Stereotactic body radiation therapy (SBRT) for definitive treatment and as a bridge to liver transplantation in early stage inoperable Hepatocellular carcinoma

Stereotactic Body Radiotherapy and Liver Transplant for Liver Cancer: A Nonrandomized Controlled Trial

Importance

Whether stereotactic body radiotherapy (SBRT) as a bridge to liver transplant for hepatocellular carcinoma (HCC) is effective and safe is still unknown.

Objective

To investigate the feasibility of SBRT before deceased donor liver transplant (DDLT) for previously untreated unresectable HCC.

Design, Setting, and Participants

In this phase 2 nonrandomized controlled trial conducted between June 1, 2015, and October 18, 2019, 32 eligible patients within UCSF (University of California, San Francisco) criteria underwent dual-tracer (18F-fluorodeoxyglucose and 11C-acetate [ACC]) positron emission tomography with computed tomography (PET-CT) and magnetic resonance imaging (MRI) with gadoxetate followed by SBRT of 35 to 50 Gy in 5 fractions, and the same imaging afterward while awaiting DDLT. Statistical analysis was performed on an intention-to-treat basis between October 1 and 31, 2023.

Intervention

Patients received SBRT followed by DDLT when matched deceased donor grafts were available.

Main Outcomes and Measures

Coprimary end points were progression-free survival (PFS) and objective response rates (ORRs) by the Response Evaluation Criteria in Solid Tumors, version 1.1 (RECIST 1.1), modified RECIST (mRECIST), and PET Response Criteria in Solid Tumors (PERCIST). Secondary end points were local control rate, overall survival (OS), and safety.

Results

A total of 32 patients (median age, 59 years [IQR, 54-63 years]; 22 men [68.8%]) with 56 lesions received SBRT. After a median follow-up of 74.6 months (IQR, 40.1-102.9 months), the median PFS was 17.6 months (95% CI, 6.6-28.6 months), and the median OS was 60.5 months (95% CI, 29.7-91.2 months). The 5-year PFS was 39.9% (95% CI, 19.9%-59.9%), and the 5-year OS was 51.3% (95% CI, 31.7%-70.9%). In terms of number of patients, ORRs were 62.5% ([n = 20] 95% CI, 54.2%-68.7%) by RECIST 1.1, 71.9% ([n = 23] 95% CI, 63.7%-79.0%) by mRECIST, and 78.1% ([n = 25] 95% CI, 73.2%-86.7%) by PERCIST. In terms of number of lesions, ORRs were 75.0% ([n = 42] 95% CI, 61.6%-80.8%) by RECIST 1.1, 83.9% ([n = 47] 95% CI, 74.7%-90.6%) by mRECIST, and 87.5% ([n = 49] 95% CI, 81.3%-98.6%) by PERCIST. Twenty patients with 36 lesions received DDLT, of whom 15 patients (75.0%) with 21 lesions (58.3%) exhibited pathologic complete response. Multivariable analyses revealed that pretreatment metabolic tumor volume (MTV) based on ACC (hazard ratio [HR], 1.06 [95% CI, 1.01-1.10]; P = .01) and complete metabolic response (CMR) by PERCIST (HR, 0.31 [95% CI, 0.10-0.96]; P = .04) were associated with PFS, while pretreatment MTV based on ACC (HR, 1.07 [95% CI, 1.03-1.16]; P = .01), total lesion activity based on ACC (HR, 1.01 [95% CI, 1.00-1.02]; P = .02), and CMR by PERCIST (HR, 0.21 [95% CI, 0.07-0.73]; P = .01) were associated with OS. Toxic effects associated with SBRT were reported for 9 patients (28.1%), with 1 grade 3 event.

Conclusions and Relevance

This phase 2 nonrandomized controlled trial demonstrated promising survival and safety outcomes of SBRT before DDLT for unresectable HCC. Future randomized clinical trials are warranted.

Liver transplantation for hepatocellular carcinoma in India: Are we ready for 2040?

BACKGROUND

Liver transplantation (LT) for hepatocellular carcinoma (HCC) has been widely researched and is well established worldwide. The cornerstone of this treatment lies in the various criteria formulated by expert consensus and experience. The variations among the criteria are staggering, and the short- and long-term out comes are controversial.

AIM

To study the differences in the current practices of LT for HCC at different centers in India and discuss their clinical implications in the future.

METHODS

We conducted a survey of major centers in India that performed LT in December 2022. A total of 23 responses were received. The centers were classified as high- and low-volume, and the current trend of care for patients und ergoing LT for HCC was noted.

RESULTS

Of the 23 centers, 35% were high volume center (> 500 Liver transplants) while 52% were high-volume centers that performed more than 50 transplants/year. Approximately 39% of centers had performed > 50 LT for HCC while the percent distribution for HCC in LT patients was 5%-15% in approximately 73% of the patients. Barring a few, most centers were divided equally between University of California, San Francisco (UCSF) and center-specific criteria when choosing patients with HCC for LT, and most (65%) did not have separate transplant criteria for deceased donor LT and living donor LT (LDLT). Most centers (56%) preferred surgical resection over LT for a Child A cirrhosis patient with a resectable 4 cm HCC lesion. Positron-emission tomography-computed tomography (CT) was the modality of choice for metastatic workup in the majority of centers (74%). Downstaging was the preferred option for over 90% of the centers and included transarterial chemoembolization, transarterial radioembolization, stereotactic body radiotherapy and atezolizumab/bevacizumab with varied indications. The alpha-fetoprotein (AFP) cut-off was used by 74% of centers to decide on transplantation as well as to downstage tumors, even if they met the criteria. The criteria for successful downstaging varied, but most centers conformed to the UCSF or their center-specific criteria for LT, along with the AFP cutoff values. The wait time for LT from down staging was at least 4-6 wk in all centers. Contrast-enhanced CT was the preferred imaging modality for post-LT surveillance in 52% of the centers. Approximately 65% of the centers preferred to start everolimus between 1 and 3 months post-LT.

CONCLUSION

The current predicted 5-year survival rate of HCC patients in India is less than 15%. The aim of transplantation is to achieve at least a 60% 5-year disease free survival rate, which will provide relief to the prediction of an HCC surge over the next 20 years. The current worldwide criteria (Milan/UCSF) may have a higher 5-year survival (> 70%); however, the majority of patients still do not fit these criteria and are dependent on other suboptimal modes of treatment, with much lower survival rates. To make predictions for 2040, we must prepare to arm ourselves with less stringent selection criteria to widen the pool of patients who may undergo transplantation and have a chance of a better outcome. With more advanced technology and better donor outcomes, LDLT will provide a cutting edge in the fight against liver cancer over the next two decades.

Verifying institutionally developed hybrid 3D-printed coaxial cylindrical phantom for patient-specific quality assurance in stereotactic body radiation therapy of hepatocellular carcinoma

An accurate and reliable patient-specific quality assurance (PSQA) is crucial to ensure the safety and precision of Stereotactic body radiation therapy (SBRT) in treating Hepatocellular carcinoma (HCC). This study examines the effectiveness of a novel hybrid 3D-printed hybrid coaxial cylindrical phantom for PSQA in the SBRT of HCC. The study compared three different point dose verification techniques for PSQA: a traditional solid water phantom, two dimensional detector array I'MatriXX, and a newly developed hybrid 3D-printed phantom. Thirty SBRT HCC liver cases were examined using these techniques, and point doses were measured and compared to planned doses using the perpendicular composite method with solid water and I'MatriXX phantoms. Unlike the other two methods, the point dose was compared in true composite geometry using the hybrid 3D-printed phantom, which enhanced the accuracy and consistency of PSQA. The study aims to assess the statistical significance and accuracy of the hybrid 3D-printed phantom compared to other methods. The results showed all techniques complied with the institutional threshold criteria of within ± 3% for point-dose measurement discrepancies. The hybrid 3D-printed phantom was found to have better consistency with a lower standard deviation than traditional methods. Statistical analysis using Student's t-test revealed the statistical significance of the hybrid 3D-printed phantom technique in patient-specific point-dose assessments with a p-value < 0.01. The hybrid 3D-printed phantom developed institutionally is cost-effective and easy to handle. It has been proven to be a valuable tool for PSQA in SBRT for the treatment of HCC and has demonstrated its practicality and reliability.

Role of Stereotactic Body Radiation Therapy in Hepatocellular Carcinoma

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

Combination treatment of HCC with SBRT and immune checkpoint inhibition

The treatment of unresectable or metastatic HCC has been significantly advanced in recent years by developments in both radiotherapy and systemic cancer therapies. Independently, both Stereotactic Ablative Body Radiotherapy (SBRT) and Immune Checkpoint Inhibitors (ICIs) are licensed for the treatment of these tumours. Building on the successes seen in other solid tumours, there is significant interest in exploring combination treatments. In this review article we briefly present the evidence base for the use of these treatments in patients with HCC. With reference to our current understanding of the immuno-oncology and radiobiology of HCCs, we demonstrate why combining these two modalities is of interest. Finally, we discuss the clinical trials that are currently underway or planned and the direction that future research may take.

Liver parenchymal changes detected by MR elastography and diffusion-weighted imaging after stereotactic body radiotherapy for hepatocellular carcinoma

BACKGROUND

Stereotactic body radiotherapy (SBRT) is a local treatment option for hepatocellular carcinoma (HCC). SBRT-induced focal reactions on the liver parenchyma have not been thoroughly evaluated using quantitative magnetic resonance imaging (MRI).

PURPOSE

To quantitatively evaluate liver parenchymal changes caused by SBRT for HCC using magnetic resonance elastography (MRE) and diffusion-weighted imaging (DWI).

METHOD

We retrospectively evaluated 22 adult patients who received SBRT for HCC and 27 who received locoregional therapy other than SBRT (controls). Liver stiffness by MRE and apparent diffusion coefficient (ADC) values by DWI of the liver parenchyma were measured before and after SBRT. Regions of interest (ROIs) were drawn on the two areas of radiation dose distribution levels, > 30 Gy and ≤ 30 Gy; a ROI was drawn in the control group. The two indices were compared before and after SBRT using a Wilcoxon matched-pairs signed-rank test.

RESULTS

Liver stiffness and ADC values were significantly increased after SBRT in the dose areas of > 30 Gy compared with those before SBRT (4.05 vs 4.85 kPa; p < 0.05 in liver stiffness, and 1.10 vs 1.40 ×10-3 s/mm2; p < 0.05 in ADC values). In the dose area of ≦ 30 Gy, liver stiffness showed a significant increase in one reader (p = 0.033) but not in another reader (p = 0.085); ADC value showed no significant difference before and after SBRT as per both readers (p > 0.05). The control group demonstrated no significant differences before and after treatment (p > 0.05).

CONCLUSION

MRE and DWI can be used to detect SBRT-induced liver parenchymal changes.

Optimal treatment for small HCC (<3 cm): Resection, liver transplantation, or locoregional therapy?

Hepatocellular carcinoma (HCC) remains the most common form of liver cancer, accounting for 90% of all primary liver cancers. Up to 30% of HCC cases could be small (2-3 cm in diameter) at the time of diagnosis with advances in imaging techniques and surveillance programmes. Treating patients with early-stage HCC can be complex and often requires interdisciplinary care, owing to the wide and increasing variety of treatment options, which include liver resection, liver transplantation, and various locoregional therapies offered by interventional radiology and radiation oncology. Decisions regarding the optimal management strategy for a patient involve many considerations, including patient- and tumour-specific characteristics, as well as socioeconomic factors. In this review, we aim to comprehensively summarise the commonly used therapies for single, small HCC (<3 cm), with a focus on the impact of tumour size (<2 cm vs. 2-3 cm), as well as a brief discussion on the cost-effectiveness of the different treatment options.

Refining stereotactic body radiation therapy as a bridge to transplantation for hepatocellular carcinoma: An institutional experience

BACKGROUND

Stereotactic body radiotherapy (SBRT) has been established as a safe and effective treatment for hepatocellular carcinoma (HCC). Currently, there are no consensus guidelines to advise optimal patient selection and radiotherapy planning parameters to minimise the risk of surgical and medical complications after liver transplant (LT) in patients who have had prior SBRT for HCC, whilst optimising treatment benefit.

METHODS

We performed a retrospective analysis of all adult patients who received liver SBRT as a bridge to LT at a tertiary institution between 2017 and 2019.

RESULTS

Nine patients received SBRT as bridging therapy to LT. HCC location varied from peripheral to central/hilar regions and HCC diameter was 13-54 mm. Median time between SBRT and LT was 141 days (range 27-461 days). Median operating time was 360 min (range 270-480 min). Four patients (44%) had visible SBRT reaction or fibrosis at the time of LT. SBRT reaction resulted in clinical impact in one patient (11%) only, where vascular clamping of the IVC was required for 10 min.

CONCLUSION

SBRT is a safe and effective treatment for HCC enabling patients to remain within LT criteria, even for lesions not amenable to other more conventional bridging therapies. We describe a preliminary decision pathway to guide the optimal use of SBRT as a bridge to LT developed in our institution.

Stereotactic Body Radiotherapy for Hepatocellular Carcinoma: A Brief Overview

Stereotactic body radiotherapy (SBRT), a type of external beam radiotherapy, yields local control of hepatocellular carcinoma (HCC) at rates as high as 90%. SBRT has been recognized as an alternative therapy for patients for whom standard modalities such as surgery (resection or transplantation) or ablation are deemed unsuitable. SBRT has the potential to improve the prognosis of HCC, as it can be used as an adjunct to other treatment modalities. The assessment of post-SBRT images of the treated tumor and surrounding normal liver tissue requires special attention. Future research is warranted to determine how best to use SBRT versus other therapies and how to combine them.

Imaging Features in the Liver after Stereotactic Body Radiation Therapy

Historically, radiation therapy was not considered in treatment of liver tumors owing to the risk of radiation-induced liver disease. However, development of highly conformed radiation treatments such as stereotactic body radiation therapy (SBRT) has increased use of radiation therapy in the liver. SBRT is indicated in treatment of primary and metastatic liver tumors with outcomes comparable to those of other local therapies, especially in treatment of hepatocellular carcinoma. After SBRT, imaging features of the tumor and surrounding background hepatic parenchyma demonstrate a predictable pattern immediately after treatment and during follow-up. The goals of SBRT are to deliver a lethal radiation dose to the targeted liver tumor and to minimize radiation dose to normal liver parenchyma and other adjacent organs. Evaluation of tumor response after SBRT centers on changes in size and enhancement; however, these changes are often delayed secondary to the underlying physiologic effects of radiation. Knowledge of the underlying pathophysiologic mechanisms of SBRT should allow better understanding of the typical imaging features in detection of tumor response and avoid misinterpretation from common pitfalls and atypical imaging findings. Imaging features of radiation-induced change in the surrounding liver parenchyma are characterized by a focal liver reaction that can potentially be mistaken for no response or recurrence of tumor. Knowledge of the pattern and chronology of this phenomenon may allay any uncertainty in assessment of tumor response. Other pitfalls related to fiducial marker placement or combination therapies are important to recognize. The authors review the basic principles of SBRT and illustrate post-SBRT imaging features of treated liver tumors and adjacent liver parenchyma with a focus on avoiding pitfalls in imaging evaluation of response. Online supplemental material is available for this article. ^©RSNA, 2022.

The Current Role of Stereotactic Body Radiation Therapy (SBRT) in Hepatocellular Carcinoma (HCC)

The role of stereotactic body radiotherapy (SBRT), which can deliver high radiation doses to focal tumors, has greatly increased in not only early-stage hepatocellular carcinoma (HCC), but also in portal vein or inferior vena cava thrombi, thus expanding this therapy to pre-transplantation and the treatment of oligometastases from HCC in combination with immune checkpoint inhibitors (ICI). In early-stage HCC, many promising prospective results of SBRT have been reported, although SBRT is not usually indicated as a first treatment potion in localized HCC according to several guidelines. In the treatment of portal vein or inferior vena cava tumor thrombi, several reports using various dose-fraction schedules have shown relatively good response rates with low toxicities and improved survival due to the rapid advancements in systemic therapy. Although SBRT is regarded as a substitute therapy when conventional bridging therapies to transplantation, such as transarterial chemoembolization (TACE) and radiofrequency ablation (RFA), are not applicable or fail in controlling tumors, SBRT may offer advantages in patients with borderline liver function who may not tolerate TACE or RFA, according to several reports. For oligometastases, the combination of SBRT with ICI could potentially induce an abscopal effect in patients with HCC, which is expected to provide the rationale for SBRT in the treatment of oligometastatic disease in the near future.

The role of stereotactic body radiotherapy in hepatocellular carcinoma: guidelines and evidences

Hepatocellular carcinoma (HCC) is a common malignancy with high mortality rates. While surgery can be curative in early-stage disease, 80% of patients cannot undergo surgical resection. Stereotactic body radiotherapy (SBRT), an emerging, non-invasive, precision treatment, has shown promising results across various stages of HCC and has thus been adopted in practice to varying degrees around the world. This article aims to review current guideline recommendations on SBRT, clinical evidence, and outcome comparisons with other local treatment modalities. Attempts are also made to compare the differences in clinical trials between Asian and Western countries.

Stereotactic Ablative Body Radiotherapy as a Bridge to Liver Transplant for Hepatocellular Carcinoma: Preliminary Results of Başkent University Experience

OBJECTIVES

Hepatocellular carcinoma is the most common primary liver tumor, with curative treatment options being liver transplant and resection. However, approximately 20% to 30% of patients have substantial disease progression while awaiting transplant. Here, we report our initial experience on stereotactic ablative body radiotherapy as a bridge to liver transplant for patients with hepatocellular carcinoma.

MATERIALS AND METHODS

Seven patients with 9 lesions received stereotactic ablative body radiotherapy as a bridge treatment to transplant. All patients underwent radiofrequency ablation, transcatheter arterial chemoembolization, or hepatic resection before stereotactic ablative body radiotherapy. Magnetic resonance imaging was used to evaluate radiographic responses 1 month later.

RESULTS

Median age of patients was 65 years (range, 63-71 years), median stereotactic ablative body radiotherapy dose was 45 Gy (range, 30-54 Gy; delivered in 3-5 fractions), and median tumor diameter was 17 mm (range, 12-30 mm). Before stereotactic ablative body radiotherapy, all patients underwent liver-directed therapies, including transcatheter arterial chemoembolization for 3 lesions, transcatheter arterial chemoembolization and radiofrequency ablation for 4 lesions, surgical resection for 1 lesion, and surgical resection plus transcatheter arterial chemoembolization for the remaining lesion. Patients showed no evidence of gastrointestinal toxicity or radiation-induced liver disease. Acute toxicity was negligible; all patients completed the treatment course. One month after stereotactic ablative body radiotherapy administration, response rates were assessed with magnetic resonance imaging, with complete responses obtained in 5 lesions (55.5%), partial responses for 2 lesions, and stable disease for 2 lesions. No disease progression was shown following stereotactic ablative body radiotherapy application.

CONCLUSIONS

Stereotactic ablative body radiotherapy is an effective, safe, and tolerable bridging therapy option. Although we observed an early response after treatment, exact response rates will not be known for at least 3 months following stereotactic ablative body radiotherapy. Thus, our findings should be confirmed through additional prospective studies with longer follow-up.

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.

LI-RADS Treatment Response Algorithm: Performance and Diagnostic Accuracy With Radiologic-Pathologic Explant Correlation in Patients With SBRT-Treated Hepatocellular Carcinoma

PURPOSE

Our purpose was to evaluate the accuracy of LI-RADS Treatment Response Algorithm (LR-TRA) for assessing the viability of hepatocellular carcinoma (HCC) treated with stereotactic body radiation therapy (SBRT), using explant pathology as the gold standard.

METHODS AND MATERIALS

This retrospective study included patients who underwent SBRT for locoregional treatment of HCC between 2008 and 2019 with subsequent liver transplantation. Five radiologists independently assessed all treated lesions by using the LR-TRA. Imaging and posttransplant histopathology were compared. Lesions were categorized as either completely (100%) or incompletely (<100%) necrotic, and performance characteristics and predictive values for the LR-TR viable and nonviable categories were calculated for each reader. Interreader reliability was calculated using the Fleiss kappa test.

RESULTS

A total of 40 treated lesions in 26 patients (median age, 63 years [interquartile range, 59.4-65.5]; 23 men) were included. For lesions treated with SBRT, sensitivity for incomplete tumor necrosis across readers ranged between 71% and 86%, specificity between 85% and 96%, and positive predictive value between 86% and 92%, when the LR-TR equivocal category was treated as nonviable, accounting for subject clustering. When the LR-TR equivocal category was treated as viable, sensitivity of complete tumor necrosis for lesions treated with SBRT ranged from 88% to 96%, specificity from 71% to 93%, and negative predictive value from 85% to 96%. Interreader reliability was fair (k = 0.22; 95% confidence interval, 0.13-0.33). Although a loss of arterial phase hyperenhancement (APHE) was highly correlated with pathologically nonviable tumor on explant, almost half of the patients with APHE had pathologically nonviable tumor on explant.

CONCLUSIONS

LR-TRA v2018 performs well for predicting complete and incomplete necrosis in HCC treated with SBRT. In contrast to other locoregional therapies, the presence of APHE after SBRT does not always indicate viable tumor and suggests that observation may be an appropriate strategy for these patients.

Role of Pretransplant Treatments for Patients with Hepatocellular Carcinoma Waiting for Liver Transplantation

Simple Summary

Hepatocellular carcinoma (HCC) is the fifth most common cancer in men worldwide and the second leading cause of cancer death. Liver transplantation (LT) is one of the treatment options for patients with HCC. Recently, there have been many reports of the usefulness of locoregional therapy, such as transarterial chemoembolization and radiofrequency ablation, for HCC as pretreatment before LT. In Western countries, locoregional therapy is used to bridge until transplantation to prevent drop-outs from the waiting list or for downstaging to treat patients with advanced HCC who initially exceed the criteria for LT. With the progress of locoregional therapy, new reports on the effects of bridging and downstaging locoregional therapy as pretransplant treatment are increasing in number.

Abstract

Recently, there have been many reports of the usefulness of locoregional therapy such as transarterial chemoembolization and radiofrequency ablation for hepatocellular carcinoma (HCC) as pretreatment before liver transplantation (LT). Locoregional therapy is performed with curative intent in Japan, where living donor LT constitutes the majority of LT due to the critical shortage of deceased donors. However, in Western countries, where deceased donor LT is the main procedure, LT is indicated for early-stage HCC regardless of liver functional reserve, and locoregional therapy is used for bridging until transplantation to prevent drop-outs from the waiting list or for downstaging to treat patients with advanced HCC who initially exceed the criteria for LT. There are many reports of the effect of bridging and downstaging locoregional therapy before LT, and its indications and efficacy are becoming clear. Responses to locoregional therapy, such as changes in tumor markers, the avidity of FDG-PET, etc., are considered useful for successful bridging and downstaging. In this review, the effects of bridging and downstaging locoregional therapy as a pretransplant treatment on the results of transplantation are clarified, focusing on recent reports.

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.

Hepatic tumours and radiotherapy

We present the update of the recommendations of the French society of oncological radiotherapy on hepatic tumours. Recent technological progress led to develop the concept of focused liver radiation therapy. We must distinguish primary and secondary tumours, as the indications are restricted and must be discussed as an alternative to surgical or medical treatments. The tumour volume, its liver location close to the organs at risk determine the irradiation technique (repositioning method, total dose delivered, dose fractionation regimens). Tumour (and liver) breathing related motions should be taken into account. Strict dosimetric criteria must be observed with particular attention to the dose-volume histograms of non-tumoral liver as well as of the hollow organs, particularly in case of hypofractionated high dose radiotherapy "under stereotaxic conditions". Stereotactic body radiotherapy is being evaluated and is often preferred to radiofrequency for primary or secondary tumours (usually less than 5cm). An adaptation can be proposed, with a conformal fractionated irradiation protocol with or without intensity modulation, for hepatocellular carcinomas larger than 5cm.

Stereotactic body radiation therapy for primary liver tumors: An effective liver-directed therapy in the toolbox

The use of radiation for primary liver cancers has historically been limited because of the risk of radiation-induced liver disease. Treatment fields have become more conformal because of several technical advances, and this has allowed for dose escalation. Stereotactic body radiation therapy (SBRT), also known as stereotactic ablative radiotherapy, is now able to safely treat liver tumors to ablative doses while sparing functional liver parenchyma by using highly conformal therapy. Several retrospective and small prospective studies have examined the use of SBRT for liver cancers; however, there is a lack of well-powered randomized studies to definitively guide management in these settings. Recent advances in systemic therapy for primary liver cancers have improved outcomes; however, the optimal selection criteria for SBRT as a local therapy remain unclear among other liver-directed options such as radiofrequency ablation, transarterial chemoembolization, and radioembolization.

Optimal application of stereotactic body radiotherapy and radiofrequency ablation treatment for different multifocal hepatocellular carcinoma lesions in patients with Barcelona Clinic Liver Cancer stage A4-B1: a pilot study

BACKGROUND

In clinical practice, many hepatocellular carcinoma (HCC) patients in Barcelona Clinical Liver Cancer (BCLC) stage A4-B1 cannot receive the curative treatments of liver transplantation, resection, and radiofrequency ablation (RFA), which are the recommended options according to liver cancer guidelines. Our aim is to study the feasibility of RFA and stereotactic body radiotherapy (SBRT) as a curative treatment for different multifocal HCCs in BCLC stage A4-B1 patients.

METHODS

From September 2014 to August 2019, 39 multifocal HCC lesions (median diameter: 16.6 mm) from 15 patients (median age: 73 years) were retrospectively selected. Among them, 23 were treated by RFA and the other 16 by SBRT because of predictable insufficiency and/or risk related to RFA performance. The indicators for evaluating this novel therapy were the tumor response, prognosis (recurrence and survival), and adverse effects (deterioration of laboratory test values and severe complications).

RESULTS

The median follow-up duration was 31.3 months (range: 15.1-71.9 months). The total patients with a one-year complete response, stable disease, or disease progression were 11, 1, and 3, respectively. In total, 8 and 2 patients had confronted intrahepatic or local recurrence, respectively. The one-year progression-free survival rate and local control rate were 80% (12/15 patients) and 97.4% (38/39 lesions), respectively. The median time to progression was 20.1 (2.8-45.1) months. The one- and two-year survival rates were 100 and 88.9%, respectively. In up to five months' observation, no patient showed severe complications. Seven, four, and two patients had slight changes in their white blood cells, platelet count, or albumin-bilirubin grade, respectively.

CONCLUSIONS

For patients with BCLC stage A4-B1, RFA and SBRT treatment for different multifocal HCCs may be a potential option because of the favorable prognosis and safety. However, before its application in clinical practice, prospective, controlled, large-scale studies are needed to further confirm our conclusions.

Image-Guided Liver Stereotactic Body Radiotherapy Using VMAT and Real-Time Adaptive Tumor Gating: Evaluation of the Efficacy and Toxicity for Hepatocellular Carcinoma

Simple Summary

Although the use of stereotactic body radiation therapy (SBRT) in the management of hepatocellular carcinoma (HCC) remains unclear, it is a therapeutic option often considered in patients not eligible to or recurring after other local therapies. Liver SBRT can be delivered using a wide range of techniques and linear accelerators. We report the first evaluation for HCC of SBRT using volumetric modulated arc therapy (VMAT) and real-time adaptive tumor gating, which is a mainly completely non-invasive procedure (no fiducial markers for 65.2% of the patients). Our study showed that this SBRT technique has very favorable outcomes with optimal local control and a low toxicity rate.

Abstract

Liver SBRT is a therapeutic option for the treatment of HCC in patients not eligible for other local therapies. We retrospectively report the outcomes of a cohort of consecutive patients treated with SBRT for HCC at the Montpellier Cancer Institute. Between March 2013 and December 2018, 66 patients were treated with image-guided liver SBRT using VMAT and real-time adaptive tumor gating in our institute. The main endpoints considered in this study were local control, disease-free survival, overall survival, and toxicity. The median follow-up was 16.8 months. About 66.7% had prior liver treatment. Most patients received 50 Gy in five fractions of 10 Gy. No patient had local recurrence. Overall survival and disease-free survival were, respectively, 83.9% and 46.7% at one year. In multivariate analysis, the diameter of the lesions was a significant prognostic factor associated with disease-free survival (HR = 2.57 (1.19–5.53) p = 0.02). Regarding overall survival, the volume of PTV was associated with lower overall survival (HR = 2.84 (1.14–7.08) p = 0.025). No grade 3 toxicity was observed. One patient developed a grade 4 gastric ulcer, despite the dose constraints being respected. Image-guided liver SBRT with VMAT is an effective and safe treatment in patients with inoperable HCC, even in heavily pre-treated patients. Further prospective evaluation will help to clarify the role of SBRT in the management of HCC patients.

Hepatic necrosis following yttrium-90 radioembolization for hepatocellular carcinoma in a patient with a recent history of external radiotherapy

Hepatobiliary complications from yttrium-90 (⁹⁰Y) radioembolization have been described previously but are often clinically inconsequential. This report describes the case of a patient in whom a large area of hepatic necrosis occurred after the patient underwent both stereotactic body radiotherapy and glass-based⁹⁰Y radioembolization for the management of hepatocellular carcinoma. This case suggests that⁹⁰Y microspheres can cause severe local hepatic injury when administered after external radiotherapy.

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.

Current Understanding of Ablative Radiation Therapy in Hepatocellular Carcinoma

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

Dosimetric verification of stereotactic body radiotherapy treatment plan via ArcCHECK-3DVH system

OBJECTIVES

To study the feasibility of ArcCHECK-3DVH system in dosimetric verification for stereotactic body radiaotherapy (SBRT) with flattening filter free (FFF) model.

METHODS

SBRT treatment plans for 57 patients were introduced into ArcCHECK phantom and recalculated. The calculated dose distribution of treatment planning system and the measured dose distribution of ArcCHECK phantom were compared by γ analysis. Then the 3 dimensional dose distribution of target and organs at risk was reconstructed by 3DVH software. The reconstructed dose and calculated dose with treatment planning system (TPS) were compared, and the dose volume γ pass rate and deviation of dose volume parameters to the target and organs at risk were quantitatively valuated.

RESULTS

Based on the threshold criteria (3%, 3 mm, 10%), namely the deviation of measuring points between the planned value and the measured value was less than 3%, and the proportion of points with similar values in the plane or sphere with the center of the point and the radius of 3 mm was 10%, the relative and absolute dose pass rates of SBRT treatment plans in ArcCHECK system via γ analysis were greater than 95%. Based on the stricter threshold criteria (2%, 2 mm, 10%), the relative and absolute dose pass rates of SBRT treatment plan in ArcCHECK system via γ analysis were about 93%. In 3DVH dose verification, the γ pass rate of target and organs at risk was exceed 97%, and the deviations in 3DVH of the target and organs at risk were less than ±5%.

CONCLUSIONS

The ArcCHECK-3DVH system in dose verification can provide more comprehensive dose distribution information to reasonably evaluate the SBRT plan, with more significance for guiding clinical treatment.

Radiological tumor response and histopathological correlation of hepatocellular carcinoma treated with stereotactic body radiation therapy as a bridge to liver transplantation

PURPOSE

To assess the imaging findings of hepatocellular carcinoma (HCC) treated with stereotactic body radiation therapy (SBRT) as a bridging therapy prior to liver transplantation (LT), with histopathological correlation at liver explant.

METHODS

Our institutional review board approved this retrospective study. The study subjects included 25 HCC lesions in 23 patients (20 males; median age, 60 years; range 41-68 years) who underwent LT after SBRT for HCC as a bridge to LT in a single tertiary referral institution over a 12-year period. Target HCC lesions were assessed for imaging biomarkers on contrast-enhanced CT or MRI including change in HCC diameter and assessment of percentage necrosis. The radiologic response at pre-LT imaging was compared to explant pathology.

RESULTS

There was a positive correlation between the tumor size (Spearman's ρ = 0.86; p < 0.001) and percentage necrosis (p < 0.001) on Pre-LT imaging and those on pathology. Partial response (PR), stable disease (SD), and progressive disease (PD) according to RECIST 1.1 were seen in 8 (32%), 15 (60%), and 2 (8%) lesions on pre-LT imaging, respectively. Of the 15 lesions with radiologic SD, 5/15 (33%) showed necrosis of more than 50% on post-SBRT imaging, while 9/15 (60%) showed necrosis of more than 50% at explant pathologic analysis, showing a tendency to underestimate the degree of tumor necrosis compared to pathology.

CONCLUSION

RECIST 1.1 radiologic response criteria may underestimate the response to treatment with SBRT, and radiologic estimation of percent tumor necrosis was more closely correlated with pathologic percent tumor necrosis.

Use of Contrast-Enhanced Ultrasound with Sonazoid for Evaluating the Radiotherapy Efficacy for Hepatocellular Carcinoma

Radiotherapy is one of the available curative therapies for hepatocellular carcinoma (HCC). We investigate the use of contrast-enhanced ultrasound using Sonazoid (SCEUS) in evaluating the efficacy of radiotherapy for HCC. We enrolled 59 patients with 59 HCCs in this retrospective study. Tumor size and tumor vascularity were evaluated using SCEUS before and 1, 3, 7, 10, and 13 months after radiotherapy. The median follow-up period was 44.5 months (range: 16–82 months). Of the HCCs, 95% (56/59) had no local recurrence, while 5% (3/59) did. At 13 months after radiotherapy, in cases with no local recurrence, SCEUS showed a reduction in tumor vascularity in all cases, while tumor size reduction (>30% reduction, compared with pre-radiotherapy) was observed in 82.1% (46/56). In all three cases of local recurrence, vascularity and tumor size reduction were not observed during the follow-up period and residual HCCs were demonstrated pathologically. Compared with cases with local recurrence, tumor size reduction and reduction in tumor vascularity (p < 0.001) were significantly greater in cases with no local recurrence at 13 months after radiotherapy. SCEUS may be useful in evaluating radiotherapy efficacy for HCC.

Clinical outcome and pathologic correlation of stereotactic body radiation therapy as a bridge to transplantation for advanced hepatocellular carcinoma: a case series

BACKGROUND

Stereotactic body radiotherapy (SBRT) is an emerging modality for hepatocellular carcinoma (HCC). However, there is scant information about its safety and effectiveness in the neoadjuvant setting prior to liver transplantation (LT). We present the clinical outcome and pathologic assessment of SBRT followed by LT for patients with advanced HCC.

METHODS

This retrospective study included HCC patients treated with neoadjuvant SBRT prior to LT between 2009 and 2018. Radiographic response and adverse effects, including radiation-induced liver disease (RILD), were evaluated. Pathologic response was assessed by the percentage of tumor necrosis relative to the total tumor volume. Overall survival (OS) and recurrence-free survival (RFS) were calculated using the Kaplan-Meier method.

RESULTS

Fourteen patients underwent SBRT for a total of 25 HCC lesions, followed by LT. The median tumor size was 4.45 cm in diameter, and the median prescribed dose was 45 Gy in 5 fractions. SBRT provided significant AFP reduction, 100% infield control, and a 62.5% response rate. The maximum detected toxicity included grade 3 thrombocytopenia and two grade 3-4 hyperbilirubinemia. One patient developed non-classic RILD. Patients were bridged to LT with a median time of 8.4 months after SBRT, and 23.1% of them achieved a complete pathologic response. The median OS and RFS were 37.8 and 18.3 months from the time of LT, respectively.

CONCLUSIONS

SBRT provides favorable tumor control and acceptable adverse effects for patients awaiting LT. Further prospective studies to test SBRT as a bridging therapy for LT are feasible.

Stereotactic Radiotherapy for Hepatocellular Carcinoma, Radiosensitization Strategies and Radiation-Immunotherapy Combination

Simple Summary

Radiotherapy is rapidly turning into a crucial component of multidisciplinary treatment for liver cancer because many patients are not surgical treatment candidates. Thanks to technical developments, radiotherapy have achieved high precision treatments, making it possible to eliminate tumor cells without severe damage to the liver and other organs. Stereotactic Body Radiation Therapy is an advanced radiotherapy technique able to eradicate malignant tumors wherever they are located in properly selected patients. The best use of radiotherapy, the most fruitful radiotherapy strategy, and the best way to combine it with other treatments for liver cancer are largely unknown. Radiosensitizers, agents that can potentiate radiotherapy, could broaden the radiotherapeutic landscape. Radiotherapy potentiation can be achieved with diverse treatments, not only drugs but also nanoparticles. In order to clear up the performance of radiotherapy in liver cancer management in the future and the best ways to potentiate its effects, considerable medical research is needed.

Abstract

Stereotactic body radiotherapy (SBRT) is an emerging ablative modality for hepatocellular carcinoma (HCC). Most patients with HCC have advanced disease at the time of diagnosis, and therefore, are not candidates for definitive-intent therapies such as resection or transplantation. For this reason, various alternative local and regional therapies have been used to prevent disease progression, palliate symptoms, and delay liver failure. Stereotactic body radiation therapy is a non-invasive technique of delivering ablative doses of radiation to tumors while sparing normal or non-tumor hepatic tissue. Incorporation of SBRT in multidisciplinary HCC management is gradual, initially applied when other liver-directed therapies have failed or are contraindicated, and tried in combination with other locoregional or systemic therapies for more unfavorable conditions by more experienced teams. In order to improve SBRT therapeutic ratio, there has been much interest in augmenting the effect of radiation on tumors by combining it with chemotherapy, molecularly targeted therapeutics, nanoparticles, and immunotherapy. This review aims to synthesize available evidence to evaluate the clinical feasibility and efficacy of SBRT for HCC, and to explore novel radio-potentiation concepts by combining SBRT with novel therapeutics. It is expected that those approaches would result in improved therapeutic outcomes, even though many questions remain with regard to the optimal way to assemble treatments. Further trials are needed to evaluate and consolidate these promising therapies for HCC.

Benefit of dosimetry distribution for patients with multiple brain metastases from non-small cell lung cancer by a Cyberknife stereotactic radiosurgery (SRS) system

BACKGROUND

In order to obtain a high dose conformal index of tumor and steep dose fall-off in healthy tissues for brain metastasis stereotactic radiosurgery (SRS), the aim of this study was to investigate SRS planning optimization by comparing one multiple-lesions plan (MLP) with multiple single-lesion plans (SLPs) for patients with multiple brain metastases using the Cyberknife (CK) system.

METHODS

Fifty non-small cell lung cancer (NSCLC) patients (28 males and 22 females) with 2-4 brain metastases, inter-tumour distances less than 3 cm, were retrospectively replanned with the original prescription dose (12-32 Gy) in the original fractions (1-3). Two different clinical CK SRS plans (SLPs and MLP) were generated for the same patients with the same collimator and prescription isodose line (62-68%) by the CK Multiplan System. Both SLPs and MLP were able to achieve > 95% PTV volume covered prescription dose and met the Timmerman 2011 organs at risk (brainstem, optic nerve and pituitary) constraints.

RESULTS

Compared with those in the SLPs, the maximum dose (D_max) and mean dose (D_mean) of brainstem in the MLP were reduced 0.22-3.13% (2.62%) and 2.71-12.56% (5.57%), respectively, all P < 0.05. Meanwhile, the volumes of the whole brain minus the tumors that received a single dose equivalent of 8-16 Gy (V8Gy-V16Gy) were effectively reduced in the MLP. The treatment time parameters, the total number of beams and monitor units, of the MLP were reduced by 3.31 and 1.47% (P < 0.05), respectively. Although there were a few differences in the conformity index (CI) and homogeneity index (HI) between the two treatment plans, the differences were not statistically significant (P = 2.94 and 1.08 > 0.05).

CONCLUSION

One multiple-lesions plan for brain metastases could achieve higher precision in the target and lower doses in healthy tissue while shortening the treatment time and improving the treatment efficiency over multiple single-lesion plans.

Role of External Beam Radiotherapy in Hepatocellular Carcinoma

External beam radiotherapy (EBRT) has improved efficacy and safety with advancements in technology and techniques. EBRT plays an important role in management of hepatocellular carcinoma (HCC). In resectable cases, EBRT serves as a bridge to transplantation or improves local control through adjuvant radiotherapy. In unresectable patients, EBRT offers high local control rates. In metastatic settings, EBRT provides effective palliation. This review presents an overview of radiotherapy treatment modalities used for HCC, current treatment guidelines for the role of EBRT in HCC, clinical outcomes between various EBRT approaches and other locoregional treatments for HCC, and the future role of EBRT for HCC.

Hepatocellular carcinoma Liver Imaging Reporting and Data Systems treatment response assessment: Lessons learned and future directions

Hepatocellular carcinoma (HCC) is a leading cause of morbidity and mortality worldwide, with rising clinical and economic burden as incidence increases. There are a multitude of evolving treatment options, including locoregional therapies which can be used alone, in combination with each other, or in combination with systemic therapy. These treatment options have shown to be effective in achieving remission, controlling tumor progression, improving disease free and overall survival in patients who cannot undergo resection and providing a bridge to transplant by debulking tumor burden to downstage patients. Following locoregional therapy (LRT), it is crucial to provide treatment response assessment to guide management and liver transplant candidacy. Therefore, Liver Imaging Reporting and Data Systems (LI-RADS) Treatment Response Algorithm (TRA) was created to provide a standardized assessment of HCC following LRT. LI-RADS TRA provides a step by step approach to evaluate each lesion independently for accurate tumor assessment. In this review, we provide an overview of different locoregional therapies for HCC, describe the expected post treatment imaging appearance following treatment, and review the LI-RADS TRA with guidance for its application in clinical practice. Unique to other publications, we will also review emerging literature supporting the use of LI-RADS for assessment of HCC treatment response after LRT.

New advances in the diagnosis and management of hepatocellular carcinoma

Hepatocellular carcinoma is one of the leading causes of cancer related death in the world. Biannual surveillance for the disease in patients with cirrhosis and in high risk carriers of hepatitis B virus allows early stage cancer detection and treatment with good long term outcomes. Liver ultrasonography and serum α fetoprotein are the most commonly used surveillance tests. If suspicious results are found on the surveillance test, multiphasic computed tomography or magnetic resonance imaging should be undertaken to confirm the diagnosis of hepatocellular carcinoma. If radiologic tests show inconclusive results, liver biopsy or repeat imaging could be considered for confirmation of hepatocellular carcinoma. Management of the disease is complex. Patients should be evaluated by a multidisciplinary team, and the selection of treatment should consider factors such as tumor burden, severity of liver dysfunction, medical comorbidities, local expertise, and preference of patients. Early stage hepatocellular carcinoma is best managed by curative treatment, which includes resection, ablation, or transplantation. Patients with intermediate stage disease often receive locoregional treatment. Systemic treatment is reserved for patients with advanced disease. Several positive, phase III, randomized controlled trials have expanded the systemic treatment options for advanced hepatocellular carcinoma with promising long term outcomes, especially trials using combination treatments, which could also have eventual implications for the treatment of earlier stage disease.

Outcomes After Stereotactic Body Radiation Therapy as a Bridging Modality to Liver Transplantation for Hepatocellular Carcinoma

Purpose

For patients with hepatocellular carcinoma awaiting liver transplantation (LT), stereotactic body radiation therapy (SBRT) has emerged as a bridging treatment to ensure patients maintain priority status and eligibility per Milan criteria. In this study, we aimed to determine the efficacy and safety of SBRT in such situations.

Methods and Materials

A retrospective analysis was conducted of the outcomes of 27 patients treated with SBRT who were listed for LT at 1 institution. Among these, 20 patients with 26 tumors went on to LT and were the focus of this study. Operative reports and postoperative charts were evaluated for potential radiation-related complications. The explant pathology findings were correlated with equivalent dose in 2 Gy fractions and tumor size.

Results

Median pretreatment tumor size was 3.05 cm. Median total dose of radiation was 50 Gy delivered in 5 fractions. Pathologic complete response (pCR) was achieved in 16 tumors (62%). Median interval from end of SBRT to transplant was 287 days. Of the 21 tumors imaged before transplant, 16 or 76% demonstrated a clinical complete response based on modified Response Evaluation Criteria in Solid Tumors criteria. There was no significant correlation between pCR rate and increasing tumor size (odds ratio [OR], 0.95; 95% confidence interval, 0.595-1.53) or pCR rate and equivalent dose in 2 Gy fractions (OR, 1.03; 95% confidence interval, 0.984-1.07.) No patients experienced radiation-related operative or postoperative complications. Of the 27 patients who were listed for transplant, the dropout rate was 22%. Two of the 5 patients with Child-Pugh score 10 died of liver failure.

Conclusions

These data demonstrate that SBRT as a bridging modality is a feasible option, with a pCR rate comparable to that of other bridging modalities and no additional radiation-related operative or postoperative complications. There was no dose dependence nor size dependence for pCR rate, which may indicate that for the tumor sizes in this study, the radiation doses delivered were sufficiently high.

Time-Driven Activity-Based Costing Comparison of CT-Guided Versus MR-Guided SBRT

PURPOSE

Magnetic resonance-guided radiation therapy (MRgRT) has recently become commercially available, offering the opportunity to accurately image and target moving tumors as compared with computed tomography-guided radiation therapy (CTgRT) systems. However, the costs of delivering care with these 2 modalities remain poorly described. With localized unresectable hepatocellular carcinoma as an example, we were able to use time-driven activity-based costing to determine the cost of treatment on linear accelerators with CTgRT compared with MRgRT.

MATERIALS AND METHODS

Process maps, informed via interviews with departmental personnel, were created for each phase of the care cycle. Stereotactic body radiation therapy was delivered at 50 Gy in 5 fractions, either with CTgRT using fiducial placement, deep inspiration breath-hold (DIBH) with real-time position management, and volumetric-modulated arc therapy, or with MRgRT using real-time tumor gating, DIBH, and static-gantry intensity-modulated radiation therapy.

RESULTS

Direct clinical costs were $7,306 for CTgRT and $8,622 for MRgRT comprising personnel costs ($3,752 v $3,603), space and equipment costs ($2,912 v $4,769), and materials costs ($642 v $250). Increased MRgRT costs may be mitigated by forgoing CT simulation ($322 saved) or shortening treatment to 3 fractions ($1,815 saved). Conversely, adaptive treatment with MRgRT would result in an increase in cost of $529 per adaptive treatment.

CONCLUSION

MRgRT offers real-time image guidance, avoidance of fiducial placement, and ability to use adaptive treatments; however, it is 18% more expensive than CTgRT under baseline assumptions. Future studies that elucidate the magnitude of potential clinical benefits of MRgRT are warranted to clarify the value of using this technology.

Impact of successful local ablative bridging therapy prior to liver transplantation on long-term survival in patients with hepatocellular carcinoma in cirrhosis

Background

It has been shown that local ablative procedures enable downsizing, reduce drop-out from the waiting list and improve prognosis after liver transplantation. It is still unclear whether a response to the local ablative therapy is due to a favorable tumor biology or if a real benefit in tumor stabilization exists, particularly in complete pathological response.

Method

Data of 163 HCC patients who underwent liver transplantation were extracted from our prospectively maintained registry. We analyzed the tumor load, pre-transplant α-fetoprotein levels, child stage aside the application and success of local ablative therapies as bridging procedures before transplantation.

Results

87 patients received multiple and/or combined local therapies. In 20 cases, this resulted in a complete remission of the tumor as observed in the explant histology. The other 76 patients underwent no bridging procedure. The observed 5- and 10-year survival rates for patients with bridging were 67% and 47% and without bridging 56% and 46%, respectively. Tumor-related 10-year survival showed a statistically significant difference between both groups (81% versus 59%). In the multivariate analyses bridging, number of lesions and α-fetoprotein level showed an independent statistically significant influence on tumor-related survival in these patients.

Conclusions

Successful local ablative therapy before liver transplantation is an independent statistically significant factor in long-term tumor-related survival for patients with HCC in cirrhosis and reduces tumor recurrences.

Embolotherapeutic Strategies for Hepatocellular Carcinoma: 2020 Update

Hepatocellular carcinoma (HCC) represents a significant contributor to cancer-related morbidity and mortality with increasing incidence in both developing and developed countries. Embolotherapy as a locoregional therapeutic strategy consists of trans-arterial or “bland” embolization (TAE), trans-arterial chemoembolization (TACE), and selective internal radiotherapy (SIRT). Trans-catheter arterial therapies can be applied along all stages of HCC, either as an alternative or neoadjuvant to surgical resection/transplantation in very early and early stage HCC or as a palliative option for local disease control in unresectable and advanced stage HCC. In advanced stage HCC, SIRT did not demonstrate superiority in comparison to systemic treatment options in several recent large prospective trials, though for carefully selected patients, may confer improved tolerability with similar disease control rates. The latest embolotherapeutic techniques and literature as they pertain to the management of HCC, as well as future directions, are reviewed in this article.

Preoperative Stereotactic Body Radiotherapy to Portal Vein Tumour Thrombus in Hepatocellular Carcinoma: Clinical and Pathological Analysis

The prognosis of hepatocellular carcinoma (HCC) with portal vein tumour thrombus (PVTT) is poor. We conducted a prospective study to evaluate the efficacy and safety of tri-modality therapy, including preoperative stereotactic body radiotherapy (SBRT) and surgery, followed by hepatic arterial infusion chemotherapy (HAIC) in HCC patients with PVTT. In this report, we investigated the pathology of the irradiated PVTT specimen in resected cases and SBRT-related acute toxicity. A total of 8 HCC patients with PVTT received preoperative SBRT targeting the PVTT at a dose of 48 Gy in 4 fractions at our institute from 2012 to 2016. Of the eight patients, six underwent surgery, while the remaining two did not because of disease progression. At the pathological examination, all patients’ irradiated PVTT specimens showed necrotic tissue, and three of six patients showed complete pathological response. Two patients showed 30% necrosis with high degeneration and one patient, with 30% necrosis without degeneration, was the only recurrent case found during the follow-up period (median: 22.5, range: 5.9–49.6 months). No SBRT-related acute toxicity worse than grade 2 was observed from SBRT to surgery. In conclusion, the preoperative SBRT for HCC was pathologically effective and the acute toxicities were tolerable.

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.

Stereotactic body radiation therapy for early-stage hepatocellular carcinoma - a systematic review on outcome

Background: Hepatocellular carcinoma (HCC) incidence is rising worldwide, especially due to increased detection of early-stage or small-sized tumors. Nevertheless, most of the patients are still not qualified for surgical resection at diagnosis due to the localization of the tumor, underlying liver disease or comorbidities. Stereotactic body radiation therapy (SBRT) is a radiotherapy modality which can deliver a high dose of radiation to the target tissue with a high degree of precision. It shows promise in terms of efficacy and morbidity.Material and methods: The aim of this systematic review is to summarize current knowledge on patient-specific outcomes of SBRT for small HCC including overall survival, local control, the effect of dose escalation and the toxicity of the treatment. The systematic review was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). After a comprehensive database search, 16 studies (973 patients with 1034 lesions) were included in qualitative and quantitative analyses; 14 of them were retrospective.Results: Average tumor diameter was 23 mm and 95% of patients were in good general condition. Median BED10 (biologically equivalent dose calculated for α/β ratio of 10 Gy) was 100 Gy (range 59.5-180 Gy). Mean weighted local control across studies was 94%, 92% and 93% at 1, 2, and 3 years, respectively. Mean weighted overall survival across studies was 90.9%, 67.5% and 73.4% at 1, 2, and 3 years, respectively. There were 171 grade 1-2 toxicities (17.5%) and 53 ≥ grade 3 toxicities (5.3%). There was no treatment-associated mortality.Conclusion: SBRT offers high local control with overall survival that is comparable with radiofrequency ablation and surgery. Quality of findings, especially on toxicities, is decreased by incomplete reporting and retrospective designs of published studies. Therefore, there is a need for better reporting and prospective studies to univocally recommend SBRT as a definitive treatment option in the guidelines for small HCCs.

Local Tumor Control and Patient Outcome Using Stereotactic Body Radiation Therapy for Hepatocellular Carcinoma: iRECIST as a Potential Substitute for Traditional Criteria

OBJECTIVE. The purpose of this study was to investigate whether, compared with traditional criteria, the modified Response Evaluation Criteria in Solid Tumors version 1.1 for immune-based therapeutics (iRECIST) improves prediction of local tumor control and survival in patients with hepatocellular carcinoma (HCC) treated with stereotactic body radiotherapy (SBRT). MATERIALS AND METHODS. Fifty-one HCC lesions (mean size, 3.1 cm) treated with SBRT in 41 patients (mean age, 67 years) were retrospectively included. Each patient underwent CT or MRI before SBRT and at least once after SBRT. Best overall response was categorized using Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST 1.1), iRECIST, World Health Organization (WHO) criteria, modified Response Evaluation Criteria in Solid Tumors (mRECIST), and European Association for the Study of the Liver (EASL) criteria. Lesions were then classified as local tumor control (i.e., stable disease, partial response, or complete response) or local treatment failure (i.e., progressive disease) by each tumor response criteria. Proportions of local tumor control were compared using the McNemar exact test. The 1-year overall survival was estimated using the Kaplan-Meier method. RESULTS. The median follow-up after SBRT was 21.0 months. The local tumor control rate was 94.1% (48/51) by iRECIST, 88.2% (45/51) by RECIST 1.1, 72.5% (37/51) by WHO criteria, 80.4% (41/51) by mRECIST, and 72.5% (37/51) by EASL criteria. The local tumor control rate was significantly higher according to iRECIST compared with WHO (p = 0.0010) and EASL (p = 0.0225) criteria. The 1-year survival rate for patients with local tumor control according to iRECIST (86.4%) was higher (although not statistically significant) compared with the 1-year survival rate for patients with local tumor control according to the other response criteria. CONCLUSION. iRECIST may provide more robust interpretation of HCC response after SBRT, yielding improved prediction of local tumor control and 1-year survival rates compared with traditional criteria.

Stereotactic Body Radiotherapy as a Salvage Therapy after Incomplete Radiofrequency Ablation for Hepatocellular Carcinoma: A Retrospective Propensity Score Matching Study

(1) Background: To investigate the clinical outcomes between radiofrequency ablation (RFA) and stereotactic body radiotherapy (SBRT) for residual hepatocellular carcinoma (RHCC). (2) Methods: 139 patients were diagnosed with the RHCC after post-operative checkup, among whom 39 and 33 patients underwent RFA or SBRT as salvage treatments, respectively. We applied the propensity score matching (PSM) to adjust for imbalances in treatment assignment. Local disease progression, progression-free survival (PFS), overall survival (OS), and treatment-related side effects were the study endpoints. (3) Results: Before PSM, the SBRT group demonstrated significantly lower local disease progression rate (6/33 vs. 23/39; p = 0.002), better PFS (the 1- and 3-year PFS were 63.3% and 49.3% vs. 41.5% and 22.3%, respectively, p = 0.036), and comparable OS (the 1- and 3-year OS were 85.4% and 71.1% vs. 97.3% and 57.6%, respectively, p = 0.680). After PSM of 23 matched cases, the SBRT group demonstrated significantly lower local disease progression rate, better PFS and comparable OS. Centrally located tumor predicted the worse OS. No acute grade 3+ toxicity was observed in both groups. (4) Conclusion: SBRT might be the preferred treatment for RHCC, especially for patients with larger tumors or tumors abutting major vessels, rather than repeated RFA.

Role of Radiotherapy in the Treatment of Hepatocellular Carcinoma

The role of radiotherapy in the treatment of hepatocellular carcinoma (HCC) has evolved over the past few decades with the advancement of technology and improved imaging. Radiotherapy can offer high local control rates in unresectable HCC, including cases with major vascular involvement, and can provide a modality to help bridge patients to potentially curative resection or transplantation. In metastatic cases, radiotherapy can provide good palliation. This review focuses on the common radiotherapy treatment modalities used for HCC, provides outcome comparisons of these radiotherapy techniques to outcomes with other treatment modalities for HCC, and highlights the discrepancy of the role of radiotherapy in HCC amongst the current available treatment guidelines.

Efficacy and safety of external-beam radiation therapy for hepatocellular carcinoma: An overview of current evidence according to the different target population

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors. During the recent years, external-beam radiation therapy (EBRT) has been safely and effectively employed for the management of HCC. We overviewed the current evidence regarding the efficacy and safety of EBRT for HCC according to the different target population. PubMed database was searched for identifying English-language full-text articles regarding EBRT for the treatment of HCC. Search items were "hepatocellular carcinoma AND radiation therapy". Until now, preliminary evidence has suggested the following role of EBRT for HCC. 1) EBRT, especially stereotactic body radiation therapy, is an emerging choice of therapy for small HCC. 2) EBRT combined with non-surgical treatment can achieve an excellent intrahepatic tumor control and a potential survival benefit for huge HCC. 3)Adjunctive EBRT may improve the efficacy of transarterial chemoembolization for HCC with portal vein tumor thrombosis. 4) EBRT can relieve the pain and improve the quality of life for patients with extrahepatic metastases. 5) EBRT may be a bridge to liver transplantation by minimizing the tumor progression. 6) Adjunctive EBRT may reduce the tumor recurrence and improve the survival after resection. In summary, EBRT is a promising choice of treatment of HCC. However, more high-quality evidence is needed to further establish the status of EBRT for the management of HCC.

[Stereotactic hypofractionated radiation therapy as a bridge to transplantation for hepatocellular carcinoma: Case report of a complete pathological response and review of the literature]

Patients with hepatocellular carcinoma who are on liver transplant waiting list usually require local treatment to limit any risk of tumour growth. Historically percutaneous radiofrequency ablation or transarterial chemoembolization represented the major therapeutic alternatives. Depending on the size, or the topography of the lesion these two techniques may not be feasible. Radiation therapy under stereotactic conditions has recently emerged in the management of localized hepatocellular carcinoma as an alternative to the focused therapies performed to date. We herein report the case of a 43-year-old patient harbouring a complete histological response on explant after liver stereotactic irradiation and discuss its role in the management of hepatocellular carcinoma before liver transplantation.

HCRP1, ID4 and Glypican-3: an optimal panel of biomarkers for diagnosis of hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide with high morbidity and mortality. The aim of this study was to assess the diagnostic role of HCC related protein 1 (HCRP1) and inhibitor of DNA Binding 4 (ID4) as novel reliable markers for HCC diagnosis.

METHODS

Immunohistochemistry for HCRP1, ID4 and Glypican-3 (GPC-3) was performed in 98 cases of HCCs, 15 large regenerative nodules arising in cirrhotic livers, 12 hepatocellular adenomas (HCA), 10 focal nodular hyperplasias (FNH), and 20 specimens of normal liver tissues (NL).

RESULTS

HCRP1 immunoactivity was decreased in 64 of 98 (65.3%) HCC cases but present in almost all of the benign liver nodules (56/57, 98.2%, P < 0.001). 68 of 98 (69.4%) and 70 of 98 (71.4%) HCC cases were positive for ID4 and GPC-3, respectively, which were much higher than in benign lesions. Even though HCRP1 is highly specific (98.25%) in differentiating well differentiated HCC (WDHCC) from benign liver nodules, it has only a limited value because of its low sensitivity (37.5%), neither for the ID4, GPC-3 alone or combination (P > 0.05). The expression of HCRP1 alone could efficiently distinguish WDHCC from moderate-poorly differentiated HCC (M-PHCC), and the combination of using either two or three markers could notably increase the diagnosis accuracy (P < 0.05).

CONCLUSION

HCRP1 and ID4 represent potentially novel valuable biomarkers for distinguishing HCC from benign liver nodules, and it is recommended to use the combination of HCRP1, ID4 and GPC-3 as a panel in HCC differentiation estimation.