Initial clinical outcomes of proton beam radiotherapy for hepatocellular carcinoma

A phase II trial of hypofractionated high-dose proton beam therapy for unresectable liver metastases

BACKGROUND AND PURPOSE

Proton beam therapy (PBT) is an effective treatment option for primary malignant liver disease. However, evidence regarding liver metastasis is insufficient. We aimed to investigate the efficacy and safety of hypofractionated high-dose PBT in the treatment of metastatic liver disease.

MATERIALS AND METHODS

From January 2019 to January 2021, patients with unresectable liver metastases were enrolled. For PBT, the dose schemes of 60 Gy relative biological effectiveness (GyRBE) in 5 fractions (fx) (biologically effective dose [BED] 132 GyE) or 70 GyRBE in 10 fx (BED 119 GyE) were used. Either a passive scattered beam or pencil beam scanning (PBS)-based intensity-modulated proton therapy (IMPT) was performed with proper respiratory management. The primary endpoint of the study was 6-month freedom from local progression (FFLP) rate; and the Kaplan-Meier method was used to calculate the FFLP and survival rates.

RESULTS

Of the 49 liver metastases in 46 patients, the colorectum accounted for 60% of the primary cancer sites, followed by the gastrointestinal organs and pancreas/biliary tract. Forty patients presented only 1 liver metastasis, while the other 6 patients had 2 to 4 metastases. The Six-month FFLP rate was 95.2%. The 1-year FFLP rate in patients with <3 cm liver metastasis was 87.4%, while that was 74.1% in patients with > 3 cm group (p = 0.087). With regard to systemic treatment, the 1-year FFLP rate after PBT was better (94.1%) than that without systemic treatment (75.8%; p = 0.051). Regarding PBT-related toxicity, one patient developed a grade 2 gastric ulcer, while none of the patients developed grade ≥3 toxicities.

CONCLUSIONS

Hypofractionated PBT with a BED > 100 GyRBE for liver metastasis is safe and effective, given the high rate of 6-month FFLP without grade ≥3 treatment-related toxicities. However, further improvements are required for larger tumors and/or those without prior systemic therapy.

Proton Therapy in the Management of Hepatocellular Carcinoma

Simple Summary

Radiation therapy is among the locoregional therapy modalities used to treat unresectable or medically inoperable hepatocellular carcinoma (HCC). Proton radiation therapy plays a major role in the treatment of HCC, especially when liver toxicity is a concern. The aim of this review is to provide a concise and comprehensive summary on the use of proton therapy in the management of HCC.

Abstract

Proton radiation therapy plays a central role in the treatment of hepatocellular carcinoma (HCC). Because of the near-zero exit dose and improved sparing of normal liver parenchyma, protons are being used even in challenging scenarios, including larger or multifocal liver tumors, and those associated with vascular tumor thrombus. There is a mounting level of evidence that suggests that protons are superior to photons in terms of survival and toxicity outcomes, specifically the progression to liver failure. A randomized controlled trial comparing protons to photons is currently underway to verify this hypothesis.

Favorable response to multimodal treatment in hepatocellular carcinoma with inferior vena cava and right atrial tumor thrombus and left adrenal gland metastasis: A case report and literature review

RATIONALE

Hepatocellular carcinoma (HCC) is the fourth most common cause of cancer-related deaths and the sixth most commonly diagnosed cancer globally. Interdisciplinary and multimodal treatment strategies are essential for a successful therapy in HCC. Established therapies for HCC treatment include surgical resection, liver transplantation, local ablative therapies, transarterial chemoembolization (TACE), tyrosine kinase inhibitors (TKIs), immunotherapy, and radiotherapy (RT).

PATIENT CONCERNS

A 52-year-old male patient did an ultrasound scan and found a large mass within the right lobe of the liver and gallstones in December 2018. He had a history of chronic hepatitis C virus infection (30 years) and was treated with sofosbuvir (400 mg, q.d.) for 1 year. The patient never had any symptoms of gallstones. Enhanced abdominal computed tomography of this patient showed a heterogeneous irregular mass with the largest measurement of up to 13.7 × 11.1 cm in size in the right lobe of the liver, meanwhile also had inferior vena cava (IVC) tumor thrombus, right atrial (RA) tumor thrombus, and left adrenal gland metastasis. The laboratory test data revealed that the serum tumor marker α-fetoprotein was 2.63 ng/mL, cancer antigen 19-9 (CA 19-9) was 34.40 U/mL, and protein induced by Vitamin K absence was 391.94 mAU/mL.

DIAGNOSIS

HCC with IVC tumor thrombus, RA tumor thrombus, and left adrenal gland metastasis, and gallstones.

INTERVENTIONS

He was hospitalized and received TACE treatment, oral TKIs, intravenous drip programmed cell death-1 (PD-1) inhibitor and RT.

OUTCOMES

The patient showed a favorable response after consecutive treatment with TACE, TKIs, PD-1 inhibitor, and RT. Until now, the patient has survived 34 months since the diagnosis of the disease.

LESSONS

Our case suggests that TACE combined with TKIs, PD-1 inhibitor, and RT may be a suitable treatment option for advanced HCC patients with IVC tumor thrombus and/or RA tumor thrombus, and/or adrenal gland metastasis.

A preliminary study of hepatocellular carcinoma post proton beam therapy using MRI as an early prediction of treatment effectiveness

Purpose

To demonstrate the feasibility of magnetic resonance imaging (MRI) for early prediction of proton beam therapy (PBT) effectiveness in hepatocellular carcinoma (HCC).

Methods

Clinical data of the HCC patients without regional lymph node involvement or distant metastasis who received PBT at this institution between 2014 and 2017 were reviewed. A total of 43 patients were included. Tumor regression pattern after PBT were examined on the basis of follow-up duration. The variables were compared between patients with and without early tumor regression (ETR).

Results

The median follow-up duration was 40 months (range, 9–62 months). The cumulative overall survival rate at 6 months, 1 years and 5 years was 100%, 88.4%, 63.4%, respectively. Child-Pugh class A, local tumor control (LTC), complete response (CR), and ETR were significantly associated with overall survival (p < 0.05 each). Of 43 patients, 25 patients (58.1%) reached CR in the PBT-irradiated region. Twelve patients (27.9%) had a partial response and 3 patients (7.0%) had a stationary disease. Three patients (7.0%) developed in-field progression. The LTC rate at 5 years was 93.0%. Of the 25 patients who achieved a CR in the PBT-irradiated region, the median time to CR was 5 months (range, 1–19 months). Twenty-two patients (51.2%) showed ETR of the HCC, while 21 patients (48.8%) showed non-ETR. A significant association was observed between ETR and CR of the HCC after PBT (p < 0.001).

Conclusion

The post-PBT MRI follow-up at 3 months is helpful for monitoring therapeutic response. ETR of the HCC predicted a higher rate of CR and was associated with overall survival, which provides more accurate clinical management.

Do Biliary Complications after Proton Beam Therapy for Perihilar Hepatocellular Carcinoma Matter?

We aimed to evaluate the biliary complications and efficacy of proton beam therapy (PBT) for hepatocellular carcinoma (HCC). We retrospectively analyzed 167 patients who received PBT with ≥ 75 GyRBE of biological effective dose with 𝛼/β = 10 for primary HCC. The perihilar region was defined as a 1-cm area extending from the right, left, and common hepatic ducts, including the gallbladder and cystic duct. PBT-related biliary complications were defined as follows: significant elevation in bilirubin level to > 3.0 mg/dL; elevation to more than twice of the baseline level after the completion of PBT; or newly developed radiological biliary abnormalities, which were not caused by HCC progression, comorbidities, or other treatments. Eighty (47.9%) had perihilar HCC. PBT-related events occurred in seven (4.2%), three of whom had perihilar HCC. Radiologic biliary abnormalities developed in 12 patients (7.2%); however, no events were PBT-related. All patients who experienced PBT-related biliary complications had underlying liver cirrhosis. The albumin-bilirubin grade was identified as an independent factor associated with PBT-related biliary complications. PBT at the current dose showed a low rate of PBT-related biliary complications even for patients with perihilar HCC. PBT for HCC patients with risk factors requires attention to reduce PBT-related biliary complications.

Clinical Significance of Systemic Inflammation Markers in Newly Diagnosed, Previously Untreated Hepatocellular Carcinoma

This study aimed to investigate the clinical significance of systemic inflammation markers (SIMs)-including neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and lymphocyte-to-monocyte ratio (LMR)-in patients with newly diagnosed, previously untreated hepatocellular carcinoma (HCC). The present study was performed using prospectively collected registry data of newly diagnosed, previously untreated HCC from a single institution. The training set included 6619 patients from 2005 to 2013 and the validation set included 2084 patients from 2014 to 2016. The SIMs as continuous variables significantly affected the overall survival (OS), and the optimal cut-off value of NLR, PLR, and LMR was 3.0, 100.0, and 3.0, respectively. There were significant correlations between SIMs and the albumin-bilirubin grade/Child-Turcotte-Pugh class (indicative of liver function status) and the staging system/portal vein invasion (indicative of the tumor burden). The OS curves were well stratified according to the prognostic model of SIMs and validated using the bootstrap method (1000 times, C-index 0.6367, 95% confidence interval (CI) 0.6274-0.6459) and validation cohort (C-index 0.6810, 95% CI 0.6570-0.7049). SIMs showed significant prognostic ability for OS, independent of liver function and tumor extent, although these factors were significantly correlated with SIMs in patients with newly diagnosed, previously untreated HCC.

Comparison of clinical outcomes between passive scattering versus pencil-beam scanning proton beam therapy for hepatocellular carcinoma

BACKGROUND AND PURPOSE

Our study aimed to compare the oncologic outcomes and toxicities between passive scattering (PS) proton beam therapy (PBT) and pencil-beam scanning (PBS) PBT for primary hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

The multidisciplinary team for liver cancer identified the PBT candidates who were ineligible for resection or radiofrequency ablation. We retrospectively analyzed 172 patients who received PBT for primary HCC from January 2016 to December 2017. The PS with wobbling method was applied with both breath-hold and regular breathing techniques, while the PBS method was utilized only for regular breathing techniques covering the full amplitude of respiration. To maintain the balance of the variables between the PS and PBS groups, we performed propensity score matching.

RESULTS

The median follow-up duration for the total cohort was 14 months (range, 1-31 months). After propensity score matching, a total of 103 patients (70 in the PS group and 33 in the PBS group) were included in analysis. There were no significant differences in the rates of overall survival (OS), in-field local control (IFLC), out-field intrahepatic control (OFIHC), extrahepatic progression-free survival (EHPFS), and complete response (CR) between the matched groups. In the subgroup analyses, no subgroup showed a significant difference in IFLC between the PS and PBS groups. There was also no significant difference in the toxicity profiles between the groups.

CONCLUSION

There are no differences in oncologic outcomes, including OS, IFLC, OFIHC, EHPFS, and CR rates, or in the toxicity profiles between PS and PBS PBT for primary HCC.

Clinical significance of radiotherapy before and/or during nivolumab treatment in hepatocellular carcinoma

Background

This study aimed to investigate the clinical significance of previous and/or concurrent application of radiotherapy (RT) in the course of nivolumab treatment for advanced hepatocellular carcinoma (HCC).

Methods

Patients with advanced HCC who received nivolumab treatment between March 2017 and May 2018. were included. Nivolumab treatment was indicated in patients who did not respond to conventional therapy including locoregional therapy and/or sorafenib. RT was performed when necessary for curative/palliative purpose.

Results

Among the 76 HCC patients who received nivolumab, 54 (71.1%) had received RT for HCC before and/or during the treatment. The period from initial HCC diagnosis to nivolumab treatment was significantly longer (P = .007) and the rate of undergoing transarterial chemoembolization (TACE; P = .006) and sorafenib treatment (P = .007) was significantly higher in patients who received previous/concurrent RT than in those who did not. Nivolumab‐related toxicities were generally tolerable regardless of the history of RT. During the follow‐up, 39 (51.3%) patients died and 54 (71.1%) patients experienced disease progression according to the RECIST v1.1. Patients who had received previous/concurrent RT had a significantly longer progression‐free survival (PFS; P = .008) and overall survival (OS; P = .007) than those who did not receive RT; however, this trend was not observed in patients with a history of radiofrequency ablation or TACE (all P > .05).

Conclusion

Previous and/or concurrent application of RT in the course of nivolumab treatment was related with longer PFS and OS in advanced HCC patients. Nonetheless, further clinical studies are warranted to confirm our findings.

Optimizing radiotherapy with immune checkpoint blockade in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common cancer, and its incidence is rapidly increasing in North America and Western Europe as well as South-East Asia. Patients with advanced stage HCC have very poor outcomes; therefore, the discovery of new innovative approaches is urgently needed. Cancer immunotherapy has become a game-changer and revolutionized cancer treatment. A comprehensive understanding of tumor-immune interactions led to the development of immune checkpoint inhibitors (ICIs) as new therapeutic tools, which have been used with great success. Targeting immune checkpoint molecules such as programmed cell death-1 (PD-1) and cytotoxic T lymphocyte-associated protein-4 (CTLA-4) reinvigorates anti-tumor immunity by restoring exhausted T cells. Despite their effectiveness in several types of cancer, of the many immune suppressive mechanisms limit the efficacy of ICI monotherapy. Radiation therapy (RT) is an essential local treatment modality for a broad range of malignancies, and it is currently gaining extensive attention as a promising combination partner with ICIs because of its ability to trigger immunogenic cell death. The efficacy of combination approaches using RT and ICIs has been well documented in numerous preclinical and clinical studies on various types of cancers but not HCC. The application of ICIs has now expanded to HCC, and RT is recognized as a promising modality in HCC. This review will highlight the current roles of PD-1 and CTLA-4 therapies and their combination with RT in the treatment of cancers, including HCC. In addition, this review will discuss the future perspectives of the combination of ICIs and RT in HCC treatment.

Successful Endoscopic Closure Using Polyglycolic Acid Sheets with Fibrin Glue for Nonhealing Duodenal Ulcer with Perforation after Proton Beam Therapy of Liver Tumor

We describe the first case of a nonhealing duodenal ulcer with perforation after proton beam therapy (PBT) of a liver tumor that was successfully treated endoscopically using polyglycolic acid (PGA) sheets with fibrin glue. A 69-year-old man received PBT for a liver tumor. Esophagogastroduodenoscopy (EGD) 3 months after PBT revealed a duodenal ulcer. A proton pump inhibitor was administered for 7 weeks, and the ulcer healed. Six months after the EGD, recurrence of the duodenal ulcer with perforation occurred. An emergency open surgery with placement of the omental patch was performed. However, 5 days after the surgery, because the EGD revealed a perforation site in the duodenal ulcer that was not closed, the conservative treatment was continued. Twenty-eight days after the surgery, EGD revealed that the perforation size had increased. Therefore, we conducted endoscopic closure therapy using PGA sheets with fibrin glue. Eleven days after the closure procedure, the EGD showed that the perforation site was filled with granulation tissue and was closed. Forty-nine days after the procedure, EGD revealed that the ulcer had healed. This endoscopic closure treatment was effective for a nonhealing duodenal ulcer with perforation after PBT of a liver tumor.

Patient specific outcomes of charged particle therapy for hepatocellular carcinoma - A systematic review and quantitative analysis

Hepatocellular carcinoma (HCC) is a raising condition world-wide. Most of patients are ineligible for surgery at diagnosis due to the advanced stage of the disease or poor medical condition of the patient. Charged particle therapy (CPT) is a radiotherapy modality showing promising results. The aim of this systematic review was to summarize current knowledge on patient-specific outcomes of CPT for HCC, including overall survival, local control, the effect of radiation dose and the toxicity burden. The systematic review was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). After comprehensive database search 17 cohorts (16 studies, 1516 patients) were included into qualitative and quantitative analyses; 11 of 16 studies were retrospective. Eleven studies were on protons, 2 studies were on protons and carbon ions and 4 on carbon ions alone, were identified. Median BED10 (biologically equivalent dose) range was 68.75-122.5 GyE. Mean weighted overall survival across studies was 86%, 62%, 59% and 35% at 1, 2, 3 and 5 years, respectively. Mean weighted local control was 86%, 89%, 87% and 89% at 1, 2, 3 and 5 years, respectively. Adjusted morbidity rates were: 54% for acute G1-2 toxicities and 6% for acute ≥G3 toxicities; 9% for late G1-2 toxicities and less than 4% for late ≥G3 toxicities. There was no treatment-associated mortality. CONCLUSIONS: CPT offers high local control, acceptable overall survival and low post-treatment morbidity. Quality of findings, especially on toxicities, is decreased by incomplete reporting and retrospective designs of available studies. Therefore, there is a strong need for better reporting and prospective studies.

Proton therapy for hepatocellular carcinoma: Current knowledges and future perspectives

Hepatocellular carcinoma (HCC) is the second leading cause of cancer-related death, as few patients can be treated with currently available curative local modalities. In patients with HCC where curative modalities are not feasible, radiation therapy (RT) has emerged as an alternative or combination therapy. With the development of various technologies, RT has been increasingly used for the management of HCC. Among these advances, proton beam therapy (PBT) has several unique physical properties that give it a finite range in a distal direction, and thus no exit dose along the beam path. Therefore, PBT has dosimetric advantages compared with X-ray therapy for the treatment of HCC. Indeed, various reports in the literature have described the favorable clinical outcomes and improved safety of PBT for HCC patients compared with X-ray therapy. However, there are some technical issues regarding the use of PBT in HCC, including uncertainty of organ motion and inaccuracy during calculation of tissue density and beam range, all of which may reduce the robustness of a PBT treatment plan. In this review, we discuss the physical properties, current clinical data, technical issues, and future perspectives on PBT for the treatment of HCC.