were treated with SBRT. BT was performed with a prescribed dose of 1 × 15 Gy, while SBRT was applied with 37 Gy (65%-iso) in three fractions in six patients, and one patient was treated with 54 Gy (100%-iso) in nine fractions. The treatment was generally well tolerated. One case of grade 3 bleeding was reported after BT, and one case of liver failure occurred following SBRT. All patients underwent LT after a median time interval of 152 days (range 47–311) after BT and 202 days (range 44–775) following SBRT. In eight cases, no viable tumor was found in the explanted liver, while four liver specimens showed vital tumor. The median follow-up after SBRT was 41 months and 17 months following BT. Overall, no hepatic HCC recurrence occurred following LT.

Conclusion

Both SBRT and BT are feasible and well tolerated as bridging to LT when applied with caution in patients with impaired liver function. Radiation-based treatments can close the gap for patients not suitable for other locally ablative treatment options.

A Prospective Study of Liver Regeneration After Radiotherapy Based on a New (Su'S) Target Area Delineation

Background

In this study, we designed a new (Su’S) target area delineation to protect the normal liver during liver regeneration and prospectively evaluate liver regeneration after radiotherapy, as well as to explore the clinical factors of liver regeneration and established a model and nomogram.

Methods

Thirty patients treated with preoperative downstaging radiotherapy were prospectively included in the training cohort, and 21 patients treated with postoperative adjuvant radiotherapy were included in the validation cohort. The cut-off points of each optimal predictor were obtained using receiver-operating characteristic analysis. A model and nomogram for liver regeneration after radiotherapy were developed and validated.

Results

After radiotherapy, 12 (40%) and 13 (61.9%) patients in the training and validation cohorts experienced liver regeneration, respectively. The risk stratification model based on the cutoffs of standard residual liver volume spared from at least 20 Gy (SVs20 = 303.4 mL/m²) and alanine aminotransferase (ALT=43 u/L) was able to effectively discriminate the probability of liver regeneration. The model and nomogram of liver regeneration based on SVs20 and ALT showed good prediction performance (AUC=0.759) in the training cohort and performed well (AUC=0.808) in the validation cohort.

Conclusions

SVs20 and ALT were optimal predictors of liver regeneration. This model may be beneficial to the constraints of the normal liver outside the radiotherapy-targeted areas.

Unrecognized digestive toxicities of radiation therapy

The aim of this article is to review unrecognized toxicities resulting from radiation therapy of digestive neoplasms. Due to their precocious occurrence, acute toxicities are well-known by radiation oncologist, and their treatment well-established. Thus, acute toxicities will not be described in this review. We will focus on incidence, diagnosis, and management of late and uncommon toxicities occurring in the digestive tract and digestive organs. Prevention, by respecting healthy tissues constraints, is the main tool to reduce incidence of those rare complications. Nonetheless, once installed, late toxicities remain a major burden in terms of quality of life and can even be life threatening. Hence, information and education about their diagnosis and management is important.

Role of modern radiotherapy in managing patients with hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer. Several treatment options are available for managing HCC patients, classified roughly as local, local-regional, and systemic therapies. The high post-monotherapy recurrence rate of HCC urges the need for the use of combined modalities to increase tumor control and patient survival. Different international guidelines offer treatment recommendations based on different points of view and classification systems. Radiotherapy (RT) is a well-known local-regional treatment modality for managing many types of cancers, including HCC. However, only some of these treatment guidelines include RT, and the role of combined modalities is rarely mentioned. Hence, the present study reviewed clinical evidence for the use of different combined modalities in managing HCC, focusing on modern RT's role. Modern RT has an increased utility in managing HCC patients, mainly due to two driving forces. First, technological advancement (e.g., stereotactic body radiotherapy and advanced proton-beam therapy) enables precise delivery of radiation to increase tumor control and reduce side effects in the surrounding normal tissue. Second, the boom in developing target therapies and checkpoint-blockade immunotherapy prolongs overall survival in HCC patients, re-emphasizing the importance of local tumor control. Remarkably, RT combines with systemic therapies to generate the systemic therapy augmented by radiotherapy effect, a benefit now being actively investigated.

Assessment of the confidence interval in the multivariable normal tissue complication probability model for predicting radiation-induced liver disease in primary liver cancer

We developed a confidence interval-(CI) assessing model in multivariable normal tissue complication probability (NTCP) modeling for predicting radiation-induced liver disease (RILD) in primary liver cancer patients using clinical and dosimetric data. Both the mean NTCP and difference in the mean NTCP (ΔNTCP) between two treatment plans of different radiotherapy modalities were further evaluated and their CIs were assessed. Clinical data were retrospectively reviewed in 322 patients with hepatocellular carcinoma (n = 215) and intrahepatic cholangiocarcinoma (n = 107) treated with photon therapy. Dose-volume histograms of normal liver were reduced to mean liver dose (MLD) based on the fraction size-adjusted equivalent uniform dose. The most predictive variables were used to build the model based on multivariable logistic regression analysis with bootstrapping. Internal validation was performed using the cross-validation leave-one-out method. Both the mean NTCP and the mean ΔNTCP with 95% CIs were calculated from computationally generated multivariate random sets of NTCP model parameters using variance-covariance matrix information. RILD occurred in 108/322 patients (33.5%). The NTCP model with three clinical and one dosimetric parameter (tumor type, Child-Pugh class, hepatitis infection status and MLD) was most predictive, with an area under the receiver operative characteristics curve (AUC) of 0.79 (95% CI 0.74-0.84). In eight clinical subgroups based on the three clinical parameters, both the mean NTCP and the mean ΔNTCP with 95% CIs were able to be estimated computationally. The multivariable NTCP model with the assessment of 95% CIs has potential to improve the reliability of the NTCP model-based approach to select the appropriate radiotherapy modality for each patient.

Stereotactic body radiotherapy versus intensity-modulated radiotherapy for hepatocellular carcinoma with portal vein tumor thrombosis

BACKGROUND

It is unclear whether robotic stereotactic body radiotherapy (SBRT) is superior to intensity-modulated radiotherapy (IMRT) in advanced hepatocellular carcinoma (HCC). This study aimed to compare the long-term outcomes of SBRT with those of IMRT in HCCs with portal vein tumor thrombosis (PVTT).

METHODS

We retrospectively evaluated 287 HCC patients with PVTT who underwent radiotherapy between January 2000 and January 2017. Of them, 154 and 133 patients were treated with IMRT and SBRT, respectively. Overall survival (OS), progression-free survival (PFS), intrahepatic control (IC), and local control (LC) were evaluated in univariable and propensity-score matched analyses.

RESULTS

After matching, 102 well-paired patients were selected. There was no significant difference in the 6-, 12-, 24-, and 60-month cumulative OS (73.5, 42.9, 23.6, 7.6% vs. 72.4, 45.1, 29.8, 13.2%, p = 0.151), PFS (53.9, 29.3, 21.8, 7.5% vs. 54.5, 19.3, 12.0, 9.6%, p = 0.744), IC (61.4, 45.7, 39.0, 26.8% vs. 75.1, 45.8, 35.9, 28.7%, p = 0.144), and LC (85.2, 56.5, 52.1, 47.4% vs. 87.4, 65.2, 62.1, 62.1%, p = 0.191) between the IMRT and SBRT groups. A biologically effective dose assumed at an a/b ratio of 10 (BED₁₀) of ≥ 100 Gy was the optimal cutoff for predicting the OS, PFS, IC, and LC in the patients who received SBRT.

CONCLUSIONS

When high-precision tracking technology is available, SBRT appears to be a safe and more time-efficient treatment, achieving comparable OS, PFS, IC and LC to IMRT for local advanced HCC with PVTT. A BED₁₀ ≥ 100 Gy is recommended if tolerated by normal tissue.

Magnetic Resonance Imaging-Guided Adaptive Radiotherapy for Colorectal Liver Metastases

Technological advances have enabled well tolerated and effective radiation treatment for small liver metastases. Stereotactic ablative radiation therapy (SABR) refers to ablative dose delivery (>100 Gy BED) in five fractions or fewer. For larger tumors, the safe delivery of SABR can be challenging due to a more limited volume of healthy normal liver parenchyma and the proximity of the tumor to radiosensitive organs such as the stomach, duodenum, and large intestine. In addition to stereotactic treatment delivery, controlling respiratory motion, the use of image guidance, adaptive planning and increasing the number of radiation fractions are sometimes necessary for the safe delivery of SABR in these situations. Magnetic Resonance (MR) image-guided adaptive radiation therapy (MRgART) is a new and rapidly evolving treatment paradigm. MR imaging before, during and after treatment delivery facilitates direct visualization of both the tumor target and the adjacent normal healthy organs as well as potential intrafraction motion. Real time MR imaging facilitates non-invasive tumor tracking and treatment gating. While daily adaptive re-planning permits treatment plans to be adjusted based on the anatomy of the day. MRgART therapy is a promising radiation technology advance that can overcome many of the challenges of liver SABR and may facilitate the safe tumor dose escalation of colorectal liver metastases.

Prediction of impacts on liver enzymes from the exposure of low-dose medical radiations through artificial intelligence algorithms

OBJECTIVES

This study aimed to develop artificial intelligence and machine learning-based models to predict alterations in liver enzymes from the exposure of low annual average effective doses in radiology and nuclear medicine personnel of Institute of Nuclear Medicine and Oncology Hospital.

METHODS

Ninety workers from the Radiology and Nuclear Medicine departments were included. A high-capacity thermoluminescent was used for annual average effective radiation dose measurements. The liver function tests were conducted for all subjects and controls. Three supervised learning models (multilayer precentron; logistic regression; and random forest) were applied and cross-validated to predict any alteration in liver enzymes. The t-test was applied to see if subjects and controls were significantly different in liver function tests.

RESULTS

The annual average effective doses were in the range of 0.07-1.15 mSv. Alanine transaminase was 50% high and aspartate transaminase was 20% high in radiation workers. There existed a significant difference (p=0.0008) in Alanine-aminotransferase between radiation-exposed and radiation-unexposed workers. Random forest model achieved 90-96.6% accuracies in Alanine-aminotransferase and Aspartate-aminotransferase predictions. The second best classifier model was the Multilayer perceptron (65.5-80% accuracies).

CONCLUSION

As there is a need of regular monitoring of hepatic function in radiation-exposed people, our artificial intelligence-based predicting model random forest is proved accurate in prediagnosing alterations in liver enzymes.

Radiation-induced liver disease in the era of SBRT: a review

INTRODUCTION

Stereotactic Body Radiotherapy (SBRT) in liver tumors allows ablative radiation doses in tumors preserving the liver tissue. However, liver is a parallel organ allowing high doses in a small region to preserve its function. If this is not possible, radio-induced liver toxicity is produced. Radio-induced liver toxicity or radio-induced liver disease (RILD) is the most serious toxicity in liver radiotherapy.

AREAS COVERED

In this review, we analyzed published literature on PubMed and MEDLINE. We included papers in English language with information about RILD characteristics, diagnostic, risk factors, pathophysiology, and treatment. All citations were evaluated for relevant content and validation.

EXPERT OPINION

The study of RILD is fundamental before the implementation of liver SBRT. Radio-induced liver toxicity is a complication that can be fatal for patients. This is a diagnosis of exclusion and it is essential that experts in the treatment of hepatic SBRT know about it and anticipate its development. The study and development of molecular or imaging biomarkers could be key in their diagnosis and prevention.

External Beam Radiation Therapy for Liver Metastases

Stereotactic ablative radiotherapy (SABR) commonly is used for small liver metastases. Modern conformal radiotherapy techniques, including 3-dimensional conformal radiotherapy and intensity-modulated radiation therapy, enable the safe delivery of SABR to small liver volumes. For larger tumors, the safe delivery of SABR can be challenging due to a more limited volume of healthy normal liver parenchyma and the proximity of the tumor to radiosensitive organs, such as the stomach, duodenum, and large intestine. Controlling respiratory motion, the use of image guidance, and increasing the number of radiation fractions sometimes are necessary for the safe delivery of SABR in these situations.

Test the Effectiveness of Quantitative Linear-Quadratic-Based (qLQB) Model on Evaluating Irradiation-Induced Liver Injury (ILI) Against Normal Tissue Complication Probability (NTCP)

Objectives:

To test the effectiveness of quantitative linear-quadratic-based (qLQB) model on evaluating irradiation-induced liver injury (ILI) and establish the relation between the damaged ratio/percent (DRP) in qLQB model and normal tissue complication probility (NTCP).

Materials and Methods:

We established the qLQB model to calculate the ratio/percent (RP) between damaged cell/functional subunit (FSU) and entire cell/FSU of liver for radiation dose response, tested the qLQB against the Lyman-Kutcher-Burman (LKB) model, and established relation between the RP and NTCP through analyzing the dose of 32 patients with cancer of abdominal cavity who were treated with radiation therapy at our department. Based on varied α/β and varied parameters for NTCP, we put the calculated results into varied arrays for the next analysis. We named the 2 groups of RPs: RP1 (α/β = 3.0, α = 0.03) and RP2 (α/β = 8.0, α = 0.26), and named the 2 groups of NTCPs: NTCP1 (n = 0.32, m = 0.15, TD50(1) = 4000 cGy) and NTCP2 (n = 1.10, m = 0.28, TD50(1) = 4050 cGy).

Results:

Spearman correlation analysis was used to analyze the correlations among the groups, the results were as follows: RP1 vs NTCP1, rs = 0.83827, p < 0.0001; RP1 vs NTCP2, rs = 0.83827, p < 0.0001; RP2 vs NTCP2, rs = 0.79289, p < 0.0001; and RP2 vs NTCP1, rs = 0.79289, p < 0.0001.

Conclusions:

There is a significant correlation between RP value and NTCP for evaluating ILI, and there is no difference between qLQB model and LKB model on evaluating ILI.

Clinical impact of Hypofractionated carbon ion radiotherapy on locally advanced hepatocellular carcinoma

Background

Hepatocellular carcinoma (HCC) involving a major branch of the portal or hepatic vein is in a locally advanced stage and remains difficult to cure. This study aimed to evaluate the clinical effects of carbon ion radiotherapy (C-ion RT) in locally advanced HCC (LAHCC).

Methods

The data of 11 consecutive patients with LAHCC who received C-ion RT were analyzed. The C-ion RT doses of 52.8 Gy (relative biological effectiveness [RBE]) and 60.0 Gy (RBE) were delivered in 4 fractions for standard cases, and the 60.0 Gy dose was delivered in 12 fractions for close-to-gastrointestinal-tract cases. Survival and local control probabilities were calculated using the Kaplan-Meier method.

Results

The median follow-up duration after C-ion RT was 36.4 months. The median age at the time of registration for C-ion RT was 76 years. The median tumor size was 53 mm. The numbers of treatment-naive and recurrent HCC patients were 1 and 10, respectively. Direct invasion of the major branch of the portal vein, hepatic vein, or both portal and hepatic veins was observed in three, five, and three patients, respectively. The 3-year overall survival, local control, and progression-free survival rates were 64, 78, and 18%, respectively. No patient developed radiation-induced liver diseases or grade 3 or higher toxicities in the acute and late phases.

Conclusions

C-ion RT showed favorable clinical outcomes with a high rate of local control and minimal toxicities in LAHCC. Our findings suggest that C-ion RT is a promising multidisciplinary treatment option in LAHCC.

Long-Term Survival Analysis of Transarterial Chemoembolization Plus Radiotherapy vs. Radiotherapy for Hepatocellular Carcinoma With Macroscopic Vascular Invasion

Background: Macroscopic vascular invasion (MVI) is a terminal manifestation of hepatocellular carcinoma (HCC) and carries an extremely poor prognosis. In Chinese and Korean HCC guidelines, transarterial chemoembolization (TACE), or/and radiotherapy (RT) is adopted for treatment of MVI. In the current study, we aimed to compare the long-term outcome of TACE + RT to that of RT alone in patients with local advanced HCC with MVI.

Methods: In this retrospective study, 148 treatment-naive patients of HCC with MVI were enrolled. Of the patients enrolled, 49 received TACE + RT treatment, whereas 99 patients received RT alone as a monotherapy. Overall survival (OS), progression-free survival (PFS), and intrahepatic control were evaluated using univariable and propensity score–matched analyses.

Results: During follow-up, 126 patients (85.1%) died. The median follow-up time was 55.0 months in the RT group and 57.0 months in the TACE + RT group. The TACE + RT group showed better OS and PFS than the RT group, but intrahepatic control was comparable in these two groups. Of 41 cases well-pairs after propensity score matching, the associations between TACE + RT and better OS and PFS remained (15.0 vs. 8.0 months, and 8.0 vs. 4.0 months, all P < 0.05). The 1-, 2-, 3-, and 5-years OS rates in the TACE + RT group were 56.1, 28.6, 20.8, and 15.7 vs. 31.5%, 13.1%, 9.8%, and 6.7% in the RT group, respectively (P = 0.017). The 6-, 12-, and 24-months rates in the TACE + RT group were 51.2, 39.0, and 23.1% vs. 36.6%, 13.9%, and 11.1% in the RT group, respectively (P = 0.04). Two patients (4.1%) experienced radiation-induced liver disease (RILD), and one (2.0%) experienced RT-related gastrointestinal (GI) bleed in the TACE + RT groups. Nine patients (9.1%) experienced RILD, and two (2.0%) experienced RT-related GI bleed in the RT groups.

Conclusion: Transarterial chemoembolization + RT had well-complementarity with no more complications than RT alone, providing a better PFS and OS compared with RT-alone treatment for HCC with MVI.

Low Molecular Weight Fucoidan Prevents Radiation-Induced Fibrosis and Secondary Tumors in a Zebrafish Model

Radiotherapy often causes unwanted side effects such as radiation-induced fibrosis and second malignancies. Fucoidan, a sulfated polysaccharide extracted from brown seaweed, has many biological effects including anti-inflammation and anti-tumor. In the present study, we investigated the radioprotective effect of Oligo-Fucoidan (OF) using a zebrafish animal model. Adult zebrafish of wild-type and transgenic fish with hepatocellular carcinoma were orally fed with Oligo-Fucoidan before irradiation. Quantitative PCR, Sirius red stain, hematoxylin, and eosin stain were used for molecular and pathological analysis. Whole genomic microarrays were used to discover the global program of gene expression after Oligo-Fucoidan treatment and identified distinct classes of up- and downregulated genes/pathways during this process. Using Oligo-Fucoidan oral gavage in adult wild-type zebrafish, we found Oligo-Fucoidan pretreatment decreased irradiation-induced fibrosis in hepatocyte. Using hepatitis B virus X antigen (HBx), Src and HBx, Src, p53−/+ transgenic zebrafish liver cancer model, we found that Oligo-Fucoidan pretreatment before irradiation could lower the expression of lipogenic factors and enzymes, fibrosis, and cell cycle/proliferation markers, which eventually reduced formation of liver cancer compared to irradiation alone. Gene ontology analysis revealed that Oligo-Fucoidan pretreatment increased the expression of genes involved in oxidoreductase activity in zebrafish irradiation. Oligo-Fucoidan also decreased the expression of genes involved in transferase activity in wild-type fish without irradiation (WT), nuclear outer membrane-endoplasmic reticulum membrane network, and non-homologous end-joining (NHEJ) in hepatocellular carcinoma (HCC) transgenic fish. Rescue of those genes can prevent liver cancer formation. Conclusions: Our results provide evidence for the ability of Oligo-Fucoidan to prevent radiation-induced fibrosis and second malignancies in zebrafish.

Histopathologic Evaluation of Radio-Protective Effect of Hesperidin on the Liver of Sprague Dawely Rats

BACKGROUND

Hesperidin is a bioflavonoid glycoside mainly found in citrus fruit and has been shown radio-protective potential in various measurement systems.

OBJECTIVE

In this article aims to investigate the radio-protective effect of hesperidin on the liver of Sprague Dawely rats.

MATERIAL AND METHODS

In this clinical study, 40 male rats were selected randomly and divided into 8 groups. Group 1 did not receive radiation and hesperidin (sham control). Group 2 received only 100 mg/kg body weight (b.w) of hesperidin for 7 consecutive days (HES group); group 3 exposed to dose of 2Gy whole body gamma radiation (2Gy group), and group 4 and 5 received 50 and 100 mg/kg b.w of HES for 7 consecutive days before 2 Gy gamma radiation, respectively.Group 6 exposed to dose of 8Gy gamma radiation (8Gy group); group 7 and 8 received 50 and 100 mg/kg b.w of HES for 7 days before 8Gy gamma irradiation, respectively. Histopathological evaluation was perfomred 24 hours after radiation.

RESULTS

Administration of hesperidin (50 mg/kg b.w, 7 days) before 2Gy of gamma irradiation led to remove inflammatory mononuclear cells in the portal space. Microscopic findings in the groups receiving two doses of hesperidin (50 and 100 mg/kg b.w, orally, 7 days), before 8Gy of gamma radiation, were similar in a way that extreme dilation of central veins to be seen, however, there was no capillarization.

CONCLUSION

HES can be offered as a suitable radio-protector in radiotherapy patients and radiation workers.

Chinese Expert Consensus on Multidisciplinary Diagnosis and Treatment of Hepatocellular Carcinoma with Portal Vein Tumor Thrombus (2018 Edition)

Portal vein tumor thrombus (PVTT) is very common, and it plays a major role in the prognosis and clinical staging of hepatocellular carcinoma (HCC). We have published the first version of the Consensus in 2016. Over the past several years, many new evidences for the treatment of PVTT become available especially for the advent of new targeted drugs which have further improved the prognosis of PVTT. So, the Chinese Association of Liver Cancer revised the 2016 version of consensus to adapt to the development of PVTT treatment. Future treatment strategies for HCC with PVTT in China would depend on new evidences from more future clinical trials.

Assessment of hepatocellular carcinoma treatment response with LI-RADS: a pictorial review

Computed tomography (CT) and magnetic resonance imaging (MRI) play critical roles for assessing treatment response of hepatocellular carcinoma (HCC) after locoregional therapy. Interpretation is challenging because posttreatment imaging findings depend on the type of treatment, magnitude of treatment response, time interval after treatment, and other factors. To help radiologists interpret and report treatment response in a clear, simple, and standardized manner, the Liver Imaging Reporting and Data System (LI-RADS) has developed a Treatment Response (LR-TR) algorithm. Introduced in 2017, the system provides criteria to categorize response of HCC to locoregional treatment (e.g., chemical ablation, energy-based ablation, transcatheter therapy, and radiation therapy). LR-TR categories include Nonevaluable, Nonviable, Equivocal, and Viable. LR-TR does not apply to patients on systemic therapies. This article reviews the LR-TR algorithm; discusses locoregional therapies for HCC, treatment concepts, and expected posttreatment findings; and illustrates LI-RADS treatment response assessment with CT and MRI.

Current status of stereotactic body radiotherapy for the treatment of hepatocellular carcinoma

Stereotactic body radiotherapy (SBRT) is an advanced form of radiotherapy (RT) with a growing interest on its application in the treatment of hepatocellular carcinoma (HCC). It can deliver ablative radiation doses to tumors in a few fractions without excessive doses to normal tissues, with the help of advanced modern RT and imaging technologies. Currently, SBRT is recommended as an alternative to curative treatments, such as surgery and radiofrequency ablation. This review discusses the current status of SBRT to aid in the decision making on how it is incorporated into the HCC management.

Plasma Fibrinogen-Like 1 as a Potential Biomarker for Radiation-Induced Liver Injury

Liver damage upon exposure to ionizing radiation, whether accidental or because of therapy can contribute to liver dysfunction. Currently, radiation therapy is used for various cancers including hepatocellular carcinoma; however, the treatment dose is limited by poor liver tolerance to radiation. Furthermore, reliable biomarkers to predict liver damage and associated side-effects are unavailable. Here, we investigated fibrinogen-like 1 (FGL1)-expression in the liver and plasma after radiation exposure. We found that 30 Gy of liver irradiation (IR) induced cell death including apoptosis, necrosis, and autophagy, with fibrotic changes in the liver occurring during the acute and subacute phase in mice. Moreover, FGL1 expression pattern in the liver following IR was associated with liver damage represented by injury-related proteins and oxidative stress markers. We confirmed the association between FGL1 expression and hepatocellular injury by exposing human hepatocytes to radiation. To determine its suitability, as a potential biomarker for radiation-induced liver injury, we measured FGL1 in the liver tissue and the plasma of mice following total body irradiation (TBI) or liver IR. In TBI, FGL1 showed the highest elevation in the liver compared to other major internal organs including the heart, lung, kidney, and intestine. Notably, plasma FGL1 showed good correlation with radiation dose by liver IR. Our data revealed that FGL1 upregulation indicates hepatocellular injury in response to IR. These results suggest that plasma FGL1 may represent a potential biomarker for acute and subacute radiation exposure to the liver.

Management of patients with hepatocellular carcinoma and portal vein tumour thrombosis: comparing east and west

Portal vein tumour thrombosis is common among patients with advanced hepatocellular carcinoma. Tremendous differences exist in the management of hepatocellular carcinoma with portal vein tumour thrombosis between the east and the west, which derive from heterogeneities in its epidemiology, causes, pathology, comorbidities, prognosis, and other demographics. These divergences between the east and the west are not only caused by hepatocellular carcinoma itself, but are also affected by many variables including social factors, physician preferences, accessibility to costly or novel treatments, and reimbursement schemes. In this Review, we compare and contrast the management of hepatocellular carcinoma with portal vein tumour thrombosis in the east and in the west in terms of systemic and surgical treatments, radiotherapy, transcatheter arterial therapies, and portal vein revascularisation. We conclude that a personalised, data-driven approach to care with active management from a multidisciplinary team, as well as increased communication and collaboration between clinicians and researchers based in east and the west, could help to reduce the differences in management and optimise treatment strategies.

Biologically effective dose (BED) of stereotactic body radiation therapy (SBRT) was an important factor of therapeutic efficacy in patients with hepatocellular carcinoma (≤5 cm)

BACKGROUND

To explore the association between biologically effective dose (BED) and survival rates in Child-Pugh A classification (CP-A) small hepatocellular carcinoma (HCC) patients treated with stereotactic body radiation therapy (SBRT).

METHODS

This retrospective study included 108 small HCC patients who were treated with SBRT between 2011 and 2014. The prescribed dose delivered to the tumor were 48Gy/8f, 49Gy/7f, 50Gy/5f and 54Gy/6f. The median biologically effective dose (BED10) of the total prescribed dose was 100Gy (76.8-102.6Gy). Factors associated with the survival rate were examined using the Cox proportion hazards model, and the factors associated with radiation-induced liver injury (RILD) were examined by logistic regression analysis.

RESULTS

For these patients, the median follow-up time was 42 months (6-77 months), and the 1-, 2- and 3-year overall survival (OS) rates were 96.3, 89.8 and 80.6%, respectively. The 1-, 2- and 3-year progression-free survival (PFS) rates were 85.2, 70.1 and 60.6%, respectively. The 1-, 2- and 3-year local control (LC) rates were 98.1, 96.2 and 95.1%, respectively. The 1-, 2- and 3-year distant metastasis- free survival (DMFS) rates were 86.1, 72.8 and 61.2%. The OS, PFS and DMFS were significantly higher in the BED10 ≥ 100Gy group than in the BED10 < 100Gy group (OS: p = 0.020; PFS: p = 0.017; DMFS: p = 0.012). The PLT count was a predictive factor of RILD.

CONCLUSIONS

SBRT is a safe and effective option for CP-A HCC patients. A BED10 value greater than 100Gy and lower CP score are associated with improved OS and PFS. Additionally, the peripheral PLT count are predictive factors of RILD.

Outcome of postoperative radiation therapy for cholangiocarcinoma and analysis of dose-volume histogram of remnant liver

The aim of this study was to analyze dose-volume histogram (DVH) of the remnant liver for postoperative cholangiocarcinoma (CCA) patients, to find toxicity rates, and to confirm efficacy of postoperative radiation therapy (RT).Thirty-two postoperative CCA patients received partial liver resection and postoperative RT with curative intent. The "liver reduction rate" was calculated by contouring liver volume at computed tomography (CT) just before the surgery and at CT for planning the RT. To evaluate late toxicity, the radiation-induced hepatic toxicity (RIHT) was determined by the common terminology criteria for adverse events toxicity grade of bilirubin, aspartate transaminase, alanine transaminase, alkaline phosphatase, and albumin, and was defined from 3 months after RT until liver metastasis was revealed. The radiation-induced liver disease (RILD) was also evaluated.Tumor stages were distributed as follows: I: 1, II: 8, IIIA: 1, IIIB: 6, IIIC: 14, IVA: 2. Median prescribed total dose was 50 Gy. Median follow-up time was 27 months. Two-year overall survival (OS): 72.4%, disease-free survival: 47.7%, local control: 65.3%, and the median survival time was 40 months. The median "liver reduction rate" was 21%. The OS had statistically significant difference in nodal status (P = .032) and "liver reduction rate" >30% (P = .016). In the association between the ≥grade 2 RIHT and DVH, there were significantly differences in V30 and V40 (P = .041, P = .034), respectively. The grade ≥2 RIHT rates differ also significantly by sex (P = .008). Two patients (6.2%) were suspected of RILD.We suggest that RT for remnant liver should be considered the liver V30, V40 to prevent radiation-induced liver dysfunction.