Stereotactic Body Radiation Therapy for Hepatocellular Carcinoma: Current Trends and Controversies

Combining Immune Checkpoint Inhibitors with Loco-Regional Treatments in Hepatocellular Carcinoma: Ready for Prime Time?

Hepatocellular carcinoma (HCC) is a disease with a poor prognosis, often diagnosed at an advanced stage. Therapeutic options have developed considerably in recent years, particularly with trans-arterial treatments. Systemic treatments have also evolved significantly, with the rise of immune checkpoint inhibitors (ICI) as first-line treatment for advanced HCC. The combination of loco-regional treatments and ICI is opening up new prospects and is the subject of numerous clinical trials. Recently, two global phase 3 trials investigating ICI-based adjuvant combinations have demonstrated improvements in recurrence-free survival or progression-free survival in patients treated with resection, ablation, or trans-arterial chemoembolization. However, mature data and overall survival results are still awaited but will be difficult to interpret. We are at the start of a new era of combinations of loco-regional treatments and immunotherapy. The identification of the best therapeutic strategies and predictive biomarkers is a crucial issue for future standards in clinical practice.

SBRT vs. Y90: HCC Treatment Outcomes and Costs

OBJECTIVES

Stereotactic Body Radiotherapy (SBRT) and Yttrium-90 (Y90) are among the ablative therapies used as treatment options for localized hepatocellular carcinoma (HCC). To date, direct comparisons of the 2 modalities' outcomes and costs are lacking. This study aimed to analyze demographic, treatment, and cost information for patients with HCC treated with SBRT and Y90.

METHODS

Patients with HCC treated with SBRT or Y90 radioembolization between January 2018 and January 2020 at one institution were retrospectively reviewed. Demographic and treatment data were compared utilizing χ 2 tests. Kaplan-Meier curves and log-rank tests were applied to compare overall survival and progression-free survival in different treatment groups. Cox proportional hazard models were applied to analyze the unadjusted and adjusted survival differences. Ten SBRT and 10 Y90 patients were randomly selected for Medicare cost analysis.

RESULTS

Sixty-three patients received Y90, and 21 received SBRT. On univariable and multivariable analysis, there was no significant difference in overall survival or progression-free survival between the Y90 and SBRT cohorts. SBRT patients had higher American Joint Committee on Cancer staging ( P =0.039), greater tumor size (4.07 vs. 2.96 cm, P =0.013), and greater rates of prior liver-directed therapy (71.4% SBRT vs. 12.7% Y90, P <0.001). The average cost for SBRT was $15,148, and Y90 was $41,360.

CONCLUSIONS

SBRT and Y90 are effective therapies in the treatment of HCC, specifically having similar overall survival and progression-free survival. Y90 was found to have a significantly higher cost than SBRT. This study demonstrates the need for prospective studies to assess these modalities in treating HCC.

Current perspectives on radiotherapy in hepatocellular carcinoma management: a comprehensive review

This review examines the transformative role of external beam radiotherapy (EBRT) in managing hepatocellular carcinoma (HCC), spotlighting the progression from traditional EBRT techniques to advanced modalities like intensity-modulated radiotherapy (RT), stereotactic body RT (SBRT), and innovative particle therapy, including proton beam therapy and carbon ion RT. These advancements have significantly improved the precision and efficacy of RT, marking a paradigm shift in the multimodal management of HCC, particularly in addressing complex cases and enhancing local tumor control. The review underscores the synergistic potential of integrating RT with other treatments like transarterial chemoembolization, systemic therapies such as sorafenib, and emerging immunotherapies, illustrating enhanced survival and disease control outcomes. The efficacy of RT is addressed for challenging conditions, including advanced HCC with macrovascular invasion, and RT modalities, like SBRT, are compared against traditional treatments like radiofrequency ablation for early-stage HCC. Additionally, the review accentuates the encouraging outcomes of particle therapy in enhancing local control and survival rates, minimizing treatment-related toxicity, and advocating for continued research and clinical trials. In conclusion, the integration of RT into multimodal HCC treatment strategies, coupled with the emergence of particle therapy, is crucial for advancing oncologic management, emphasizing the need for relentless innovation and personalized treatment approaches.

Efficacy of a Second Course of Radiation for Patients With Metachronous Hepatocellular Carcinoma

PURPOSE

Liver-directed radiation therapy is an effective treatment for hepatocellular carcinoma (HCC), but metachronous lesions develop outside the irradiated field in >50% of patients. We hypothesized that irradiation of these new lesions would produce an outcome like that of patients receiving a first course (C1) of treatment.

METHODS AND MATERIALS

We included patients with HCC who received a second course (C2) of radiation therapy >1 month after C1. Toxicity was defined as Child-Pugh score increase ≥2 within 6 months posttreatment (binary model) and as the change in albumin-bilirubin during the year after treatment (longitudinal model). Overall survival (OS) and local failure (LF) were captured at the patient and lesion level, respectively; both were summarized with Kaplan-Meier estimates. Predictors of toxicity and OS were assessed using generalized linear mixed and Cox regression models, respectively.

RESULTS

Of 340 patients with HCC, 47 underwent irradiation for metachronous HCC, receiving similar prescription dose in C1/C2. Median follow-up was 17 months after C1 and 15 months after C2. Twenty-two percent of patients experienced toxicity after C1, and 25% experienced toxicity after C2. Worse baseline albumin-bilirubin predicted toxicity in both binary (odds ratio, 2.40; 95% CI, 1.46-3.94; P = .0005) and longitudinal models (P < .005). Two-year LF rate was 11.2% after C1 and 8.3% after C2; tumor dose (hazard ratio [HR], 0.982; 95% CI, 0.969-0.995; P = .007) and tumor size (HR, 1.135; 95% CI, 1.068-1.206; P < .005) predicted LF. Two-year OS was 46.0% after C1 and 42.6% after C2; tumor dose (HR, 0.986; 95% CI, 0.979-0.992; P < .005) and tumor size (HR, 1.049; 95% CI, 1.010-1.088; P = .0124) predicted OS. Reirradiation was not associated with toxicity (P > .7), LF (P = .79), or OS (P = .39).

CONCLUSIONS

In this largest series in the Western hemisphere, we demonstrate that irradiation for metachronous HCC offers low rates of LF with acceptable toxicity and OS like that of patients receiving a C1. These findings support judicious selection of patients for reirradiation in metachronous HCC.

Updates on LI-RADS Treatment Response Criteria for Hepatocellular Carcinoma: Focusing on MRI

As the incidence of hepatocellular carcinoma (HCC) and subsequent treatments with liver-directed therapies rise, the complexity of assessing lesion response has also increased. The Liver Imaging Reporting and Data Systems (LI-RADS) treatment response algorithm (LI-RADS TRA) was created to standardize the assessment of response after locoregional therapy (LRT) on contrast-enhanced CT or MRI. Originally created based on expert opinion, these guidelines are currently undergoing revision based on emerging evidence. While many studies support the use of LR-TRA for evaluation of HCC response after thermal ablation and intra-arterial embolic therapy, data suggest a need for refinements to improve assessment after radiation therapy. In this manuscript, we review expected MR imaging findings after different forms of LRT, clarify how to apply the current LI-RADS TRA by type of LRT, explore emerging literature on LI-RADS TRA, and highlight future updates to the algorithm. EVIDENCE LEVEL: 3. TECHNICAL EFFICACY: Stage 2.

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.

Stereotactic Body Radiation Therapy versus Surgical Resection for Stage I/II Hepatocellular Carcinoma

SBRT is an emerging locoregional treatment modality for hepatocellular carcinoma (HCC). Although local tumor control rates seem encouraging, large-scale survival data comparing SBRT to surgical resection are lacking. We identified patients with stage I/II HCC from the National Cancer Database amenable for potential surgical resection. Patients undergoing hepatectomy were matched by propensity score (1:2) with patients who underwent SBRT as primary treatment. A total of 3787 (91%) and 366 (9%) patients underwent surgical resection or SBRT between 2004 and 2015, respectively. After propensity matching, the 5-year overall survival was 24% (95% CI 19-30%) in the SBRT group versus 48% (95% CI 43-53%) in the surgery group (p < 0.001). The association of surgery with overall survival was consistent in all subgroups. In patients treated with SBRT, a biologic effective dose (BED) of ≥100 Gy (31%, 95% CI 22%-40%) compared with BED < 100 Gy (13%, 95% CI 8-22%) was associated with a higher 5-year overall survival rate (hazard ratio of mortality of 0.58, 95% CI 0.43-0.77; p < 0.001). Surgical resection may be associated with prolonged overall survival compared with SBRT in patients with stage I/II HCC.

A simple mathematical model of cyclic hypoxia and its impact on hypofractionated radiotherapy

PURPOSE

There is evidence that the population of cells that experience fluctuating oxygen levels ("acute," or, "cyclic" hypoxia) are more radioresistant than chronically hypoxic ones and hence, this population may determine radiotherapy (RT) response, in particular for hypofractionated RT, where reoxygenation may not be as prominent. A considerable effort has been devoted to examining the impact of hypoxia on hypofractionated RT; however, much less attention has been paid to cyclic hypoxia specifically and the role its kinetics may play in determining the efficacy of these treatments. Here, a simple mathematical model of cyclic hypoxia and fractionation effects was worked out to quantify this.

METHODS

Cancer clonogen survival fraction was estimated using the linear quadratic model, modified to account for oxygen enhancement effects. An analytic approximation for oxygen transport away from a random network of capillaries with fluctuating oxygen levels was used to model inter-fraction tissue oxygen kinetics. The resulting survival fraction formula was used to derive an expression for the iso-survival biologically effective dose (BED), BED_iso-SF . These were computed for some common extra-cranial hypofractionated RT regimens.

RESULTS

Using relevant literature parameter values, inter-fraction fluctuations in oxygenation were found to result in an added 1-2 logs of clonogen survival fraction in going from five fractions to one for the same nominal BED (i.e., excluding the effects of oxygen levels on radiosensitivity). BED_iso-SF 's for most ultra-hypofractionated (five or fewer fractions) regimens in a given tumor site are similar in magnitude, suggesting iso-efficacy for common fractionation schedules.

CONCLUSIONS

Although significant, the loss of cell-killing with increasing hypofractionation is not nearly as large as previous estimates based on the assumption of complete reoxygenation between fractions. Most ultra-hypofractionated regimens currently in place offer sufficiently high doses to counter this loss of cell killing, although care should be taken in implementing single-fraction regimens.

The Additive Value of Radiomics Features Extracted from Baseline MR Images to the Barcelona Clinic Liver Cancer (BCLC) Staging System in Predicting Transplant-Free Survival in Patients with Hepatocellular Carcinoma: A Single-Center Retrospective Analysis

BACKGROUND

To study the additive value of radiomics features to the BCLC staging system in clustering HCC patients.

METHODS

A total of 266 patients with HCC were included in this retrospective study. All patients had undergone baseline MR imaging, and 95 radiomics features were extracted from 3D segmentations representative of lesions on the venous phase and apparent diffusion coefficient maps. A random forest algorithm was utilized to extract the most relevant features to transplant-free survival. The selected features were used alongside BCLC staging to construct Kaplan-Meier curves.

RESULTS

Out of 95 extracted features, the three most relevant features were incorporated into random forest classifiers. The Integrated Brier score of the prediction error curve was 0.135, 0.072, and 0.048 for the BCLC, radiomics, and combined models, respectively. The mean area under the receiver operating curve (ROC curve) over time for the three models was 81.1%, 77.3%, and 56.2% for the combined radiomics and BCLC models, respectively.

CONCLUSIONS

Radiomics features outperformed the BCLC staging system in determining prognosis in HCC patients. The addition of a radiomics classifier increased the classification capability of the BCLC model. Texture analysis features could be considered as possible biomarkers in predicting transplant-free survival in HCC patients.

Phase 1 Randomized Trial of Stereotactic Body Radiation Therapy Followed by Nivolumab plus Ipilimumab or Nivolumab Alone in Advanced/Unresectable Hepatocellular Carcinoma

PURPOSE

Immunotherapy has emerged as a promising therapeutic option for advanced or unresectable hepatocellular carcinoma (HCC). However, survival remains poor with only a subset of patients deriving benefit. This trial investigated the safety and efficacy of stereotactic body radiation therapy (SBRT) with immunotherapy in HCC.

METHODS AND MATERIALS

In this multicenter phase 1 randomized trial, patients with advanced or unresectable HCC received liver SBRT (40 Gy in 5 fractions) followed by either nivolumab alone or nivolumab plus ipilimumab. The primary endpoint was dose-limiting toxicity occurring within 6 months of SBRT. Secondary endpoints included overall response rate, progression-free survival, overall survival (OS), distant disease control, and local control of the irradiated tumor. Disease status and response endpoints were assessed radiographically every 8 weeks until progression or initiation of nonprotocol therapy. Response was determined using both RECIST (Response Evaluation Criteria in Solid Tumors) 1.1 and iRECIST.

RESULTS

Fourteen patients were enrolled across 3 centers. Thirteen patients were evaluated for study endpoints. The study was closed early because of slow accrual. The median follow-up time was 42.7 months. Dose-limiting toxicities within 6 months occurred in 2 (15.4%) of 13 patients: 1 of 6 patients in the nivolumab arm (16.7%; 90% confidence interval [CI], 0.9%-58.2%) and 1 of 7 patients in the nivolumab plus ipilimumab arm (14.3%; 90% CI, 0.7%-52.1%). Grade 3 adverse events occurred in 8 (61.6%), 5 (71.4%), and 3 (50.0%) patients in the overall nivolumab plus ipilimumab and nivolumab cohorts. Grade 3 hepatotoxicity occurred in 4 (30.8%), 3 (42.9%), and 1 (16.7%) patients in the respective cohorts. Clinical outcomes favored the nivolumab plus ipilimumab arm compared with nivolumab alone, including an overall response rate of 57% (4 of 7 patients; 90% CI, 23%-87%) versus 0% (0 of 6 patients; 90% CI, 0%-39%), median progression-free survival of 11.6 months (90% CI, 4.5 months to not reached) versus 2.7 months (90% CI, 1.3-4.7 months), and median OS of 41.6 months (90% CI, 4.5 months to not reached) versus 4.7 months (90% CI, 2.0-16.2 months) (all P < .05). With combination immunotherapy, 3-year OS was 57% (90% CI, 23%-81%), with 2 patients alive after 42.7 months without progression and negative PET.

CONCLUSIONS

In this first prospective trial investigating the combination of SBRT and immunotherapy for HCC, multimodal therapy demonstrated acceptable safety. SBRT with nivolumab plus ipilimumab compared favorably to outcomes of immunotherapy alone and warrants further investigation.

Proton Beam Therapy and Photon-Based Magnetic Resonance Image-Guided Radiation Therapy: The Next Frontiers of Radiation Therapy for Hepatocellular Carcinoma

External beam radiation therapy (EBRT) has increasingly been utilized in the treatment of hepatocellular carcinoma (HCC) due to technological advances with positive clinical outcomes. Innovations in EBRT include improved image guidance, motion management, treatment planning, and highly conformal techniques such as intensity-modulated radiation therapy (IMRT) and stereotactic body radiation therapy (SBRT). Moreover, proton beam therapy (PBT) and magnetic resonance image-guided radiation therapy (MRgRT) have expanded the capabilities of EBRT. PBT offers the advantage of minimizing low- and moderate-dose radiation to the surrounding normal tissue, thereby preserving uninvolved liver and allowing for dose escalation. MRgRT provides the advantage of improved soft tissue delineation compared to computerized tomography (CT) guidance. Additionally, MRgRT with online adaptive therapy is particularly useful for addressing motion not otherwise managed and reducing high-dose radiation to the normal tissue such as the stomach and bowel. PBT and online adaptive MRgRT are emerging technological advancements in EBRT that may provide a significant clinical benefit for patients with HCC.

ACR Appropriateness Criteria® Management of Liver Cancer: 2022 Update

The treatment and management of hepatic malignancies can be complex because it encompasses a variety of primary and metastatic malignancies and an assortment of local and systemic treatment options. When to use each of these treatments is critical to ensure the most appropriate care for patients. Interventional radiologists have a key role to play in the delivery of a variety of liver directed treatments including percutaneous ablation, transarterial embolization with bland embolic particles alone, transarterial chemoembolization (TACE) with injection of a chemotherapeutic emulsion, and transarterial radioembolization (TARE). Based on 9 clinical variants, the appropriateness of each treatment is described in this document. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances in which peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Role of gadoxetic acid-enhanced liver magnetic resonance imaging in the evaluation of hepatocellular carcinoma after locoregional treatment

Locoregional treatments, as alternatives to surgery, play a key role in the management of hepatocellular carcinoma (HCC). Liver magnetic resonance imaging (MRI) enables a multiparametric assessment, going beyond the traditional dynamic computed tomography approach. Moreover, the use of hepatobiliary agents can improve diagnostic accuracy and are becoming important in the diagnosis and follow-up of HCC. However, the main challenge is to quickly identify classical responses to loco-regional treatments in order to determine the most suitable management strategy for each patient. The aim of this review is to provide a summary of the most common and uncommon liver MRI findings in patients who underwent loco-regional treatments for HCC, with a special focus on ablative therapies (radiofrequency, microwaves and cryoablation), trans-arterial chemoembolization, trans-arterial radio-embolization and stereotactic ablative radiotherapy techniques, considering the usefulness of gadoxetate disodium (Gd-EOB-DTPA) contrast agent.

PIVKA-II as a surrogate marker for prognosis in patients with localized hepatocellular carcinoma receiving stereotactic body radiotherapy

Purpose

This study aimed to determine the correlation between protein induced by vitamin K absence or antagonist-II (PIVKA-II) and stereotactic body radiotherapy (SBRT) in patients with hepatocellular carcinoma (HCC).

Materials and Methods

Sixty-one patients received SBRT between 2015 and 2020 with a median dose of 48 Gy (range, 39 to 60 Gy) with a median of 4 fractions. Changes in tumor markers before and after SBRT were analyzed.

Results

The median follow-up period was 31 months (range, 12 to 64 months). The estimated 2-year in-field failure-free survival, progression-free survival (PFS), and overall survival rates were 82.0%, 39.3%, and 96.7%, respectively. Patients with decreased PIVKA-II levels through SBRT had significantly few in-field failures (p = 0.005). Patients with PIVKA-II levels of ≤25 mAU/mL after SBRT had significantly long PFS (p = 0.004).

Conclusion

PIVKA-II could be a useful surrogate marker for response or survival outcomes in patients with localized HCC receiving SBRT.

Neutrophil‑to‑lymphocyte ratio as a prognostic predictor for patients with cancer treated with stereotactic body radiation therapy: A meta‑analysis

Stereotactic body radiation therapy (SBRT) is effective for the treatment of cancer. Neutrophil-to-lymphocyte ratio (NLR) is a common prognostic factor in predicting survival of patients with cancer. Previous studies have reported that NLR may be able to predict survival of patients with cancer treated with SBRT; however, the results are inconsistent. Therefore, the present study performed a meta-analysis to pool the data of prognostic prediction using NLR for patients with cancer who underwent SBRT. PubMed, Google Scholar, Embase and The Cochrane Library were used to search for articles published before October 2020. Pooled hazard radios (HRs) with 95% confidence intervals (CIs) were used to evaluate the association of NLR levels with patient outcome following SBRT. The primary endpoint was overall survival (OS). Subgroup analyses were used to detect sources of heterogeneity. Publication bias was assessed by Egger's test and Begg's test. A total of nine studies involving 1,010 participants were included in the present meta-analysis. Univariate and multivariate analyses revealed that elevated NLR predicted a worse outcome for OS (HR, 1.35; 95% CI, 1.22-1.49; P<0.001 and HR, 1.29; 95% CI, 1.16-1.44; P<0.001, respectively), regardless of pre- and post-treatment groups. Subgroup analysis demonstrated that the prospective group showed more significant heterogeneity (I²=57.7%; P=0.124) than the retrospective group (I²=0%) and overall (I²=47.5%). In conclusion, both pre- and post-SBRT elevated NLRs were revealed to be independently associated with poor survival in patients with cancer who received SBRT.

Comparison of External Beam Radiation Therapy Modalities for Hepatocellular Carcinoma With Macrovascular Invasion: A Meta-Analysis and Systematic Review

Purpose

We performed a systematic review and meta-analysis to compare external beam radiation therapy modalities for hepatocellular carcinoma (HCC) with macrovascular invasion (MVI).

Methods

Studies were selected from online databases from the date of inception to November 2021. The outcomes of interest were overall survival (OS), objective response rate (ORR), and local control rate (LCR).

Results

Forty-four studies (n = 3730) were selected from 1050 articles. The pooled 1-year OS were 60.9%, 45.3%, and 44.9 for particle radiotherapy (PRT) group, conventional radiotherapy (CRT), and stereotactic body radiotherapy (SBRT) group, respectively; p = 0.005 and 0.002 for PRT vs. CRT and SBRT, respectively. Both the PRT group and the SBRT group have the advantage over the CRT group in the pooled ORR. The PRT group showed significantly higher than the CRT group (p = 0.007) in LCR. For combination therapy, CRT plus transarterial chemoembolization can prolong survival than CRT alone (p = 0.006 for 1-year OS; p = 0.014 for 2-year OS). Among grade ≥ 3 complications, the most frequent type of toxicity in CRT, SBRT, PRT group was hematological toxicity, hepatotoxicity, dermatological toxicity, respectively.

Conclusions

Among patients with HCC with MVI, the 1-year OS and the 2-year OS were both higher in the PRT group than in the CRT, SBRT groups. The ORR was similar between the PRT and SBRT groups. The combination therapy based on radiotherapy is expectable. PRT is associated with less complications than photon radiotherapy.

The radiobiological effect of using Acuros XB vs anisotropic analytical algorithm on hepatocellular carcinoma stereotactic body radiation therapy

The purpose of this work was to study the radiobiological effect of using Acuros XB (AXB) vs Analytic Anisotropic Algorithm (AAA) on hepatocellular carcinoma (HCC) stereotactic body radiation therapy (SBRT). Seventy SBRT volumetric modulated arc therapy (VMAT) plans for HCC were calculated using AAA and AXB respectively with the same treatment parameters. Published tumor control probability (TCP) and normal tissue complication probability (NTCP) models were used to quantify the effect of dosimetric difference between AAA and AXB on TCP, NTCP and uncomplicated tumor control probability (UTCP). There was an average decrease of 2.5% in 6-month TCP. Normal liver has the largest average decrease in NTCP which was 59.7%. Bowels followed with 26.6% average decrease in NTCP. Duodenum, stomach and esophagus had 10.2%, 5.1%, and 4.3% average decrease in NTCP. There was an average decrease of 1.8% and up to 7.2% in 6-month UTCP. There was an overall decrease in TCP, NTCP, and UTCP for HCC SBRT plans calculated using AXB compared to AAA which could be clinically significant.

Recent Progress in Understanding the Action of Natural Compounds at Novel Therapeutic Drug Targets for the Treatment of Liver Cancer

Liver cancer is the third most common cause of cancer-related death following lung and stomach cancers. As a highly lethal disease, liver cancer is diagnosed frequently in less developed countries. Natural compounds extracted from herbs, animals and natural materials have been adopted by traditional Chinese medicine (TCM) practices and reported to be effective in the development of new medications for the treatment of diseases. It is important to focus on the mechanisms of action of natural compounds against hepatocellular carcinoma (HCC), particularly in terms of cell cycle regulation, apoptosis induction, autophagy mediation and cell migration and invasion. In this review, we characterize novel representative natural compounds according to their pharmacologic effects based on recently published studies. The aim of this review is to summarize and explore novel therapeutic drug targets of natural compounds, which could accelerate the discovery of new anticancer drugs.

Approach to Stereotactic Body Radiotherapy for the Treatment of Advanced Hepatocellular Carcinoma in Patients with Child-Pugh B-7 Cirrhosis

OPINION STATEMENT

Patients with hepatocellular carcinoma (HCC) with underlying Child-Pugh B-7 cirrhosis benefit from management from an experienced, multidisciplinary team. In patients with localized disease who meet criteria for liver transplant, establishing care at a liver transplant center is crucial. For those awaiting transplant, local bridge therapies have emerged as a strategy to maintain priority status and eligibility. Multiple liver-directed therapies exist to provide locoregional tumor control. The careful selection of locoregional therapy is a multidisciplinary endeavor that takes into account patient factors including tumor resectability, underlying liver function, performance status, previous treatment, tumor location/size, and vascular anatomy to determine the optimal management strategy. Technological advances in external beam radiation therapy have allowed stereotactic body radiation therapy (SBRT) to emerge in recent years as a versatile and highly effective bridge therapy consisting of typically between 3 and 5 high dose, highly focused, and non-invasive radiation treatments. When treating cirrhotic patients with HCC, preserving liver function is of utmost importance to prevent clinical decline and decompensation. SBRT has been shown to be both safe and effective in carefully selected patients with Child-Pugh B cirrhosis; however, care must be taken to prevent radiation-induced liver disease. This review summarizes the evolving role of SBRT in the treatment of HCC in patients with Child-Pugh B-7 cirrhosis.

Clinical application of advances and innovation in radiation treatment of hepatocellular carcinoma

Background

Hepatocellular carcinoma (HCC) management has evolved over the past two decades, with the development of newer treatment modalities. While various options are available, unmet needs are reflected through the mixed treatment outcome for intermediate-stage HCC. As HCC is radiosensitive, radiation therapies have a significant role in management. Radiation therapies offer local control for unresectable lesions and for patients who are not surgical candidates. Radiotherapy also provides palliation in metastatic disease, and acts as a bridge to resection and transplantation in selected patients. Advancements in radiotherapy modalities offer improved dose planning and targeted delivery, allowing for better tumor response and safer dose escalations while minimizing the risks of radiation-induced liver damage. Radiotherapy modalities are broadly classified into external beam radiation therapy and selective internal radiation therapy. With emerging modalities, radiotherapy plays a complementary role in the multidisciplinary care of HCC patients.

Aim

We aim to provide an overview of the role and clinical application of radiation therapies in HCC management.

Relevance for Patients

The continuous evolution of radiotherapy techniques allows for improved therapeutic outcomes while mitigating unwanted adverse effects, making it an attractive modality in HCC management. Rigorous clinical studies, quality research and comprehensive datasets will further its application in the present era of evidence-based practice in Medicine.

Effectiveness of individual audio-visual coaching, respiratory modulated stereotactic body radiotherapy for localized hepatocellular carcinoma: Analysis of 29 cases from a single academic radiotherapy center

Objectives:

Recently, Stereotactic Body Radiotherapy (SBRT) has been suggested for managing hepatocellular carcinoma (HCC) curatively. Thus, we conducted this clinical study to evaluate retrospectively the effect of individualized audio-visual (AV) coaching, respiratory modulated SBRT.

Materials and Methods:

Between 2014 and 2018, 29 patients with inoperable Barcelona Clinic Liver Cancer (BCLC) stage 0-B HCC received AV coaching, respiratory-modulated SBRT. We constructed a task-oriented multidisciplinary team to establish a standard operation process of respiratory modulation procedures and developed our AV coaching devices. In the training period, a goodness-of-fit test was applied individually. SBRT was delivered with a total dose of 40–54 Gy in 5–6 fractions individually. Freedom from local progression (FFLP) and overall survival (OS) were estimated using SPSS (version 17, SPSS Inc., Chicago, IL, USA) life tables.

Results:

The patient characteristics were as follows: 32.7 ± 16 mm in maximum tumor diameter (range 11–94); BCLC stage 0: 3.4%, BCLC A: 48.3%, BCLC B: 48.3%; Child-Pugh classification A: 86.2%, Child-Pugh classification B: 13.8%, and a median of 2 prior liver-directed treatments (range 0–7). One-, 2-, and 3-year rates of FFLP of SBRT were 96.6%, 96.6%, and 96.6%, respectively. One-, 2-, and 3-year rates of OS were 81.5%, 72.4%, and 67.2%, respectively. No adverse event (AE) occurred in 41.4% of patients, 48.3% developed grade (G) 1–2 AE, 10.3% had G3 AE and none had G4-5 AE.

Conclusion:

Respiration-modulated SBRT is a promising noninvasive treatment option for patients with inoperable and localized HCC. Our data show that SBRT provides comparable tumor control to historical curative options like surgery and radiofrequency ablation of localized tumors. Thus, we are conducting a further prospective clinical trial with the intent to demarcate the clinical effectiveness of SBRT in a larger population of patients with HCC.

Uniform versus non-uniform dose prescription for proton stereotactic body radiotherapy of liver tumors investigated by extensive motion-including treatment simulations

Compared to x-ray-based stereotactic body radiotherapy (SBRT) of liver cancer, proton SBRT may reduce the normal liver tissue dose. For an optimal trade-off between target and liver dose, a non-uniform dose prescription is often applied in x-ray SBRT, but lacks investigation for proton SBRT. Also, proton SBRT is prone to breathing-induced motion-uncertainties causing target mishit or dose alterations by interplay with the proton delivery. This study investigated non-uniform and uniform dose prescription in proton-based liver SBRT, including effects of rigid target motion observed during planning-4DCT and treatment. The study was based on 42 x-ray SBRT fractions delivered to 14 patients under electromagnetic motion-monitoring. For each patient, a non-uniform and uniform proton plan were made. The uniform plan was renormalized to be iso-toxic with the non-uniform plan using a NTCP model for radiation-induced liver disease. The motion data were used in treatment simulations to estimate the delivered target dose with rigid motion. Treatment simulations were performed with and without a repainting scheme designed to mitigate interplay effects. Including rigid motion, the achieved CTV mean dose after three fractions delivered without repainting was on average (±SD) 24.8 ± 8.4% higher and the D_98%was 16.2 ± 11.3% higher for non-uniform plans than for uniform plans. The interplay-induced increase in D_2%relative to the static plans was reduced from 3.2 ± 4.1% without repainting to -0.5 ± 1.7% with repainting for non-uniform plans and from 1.5 ± 2.0% to 0.1 ± 1.3% for uniform plans. Considerable differences were observed between estimated CTV doses based on 4DCT motion and intra-treatment motion. In conclusion, non-uniform dose prescription in proton SBRT may provide considerably higher tumor doses than uniform prescription for the same complication risk. Due to motion variability, target doses estimated from 4DCT motion may not accurately reflect the delivered dose. Future studies including modelling of deformations and associated range uncertainties are warranted to confirm the findings.

LncRNA GAS5 enhances radiosensitivity of hepatocellular carcinoma and restricts tumor growth and metastasis by miR-144-5p/ATF2

BACKGROUND

This study aimed to evaluate the biologic role of growth arrest-specific 5 (GAS5) in radiosensitivity of hepatocellular carcinoma (HCC).

METHODS

The levels of GAS5, miR-144-5p, and activating transcription factor 2 (ATF2) were quantified in HCC tissues and cell lines. RNA immunoprecipitation (RIP) and RNA pull-down assays were used to test the interaction between GAS5 and miR-144-5p. The regulatory relationship between miR-144-5p and ATF2 was identified by the dual-luciferase reporter (DLR) assay. A nude mouse model of HCC was induced to verify the effect of GAS5 on radiosensitivity of HCC in vivo.

RESULTS

Lower levels of GAS5 and ATF2, and higher levels of miR-144-5p, were found in radiation-resistant human HCC tissues and cell lines. Overexpression of ATF2 or GAS5 enhanced the radiosensitivity of HCC cell lines, while knockdown of ATF2 or GAS5 decreased the radiosensitivity. In addition, GAS5 acted as a miR-144-5p sponge, and miR-144-5p inversely regulated ATF2. Also, GAS5 mediated ATF2 levels through miR-144-5p, and increased the radiosensitivity of HCC by suppressing miR-144-5p both in vivo and in vitro.

CONCLUSION

Overexpression of GAS5 upregulates ATF2 through miR-144-5p and is able to enhance the radiosensitivity of HCC.

Toward Personalized Medicine in Radiotherapy of Hepatocellular Carcinoma: Emerging Radiomic Biomarker Candidates of Response and Toxicity

Radiology and radiotherapy are currently undergoing radical transformation with use of biomarkers and digital technologies such as artificial intelligence. These current and upcoming changes in radiology speak of an overarching new vision for personalized medicine. This is particularly evident in the case of radiotherapy of cancers, and of liver cancer in particular. The development of modern radiotherapy with stereotactic body radiotherapy allows targeted treatments to be delivered to the tumor site, limiting the dose to surrounding healthy organs, thus becoming a new therapeutic alternative for hepatocellular carcinoma and other liver tumors. However, not all patients have the same response to radiotherapy or display the same side-effect profile. Biomarkers of response and toxicity in liver radiotherapy would facilitate the vision and practice of personalized medicine. This expert review examines the available molecular, radiomic, and radiogenomic biomarker candidates for acute liver toxicity with potential use for prediction of radiotherapy-induced liver toxicity. To this end, I highlight for oncologists and life scientists that radiomics allows diagnostic images to be analyzed using computer algorithms to extract information imperceptible to the human eye and of relevance to forecasting clinical outcomes. This article underscores particularly (1) the microRNA-based biomarker candidates as among the most promising predictors of radiation-induced liver toxicity and (2) the texture features in radiomic analyses for response prediction. Radiotherapy of hepatocellular carcinoma is edging toward personalized medicine with emerging radiomic biomarker candidates. Future large-scale biomarker studies are called for to enable personalized medicine in liver cancers.

Efficacy and toxicity of SBRT in advanced hepatocellular carcinoma with portal vein tumor thrombosis - a retrospective study

BACKGROUND

The purpose of this study was to evaluate the outcome of stereotactic body radiation therapy (SBRT) in patients of unresectable hepatocellular carcinoma (HCC ) complicated with portal vein tumor thrombosis (PVTT) who are also unsuitable for other locoregional therapies.

MATERIALS AND METHODS

Between May 2018 and January 2020, twenty-nine patients with advanced unresectable HCC s, treated with SBRT, were enrolled in this retrospective audit. Patients of Child status A5-B7 and with healthy liver volume, ≥ 700 ccs were treated. Local control (LC), overall survival (OS), progression-free survival (PFS), PVTT opening rate, and effect of prognostic factors were analyzed.

RESULTS

The median tumor diameter was 8.6 cm (5-14), and the median tumor volume was 275 cc (151-1196). The median SBRT dose prescription was 48 Gy in 6 fractions (32-50 Gy in 5-6 fractions). The median follow up was eight months (1-20), 1-year local control, progression-free survival, and overall survival were 95%, 53.4%, and 60%, respectively. Overall rate of grade III toxicity was less than 5%, and the most common toxicity was lymphocytopenia. Tumors of more than 350cc had worse OS and PFS when compared to tumors < 350 cc (median OS and PFS of tumors > 350 cc was 4 months and two months, p = .01 and .003, respectively). A total of fifteen patients progressed with the disease and the median time to progression was two months [1-4].

CONCLUSION

SBRT is safe and provides excellent local control in advanced HCC complicated with PVTT. The out of field failure pattern and time to failure in these patients highlights the need for adjuvant systemic therapy after completion of local treatment. Our data warrant the need for multimodality trials in this patient cohort.

Stereotactic ablative radiotherapy for hepatocellular carcinoma: A systematic review and meta-analysis of local control, survival and toxicity outcomes

There is a growing body of literature supporting the use of stereotactic ablative body radiotherapy (SABR) in the management of primary hepatocellular carcinoma (HCC). This systematic review and meta-analysis of the current published evidence for SABR for HCC assessed the impact of treatment dose, fractionation and tumour size on the outcomes of local control (LC), overall survival (OS) and toxicity. A systematic search was independently performed by two authors for articles published in peer-reviewed journals between January 2005 and December 2019. A DerSimonian and Laird random effects model was used to assess pooled results. A multivariate meta-regression analysis incorporated the effect of explanatory variables (radiation dose in EQD2_[10], fractionation and tumour size) on outcomes of OS, LC and toxicity. Forty-nine cohorts involving 2846 HCC patients with 3088 lesions treated with SABR were included. Pooled 1-, 2- and 3-year LC rates were 91.1% (95% confidence interval [CI] 88.3-93.2), 86.7% (95% CI 82.7-89.8) and 84.2% (95% CI 77.9-88.9) respectively. Pooled 1-, 2- and 3-year OS rates were 78.4% (95% CI 73.4-82.6), 61.3% (55.2-66.9) and 48.3% (95% CI 39.0-57). Population-weighted median grade 3 toxicity rates were 6.5% (IQR 3.2-16) and mean grade 4/5 rates were 1.4% (IQR 0-2.1). Within EQD2_[10] ranges of 40 to 83.33 Gy corresponding to common dose-fractionation regimens of 30-50 Gy in 5 fractions, there was a multivariate association between superior LC and OS with increasing EQD2_[10] , with a proportionately smaller increase in grade 3 toxicity and no association with grade 4/5 toxicity. Stereotactic ablative body radiotherapy is a viable treatment option for HCC with high LC rates and low rates of reported grade 3/4 toxicity. Increasing EQD2_[10] was associated with improvements in LC and OS with a comparatively smaller increase in toxicity. Prospective randomised trials are warranted to define optimal patient selection and dose-fractionation regimens.

Comparison of stereotactic body radiation therapy versus fractionated radiation therapy for primary liver cancer with portal vein tumor thrombus

Background

To compare the clinical outcomes of stereotactic body radiation therapy (SBRT) and fractionated radiation therapy (FRT) for primary liver cancer with portal vein tumor thrombus (PVTT).

Methods

This retrospective study included 36 patients who underwent SBRT and 36 patients who underwent FRT from August 2016 to June 2018. Patients were evaluated for short-term efficacy, long-term efficacy, AEs, and quality of life before and after treatment.

Results

With a median follow-up of 28.8 months (26–36 months), 27 patients survived in the SBRT group while 19 patients survived in the FRT group. The survival rate in the SBRT group was statistically higher than that of the FRT group after 6 months (80.56% vs. 58.33%; P = 0.041), 12 months (77.78% vs. 55.56%; P = 0.046) and 24 months 75.00% vs. 52.78%; P = 0.049). The median whole survival time of the SBRT group was 13.3 months (95% CI 12.83–13.97), which was statistically longer than 9.8 months in the FRT group (95% CI 8.83–10.97, P < 0.05) based on the Kaplan–Meier method. The SBRT group had better survival quality and fewer adverse events than the FRT group.

Conclusion

SBRT had better clinical outcomes than FRT for primary liver cancer with PVTT.

URI1 suppresses irradiation-induced reactive oxygen species (ROS) by activating autophagy in hepatocellular carcinoma cells

Radiotherapy has been extensively applied in cancer treatment. However, this treatment is ineffective in Hepatocellular carcinoma (HCC) due to lack of radiosensitivity. Unconventional prefoldin RPB5 interactor 1 (URI1) exhibits characteristics similar to those oncoproteins, which promotes survival of cancer cells. As a consequence of the irradiation, the levels of endogenous reactive oxygen species (ROS) rise. In the current study, we analyzed the role of URI1 in the control of ROS levels in HepG2 cells. Upon URI1 overexpression, HepG2 cells significantly suppressed irradiation-induced ROS, which may help cells escape from oxidative toxicity. And our data demonstrated that overexpression of URI1 not only resulted in an increase of autophagic flux, but also resulted in an further increased capacity of autophagy to eliminate ROS. It indicated that URI1 suppressed irradiation-induced ROS through activating autophagy. Moreover, URI1 activated autophagy by promoting the activities of AMP-activated protein kinase (AMPK). Results showed that overexpression of URI1 increased the phosphorylation of AMPKα at the Thr172 residue and the activated-AMPK promoted the phosphorylation of forkhead box O3 (FOXO3) at the Ser253 residue, which significantly induced autophagy. Taken together, our findings provide a mechanism that URI1 suppresses irradiation-induced ROS by activating autophagy through AMPK/FOXO3 signaling pathway. These new molecular insights will provide an important contribution to our better understanding about irradiation insensitivity of HCC.

Diagnosis and treatment of hepatocellular carcinoma. Update of the consensus document of the AEEH, AEC, SEOM, SERAM, SERVEI, and SETH

Hepatocellular carcinoma (HCC) is the most common primary liver neoplasm and one of the most common causes of death in patients with cirrhosis of the liver. In parallel, with recognition of the clinical relevance of this cancer, major new developments have recently appeared in its diagnosis, prognostic assessment and in particular, in its treatment. Therefore, the Spanish Association for the Study of the Liver (AEEH) has driven the need to update the clinical practice guidelines, once again inviting all the societies involved in the diagnosis and treatment of this disease to participate in the drafting and approval of the document: Spanish Society for Liver Transplantation (SETH), Spanish Society of Diagnostic Radiology (SERAM), Spanish Society of Vascular and Interventional Radiology (SERVEI), Spanish Association of Surgeons (AEC) and Spanish Society of Medical Oncology (SEOM). The clinical practice guidelines published in 2016 and accepted as National Health System Clinical Practice Guidelines were taken as the reference documents, incorporating the most important recent advances. The scientific evidence and the strength of the recommendation is based on the GRADE system.

Imaging After Locoregional Therapy for Hepatocellular Carcinoma with Emphasis on LIRADS Treatment Response Assessment Criteria

Radiologists play an essential role in assessing hepatocellular carcinoma treatment response and help guide further clinical management of patients. Interpretation of treatment response after locoregional therapy is challenging. The post-treatment imaging findings vary and depend on the type of treatment, the degree of treatment response, time interval after treatment and several other factors. Given the widespread use of local-regional therapies, understanding the appearance of treated lesions has become crucial to allow for a more accurate interpretation of post-treatment imaging. Several response criteria including the recently introduced Liver Imaging Reporting and Data System (LI-RADS) treatment response algorithm (TRA) are currently used to assess treatment response. This review article describes the imaging assessment of HCC treatment response after several locoregional therapies using various response assessment criteria, emphasizing the LI-RADS treatment algorithm.

Comparison of the [18F]-FDG and [18F]-FLT PET Tracers in the Evaluation of the Preclinical Proton Therapy Response in Hepatocellular Carcinoma

PURPOSE

The main objective of the present study was to compare the 2-deoxy-2-[¹⁸F]fluoro-D-glucose ([¹⁸F]-FDG) and 3'-[¹⁸F]fluoro-3'-deoxythymidine ([¹⁸F]-FLT) PET imaging biomarkers for the longitudinal follow-up of small animal proton therapy studies in the context of hepatocellular carcinoma (HCC).

PROCEDURES

SK-HEP-1 cells were injected into NMRI nude mice to mimic human HCC. The behavior of [¹⁸F]-FDG and [¹⁸F]-FLT tumor uptake was evaluated after proton therapy procedures. The proton single-fraction doses were 5, 10, and 20 Gy, with a dose rate of 10 Gy/min. The experimental protocol consisted of 8 groups of 10 mice, each group experiencing a particular dose/radiotracer condition. A reference PET exam was performed on each mouse the day before the irradiation procedure, followed by PET exams every 3 days up to 16 days after irradiation.

RESULTS

[¹⁸F]-FDG uptake showed a linear dose-dependent increase in the first days after treatment (37%, p < 0.05), while [¹⁸F]-FLT uptake decreased in a dose-dependent manner (e.g., 21% for 5 Gy compared to 10 Gy, p = 1.1e-2). At the later time point, [¹⁸F]-FDG normalized activity showed an 85% decrease (p < 0.01) for both 10 and 20 Gy doses and no variation for 5 Gy. Conversely, a significant 61% (p = 0.002) increase was observed for [¹⁸F]-FLT normalized activity at 5 Gy and no variation for higher doses.

CONCLUSION

We showed that the use of the [¹⁸F]-FDG and [¹⁸F]-FLT radiolabeled molecules can provide useful and complementary information for longitudinal follow-up of small animal proton therapy studies in the context of HCC. [¹⁸F]-FDG PET imaging enables a treatment monitoring several days/weeks postirradiation. On the other hand, [¹⁸F]-FLT could represent a good candidate to monitor the treatment few days postirradiation, in the context of hypo-fractioned and close irradiation planning. This opens new perspectives in terms of treatment efficacy verification depending on the irradiation scheme.

A deep survival interpretable radiomics model of hepatocellular carcinoma patients

This work aims to identify a new radiomics signature using imaging phenotypes and clinical variables for risk prediction of overall survival (OS) in hepatocellular carcinoma (HCC) patients treated with stereotactic body radiation therapy (SBRT). 167 patients were retrospectively analyzed with repeated nested cross-validation to mitigate overfitting issues. 56 radiomic features were extracted from pre-treatment contrast-enhanced (CE) CT images. 37 clinical factors were obtained from patients' electronic records. Variational autoencoders (VAE) based survival models were designed for radiomics and clinical features and a convolutional neural network (CNN) survival model was used for the CECT. Finally, radiomics, clinical and raw image deep learning network (DNN) models were combined to predict the risk probability for OS. The final models yielded c-indices of 0.579 (95%CI: 0.544-0.621), 0.629 (95%CI: 0.601-0.643), 0.581 (95%CI: 0.553-0.613) and 0.650 (95%CI: 0.635-0.683) for radiomics, clinical, image input and combined models on nested cross validation scheme, respectively. Integrated gradients method was used to interpret the trained models. Our interpretability analysis of the DNN showed that the top ranked features were clinical liver function and liver exclusive of tumor radiomics features, which suggests a prominent role of side effects and toxicities in liver outside the tumor region in determining the survival rate of these patients. In summary, novel deep radiomic analysis provides improved performance for risk assessment of HCC prognosis compared with Cox survival models and may facilitate stratification of HCC patients and personalization of their treatment strategies. Liver function was found to contribute most to the OS for these HCC patients and radiomics can aid in their management.

Stereotactic radiotherapy for hepatocellular carcinoma induced by hepatitis C and the relationships of changes in carbohydrate antigen 19-9 with AFP and PIVKA-II

PURPOSE

Assessing the therapeutic effects of stereotactic body radiotherapy (SBRT) for hepatocellular carcinoma (HCC) takes time. Purpose of our study was to explore the relationships of changes in carbohydrate antigen 19-9 (CA 19-9) with those in the existing markers alpha-fetoprotein (AFP) and protein induced by vitamin K absence or antagonist-II (PIVKA-II).

PATIENTS AND METHODS

The subjects were 16 patients who underwent SBRT for solitary HCC ≤3cm induced by hepatitis C between June 2016 and July 2019. Observation periods ranged from 8-43 (median: 28) months, ages from 59-85 (median: 65) years.

RESULTS

Changes in CA 19-9 levels after SBRT were categorised into three patterns: 1) a transient elevation followed by a decline (75%); 2) a transient decline followed by an elevation (18.8%); and 3) no change (6.3%). Among patients showing a transient CA 19-9 elevation followed by a decline, which was the most frequent pattern, 75% showed these changes in synchronisation with AFP and preceded the changes in PIVKA-II, while in the other 25%, CA 19-9 changes were in synchronisation with PIVKA-II and preceded those in AFP. At the time of recurrence, 62.5% showed a continuous CA 19-9 elevation, either in synchronisation with other markers or by itself.

CONCLUSIONS

This is the first investigation of changes in CA 19-9 levels after SBRT for HCC induced by hepatitis C. Characteristic changes in CA 19-9, AFP, and PIVKA-II levels were observed as responses after treatment. As for its correlations with tumour markers, the acute responses of PIVKA-II tended to be slower than those of CA 19-9 and AFP. Although the sample size was small, our findings raise the possibility that measuring these 3 biomarkers after SBRT may be useful for monitoring patients for HCC recurrence.

Image-guided Radiotherapy to Manage Respiratory Motion: Lung and Liver

Organ motion as a result of respiratory and cardiac motion poses significant challenges for the accurate delivery of radiotherapy to both the thorax and the upper abdomen. Modern imaging techniques during radiotherapy simulation and delivery now permit better quantification of organ motion, which in turn reduces tumour and organ at risk position uncertainty. These imaging advances, coupled with respiratory correlated radiotherapy delivery techniques, have led to the development of a range of approaches to manage respiratory motion. This review summarises the key strategies of image-guided respiratory motion management with a focus on lung and liver radiotherapy.

Contrast-Enhanced Ultrasonography for Screening and Diagnosis of Hepatocellular Carcinoma: A Case Series and Review of the Literature

Background: Contrast-enhanced ultrasound (CEUS) is a safe and noninvasive imaging technique that can characterize and evaluate liver lesions, and has been approved for this use in the Unites States since 2016. CEUS has been shown to be similar in accuracy to computed tomography (CT) and magnetic resonance imaging (MRI) for noninvasive diagnosis of hepatocellular carcinoma (HCC) and offers several advantages in certain patient populations who have contraindications for CT or MRI. However, CEUS has inherent limitations and has not been widely employed for evaluation of HCC. Methods: We present three retrospective cases of liver lesions in patients with cirrhosis, who underwent screening for HCC using concurrent, well-timed CT and CEUS. Results: In these cases, the liver lesions were better visualized and then diagnosed as malignancy via CEUS, whereas the lesions were best appreciated on CT only in retrospect. Conclusions: In some cirrhotic patients, a focal lesion may be more easily identifiable via CEUS than on CT and thus accurately characterized, suggesting an important and complementary role of CEUS with CT or MRI. Further studies are indicated to support the use of CEUS for the diagnosis and characterization of liver lesions in screening patients at risk for developing HCC.

Local control by salvage stereotactic body radiotherapy for recurrent/residual hepatocellular carcinoma after other local therapies

Background: To clarify local control by salvage stereotactic body radiotherapy (SBRT) for recurrent/residual hepatocellular carcinoma (HCC) compared with initial definitive SBRT for local treatment-naïve HCC.Material and methods: We retrospectively investigated HCC patients that received SBRT between July 2005 and December 2017. We classified HCC tumors as the initial definitive SBRT group (Arm-1; initial definitive SBRT, Arm-2; initial definitive planned SBRT following transarterial chemoembolization (TACE)) and salvage SBRT group (Arm-3; salvage SBRT for recurrent/residual tumors after TACE, Arm-4; salvage SBRT for recurrent/residual tumors after radiofrequency ablation (RFA), Arm-5; salvage SBRT for recurrent/residual other than Arm-3 or Arm-4). Local control was evaluated by mRECIST.Results: We reviewed 389 HCC tumors of 323 patients treated by 35-40 Gy/5 fr. The median follow-up time for local recurrence of tumors was 34.8 months (range, 6.5-99.2). The cumulative local recurrence rates at 3 years of Arm-1-5 were 1.4% (95% CI, 0.3-4.4%), 5.0% (95% CI, 1.6-11.5%), 12.4% (95% CI, 5.7-21.9%), 14.8% (95% CI, 3.3-34.3%) and 7.3% (95% CI, 1.9-18.0%), respectively. The cumulative local recurrence rates at 3 years of initial definitive treatment and salvage treatment groups were 2.8% (95% CI, 1.1-5.6%) and 11.1% (95% CI, 6.3-17.3%), respectively (p=.004). On multivariate analysis, salvage treatment and the tumor diameter were significant risk factors of local recurrence (p = .02, p < .001 respectively). Estimated overall survival at 3 years for all patients in initial definitive treatment and salvage treatment groups were 71.5% (95% CI, 63.4-78.1%) and 66.1% (95% CI, 56.4-74.2%), respectively (p = .20). No treatment-related death caused by SBRT was observed.Conclusions: This analysis showed local control of salvage SBRT for recurrent/residual HCC was significantly worse than that of initial definitive SBRT for local treatment-naïve HCC. However, local control of salvage SBRT was relatively good, and salvage SBRT is one of the favorable treatment options for recurrent/residual HCC.

Stereotactic ablative radiotherapy for colorectal cancer liver metastasis

Survival improvement of colorectal liver metastasis (CRLM) benefits from systemic therapy and metastasis-directed local therapy. Stereotactic ablative body radiotherapy (SABR), as a new efficient metastasis-directed local therapy with a systematic impact, plays a vital role in CRLM multidisciplinary treatment. SABR leads to a dramatic immunological change in the tumor microenvironment (TME) via differential activation of cytoprotective and cytotoxic pathways in malignant and non-malignant cells, in addition to direct tumor cell death. The synergy of SABR and immunotherapy might increase the abscopal response rate of out-field lesions by targeting different steps of the immune-mediated response, in addition to direct intratumoral cell death. The clinical treatment and efficacy of SABR, its influence on TME, and potential molecular underpinnings of which are the topic of this review.

Stereotactic body radiation therapy vs. radiofrequency ablation in Asian patients with hepatocellular carcinoma

BACKGROUND & AIMS

Few studies have been conducted to compare the efficacies of stereotactic body radiation therapy (SBRT) and radiofrequency ablation (RFA). Thus, in this multinational study, we compared the effectiveness of SBRT and RFA in patients with unresectable HCC.

METHODS

The retrospective study cohort included 2,064 patients treated in 7 hospitals: 1,568 and 496 in the RFA and SBRT groups, respectively. More than half of the patients (56.5%) developed recurrent tumors, mainly after transarterial chemoembolization (44.8%). Propensity score matching was performed to adjust for clinical factors (n = 313 in each group).

RESULTS

At baseline, the SBRT group had unfavorable clinical features compared to the RFA group, including BCLC stage (B-C 65% vs. 16%), tumor size (median 3.0 cm vs. 1.9 cm), and frequent history of liver-directed treatment (81% vs. 49%, all p <0.001). With a median follow-up of 27.7 months, the 3-year cumulative local recurrence rates in the SBRT and RFA groups were 21.2% and 27.9%, respectively (p <0.001). After adjusting for clinical factors, SBRT was related to a significantly lower risk of local recurrence than RFA in both the entire (hazard ratio [HR] 0.45, p <0.001) and matched (HR 0.36, p <0.001) cohorts. In subgroup analysis, SBRT was associated with superior local control in small tumors (≤3 cm) irrespective of location, large tumors located in the subphrenic region, and those that progressed after transarterial chemoembolization. Acute grade ≥3 toxicities occurred in 1.6% and 2.6% of the SBRT and RFA patients, respectively (p = 0.268).

CONCLUSIONS

SBRT could be an effective alternative to RFA for unresectable HCC, particularly for larger tumors (>3 cm) in a subphrenic location and tumors that have progressed after transarterial chemoembolization.

LAY SUMMARY

It is currently not known what the best treatment option is for patients with unresectable hepatocellular carcinoma. Here, we show that stereotactic body radiation therapy provides better local control than radiofrequency ablation, with comparable toxicities. Stereotactic body radiation therapy appears to be an effective alternative to radiofrequency ablation that should be considered when there is a higher risk of local recurrence or toxicity after radiofrequency ablation.

Bridging the Radiation Oncology and Diagnostic Radiology Communication Gap: A Survey to Determine Usefulness and Optimal Presentation of Radiotherapy Treatment Plans for Radiologists

RATIONALE AND OBJECTIVES

We hypothesized that providing visual-spatial information to radiologists on where radiation has been delivered in an easily accessible way may improve the accuracy of image interpretation and thereby improve quality of patient care. We present a national representation of radiologists' opinions regarding the usefulness and optimal approach for implementing a system to promote access to radiotherapy (RT) plans.

METHODS

An anonymous survey was sent to the members of the Association of University Radiologists. Descriptive statistics were performed.

RESULTS

Questionnaires were returned by 95 of 1383 members. Demographics comprised of 76% attendings with 94% practicing within an academic setting. Only 40% of radiologists reported that they knew most of the time whether a patient has received RT in the field scanned. A large majority of respondents (88%) felt that a history of prior radiation in a cancer patient was at least an occasional barrier that affected the ability to interpret imaging findings in a clinically useful way. The following types of information was considered helpful when interpreting a scan: screenshots of the radiation plan (85%), scrollable DICOM data on planning CT showing delivered RT dose lines (54%), and written text RT treatment summary (47%). Nearly all (89%) desired DICOM data within the clinical radiology Picture Archiving and Communication System system. Radiologists expected the ease of accessibility to RT plans to result in increased efficiency (76%) and accuracy (88%).

CONCLUSION

Diagnostic radiologists desire improved access and integration of radiotherapy plans into the diagnostic radiology clinical workup in the form of visual-spatial data.

Efficacy and Toxicity of Stereotactic Body Radiotherapy for Early to Advanced Stage Hepatocellular Carcinoma - Initial Experience From an Australian Liver Cancer Service

AIMS

Intrahepatic progression remains the predominant mode of cancer-related death in hepatocellular carcinoma (HCC) underscoring the need for effective local therapies. We report our initial experience with liver stereotactic body radiotherapy (SBRT) in the management of early to advanced stage HCC at an Australian tertiary liver cancer service.

MATERIALS AND METHODS

Patients with liver-confined HCC unsuitable for surgical resection or thermal ablation treated with SBRT between October 2013 and December 2018 were retrospectively evaluated. The primary end point was freedom from local progression. Secondary end points were progression-free survival, disease-specific survival, overall survival and toxicity.

RESULTS

Ninety-six patients were treated for 112 lesions (median size 3.8 cm, range 1.5-17 cm). The median follow-up was 13 months (range 3-65). Forty-six patients had received prior local therapies (median 1, range 1-5), 83 (86%) patients had cirrhosis with baseline Child-Pugh scores of A (88%) and B7-8 (12%). Fifty-nine (61%) patients had Barcelona Clinic Liver Cancer (BCLC) stage 0/A disease and 37 (39%) had stage B/C. Macrovascular invasion was present in 20 (21%). The median biologically effective dose (BED₁₀) was 86 and 60 Gy for the BCLC 0/A and B/C cohorts, respectively. Freedom from local progression at 18 months was 94% for BCLC 0/A and 74% for BCLC B/C. Progression-free survival and overall survival at 12 months were 80 and 95% for BCLC 0/A and 40 and 71% for BCLC B/C, respectively. Five patients (7%) with cirrhosis and without disease progression had an increase in Child-Pugh score >1 within 3 months of SBRT, four of whom had intercurrent infections. Clinical toxicities grade ≥2 were reported in 20% of patients.

CONCLUSION

SBRT is an effective ablative modality for early stage HCC with low rates of significant toxicity. Lower dose SBRT can provide durable local control for advanced stage HCC. However, out-of-field relapse remains common, providing a rationale to investigate SBRT in combination with other therapies.

Characterization of robust optimization for VMAT plan for liver cancer

Purpose

We investigated the feasibility of robust optimization for volumetric modulated arc therapy (VMAT) stereotactic body radiation therapy (SBRT) for liver cancer in comparison with planning target volume (PTV)-based optimized plans. Treatment plan quality, robustness, complexity, and accuracy of dose delivery were assessed.

Methods

Ten liver cancer patients were selected for this study. PTV-based optimized plans with an 8-mm PTV margin and robust optimized plans with an 8-mm setup uncertainty were generated. Plan perturbed doses were evaluated using a setup error of 8 mm in all directions from the isocenter. The dosimetric comparison parameters were clinical target volume (CTV) doses (D_98%, D_50%, and D_2%), liver doses, and monitor unit (MU). Plan complexity was evaluated using the modulation complexity score for VMAT (MCSv).

Results

There was no significant difference between the two optimizations with respect to CTV doses and MUs. Robust optimized plans had a higher liver dose than did PTV-based optimized plans. Plan perturbed dose evaluations showed that doses to the CTV for the robust optimized plans had small variations. Robust optimized plans were less complex than PTV-based optimized plans. Robust optimized plans had statistically significant fewer leaf position errors than did PTV-based optimized plans.

Conclusions

Comparison of treatment plan quality, robustness, and plan complexity of both optimizations showed that robust optimization could be feasibile for VMAT of liver cancer.

Stereotactic Body Radiation Therapy for Hepatocellular Carcinoma in Patients With Child-Pugh B or C Cirrhosis

Purpose

Our purpose was to report outcomes in patients with Child-Pugh B or C (CP B/C) hepatocellular carcinoma (HCC) treated with stereotactic body radiation therapy (SBRT).

Methods and Materials

Patients with HCC suitable for SBRT were prospectively enrolled in the study from 2012 to 2018. Outcomes in patients with CP B/C were analyzed. Cox proportional hazard models were used to compare survival outcomes between baseline CP score and post-SBRT CP score.

Results

Twenty-three patients with CP B/C with a total of 29 HCC tumors were treated with SBRT. Eighty-seven percent of patients were CP B8-C10. Median tumor size was 3.1 cm (range, 1-10 cm). Median dose delivered was 40 Gy in a median of 5 fractions. Eighteen of 23 patients (78.3%) had been previously treated with transarterial chemoembolization. Median follow-up was 14.5 months. Rates of 6- and 12-month local control were 100% and 92.3%, respectively. Six- and 12-month survival rates were 73.9% and 56.5%, respectively. Median survival was 14.5 months overall and 9.2, 22.5, 14.5, and 14.4 months for patients with CP B7, B8, B9, and C10, respectively. No patients exhibited symptoms of classic radiation-induced liver disease. However, 10 patients had CP score progression, with 4 patients (17%) having a ≥2-point increase in CP score by 6 months (or time of censor). There were 7 liver-related deaths, and based on independent review by a hepatologist, 1 of these deaths may have been attributable to SBRT-related liver injury. Fifteen of 23 patients were listed for liver transplant (LT) at the time of SBRT and 9 went on to receive LT with a pathologic complete response rate of 63.6%. Median survival, excluding patients who received LT, was 7.3 months.

Conclusions

SBRT is a reasonable treatment option for carefully selected patients with CP B7-C10. In our small cohort, there was no detectable difference between local control or overall survival and baseline CP score.

Stereotactic Body Radiotherapy for Large Unresectable Hepatocellular Carcinomas - A Single Institution Phase II Study

AIMS

To evaluate the safety and efficacy of liver stereotactic body radiotherapy (SBRT) in the treatment of unresectable hepatocellular carcinomas (HCC) measuring >5 cm.

MATERIALS AND METHODS

Between November 2013 and February 2016, 13 patients with unresectable HCC (>5 cm), ineligible for other local treatments, with a Child-Pugh score (CPS) ≤ B7, were enrolled into a single-institution phase II study. SBRT was delivered by volumetric-modulated arc radiotherapy. Radiological response was reported using modified Response Evaluation Criteria in Solid Tumours criteria and toxicities graded by Common Terminology Criteria for Adverse Events v4 criteria.

RESULTS

Sixteen hepatomas (median size 7.5 cm, range 5.1-9.7 cm) were treated in 13 patients. The baseline CPS was A5/6 in nine patients (69%) and B7 in four patients (31%). Five patients (38%) received previous liver-directed treatment. The median prescribed dose was 45 Gy (range 40-45 Gy) in five fractions. The median follow-up was 17.7 months. The 1-year local control rate was 92%. The median overall survival was 17.7 months and the 1-year overall survival was 62%. The median time to local progression was not reached. Five patients (39%) had an increase in CPS by two or more points at 3 months. Overall, there were 10 grade 3 acute toxicities occurring in seven patients, of which six were haematological. Quality of life remained clinically stable or improved at 3 months in 61.5% and 53.8% of patients based on the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Core-30 Global Health Score and Functional Assessment of Cancer Therapy - Hepatobiliary version 4 score, respectively.

CONCLUSIONS

In our cohort, SBRT to unresectable large HCC tumours provided excellent local control with acceptable toxicities. Regional recurrence remained the major cause of failure. Further studies are warranted to examine the role for SBRT in combination with other modalities to maximise disease control in the liver.

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.

Overexpression of MiR-452-5p in hepatocellular carcinoma tissues and its prospective signaling pathways

BACKGROUND

The implication of miR-452-5p and its prospective machinery in hepatocellular carcinoma (HCC) remains largely unknown. For this reason, this study aimed to inspect the clinical implication of miR-452-5p expression in HCC tissues with multiple detection approaches, to analyze its potential function via in silico methods, and to validate this using a dual-luciferase reporter assay.

METHODS

The assessment of the expression level of miR-452-5p in HCC was conducted via four methods: 1) in-house real-time quantitative PCR (RT-qPCR), 2) miRNA-sequencing (miRNA-seq) from The Cancer Genome Atlas (TCGA), 3) miRNA microarrays from the Gene Expression Omnibus (GEO), and 4) comprehensive meta-analyses calculating the standard mean difference (SMD) and summary of receiver operator characteristic (sROC). Following the target prediction, one of the potential targets of miR-452-5p was validated through a dual-luciferase reporter assay.

RESULTS

MiR-452-5p was consistently elevated in HCC tissues via various detection methods, including in-house RT-qPCR, miRNA-seq, and miRNA microarrays. The final SMD was 0.842 for 820 cases of HCC samples. Simultaneously, the area under curve (AUC) of the sROC was 0.80 (0.76-0.83). The 1,135 predicted targets of miR-452-5p were enriched in the pathways of cytokine-cytokine receptor interaction, carbon metabolism, and complement and coagulation cascades. Among these predicted targets, CDKN1B was verified to be a real target of miR-452-5p.

CONCLUSION

The overexpression of miR-452-5p may play a pivotal role in the carcinogenesis of HCC via targeting multiple signaling pathways and genes. The function and molecular machinery of miR-452-5p in HCC requires further in-depth exploration.

Inoperable Biliary Tract and Primary Liver Tumors: Palliative Treatment Options

Primary liver tumors are most commonly hepatocellular carcinoma and intrahepatic cholangiocarcinoma. Although surgical resection offers a chance for cure, these tumors generally present at a late, inoperable stage, necessitating an understanding of noncurative and palliative treatment options. These options include ablative therapies, including radiofrequency ablation; intra-arterial therapies, including transcatheter chemoembolization; biliary decompression; radiotherapy; systemic therapies, including traditional chemotherapeutic agents; and molecular therapies, such as sorafenib. Selection of nonoperative treatment depends on patient and tumor factors as well as institutional resources and expertise.

Geometrical tracking accuracy and appropriate PTV margins for robotic radiosurgery of liver lesions by SBRT

Purpose: To assess the geometrical accuracy and estimate adequate PTV margins for liver treatments using the Synchrony respiratory tracking system. Material and methods: Treatment log files are analyzed for 72 liver patients to assess tracking accuracy. The tracking error is calculated as the quadratic sum of the correlation, the predictor and the beam positioning errors. Treatment target rotations and rigid body errors reported by the system are also evaluated. The impact of uncorrected rotations is assessed by rotating the planned dose distribution and reassessing target coverage. Total PTV margins are estimated by summing in quadrature tracking errors and rigid body errors. Relationships are explored between tracking errors, model linearity and motion amplitudes of internal and external markers. Results: Margins of 3, 2, 2 mm in SUP-INF, LT-RT and ANT-POST directions, respectively, are sufficient to account for tracking and beam positioning errors for 95% of patients. If rigid body error is also considered, margins increase to 4 mm isotropic. Rotations could not be corrected for 92% of patients due to imperfect fiducial implantation and limitations in the magnitude of corrections that the system can apply. Uncorrected rotations would lead to average estimated dose reductions of 2.7% ± 5.8% of the prescribed dose for D99 of GTVs (5 mm PTV expansion) in which the target was well covered in the original plan (28 of 31 GTVs). 80% of tracking models exhibit near linear correlation between internal and external marker motions with small tracking errors (<2.2 mm). Conclusions: Isotropic PTV margins considering tracking errors and target rigid body errors could be used for liver SBRT treatments if rotational corrections can be calculated accurately so that systematic rotational offsets can be avoided. The linearity of the internal and external breathing motions might be useful for other types of treatment modalities for liver cancer.

Gross and microscopic changes of liver neoplasms and background hepatic structures following neoadjuvant therapy

Liver transplantation is a surgical option with curative intent used in the management of some cases of hepatocellular carcinoma and cholangiocarcinoma (hilar, rarely intrahepatic). A number of different therapeutic modalities including ablative techniques, arterially directed therapies, radiation and chemotherapy are used in the neoadjuvant setting prior to liver transplantation with the goals of preventing tumour progression, decreasing post-transplant recurrence and possibly downstaging patients with tumour burden beyond what is acceptable by current transplant criteria. Pathologists evaluating hepatic explants must be aware of these neoadjuvant therapies and the alterations induced by them in both tumourous and non-tumourous tissue. In this review, we discuss common neoadjuvant therapies used in in this setting, as well as the gross and microscopic changes induced by these presurgical treatments within hepatic neoplasms as well as the background hepatic parenchyma and nearby structures. Select secondary tumours involving the liver which are pretreated will also be discussed. Finally, proper reporting of these changes will be mentioned.