Phase II trial of high-dose conformal radiation therapy with concurrent hepatic artery floxuridine for unresectable intrahepatic malignancies

Case report: Massive hepatocellular carcinoma with complete response to the non-surgical systematic treatment strategy

Background

The five-year recurrence rate of hepatocellular carcinoma (HCC) remains as high as 70%. A complete clinical response has not been observed without surgical resection. Here, we report a rare case of clinical complete response and long-term survival in a patient with massive HCC receiving treatment with immunotherapy, anti-angiogenic therapy, and radiotherapy.

Case description

A 38-year-old woman presented to our hospital for abdominal pain that persisted for 3 months. She was diagnosed as Barcelona Clinic Liver Cancer(BCLC) stage A, with a Cancer of the Liver Italian Program (CLIP) score of 3, American Joint Committee on Cancer (AJCC) Tumor-Node-Metastasis (TNM) staging systems stage IB. She refused surgical resection and trans-arterial chemoembolization and accepted a non-invasive systematic treatment strategy involving immunotherapy, anti-angiogenic therapy, and radiotherapy. Her tumor burden decreased, and she experienced partial response before radiotherapy. Following radiotherapy, she experienced a complete clinical response and has been alive for more than 36 months after her initial presentation. She is currently alive.

Conclusion

A non-invasive systematic treatment strategy is a potential radical treatment option for patients with massive HCC.

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.

Evolution of Response-Based Radiotherapy for Hepatocellular Cancer

ABSTRACT

Stereotactic body radiation therapy has emerged as a safe and effective treatment modality for properly selected hepatocellular cancer (HCC) patients with normal liver function. However, many HCC patients have reduced baseline liver function due to underlying cirrhosis or prior liver-directed therapies. Therefore, because of the increased risk of hepatotoxicity, the use of stereotactic body radiation therapy for patients with reduced liver function has been approached with caution. Individualized, response-based radiotherapy incorporates models, imaging tools, and biomarkers that determine the dose-response relationship of the liver before, during, and after treatment and has been useful in reducing the likelihood of liver damage without sacrificing tumor control. This review discusses the evolution of response-based radiotherapy for HCC and highlights areas for further investigation.

Radiation dose is associated with improved local control for large, but not small, hepatocellular carcinomas

BACKGROUND

With advances in understanding liver tolerance, conformal techniques, image guidance, and motion management, dose-escalated radiotherapy has become a potential treatment for inoperable hepatocellular carcinoma (HCC). We aimed to evaluate the possible impact of biologically effective dose (BED) on local control and toxicity among patients with HCC.

METHODS AND MATERIALS

Patients treated at our institution from 2009 to 2018 were included in this retrospective analysis if they received definitive-intent radiotherapy with a nominal BED of at least 60 Gy. Patients were stratified into small and large tumors using a cutoff of 5 cm, based on our clinical practice. Toxicity was assessed using ALBI scores and rates of clinical liver function deterioration.

RESULTS

One hundred and twenty-eight patients were included, with a mean follow-up of 16 months. The majority of patients (90.5%) had a good performance status (ECOG 0-1), with Child-Pugh A (66.4%) and ALBI Grade 2 liver function at baseline (55.4%). Twenty (15.6%) patients had a local recurrence in the irradiated field during the follow-up period. Univariate and multivariate Cox proportional hazard analyses showed that only BED significantly predicted local tumor recurrence. Higher BED was associated with improved local control in tumors with equivalent diameters over 5 cm but not in smaller tumors. There was no difference in liver toxicity between the low and high-dose groups.

CONCLUSIONS

Higher radiotherapy dose is associated with improved local control in large tumors but not in tumors smaller than 5 cm in diameter. High-dose radiotherapy was not associated with increased liver toxicity.

A phase II single arm study of Nivolumab with stereotactic Ablative radiation Therapy after induction chemotherapy in CHOlangiocarcinoma (NATCHO)

BACKGROUND

Intrahepatic cholangiocarcinoma (CCA) is amongst the most common primary liver tumors worldwide. CCA carries a bad prognosis prompting research to establish new treatment modalities other than surgery and the current chemotherapeutic regimens adopted. Hence, this trial explores a new therapeutic approach, to combine stereotactic body radiation therapy (SBRT) and immunotherapy (Nivolumab), and asses its clinical benefit and safety profile after induction chemotherapy in CCA.

METHODOLOGY

This is a Phase II open-label, single-arm, multicenter study that investigates Nivolumab (PD-1 inhibitor) treatment at Day 1 followed by SBRT (30 Gy in 3 to 5 fractions) at Day 8, then monthly Nivolumab in 40 patients with non-resectable locally advanced, metastatic or recurrent intrahepatic or extrahepatic CCA. Eligible patients were those above 18 years of age with a pathologically and radiologically confirmed diagnosis of non-resectable locally advanced or metastatic or recurrent intrahepatic or extrahepatic CCA, following 4 cycles of cisplatin-based chemotherapy with an estimated life expectancy of more than 3 months, among other criteria. The primary endpoint is the progression free survival (PFS) rate at 8 months and disease control rate (DCR). The secondary endpoints are overall survival (OS), tumor response rate (TRR), duration of response, evaluation of biomarkers: CD3 + , CD4 + and CD8 + T cell infiltration, as well as any change in the PD-L1 expression through percutaneous core biopsy when compared with the baseline biopsy following 1 cycle of Nivolumab and SBRT.

DISCUSSION

SRBT alone showed promising results in the literature by both inducing the immune system locally and having abscopal effects on distant metastases. Moreover, given the prevalence of PD-L1 in solid tumors, targeting it or its receptor has become the mainstay of novel immunotherapeutic drugs use. A combination of both has never been explored in the scope of CCA and that is the aim of this study.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04648319 , April 20, 2018.

Phase 1 trial of apatinib combined with intensity-modulated radiotherapy in unresectable hepatocellular carcinoma

Background

To investigate the maximum tolerated dose (MTD) of apatinib delivered during and after intensity-modulated radiotherapy (IMRT) for unresectable hepatocellular carcinoma (HCC).

Methods

Patients with unresectable HCC who were not eligible for radiofrequency ablation (RFA), transcatheter arterial chemoembolization (TACE), or residual/ recurrent after the prior local treatment were enrolled. Patients were scheduled to be treated with IMRT at 50–60 Gy/25–30 fractions. Oral apatinib tablets were administered concurrently with IMRT and continued thereafter. We used a 3 + 3 dose-escalation design, with three dose levels of apatinib (250, 500, and 750 mg). Grade 3 or more severe adverse events (AEs) were defined as dose-limiting toxicities (DLTs). The treatment response was calculated using the Modified Response Evaluation Criteria in Solid Tumours.

Results

Nine patients with Barcelona Clinic Liver Cancer Stage C were included. One patient withdrew from the apatinib 250 mg group and another patient was added. No DLTs occurred in the apatinib 250 mg group. Five patients were included in the apatinib 500 mg group, and 2 cases of DLT (grade 3 leukopenia) were found among them. Dose escalation was terminated and the MTD was determined to be 250 mg. Common grade 1–2 AEs included fatigue, hypertension, dizziness, bone marrow suppression, and hyperbilirubinemia. The median follow-up time for all patients was 16.0 months. Three patients achieved complete response and another three achieved partial response. The objective response rate was 6/9 (66.7%), and the disease control rate was 9/9 (100%). Three patients relapsed out of the radiation field. The median progression-free survival was 17.0 months, and the median overall survival was 16.7 months.

Conclusions

When combined with IMRT, apatinib 250 mg daily was recommended for a phase 2 study of unresectable HCC. The antitumor activity of the combination treatment was encouraging. The safety and efficacy of apatinib combined with IMRT for unresectable HCC should be further investigated in future studies.

Trial registration

Registration No. ChiCTR1800018309. Registered 11 September 2018. Retrospectively registered, https://www.chictr.org.cn/showproj.aspx?proj=30461.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09819-3.

Methyltransferase 1 is required for nonhomologous end-joining repair and renders hepatocellular carcinoma resistant to radiotherapy

BACKGROUND AND AIMS

Radiotherapy is an increasingly essential therapeutic strategy in the management of hepatocellular carcinoma (HCC). Nevertheless, resistance to radiotherapy is one of the primary obstacles to successful treatment outcomes. Hence, we aim to elucidate the mechanisms underlying radioresistance and identify reliable biotargets that would be inhibited to enhance the efficacy of radiotherapy in HCC.

APPROACH AND RESULTS

From a label-free quantitative proteome screening, we identified transfer RNA (tRNA; guanine-N [7]-) methyltransferase 1 (METTL1), a key enzyme for N7-methylguanosine (m⁷ G) tRNA modification, as an essential driver for HCC cells radioresistance. We reveal that METTL1 promotes DNA double-strand break (DSB) repair and renders HCC cells resistant to ionizing radiation (IR) using loss-of-function and gain-of-function assays in vitro and in vivo. Mechanistically, METTL1-mediated m⁷ G tRNA modification selectively regulates the translation of DNA-dependent protein kinase catalytic subunit or DNA ligase IV with higher frequencies of m⁷ G-related codons after IR treatment, thereby resulting in the enhancement of nonhomologous end-joining (NHEJ)-mediated DNA DSB repair efficiency. Clinically, high METTL1 expression in tumor tissue is significantly correlated with poor prognosis in radiotherapy-treated patients with HCC.

CONCLUSIONS

Our findings show that METTL1 is a critical enhancer for HCC cell NHEJ-based DNA repair following IR therapy. These findings give insight into the role of tRNA modification in messenger RNA translation control in HCC radioresistance.

Targeting nucleotide metabolism: a promising approach to enhance cancer immunotherapy

Targeting nucleotide metabolism can not only inhibit tumor initiation and progression but also exert serious side effects. With in-depth studies of nucleotide metabolism, our understanding of nucleotide metabolism in tumors has revealed their non-proliferative effects on immune escape, indicating the potential effectiveness of nucleotide antimetabolites for enhancing immunotherapy. A growing body of evidence now supports the concept that targeting nucleotide metabolism can increase the antitumor immune response by (1) activating host immune systems via maintaining the concentrations of several important metabolites, such as adenosine and ATP, (2) promoting immunogenicity caused by increased mutability and genomic instability by disrupting the purine and pyrimidine pool, and (3) releasing nucleoside analogs via microbes to regulate immunity. Therapeutic approaches targeting nucleotide metabolism combined with immunotherapy have achieved exciting success in preclinical animal models. Here, we review how dysregulated nucleotide metabolism can promote tumor growth and interact with the host immune system, and we provide future insights into targeting nucleotide metabolism for immunotherapeutic treatment of various malignancies.

Interventional Radiology Image-Guided Locoregional Therapies (LRTs) and Immunotherapy for the Treatment of HCC

Image-guided locoregional therapies (LRTs) are a crucial asset in the treatment of hepatocellular carcinoma (HCC), which has proven to be characterized by an impaired antitumor immune status. LRTs not only directly destroy tumor cells but also have an immunomodulating role, altering the tumor microenvironment with potential systemic effects. Nevertheless, the immune activation against HCC induced by LRTs is not strong enough on its own to generate a systemic significant antitumor response, and it is incapable of preventing tumor recurrence. Currently, there is great interest in the possibility of combining LRTs with immunotherapy for HCC, as this combination may result in a mutually beneficial and synergistic relationship. On the one hand, immunotherapy could amplify and prolong the antitumoral immune response of LRTs, reducing recurrence cases and improving outcome. On the other hand, LTRs counteract the typical immunosuppressive HCC microenvironment and status and could therefore enhance the efficacy of immunotherapy. Here, after reviewing the current therapeutic options for HCC, we focus on LRTs, describing for each of them the technique and data on its effect on the immune system. Then, we describe the current status of immunotherapy and finally report the recently published and ongoing clinical studies testing this combination.

Non-surgical treatment of hilar cholangiocarcinoma

Cancer of the biliary confluence also known as hilar cholangiocarcinoma (HC) or Klatskin tumor, is a rare type of neoplastic disease constituting approximately 40%-60% of intrahepatic malignancies, and 2% of all cancers. The prognosis is extremely poor and the majority of Klatskin tumors are deemed unresectable upon diagnosis. Most patients with unresectable bile duct cancer die within the first year after diagnosis, due to hepatic failure, and/or infectious complications secondary to biliary obstruction. Curative treatments include surgical resection and liver transplantation in highly selected patients. Nevertheless, very few patients are eligible for surgery or transplant at the time of diagnosis. For patients with unresectable HC, radiotherapy, chemotherapy, photodynamic therapy, and liver-directed minimally invasive procedures such as percutaneous image-guided ablation and intra-arterial chemoembolization are recommended treatment options. This review focuses on currently available treatment options for unresectable HC and discusses future perspectives that could optimize outcomes.

Liver resection versus intensity-modulated radiation therapy for treatment of hepatocellular carcinoma with hepatic vein tumor thrombus: a propensity score matching analysis

Background

The presence of hepatic vein tumor thrombus (HVTT) is a major determinant of survival outcomes in hepatocellular carcinoma (HCC) patients. This study compared survival outcomes between liver resection (LR) and intensity-modulated radiation therapy (IMRT) in HCC patients with HVTT.

Methods

Data from patients who underwent LR or IMRT for HCC with HVTT at the Eastern Hepatobiliary Surgery Hospital were retrospectively analyzed. Their survival outcomes were compared before and after propensity score matching (PSM).

Results

Three hundred and seven HCC patients with HVTT who underwent either LR (n=140) or IMRT (n=167) were enrolled. PSM matched 82 pairs of patients. The overall survival (OS) and recurrence-free survival (RFS) rates were significantly higher for patients in the LR group than those in the IMRT group. On subgroup analysis, significantly better survival outcomes were obtained after LR than IMRT in patients with peripheral type of HVTT (pHVTT) and major type of HVTT (mHVTT). However, similar survival outcomes were obtained after LR and IMRT when the HVTT had developed into inferior vena cava tumor thrombus (IVCTT).

Conclusions

LR resulted in significantly better survival outcomes in HCC patients with HVTT when compared to IMRT. Once the HVTT had developed IVCTT, LR and IMRT resulted in similarly bad survival outcomes.

Radiation Segmentectomy

Radiation segmentectomy is an yttrium-90 transarterial radioembolization treatment where a high radiation dose is administered to a small volume of liver to achieve a high tumoricidal dose to a target with anatomic surgical precision while sparing surrounding parenchyma. This therapeutic modality is often used to treat hepatocellular carcinoma, and recent studies have demonstrated that radiation segmentectomy is an effective treatment as a neoadjuvant to transplant, resection, or as a standalone treatment. This article provides a review of radiation segmentectomy, indications for treatment, recent outcome data, and guidelines for postprocedural management.

Twenty Years of Radiation Therapy of Unresectable Intrahepatic Cholangiocarinoma: Internal or External? A Systematic Review and Meta-Analysis

PURPOSE

Both external beam radiation therapy (EBRT) and selective-internal radiation therapy (SIRT) are implemented to treat unresectable intrahepatic cholangiocarcinoma (iCCA). The present study aimed to evaluate the efficacy of EBRT and SIRT in managing iCCA through a systematic review and meta-analysis.

METHODS

PubMed and Cochrane database were queried to search for studies published from January 2000 toJune 2020 without language restrictions. Median survival time, overall survival, and radiological response were extracted. Secondary outcomes such as complication rates, predictors of survival, and downstage to surgery were pooled. Patient-level survival data were obtained to generate Kaplan-Meier survival graph. Pooled outcomes were analyzed with a random-effect model.

RESULTS

Twenty-nine and 20 studies including 732 and 443 patients from the SIRT and EBRT groups were included in the present study. From initial radiation treatment, the median survival time for patients who underwent SIRT and EBRT were 12.0 (95% confidence interval [CI]: 10.8-14.6) and 13.6 (95% CI: 11.1-16.0) months, respectively. As first-line therapy, the median survival time was 36.1 (95% CI: 20.6-39.5) months for SIRT and 11.0 (95% CI: 9.3-13.6) months for EBRT. Both radiation modalities were effective in downstaging initially unresectable iCCA to surgery (SIRT: 30.5%; EBRT: 18.3%). Patients in the SIRT group encountered more post-embolization abdominal pain (6.9 vs. 2.2%), ulcer (1.0 vs. 0.5%), nausea (1.6 vs. 0.7%), anorexia (5.9 vs. 0%), thrombocytopenia (7.3 vs. 6.0%), hyperbilirubinemia (5.2 vs. 2.1%), and hypoalbuminemia (13.2 vs. 3.3%), whereas EBRT was associated with higher rates of anemia (0.6 vs. 7.5%) and neutropenia (6.5 vs. 11.0%).

CONCLUSIONS

Both EBRT and SIRT were safe and effective in treating unresectable iCCA. However, available evidence was highly heterogeneous regarding patient population, limiting fair comparison between 2 radiation modalities. Future high-quality comparative studies are warranted.

MR-Guided Radiotherapy for Liver Malignancies

MR guided radiotherapy represents one of the most promising recent technological innovations in the field. The possibility to better visualize therapy volumes, coupled with the innovative online adaptive radiotherapy and motion management approaches, paves the way to more efficient treatment delivery and may be translated in better clinical outcomes both in terms of response and reduced toxicity. The aim of this review is to present the existing evidence about MRgRT applications for liver malignancies, discussing the potential clinical advantages and the current pitfalls of this new technology.

Magnetic Resonance Imaging-Guided Adaptive Radiotherapy for Colorectal Liver Metastases

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

Survival and morbidity following stereotactic radiotherapy of hepatocellular carcinoma: a ten-year, single institution experience

BACKGROUND AND AIM

Stereotactic ablative body radiotherapy (SABR) is an emerging treatment option in hepatocellular carcinoma (HCC) in patients ineligible for other local ablative therapies. This study reports on the safety and efficacy of SABR in a Danish cohort of HCC patients.

MATERIALS AND METHODS

Between January 2009 and December 2018, 28 patients with HCCs were treated with SABR at our institution. The primary endpoint of this retrospective study was local control; secondary endpoints were progression-free survival, overall survival and toxicity.

RESULTS

In 28 patients, 32 tumors (median size 3.7 cm, range 1.4-6.8 cm) were treated. The median follow-up time was 16 months. Most patients (68%) received previous liver-directed treatments. A dose of 48 Gy in three or six fractions were given to 43% of the patients. Grad 1 or 2 toxicity was reported in 13 patients (46%), whereas 4 patients (14%) needed hospitalization (grade 3). One-year local control and overall survivals were 90% and 71%, respectively. One-year progression-free survival was 32%, and 65% of patients with disease progression received further HCC therapy. In univariate analysis, none of the examined factors predicted recurrence or overall survival.

CONCLUSION

SABR provides high local control to inoperable HCC. SABR can be delivered safely even after previous liver-directed therapies and subsequent therapies are feasible after treatment with SABR. Despite excellent local control, disease progression outside of the irradiated site remains prominent. Further studies are warranted to examine combined therapy approaches to maximize disease control.

Axitinib in combination with radiotherapy for advanced hepatocellular carcinoma: a phase I clinical trial

BACKGROUND

To investigate maximum tolerated dose (MTD) of axitinib, a selective vascular endothelial growth factor receptor 1-3 inhibitor, in combination with radiotherapy (RT) for advanced hepatocellular carcinoma (HCC).

METHODS

This phase I study followed the rule of traditional 3 + 3 design. Major eligibility included: (1) patients with advanced HCC unsuitable for surgery, radiofrequency ablation or transarterial chemoembolization, or who failed after prior local-regional treatment; (2) failure on sorafenib or no grant for sorafenib from health insurance system. Eligible patients with advanced HCC received axitinib for total 8 weeks during and after RT. Three cohorts with axitinib dose escalation were planned: 1 mg twice daily (level I), 2 mg twice daily (level II) and 3 mg twice daily (level III). The prescribed doses of RT ranged from 37.5 to 67.5 Gy in 15 fractions to liver tumor(s) and were determined based on an upper limit of mean liver dose of 18 Gy (intended isotoxic RT for normal liver). The primary endpoint was MTD of axitinib in combination with RT. The secondary endpoints included overall response rate (ORR), RT in-field response rate, acute and late toxicities, overall survival (OS) and progression free survival (PFS).

RESULTS

Total nine eligible patients received axitinib dose levels of 1 mg twice daily (n = 3), 2 mg twice daily (n = 3) and 3 mg twice daily (n = 3). Dose-limiting toxicity (DLT) did not occur in the 3 cohorts; the MTD was defined as 3 mg twice daily in this study. ORR was 66.7%, including 3 complete responses and 3 partial responses, at 3 months after treatment initiation. With a median follow-up of 16.6 months, median OS was not reached, 1-year OS was 66.7%, and median PFS was 7.4 months.

CONCLUSIONS

Axitinib in combination with RT for advanced HCC was well tolerated with an axitinib MTD of 3 mg twice daily in this study. The outcome analysis should be interpreted with caution due to the small total cohort. Trial registration ClinicalTrials.gov (Identifier: NCT02814461), Registered June 27, 2016-Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT02814461.

The Evolving Role of Radiation Therapy in the Treatment of Biliary Tract Cancer

Biliary tract cancers (BTC) are a disease entity comprising diverse epithelial tumors, which are categorized according to their anatomical location as intrahepatic (iCCA), perihilar (pCCA), distal (dCCA) cholangiocarcinomas, and gallbladder carcinomas (GBC), with distinct epidemiology, biology, and prognosis. Complete surgical resection is the mainstay in operable BTC as it is the only potentially curative treatment option. Nevertheless, even after curative (R0) resection, the 5-year survival rate ranges between 20 and 40% and the disease free survival rates (DFS) is approximately 48–65% after one year and 23–35% after three years without adjuvant treatment. Improvements in adjuvant chemotherapy have improved the DFS, but the role of adjuvant radiotherapy is unclear. On the other hand, more than 50% of the patients present with unresectable disease at the time of diagnosis, which limits the prognosis to a few months without treatment. Herein, we review the role of radiotherapy in the treatment of cholangiocarcinoma in the curative and palliative setting.

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

Backgrounds and Aims

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

Patients and Methods

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

Results

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

Conclusion

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

Radiofrequency ablation and stereotactic body radiotherapy for hepatocellular carcinoma: should they clash or reconcile?

Until a few decades ago, surgical resection was the only valid option for treating hepatocellular carcinoma (HCC). However, various locoregional modalities including arterial-directed therapy, radiofrequency ablation (RFA), and radiotherapy have been recently shown to be effective. RFA is now established as a standard treatment for small localized HCCs, showing oncological results comparable to those of surgical resection in randomized studies. Stereotactic body radiotherapy (SBRT) is a modern radiotherapeutic modality that targets tumors with precision and delivers high radiation doses over a short period of time; it has particularly attracted clinical interest after its therapeutic efficacy was found to be similar to that of surgery in early-stage lung cancer. Given its potent disease control capability, SBRT has also been applied to early HCCs and demonstrated promising results in recent studies. It has also been noted for its suitability to treat tumors located in anatomical locations where RFA would be challenging. However, since its effectiveness has not been compared to that of RFA in randomized studies of patients eligible for RFA, the use of SBRT has been debated. This review was conducted to guide physicians from all fields involved in the treatment of early HCC. The therapeutic characteristics and indications of both SBRT and RFA are described, and recent comparative studies between the two modalities are discussed. In addition, we examined the factors that should be considered when selecting the appropriate treatments, and offer our recommendations.

External Beam Radiation Therapy for Liver Metastases

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

MRI-guided adaptive radiotherapy for liver tumours: visualising the future

MRI-guided radiotherapy is a novel and rapidly evolving technology that might enhance the risk-benefit ratio. Through direct visualisation of the tumour and the nearby healthy tissues, the radiation oncologist can deliver highly accurate treatment even to mobile targets. Each individual treatment can be customised to changing anatomy, potentially reducing the risk of radiation-related toxicities while simultaneously increasing the dose delivered to the tumour. MRI-guided radiotherapy offers a new tool for the radiation oncologist, and creates an opportunity to achieve durable local control of liver tumours that might not otherwise be possible. Future work will allow us to expand the population eligible for curative-intent radiotherapy, optimise and customise radiation doses to specific tumours, and hopefully create opportunities for improving outcomes through machine learning and radiomics-based approaches. This Review outlines the current and future applications for MRI-guided radiotherapy with respect to metastatic and primary liver cancers.

Clinical results of active scanning proton therapy for primary liver tumors

BACKGROUND

Evidence for the efficacy of radiation therapy for primary liver cancer is growing. In this context, proton therapy (PT) can potentially improve the therapeutic ratio, as demonstrated by recent clinical studies. Here we report the first European clinical experience on the use of PT for primary liver cancer.

METHODS

All patients treated for primary liver cancer in our center entered the analysis. Patients were simulated during deep expiration breath-hold. A 15-fraction treatment schedule was adopted using active scanning PT. Clinical outcome and toxicity were retrospectively analyzed.

RESULTS

Between January 2018 and December 2019, 18 patients were treated. Fourteen patients had hepatocellular carcinoma (HCC), three patients had intrahepatic cholangiocarcinoma (ICC), and one patient had synchronous ICC-HCC. The Child-Pugh score was A5 in the majority of patients with HCC (71.4%). Median prescription dose was 58.05 Gy (range, 50.31-67.5). Median follow-up was 10 months (range, 1-19). The majority of deaths occurred from liver tumor progression. One-year overall survival (OS) was 63%. A significant correlation between worse OS and patient performance status, vascular invasion, and tumor stage was recorded. One-year local control was 90%. Toxicity was low, with a decrease in Child-Pugh score ⩾2 points detected in one patient. No cases of classic radiation-induced liver disease occurred.

CONCLUSIONS

Our initial results of active scanning PT for primary liver cancer demonstrated the feasibility, safety, and effectiveness of this advanced technique in this setting. The potential of the combination of PT with other locoregional therapies is under evaluation.

Phase I Radiation Dose-Escalation Study to Investigate the Dose-Limiting Toxicity of Concurrent Intra-Arterial Chemotherapy for Unresectable Hepatocellular Carcinoma

Concurrent intra-arterial chemotherapy and radiotherapy (iA-CCRT) can increase the response rate in hepatocellular carcinoma (HCC), but may cause a higher toxicity. We conducted this Phase I study to investigate the dose-limiting toxicity of iA-CCRT for HCC. In total, 52.5 Gy in 25 fractions was prescribed as planning target volume (PTV) 1 at dose level 1. The dose escalation was 0.2 Gy per fraction and up to 2.5 Gy, with 62.5 Gy at level 3. Concurrent intra-arterial 5-fluorouracil was administered during the first and fifth weeks of radiotherapy (RT). Toxicities were graded using the Common Toxicity Criteria for Adverse Events, version 4.0. Results: Seventeen patients with HCC were analyzed: four at dose level 1, 6 at level 2, and 7 at level 3. The mean irradiated dose administered to the uninvolved liver at each dose level was 21.3, 21.6, and 18.2 Gy, respectively. There was no grade ≥3 gastrointestinal toxicity; two patients experienced grade 3 hyperbilirubinemia. All patients had Child-Pugh class A disease, but 3 patients developed class B disease after iA-CCRT. During a median follow-up of 13 months, the median progression-free survival (PFS) and overall survival (OS) were 10 and 22 months, respectively. Patients treated at dose level 3 showed improved PFS and OS. Conclusions: Radiation dose escalation of iA-CCRT did not cause any significant toxicities in patients with advanced HCC. Further large-scale studies with long-term follow-up are needed to determine the efficacy and feasibility of higher doses of iA-CCRT.

The Role of Sirtuin 3 in Radiation-Induced Long-Term Persistent Liver Injury

In patients with abdominal region cancers, ionizing radiation (IR)-induced long-term liver injury is a major limiting factor in the use of radiotherapy. Previously, the major mitochondrial deacetylase, sirtuin 3 (SIRT3), has been implicated to play an important role in the development of acute liver injury after total body irradiation but no studies to date have examined the role of SIRT3 in liver's chronic response to radiation. In the current study, ten-month-old Sirt3^-/- and Sirt3^+/+ male mice received 24 Gy radiation targeted to liver. Six months after exposure, irradiated Sirt3^-/- mice livers demonstrated histopathological elevations in inflammatory infiltration, the loss of mature bile ducts and higher DNA damage (TUNEL) as well as protein oxidation (3-nitrotyrosine). In addition, increased expression of inflammatory chemokines (IL-6, IL-1β, TGF-β) and fibrotic factors (Procollagen 1, α-SMA) were also measured in Sirt3^-/- mice following 24 Gy IR. The alterations measured in enzymatic activities of catalase, glutathione peroxidase, and glutathione reductase in the livers of irradiated Sirt3^-/- mice also implied that hydrogen peroxide and hydroperoxide sensitive signaling cascades in the absence of SIRT3 might contribute to the IR-induced long-term liver injury.

Efficacy and Safety of Liver-Directed Concurrent Chemoradiotherapy and Sequential Sorafenib for Advanced Hepatocellular Carcinoma: A Prospective Phase 2 Trial

PURPOSE

Although sorafenib as a standard of care for advanced hepatocellular carcinoma (HCC) prolongs overall survival (OS), its efficacy is limited owing to its unsatisfactory objective response and marginal survival benefit. To counter these limitations, we designed a single-arm, phase II trial with liver-directed concurrent chemoradiotherapy (LD-CCRT) and sequential sorafenib treatment in patients with advanced HCC.

METHODS AND MATERIALS

We enrolled advanced HCC patients diagnosed between 2014 and 2017 who were ineligible for curative treatment. During the first and last 5 days of 5-week radiation therapy, concurrent hepatic arterial infusion with 5-fluorouracil (500 mg/d) and leucovorin (50 mg/d) through an implanted port was administered 4 weeks after initiation of LD-CCRT and sequential sorafenib treatment (400 mg, twice daily). The primary endpoint was OS. This trial has been registered at clinicaltrials.gov.

RESULTS

Among the enrolled patients (n = 47), objective response rates 4 weeks after LD-CCRT and during/up to sorafenib maintenance were 44.7% and 53.2%, respectively. Overall, 9 patients (19.1%) underwent curative resection or transplantation after down staging. The median radiation dose was 60 Gy. The median OS was 24.6 months for the entire cohort and 13.0 months for the subgroup with tumor invasion into the main portal trunk or its first branch, whereas the median progression-free survival for the cohort and subgroup was 6.8 and 5.6 months, respectively. The most frequent treatment-related adverse events were diarrhea (36.2%) and hand-foot skin reaction (34%), which were manageable with conservative treatment.

CONCLUSIONS

LD-CCRT and sequential sorafenib treatment provided favorable OS and progression-free survival with good tolerability. Tumor reduction using an initial LD-CCRT enabled down staging, subsequent curative treatment, and long-term survival in about 20% of the patients with advanced HCC. However, further randomized trials are required to confirm these results.

Novel Radiotherapy Technologies in the Treatment of Gastrointestinal Malignancies

Over the past 2 decades, major technical advances in radiation therapy planning and delivery have made it possible to deliver higher doses to select high-risk volumes. This has helped to expand the role of radiation therapy in the treatment of gastrointestinal malignancies. Whereas dose escalation was previously limited by the radiosensitivity of normal tissues within and adjacent to the gastrointestinal tract, advances in target delineation, patient immobilization, treatment planning, and image-guided treatment delivery have greatly improved the therapeutic ratio. More conformal radiation modalities can offer further dose optimization to target volumes while sparing normal tissue from toxicity.

Clinical Outcomes Using Magnetic Resonance-Guided Stereotactic Body Radiation Therapy in Patients With Locally Advanced Cholangiocarcinoma

Purpose

Previous studies have shown that stereotactic ablative radiation therapy (SABR) increases local control for cholangiocarcinoma, but gastrointestinal toxicity resulting from this treatment approach remains a concern. SABR using magnetic resonance–guided radiation therapy (MRgRT) may improve the therapeutic ratio of treatment for cholangiocarcinoma patients given the radiosensitivity of neighboring gastrointestinal organs.

Methods

Seventeen consecutive patients with unresectable locally advanced cholangiocarcinoma were treated with SABR using MRgRT between May 2015 and August 2017, subsequent to our previously reported series of patients treated using a standard Linac with cone beam computed tomography. Twelve patients presented with extrahepatic cholangiocarcinoma and 5 patients with intrahepatic tumors. MRgRT-based SABR was administered at a median dose of 40 Gy in 5 fractions.

Results

The median overall survival (OS) was 18.5 months, with a 1-year OS of 76% and 2-year OS of 46.1%. Three of the 17 patients progressed locally, yielding a 1-year local control of 85.6% and a 2-year local control of 73.3%. Although 12 of 17 patients experienced an acute grade 1 toxicity, none experienced acute grade 2 toxicities. One patient had an acute grade 3 duodenal ulcer with perforation (6%), and one patient had a late radiation-related toxicity grade 2 gastritis/colitis.

Conclusions

Our findings demonstrate diminished toxicity and excellent overall survival and local control. The clinical outcomes and safety profile of SABR delivered with MRgRT suggest that MRgRT is a promising treatment approach for treating cholangiocarcinoma.

Proton beam therapy versus stereotactic body radiotherapy for hepatocellular carcinoma: practice patterns, outcomes, and the effect of biologically effective dose escalation

BACKGROUND

Stereotactic body radiation therapy (SBRT) and proton beam therapy (PBT) generally are safe and effective for non-operative hepatocellular carcinoma (HCC). To date, data comparing the two modalities are limited. We aimed to identify the practice patterns and outcomes of nonsurgical HCC cases treated definitively with either SBRT or PBT.

METHODS

We queried the National Cancer Database for T1-2N0 HCC patients receiving PBT or SBRT from 2004 to 2015. Patients were excluded for any treatment other than non-palliative external beam radiotherapy. A multivariable binomial regression model identified patterns of SBRT/PBT use, and propensity-matched multivariable Cox regression assessed correlates of survival.

RESULTS

A total of 71 patients received PBT and 918 patients received SBRT (median follow-up 45 months). SBRT was used in 1.8% of nonoperative early stage HCC cases in 2004 and 4.2% of cases in 2015, whereas PBT was used in 0.1-0.2% of cases every year. The median biologically effective dose (BED) for SBRT and PBT was 100 Gy10 and 98 Gy10, respectively (OR =0.70, P=0.17). Factors predictive of receiving PBT included: white race, higher comorbidity score, higher education, metropolitan residence, tumors >5 cm and recent treatment (all P<0.05). Both PBT (HR =0.48, 95% CI: 0.29-0.78) and BED ≥100 Gy10 (HR =0.61, 95% CI: 0.38-0.98) were independent predictors for longer survival.

CONCLUSIONS

Although not implying causation and requiring prospective corroboration, PBT was independently associated with longer survival than SBRT, despite being delivered to HCC patients with multiple poor prognostic factors. PBT may also allow for safer BED escalation, which also independently associated with outcomes.

Neoadjuvant conformal radiotherapy before liver transplantation for hepatocellular carcinoma: a propensity score matched analysis of postoperative morbidity and oncological results

Aim: To assess neoadjuvant conformal radiotherapy (CRT) before orthotopic liver transplantation (OLT) for hepatocellular carcinoma (HCC) not suitable for standard locoregional treatments. Methods: Patients undergoing OLT for HCC with or without prior CRT were compared using 1:3 propensity score matching. Results: After propensity score matching, 23 patients with CRT were compared with 66 control subjects. Severe morbidity rate was 34.8 versus 24.2% in the CRT and non-CRT groups (p = 0.289). Complete pathological response was observed in 47.8% of CRT-targeted nodules. The 1-/3-/5-year disease-free survivals were 77.3, 77.3 and 68.7% in the CRT group versus 85.4, 68.0 and 61.7% in the non-CRT group (p = 0.829). Conclusion: Conformal radiotherapy represents a satisfactory neoadjuvant therapy for OLT candidates not suitable for standard HCC locoregional therapies.

Phase I Trial of Dose-escalated Whole Liver Irradiation With Hepatic Arterial Fluorodeoxyuridine/Leucovorin and Streptozotocin Followed by Fluorodeoxyuridine/Leucovorin and Chemoembolization for Patients With Neuroendocrine Hepatic Metastases

OBJECTIVES

We have previously shown that refractory neuroendocrine tumors can respond to moderate doses of chemoradiotherapy. We completed a dose-escalation phase I/II trial combining hepatic arterial (HA) chemotherapy, chemoembolization, and dose-escalated whole liver radiotherapy to determine the maximum safe dose of radiation that could be delivered and to make a preliminary assessment of response.

MATERIALS AND METHODS

From 2002 to 2009, 19 patients with symptomatic neuroendocrine liver metastases who failed somatostatin analog therapy were enrolled. HA fluorodeoxyuridine, leucovorin, and streptozotocin were delivered, as concurrent whole liver radiotherapy was dose escalated from 24 to 32 Gy in 2 Gy fractions, with a target rate of dose-limiting grade ≥3 radiation-induced liver disease of 10%. Eight weeks later, for patients without grade ≥3 liver or grade ≥4 any toxicity, a 72-hour infusion of HA fluorodeoxyuridine and leucovorin was given, followed by transarterial chemoembolization.

RESULTS

Eleven patients completed the entire protocol and received 24 to 32 Gy. No patients developed radiation-induced liver disease; 7 had grade 3 to 4 transiently increased liver function tests, and 4 had other grade 4 toxicities. Three patients (14%) had partial response, 16 (84%) stable disease. Median freedom from local progression and overall survival were 35.3 and 54.6 months, respectively.

CONCLUSIONS

Thirty-two in 2 Gy daily fractions can be delivered safely when combined with HA chemotherapy and subsequent transarterial chemoembolization. However, although objective responses were observed, this combination was not significantly better than our prior approaches. Further treatment intensification strategies, including individualized dose escalation for radiation-tolerant livers, and improved radiosensitization should be investigated, along with improved systemic therapy.

The Combination of Stereotactic Body Radiation Therapy and Immunotherapy in Primary Liver Tumors

Treatment recommendations for primary liver malignancies, including hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA), are complex and require a multidisciplinary approach. Despite surgical options that are potentially curative, options for nonsurgical candidates include systemic therapy, radiotherapy (RT), transarterial chemoembolization (TACE), and radiofrequency ablation (RFA). Stereotactic Body Radiation Therapy (SBRT) is now in routine use for the treatment of lung cancer, and there is growing evidence supporting its use in liver tumors. SBRT has the advantage of delivering ablative radiation doses in a limited number of fractions while minimizing the risk of radiation-induced liver disease (RILD) through highly conformal treatment plans. It should be considered in a multidisciplinary setting for the management of patients with unresectable, locally advanced primary liver malignancies and limited treatment options. Recently, the combination of immunotherapy with SBRT has been proposed to improve antitumor effects through engaging the immune system. This review aims at shedding light on the novel concept of the combination strategy of immune-radiotherapy in liver tumors by exploring the evidence surrounding the use of SBRT and immunotherapy for the treatment of HCC and CCA.

Stereotactic Body Radiation Therapy for Hepatocellular Carcinoma: Current State and Future Opportunities

Hepatocellular carcinoma is a rising cause of morbidity and mortality in the USA and around the world. Surgical resection and liver transplantation are the preferred management strategies; however, less than 30% of patients are eligible for surgery. Stereotactic body radiation therapy is a promising local treatment option for non-surgical candidates. Local control rates between 95 and 100% have been reported at 1-2 years post-treatment, and classical radiation-induced liver disease described with conventional radiation is an unlikely complication from stereotactic radiotherapy. Enrollment in randomized trials will be essential in establishing the role of stereotactic radiation in treatment paradigms for hepatocellular carcinoma.

NRG Oncology/RTOG 0438: A Phase 1 Trial of Highly Conformal Radiation Therapy for Liver Metastases

PURPOSE

This study aimed to determine the feasibility and maximally tolerated dose of hypofractionated, conformal radiation therapy (RT) in patients with liver metastases.

METHODS AND MATERIALS

Nonsurgical patients with ≤5 liver metastases (sum of maximal diameter of all lesions ≤8 cm) were included in the study. There were 4 dose levels: 35 Gy, 40 Gy (starting level), 45 Gy, and 50 Gy, in 10 fractions. The clinical target volume included metastases identified on contrast computed tomography or magnetic resonance imaging with a 5-mm margin within the liver. The planning target volume margin ranged from 4 to 30 mm, depending on breathing motion. Dose-limiting toxicities were defined as RT-related grade ≥4 hepatic or gastrointestinal toxicities or thrombocytopenia occurring within 90 days of the start of RT.

RESULTS

A total of 26 patients with metastases from colorectal (8 patients), breast (7 patients) and other malignancies (11 patients) were enrolled between November 2005 and December 2010. Twenty-three patients were evaluable (8, 7, and 8 on the 40, 45, and 50 Gy dose levels, respectively). Two patients assigned to 50 Gy received 35 Gy owing to normal tissue limits, so 2 additional patients were treated to 50 Gy. There were no dose-limiting toxicities on any of the dose levels. On the 45 Gy dose level, 1 patient developed reversible grade 3 enteritis (37 days from RT start) and diarrhea (22 days); another patient developed grade 3 lymphopenia (23 days). At the 50 Gy dose level, 1 patient had grade 3 hyperglycemia (74 days), and another patient developed grade 3 lymphopenia (13 days), colonic hemorrhage (325 days), and colonic gastrointestinal obstruction (325 days). With a potential median follow-up of 66.1 months (range, 34.6-89.0 months), no other late toxicities were observed.

CONCLUSIONS

Treatment of liver metastases with 50 Gy in 10 fractions was feasible and safe in a multi-institutional setting.

Efficacy of stereotactic body radiotherapy for unresectable or recurrent cholangiocarcinoma: a meta-analysis and systematic review

PURPOSE

Non-surgical treatment including stereotactic body radiation therapy (SBRT) have been used practically as alternative modalities for unresectable or recurrent cholangiocarcinoma (CC). We performed a systematic review and meta-analysis to examine the efficacy of SBRT for such patients.

METHODS

Embase, PubMed, MEDLINE, and Cochrane library databases were searched systematically until October 2017. Primary endpoint was 1‑year local control (LC) rate; 1‑year overall survival (OS), response rates, and grade ≥3 toxicities were assessed as secondary endpoints.

RESULTS

Eleven studies (226 patients) were included. The prescribed median SBRT dose was 45 (range 30-55) Gy in 3-5 fractions. The pooled 1‑year LC rate was 81.8% (95% confidence interval [CI] 69.4-89.9%) in the studies using an equivalent dose in 2 Gy per fraction (EQD2) ≥71.3 Gy2 and 74.7% (95% CI 57.1-86.7%) in the studies using an EQD2 <71.3 Gy2. The median OS was 13.6 (range 10-35.5) months. The pooled 1‑year OS rate was 53.8% (95% CI 44.9-62.5%) and the pooled 1‑year LC rate was 78.6% (95% CI 69.0-85.8%). Most common toxicity was duodenal ulcer and gastric ulcer in available studies, with the acute incidence of grade ≥3 of less than 10% and the late incidence of 10-20%.

CONCLUSIONS

SBRT was a feasible treatment option with respect to achieving a high LC for unresectable or recurrent CC. Gastrointestinal toxicity is acceptable, but remains an obstacle related to dose escalation.

Stereotactic body radiation therapy for hepatocellular carcinoma: Practice patterns, dose selection and factors impacting survival

Background

Stereotactic body radiation therapy (SBRT) is an emerging option for unresectable hepatocellular carcinoma (HCC) without consensus regarding optimal dose schemas. This analysis identifies practice patterns and factors that influence dose selection and overall survival, with particular emphasis on dose and tumor size.

Materials/Methods

Query of the National Cancer Database (NCDB) identified patients with unresectable, nonmetastatic HCC who received SBRT from 2004 to 2013. Biological Effective Dose (BED) was calculated for each patient in order to uniformly analyze different fractionation regimens.

Results

A total of 456 patients met the inclusion criteria. The median BED was 100 Gy (22.5‐208.0), which corresponded to the most common dose fractionation (50 Gy in five fractions). Various factors influenced dose selection including tumor size (P < 0.001), tumor stage (P = 0.002), and facility case volume (<0.001). On multivariate analysis, low BED (<75 Gy, HR 2.537, P < 0.001; 75‐100 Gy, HR 1.986, P = 0.007), increasing tumor size (HR 1.067, P = 0.032), elevated AFP (HR 1.585, P = 0.019), stage 3 (HR 1.962, P < 0.001), low‐volume facilities (1‐5 cases HR 1.687, P = 0.006), and a longer time interval from diagnosis to SBRT (>2 to ≤4 months, HR 1.456, P = 0.048; >4 months, HR 2.192, P < 0.001) were associated with worse survival.

Conclusion

SBRT use is increasing for HCC, and multiple regimens are clinically employed. Although high BED was associated with improved outcomes, multiple factors contributed to the dose selection with favorable patients receiving higher doses. Continued efforts to enhance radiation planning and delivery may help improve utilization, safety, and efficacy.

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

PURPOSE

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

METHODS AND MATERIALS

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

RESULTS

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

CONCLUSIONS

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

Clinical Case Panel: Treatment Alternatives for Inoperable Hepatocellular Carcinoma

Surgical resection or liver transplantation offers the best chance of cure for patients with hepatocellular carcinoma (HCC). Unfortunately, most patients are not good candidates for liver resection due to locally advanced disease or compromised liver function. Moreover, liver transplantation waiting lists are long. For those cases not amenable for resection, a variety of local treatment modalities are available, such as image-guided ablative procedures, transarterial chemoembolization, and radioembolization, as well as external beam radiation. HCC presentation can vary considerably in size, number, and location of lesions. The management of inoperable HCC is, therefore, quite complex, and there is a lack of consensus on the best local treatment modality for each type tumor presentation. Here, we present 4 clinical case scenarios representative of commonly seen cases in the clinical setting, with different therapeutic perspectives from institutions with high expertise in the management of HCC.

Cholangiocarcinoma and Gallbladder Cases: An Expert Panel Case-Based Discussion

Cholangiocarcinoma and gallbladder malignancies are aggressive gastrointestinal malignancies with management dependent on resectability, comorbidities, and location. A multidisciplinary discussion with medical oncologists, radiation oncologists, and surgeons is necessary to determine the optimal treatment approach for each patient. Surgical resection offers the best chance for a long-term cure. Recent studies, such as the phase II SWOG S0809 and the phase III BILCAP study have highlighted the importance of adjuvant treatment with radiation therapy and chemotherapy, respectively, in resected disease. In patients with unresectable disease chemotherapy and chemoradiation therapy to a high dose can improve overall survival and locoregional control. In this expert panel we have brought together radiation oncologists and a medical oncologist to provide case-based feedback on their institutional practices.

Radiotherapy for Hepatocellular Carcinoma

For patients with unresectable or medically inoperable hepatocellular carcinoma, there are many local and regional therapies available, including stereotactic body radiotherapy, radiofrequency ablation, and transcatheter embolic approaches. This article will describe these treatment options and review the current comparative literature, suggesting that stereotactic body radiotherapy provides similar or better tumor control and a favorable side effect profile.