Effectiveness and safety of proton beam therapy for advanced hepatocellular carcinoma with portal vein tumor thrombosis. Strahlenther Onkol. 2014;190:806-814. [PMID: 24589917 DOI: 10.1007/s00066-014-0604-6]

Recent update of proton beam therapy for hepatocellular carcinoma: a systematic review and meta-analysis

BACKGROUNDS/AIMS

Although access to proton beam therapy (PBT) is limited worldwide, its use for the treatment of hepatocellular carcinoma (HCC) is gradually increasing with the expansion of new facilities. Therefore, we conducted a systematic review and metaanalysis to investigate the updated evidence of PBT for HCC.

METHODS

The MEDLINE, EMBASE, Cochrane Library, and Web of Science databases were systematically searched for studies that enrolled patients with liver-confined HCC that were treated with PBT for a cure up to February 2024.

RESULTS

A total of 1,858 HCC patients receiving PBT from 22 studies between 2004 and 2023 were selected for this meta-analysis. The median proportion of Child-Pugh class A was 86% (range, 41-100), and the median tumor size was 3.6 cm (range, 1.2-9.0). The median total dose ranged from 55 GyE to 76 GyE (median, 69). The pooled rates of 3- and 5-year local progression-free survival after PBT were 88% (95% confidence interval [CI], 85-91) and 86% (95% CI, 82-90), respectively. The pooled 3- and 5-year overall rates were 60% (95% CI, 54-66) and 46% (95% CI, 38-54), respectively. The pooled rates of grade 3 hepatic toxicity, classic radiationinduced liver disease (RILD), and non-classic RILD were 1%, 2%, and 1%, respectively.

CONCLUSIONS

The current study supports PBT for HCC and demonstrates favorable long-term survival and low hepatic toxicities compared with other published studies on other radiotherapy modalities. However, further studies are needed to identify the subgroups that will benefit from PBT.

Proton Beam Therapy for Treating Patients with Hepatocellular Carcinoma with Major Portal Vein Tumor Invasion: A Single Center Retrospective Study

Hepatocellular carcinoma (HCC) with portal vein tumor thrombosis (PVTT) has a poor prognosis and is generally not indicated for surgery. Proton beam therapy (PBT) may offer an alternative treatment. In this study, long-term outcomes were examined in 116 patients (median age 66 years, 100 males) with HCC with advanced PVTT (Vp3 or Vp4) who received PBT from April 2008 to March 2018. Of these patients, 63 received PBT as definitive treatment and 53 as palliative treatment. The representative dose was 72.6 Gy (RBE) in 22 fractions. Eight patients died in follow-up, including 72 due to tumor progression. The 5-year overall survival (OS) rate was 18.0% (95% CI 9.8-26.2%) and the 5-year local control (LC) rate was 86.1% (74.9-97.3%). In multivariate analyses, performance status and treatment strategy were significantly associated with OS. The median follow-up period for survivors with definitive treatment was 33.5 (2-129) months, and the 5-year OS rate was 25.1% (12.9-37.3%) in these cases. The median survival time after definitive irradiation was >20 months. The 5-year OS rate was 9.1% (0-19.7%) for palliative irradiation. These results compare favorably with those of other therapies and suggest that PBT is a useful option for cases of HCC with advanced PVTT that cannot undergo surgery, with an expected survival benefit and good local control. Determining the optimal indication for this treatment is a future challenge.

Impact of iodinated oil in proton therapy on relative stopping power of liver post-cTACE

Objective. Conventional transarterial chemoembolization (cTACE) is a common treatment for hepatocellular carcinoma (HCC), often with unsatisfactory local controls. Combining cTACE with radiotherapy shows a promise for unresectable large HCC, with proton therapy preserving healthy liver tissue. However, the proton therapy benefits are subject to the accuracy of tissue relative stopping power (RSP) prediction. The RSP values are typically derived from computed tomography (CT) images using stoichiometric calibration. Lipiodol deposition significantly increases CT numbers in liver regions of post-cTACE. Hence, it is necessary to evaluate the accuracy of RSP in liver regions of post-cTACE.Approach. Liver, water, and iodinated oil samples were prepared. Some liver samples contained iodinated oil. The water equivalent path length (WEPL) of sample was measured through the pullbacks of spread-out Bragg peak (SOBP) depth-dose profiles scanned in a water tank with and without sample in the beam path. Measured RSP values were compared to estimated RSP values derived from the CT number based on the stoichiometric calibration method.Main results. The measured RSP of water was 0.991, confirming measurement system calibration. After removing the RSP contribution from container walls, the pure iodinated oil and liver samples had RSP values of 1.12 and 1.06, while the liver samples mixed with varying oil volumes (5 ml, 10 ml, 15 ml) showed RSP values of 1.05, 1.05 and 1.06. Using the stoichiometric calibration method, pure iodinated oil and liver samples had RSP values of 2.79 and 1.06. Liver samples mixed with iodinated oil (5 ml, 10 ml, 15 ml) had calculated RSP values of 1.21, 1.34, and 1.46. The RSP discrepancy reached 149.1% for pure iodinated oil.Significance.Iodinated oil notably raises CT numbers in liver tissue. However, there is almost no effect on its RSP value. Proton treatment of post-cTACE HCC patients can therefore be overshooting if no proper measures are taken against this specific effect.

Proton Beam Therapy for Hepatocellular Carcinoma: Multicenter Prospective Registry Study in Japan

PURPOSE

A prospective multicenter registry study was started May 2016 in Japan to evaluate the efficacy and safety of proton beam therapy (PBT) for hepatocellular carcinoma (HCC).

METHODS AND MATERIALS

Patients who received PBT for HCC from May 2016 to June 2018 were registered in the database of the Particle Beam Therapy Committee and Subcommittee of the Japanese Society for Radiation Oncology. Overall survival (OS), progression-free survival (PFS), and local recurrence were evaluated.

RESULTS

Of the 755 registered patients, 576 with initial PBT and no duplicate cancer were evaluated. At final follow-up, 322 patients were alive and 254 had died. The median follow-up period for survivors was 39 months (0-58 months). The median OS time of the 576 patients was 48.8 months (95% CI, 42.0-55.6 months) and the 1-, 2-, 3-, and 4-year OS rates were 83.8% (95% CI, 80.5%-86.6%), 68.5% (64.5%-72.2%), 58.2% (53.9%-62.2%), and 50.1% (44.9%-55.0%), respectively. Recurrence was observed in 332 patients, including local recurrence in 45 patients. The median PFS time was 14.7 months (95% CI, 12.4-17.0 months) and the 1-, 2-, 3-, and 4-year PFS rates were 55.2% (95% CI, 51.0%-59.2%), 37.5% (33.5%-41.5%), 30.2% (26.3%-34.2%), and 22.8% (18.5%-27.4%), respectively. The 1-, 2-, 3-, and 4-year OS rates were significantly higher for tumor size <5 versus 5 to 10 cm (P < .001) and <5 versus ≥10 cm (P < .001); Child-Pugh score A/B versus C (P < .001); and distance of the tumor from the gastrointestinal tract <1 versus 1 to 2 cm (P < .008) and <1 versus >2 cm (P < .001). At final follow-up, 27 patients (4.7%) had late adverse events of grade 3 or higher, with liver failure (n = 7), and dermatitis (n = 7) being most common.

CONCLUSIONS

This multicenter prospective data registry indicated that PBT for HCC gives good therapeutic effects (3-year local control rate of 90%) with a low risk of severe late adverse events.

Current evidence and the potential role of proton beam therapy for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related death, and external beam radiation therapy has emerged as a promising approach for managing HCC. Proton beam therapy (PBT) offers dosimetric advantages over X-ray therapy, with superior physical properties known as the Bragg peak. PBT holds promise for reducing hepatotoxicity and allowing safe dose-escalation to the tumor. It has been tried in various clinical conditions and has shown promising local tumor control and survival outcomes. A recent phase III trial demonstrated the non-inferiority of PBT in local tumor control compared to current standard radiofrequency ablation in early-stage HCC. PBT also tended to show more favorable outcomes compared to transarterial chemoembolization in the intermediate stage, and has proven effective in-field disease control and safe toxicity profiles in advanced HCC. In this review, we discuss the rationale, clinical studies, optimal indication, and future directions of PBT in HCC treatment.

Feasibility of additional radiotherapy in patients with advanced hepatocellular carcinoma treated with atezolizumab plus bevacizumab

BACKGROUND/AIM

Radiotherapy (RT) is an effective local treatment for hepatocellular carcinoma (HCC). However, whether additional RT is safe and effective in patients with advanced HCC receiving atezolizumab plus bevacizumab remains unclear. This retrospective cohort study aimed to evaluate the feasibility of additional RT in these patients.

METHODS

Between March and October 2021, we retrospectively analyzed seven patients with advanced HCC who received RT during treatment with atezolizumab plus bevacizumab. The median prescribed RT dose was 35 Gy (range, 33-66). Freedom from local progression (FFLP), progression-free survival (PFS), and overall survival (OS) after RT were analyzed.

RESULTS

The median follow-up duration after RT was 14.2 months (range, 10.0-18.6). Of the seven patients, disease progression was noted in six (85.7%), the sites of disease progression were local in two (28.6%), intrahepatic in four (57.1%), and extrahepatic in four (57.1%). The median time of FFLP was not reached, and PFS and OS times were 4.0 (95% confidence interval [CI], 3.6-4.5) and 14.8% (95% CI, 12.5-17.2) months, respectively. The 1-year FFLP, PFS, and OS rates were 60% (95% CI, 43.8-76.2), 0%, and 85.7% (95% CI, 75.9-95.5), respectively. Grade 3 or higher hematologic adverse events (AEs) were not observed, but grade 3 nonhematologic AEs unrelated to RT were observed in one patient.

CONCLUSIONS

The addition of RT may be feasible in patients with advanced HCC treated with atezolizumab plus bevacizumab. However, further studies are required to validate these findings.

Hepatectomy versus sorafenib for advanced hepatocellular carcinoma with macroscopic portal vein tumor thrombus: A bi-institutional propensity-matched cohort study

AIM

Sorafenib was previously considered a first-line treatment for hepatocellular carcinoma (HCC) patients with macroscopic portal vein tumor thrombus (PVTT). This case-matched analysis was performed to evaluate the best first-line treatment for HCC in patients with macroscopic PVTT.

METHODS

The HCC patients with Vp2 (PVTT invaded into a second-order portal branch), Vp3 (first-order portal branch), and Vp4 (main trunk or contralateral portal vein) PVTT who underwent hepatectomy and those treated with sorafenib were included. Treatment results were compared between the two modalities for each PVTT category, and a propensity analysis was performed for patients with Vp3 and Vp4 (Vp3/4).

RESULTS

The median survival times (MSTs) of patients with Vp2, Vp3, and Vp4 PVTT who underwent hepatectomy were 21.4, 13.6, and 14.9 months, respectively; the MSTs for those with Vp2, Vp3, and Vp4 PVTT who received sorafenib treatment were 6.9, 5.5, and 3.6 months, respectively, with a significant difference. In a propensity-matched cohort of patients with Vp3/4 PVTT (36 patients in each), the MST of patients who underwent hepatectomy (15.1 months) was significantly better than the patients treated with sorafenib (4.5 months).

CONCLUSION

Hepatectomy can be associated with prolonged survival in HCC patients with macroscopic PVTT.

2022 KLCA-NCC Korea practice guidelines for the management of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide and the fourth most common cancer among men in South Korea, where the prevalence of chronic hepatitis B infection is high in middle and old age. The current practice guidelines will provide useful and sensible advice for the clinical management of patients with HCC. A total of 49 experts in the fields of hepatology, oncology, surgery, radiology, and radiation oncology from the Korean Liver Cancer Association-National Cancer Center Korea Practice Guideline Revision Committee revised the 2018 Korean guidelines and developed new recommendations that integrate the most up-to-date research findings and expert opinions. These guidelines provide useful information and direction for all clinicians, trainees, and researchers in the diagnosis and treatment of HCC.

2022 KLCA-NCC Korea Practice Guidelines for the Management of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide and the fourth most common cancer among men in South Korea, where the prevalence of chronic hepatitis B infection is high in middle and old age. The current practice guidelines will provide useful and sensible advice for the clinical management of patients with HCC. A total of 49 experts in the fields of hepatology, oncology, surgery, radiology, and radiation oncology from the Korean Liver Cancer Association-National Cancer Center Korea Practice Guideline Revision Committee revised the 2018 Korean guidelines and developed new recommendations that integrate the most up-to-date research findings and expert opinions. These guidelines provide useful information and direction for all clinicians, trainees, and researchers in the diagnosis and treatment of HCC.

Clinical Efficacy of Hypofractionated Proton Beam Therapy for Intrahepatic Cholangiocarcinoma

Forty-seven patients with intrahepatic cholangiocarcinoma (IHCC) who received proton beam therapy (PBT) were analyzed to evaluate the clinical efficacy and safety of hypofractionated PBT in patients with inoperable or recurrent IHCC. The median prescribed dose of PBT was 63.3 GyE (range: 45-80 GyE) in 10 fractions, and the median duration of follow-up in all the patients was 18.3 months (range: 2.4-89.9 months). Disease progression occurred in 35 of the 47 (74.5%) patients; local, intrahepatic, and extrahepatic progression occurred in 5 (10.6%), 20 (42.6%), and 29 (61.7%) patients, respectively. The 2-year freedom from local progression (FFLP), progression-free survival (PFS), overall survival (OS) rates, and median time of OS were 86.9% (95% confidence interval [CI], 74.4-99.4%), 16.8% (95% CI, 4.3-29.3%), 42.7% (95% CI, 28.0-57.4%), and 21.9 months (95% CI, 16.2-28.3 months), respectively; grade ≥ 3 adverse events were observed in four (8.5%) patients. In selected patients with localized disease (no viable tumors outside of the PBT sites), the median time of OS was 33.8 months (95% CI, 5.4-62.3). These findings suggest that hypofractionated PBT is safe and could offer a high rate of FFLP and promising OS in patients with inoperable or recurrent IHCC.

2022 KLCA-NCC Korea practice guidelines for the management of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide and the fourth most common cancer among men in South Korea, where the prevalence of chronic hepatitis B infection is high in middle and old age. The current practice guidelines will provide useful and sensible advice for the clinical management of patients with HCC. A total of 49 experts in the fields of hepatology, oncology, surgery, radiology, and radiation oncology from the Korean Liver Cancer Association-National Cancer Center Korea Practice Guideline Revision Committee revised the 2018 Korean guidelines and developed new recommendations that integrate the most up-to-date research findings and expert opinions. These guidelines provide useful information and direction for all clinicians, trainees, and researchers in the diagnosis and treatment of HCC.

Evaluating the long-term survival benefits of high intensity focused ultrasound ablation for hepatocellular carcinoma with portal vein tumor thrombus: a single center retrospective study

AIMS

To evaluate the long-term survival benefits of high intensity focused ultrasound (HIFU) ablation in patients with hepatocellular carcinoma (HCC) combined with portal vein tumor thrombus (PVTT).

METHODS

The data of patients with HCC-PVTT treated with HIFU from January 2014 to December 2019 were retrospectively analyzed. All patients received HIFU ablation for both PVTT and liver tumor in one session. Perioperative adverse events (AEs) were recorded, and follow-up was performed postoperatively. The Kaplan-Meier method was used for survival analysis.

RESULTS

Median follow-up was 13.75 ± 1.31 months. A total of 144 patients (male/female: 122/22, age: 54.15 ± 11.84 years old) were included in the study. A total of 267 liver tumors (tumor number: 1.87 ± 1.65, range 1-10) were treated with HIFU. The mean ± SD diameter of viable liver tumors was 100.98 ± 61.65 mm. The reported postoperative AEs of HIFU were skin edema (93.75%), local pain (69.44%) and fever (7.64%). There was no liver failure, gastrointestinal bleeding or perioperative death. The median overall survival (OS) time was 14 months, while the cumulative survival rates of 0.5, 1, 2 and 3 years were 79.0%, 58.6%, 33.3% and 5.9%, respectively. The median OS of PVTT types I, II and III was 22, 13 and 14 months, respectively, and the difference was not statistically significant (p > 0.05).

CONCLUSION

HIFU is a minimally invasive method for HCC-PVTT with fewer complications, which could prolong the OS. Patients with PVTT type III could benefit more from HIFU, compared to types I and II.

Proton Beam Therapy for Treatment-Naïve Hepatocellular Carcinoma and Prognostic Significance of Albumin-Bilirubin (ALBI) Grade

To evaluate the efficacy of proton beam therapy (PBT) as an initial treatment in treatment-naïve hepatocellular carcinoma (HCC) patients and to assess the prognostic significance of albumin-bilirubin (ALBI) grade, 46 treatment-naïve HCC patients treated with PBT were analyzed. The ALBI grade distribution was grade 1 in 11 (23.9%) patients, grade 2 in 34 (73.9%) patients, and grade 3 in 1 (2.2%) patient. The median duration of follow-up was 56.5 months (95% confidence interval [CI], 48.2−64.7). Among the 46 patients, disease progression was observed in 23 (50%) patients: local progression in 3 (6.5%) patients; intrahepatic progression in 22 (47.8%); and extrahepatic progression in 5 (10.9%). The 5-year freedom from local progression (FFLP), progression-free survival (PFS), and overall survival (OS) rates were 92.7% (95% CI, 84.7−100.7), 43.3% (95% CI, 28.2−58.4), and 69.2% (95% CI, 54.9−83.5), respectively. In multivariate analysis, there were no independent factors for FFLP (p > 0.05 each), but tumor stage and ALBI grade were independent factors for PFS and OS (p < 0.05 each). PBT could result in comparable OS in treatment-naïve HCC patients to other recommended first-line treatments, and ALBI grade, in addition to tumor stage, could be useful for predicting OS.

Treatment and the prognosis of hepatocellular carcinoma in Asia

Hepatocellular carcinoma is the most common type of malignant tumour in Asia. Treatment is decided according to the staging system with information on tumour burden and liver function. The Barcelona Clinic Liver Cancer staging system is the most commonly used staging system for the selection of appropriate treatments worldwide, and although it is highly evidenced-base, it has very strict guidelines for treatment. In Asian countries, many efforts have been made to expand the indications of each treatment and combination therapies as well as alternative therapies for better outcomes. The guidelines in Asia are less evidence-based than those in Western countries. More aggressive treatments for hepatocellular carcinoma are generally employed in the guidelines of Asian countries. Surgical resection is frequently employed for selected hepatocellular carcinoma patients with the Barcelona Clinic Liver Cancer stages B and C, and combination therapies are sometimes selected, which are contrary to the recommendations of American and European association for the study of the liver guidelines. Recently, a paradigm shift in treatments for advanced hepatocellular carcinoma has occurred with molecular targeted agents, antibodies and immune checkpoint inhibitors in Asia. Atezolizumab+bevacizumab therapy has become the first-line systemic treatment ineligible for radical treatment or transarterial chemoembolization in Asian countries. The overall survival of patients with hepatocellular carcinoma varies substantially across Asia. Taiwan and Japan have the best clinical outcomes for patients with hepatocellular carcinoma worldwide. Intensive surveillance programmes and the development of radical and non-radical treatments are indispensable for the improvement of prognosis in patients with hepatocellular carcinoma.

Proton Therapy in the Management of Hepatocellular Carcinoma

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.

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

Purpose

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

Methods

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

Results

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

Conclusions

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

Salvage hepatectomy for local recurrence after particle therapy using proton and carbon ion beams for liver cancer

AIM

With the increased use of particle therapy for liver cancer, local recurrence after particle therapy increased. Salvage hepatectomy is an acceptable treatment option for local recurrence following particle therapy; however, its safety and effectiveness remain unclear. Therefore, this multi-center study aimed to verify the feasibility and efficacy of salvage hepatectomy and assess clinical issues associated with its application.

METHODS

We retrospectively assessed the perioperative outcomes, prognosis, and pathological characteristics of 15 patients who underwent salvage hepatectomy for local recurrence after particle therapy between 2006 and 2019.

RESULTS

Hepatocellular carcinoma and metastatic liver tumors were noted in eight and seven patients, respectively. The mean total dose and number of fractions were 66.5 Gy and 12, respectively, and the mean interval between particle therapy and surgery was 30.1 months. Major hepatectomy was performed in seven cases. Moreover, the mortality rate was 0%, and surgical complications of Clavien-Dindo grade IIIa or higher were observed in four cases (27%)-two bile leakages, one pleural effusion, and one refractory skin fistula. The median overall survival time and 5-year overall survival rate after salvage hepatectomy were 29.9 months and 43.1%, respectively. Histological examination of the irradiated liver tissue surrounding the tumor showed sinusoidal dilatation, loss of hepatocyte, and fibrosis in most cases.

CONCLUSION

Salvage hepatectomy after particle therapy is a feasible therapy; however, the risk of refractory complications associated with particle therapy is relatively high. Therefore, the first-line treatment for resectable liver cancer should be carefully determined considering second-line treatment after local recurrence.

Frontiers of therapy for hepatocellular carcinoma

The incidence of hepatocellular carcinoma continues to increase worldwide. Fortunately, there have been notable recent advances in locoregional and systemic therapy. In this current review, we will highlight these new developments and future directions of hepatocellular carcinoma treatment and address the importance of a multidisciplinary approach to treatment.

Long-term clinical outcomes of patients receiving proton beam therapy for caudate lobe hepatocellular carcinoma

Hepatocellular carcinoma (HCC) located in the caudate lobe (caudate HCC) is rare; however, patients with this type of tumour have poorer prognoses than those with HCC in other segments. Despite many published reports on the clinical usefulness of proton beam therapy (PBT) for HCC, data on the clinical outcomes of patients undergoing PBT for caudate HCC remain scarce. Therefore, the present study aimed to investigate the outcomes of this group of patients. Thirty patients with caudate HCC who underwent definitive PBT between February 2002 and February 2014 were retrospectively analysed. The total irradiation doses ranged from 55 to 77 (median 72.6) Gy relative biological dose. The median follow-up period was 37.5 (range, 3.0-152.0) months. The overall survival (OS) rates at one, three and five years were 86.6%, 62.8% and 46.1%, respectively. According to univariate and multivariate analyses, Child-Pugh A (P < 0.01), having a single tumour (P = 0.02) and a low serum alpha-fetoprotein level (AFP; P < 0.01) were significant factors predicting longer survival. The local control (LC) rates at one, three and five years were 100%, 85.9% and 85.9%, respectively, while the corresponding progression-free survival (PFS) rates were 65%, 27.5% and 22%, respectively. No grade 3 or worse adverse events were observed. PBT is effective and safe for the treatment of caudate HCC, and should therefore be considered a feasible option for intervention in patients with this disease.

Who Will Benefit from Charged-Particle Therapy?

Charged-particle therapy (CPT) such as proton beam therapy (PBT) and carbon-ion radiotherapy (CIRT) exhibit substantial physical and biological advantages compared to conventional photon radiotherapy. As it can reduce the amount of radiation irradiated in the normal organ, CPT has been mainly applied to pediatric cancer and radioresistent tumors in the eloquent area. Although there is a possibility of greater benefits, high set-up cost and dearth of high level of clinical evidence hinder wide applications of CPT. This review aims to present recent clinical results of PBT and CIRT in selected diseases focusing on possible indications of CPT. We also discussed how clinical studies are conducted to increase the number of patients who can benefit from CPT despite its high cost.

Patterns of Proton Beam Therapy Use in Clinical Practice Between 2007 and 2019 in Korea

Purpose

Proton beam therapy (PBT) is a state-of-the-art technology employed in radiotherapy (RT) for cancer patients. This study characterized how PBT has been used in clinical practice in Korea.

Materials and Methods

Patients who received any type of RT between 2007 and 2019 were identified from the radiation oncology registry of the two PBT facilities operating in Korea (National Cancer Center and Samsung Medical Center). The χ2 test was used to identify patient- and treatment-related characteristics associated with the receipt of PBT.

Results

A total of 54,035 patients had been treated with some form of RT in the two institutions, of whom 5,398 received PBT (10.0%). The number of patients who receive PBT has gradually increased since PBT first started, from 162 patients in 2007 to 1304 patients in 2019. Among all types of cancer, PBT use in liver cancer has been steadily increasing from 20% in 2008-2009 to 32% in 2018-2019. In contrast, that in prostate cancer has been continuously decreasing from 20% in 2008-2009 to <10% in 2018-2019. Male sex, very young or old age, stage I-II disease, residency in non-capital areas, a definitive setting, a curative treatment aim, enrollment in a clinical trial, re-irradiation and insurance coverage were significantly associated with the receipt of PBT (all p < 0.05).

Conclusion

Since PBT started in Korea, the number of patients receiving PBT has increased to more than 1,000 per year and treatment indications have expanded. Liver cancer is the most common primary tumor among all PBT cases in Korea.

Conversion hepatectomy for hepatocellular carcinoma with main portal vein tumour thrombus after lenvatinib treatment: A case report

BACKGROUND

Hepatocellular carcinoma (HCC) accompanied by portal vein tumour thrombus (PVTT) presents an aggressive disease course, worsening liver function reserve, and a high recurrence rate. Clinical practice guidelines recommend systemic therapy as the first-line option for HCC with portal invasion. However, to achieve longer survival in these patients, the treatment strategy should be concluded with removal of the tumour by locoregional therapy. We experienced a case of initially unresectable HCC with main PVTT converted to radical hepatectomy after lenvatinib treatment.

CASE SUMMARY

A 59-year-old male with chronic hepatitis C infection visited our clinic as a regular post-surgery follow-up. Contrast-enhanced abdominal computed tomography revealed a liver mass diffusely located at the lateral segment with a massive PVTT extending from the umbilical portion to the main and contralateral third-order portal branches. With the diagnosis of unresectable HCC with Vp4 (main trunk/contralateral branch) PVTT, lenvatinib was started at 12 mg/d. The computed tomography taken 3 mo after starting lenvatinib showed regression of the PVTT, which had retreated to the contralateral first-order portal branch. He tolerated the full dose without major adverse effects. With cessation of lenvatinib for 7 d, radical left lobectomy and PVTT thrombectomy were conducted. The patient’s postoperative course was uneventful. Microscopically, the primary lesion showed fibrotic changes, with moderately to poorly differentiated tumour cells surrounded by granulation tissues in some areas. The majority of the PVTT showed necrosis. He was alive without recurrence for 8 mo.

CONCLUSION

This is the first case of HCC with Vp4 PVTT in which radical conversion hepatectomy was succeeded after lenvatinib treatment.

Nomogram for Predicting the Prognosis of Patients with Hepatocellular Carcinoma Presenting with Pulmonary Metastasis

Background

Only a few studies have investigated the clinical features and outcomes of patients with pulmonary metastasis from hepatocellular carcinoma (HCC) at the initial diagnosis. This study aimed to evaluate the prevalence, risk factors and prognostic factors related to pulmonary metastasis and then construct a nomogram to predict the outcomes of patients with HCC presenting with pulmonary metastasis.

Methods

The Surveillance, Epidemiology, and End Results (SEER) database was used to select patients. A total of 25,236 eligible patients diagnosed with HCC from 2010 to 2015 were selected. Then, 897 patients with HCC presenting with pulmonary metastasis at the initial diagnosis were included in the primary set (n=598) and validation set (n=299). Logistic and Cox regression analyses were used to determine the risk factors and prognostic factors for pulmonary metastasis. A nomogram predicting the prognosis of patients with HCC presenting with pulmonary metastasis was constructed based on independent prognostic factors identified in Cox regression analyses. Both internal and external validations of the nomogram were performed using discrimination and calibration plots.

Results

The prevalence of pulmonary metastasis was 3.6% (897/25,236) in the entire cohort diagnosed with HCC as the initial diagnosis. Age, race, Edmonson-Steiner classification grade I/III, higher T stage, N stage, alpha fetoprotein(AFP) levels, brain metastasis, bone metastasis and intrahepatic metastasis were positively correlated with the development of HCC with pulmonary metastasis at the initial diagnosis. Prognostic factors incorporated in the nomogram were sex, T stage, bone metastasis, AFP levels, treatment, radiation and chemotherapy. The concordance index (C-index) of the nomogram in the primary set was 0.661 (95% CI: 0.633-0.688), indicating considerable predictive accuracy. The calibration curves showed consistency between the nomogram and the actual observations. When the nomogram was applied to the validation set, the results also remained reconcilable, and the C-index of the nomogram was 0.657 (95% CI: 0.626-0.698).

Conclusion

A list of risk factors associated with pulmonary metastasis occurrence in patients with HCC was selected, and the nomogram accurately predicted the prognosis of patients with HCC presenting with pulmonary metastasis at the initial diagnosis.

Capacity of proton beams in preserving normal liver tissue during proton beam therapy for hepatocellular carcinoma

Unirradiated liver volume (ULV) preservation rate is an important factor associated with radiation-induced liver disease (RILD) in patients with hepatocellular carcinoma (HCC) undergoing proton beam therapy (PBT). The purpose of this study is to identify the predictors for ULV preservation and quantify the capacity of proton beams in normal liver sparing during PBT. We reviewed planning data of 92 patients with single intrahepatic HCC tumors undergoing PBT. The potential clinical and planning factors that may affect ULV preservation were involved in multiple linear regression for ULV preservation rate. The significant factors were determined to be predictors and their influences were quantified. The median ULV preservation rate was 62.08%. All the assessed clinical factors showed significant effects on ULV preservation rate: clinical target volume (CTV), P < 0.001; portal vein tumor thrombosis (PVTT), P = 0.010; left lobe tumor, P = 0.010. In contrast, none of the planning factors demonstrated significance. The coefficients of significant factors in multiple linear regression were 60.85 for intercept, -0.02 for CTV, -9.01 for PVTT and 8.31 for left lobe tumors. The capacity of proton beams to spare normal liver tissue during PBT for HCC is mainly affected by clinical factors. The baseline of the ULV preservation rate is 60.85%, decreasing 0.02% with each milliliter of CTV increase and 9.01% for tumors with PVTT, and increasing 8.31% for tumors limited to the left lobe. Further clinical studies should be carried out to correlate our dosimetric findings with clinical outcomes.

Phase II Study of Hypofractionated Proton Beam Therapy for Hepatocellular Carcinoma

Background: Proton beam has an excellent depth dose distribution due to its unique physical properties, and thus proton beam therapy (PBT) has been tried and showed promising outcomes in hepatocellular carcinoma (HCC). The purpose of this phase II study is to evaluate the efficacy of hypofractionated PBT in HCC.

Methods: The eligibility criteria for this study were as follows: patients with HCC lesion(s) who were failed after, were difficult to treat with, or refused to other local treatments; tumor size and number of ≤7 and ≤2 cm, respectively, and HCC lesion(s) of ≥2 cm from gastrointestinal organs; Child–Pugh score of ≤7; Eastern Cooperative Oncology Group performance status ≤1; and age ≥18 years. The prescribed dose of PBT was 70 Gy equivalent in 10 fractions. The primary endpoint was 3-year local progression-free survival (LPFS) rate.

Results: Forty-five patients were prospectively enrolled, and there were 35 men and 10 women with a median age of 63 years (range, 46–78 years). Thirty-seven patients had recurrent and/or residual disease, and eight patients had treatment-naive disease. All patients received the planned treatments without treatment interruption, and grade ≥3 acute toxicity did not occur. The median follow-up duration was 35.1 months (range, 11.2–56.3 months) and local progression occurred in two patients (8.7%). The 3-year rates of LPFS and overall survival (OS) were 95.2% (95% confidence interval [CI], 89.1%−100%) and 86.4% (95% CI, 72.9–99.9%), respectively.

Conclusion: Hypofractionated PBT showed promising LPFS and OS, and further studies are warranted to compare PBT with other local modalities.

Proton beam therapy for liver cancers

Proton beam therapy (PBT) delivers less dose to nearby normal organs compared to X-ray therapy (XRT), which is particularly relevant for treating liver cancers given that both mean and low liver dose are among the most significant predictors of radiation induced liver disease (RILD). High-dose PBT has been shown to achieve excellent long-term tumor control with minimal toxicity in hepatocellular carcinoma (HCC) patients. Increasing data support ablative PBT for patients with unresectable cholangiocarcinoma or liver metastases, especially those with larger tumors not suitable for XRT.

Proton beam therapy for hepatocellular carcinoma associated with inferior vena cava tumor thrombus

PURPOSE

Hepatocellular carcinoma (HCC) with inferior vena cava tumor thrombus (IVCTT) is rare and regarded as an advanced disease stage with poor prognosis. Treatment effect data regarding HCC with IVCTT is scarce and clear evidence has not been established. This study, therefore, aims to examine the safety and effectiveness of proton beam therapy (PBT) for HCC patients with IVCTT.

METHODS

From January 2005 to December 2014, a total of 21 HCC patients with IVCTT were analyzed. The total irradiation doses ranged from 50 to 74 (median 72.6) gray relative biological effectiveness.

RESULTS

The follow-up period was 4-120 (median 21) months. Regarding acute toxicities, dermatitis of grade 1-2 was observed in all patients, while no grade 3 or higher late toxicity events were encountered. The overall survival (OS) rates for all patients were 62%, 33%, and 19% at 1, 2, and 3 years, respectively. No local recurrences for the treated lesions, including IVCTT, were observed. According to univariate analysis, IVCTT extension type was not associated with prognosis, but only tumor number significantly affected the OS rate (p = 0.003). For 10 single lesion patients, the longest survival time was 120 months with OS rates of 82%, 64%, and 36% at 1, 2, and 3 years, respectively.

CONCLUSION

PBT is safe and effective for HCC patients with IVCTT, especially those with single lesion status. PBT is an important treatment option for HCC patients with IVCTT.

2018 Korean Liver Cancer Association-National Cancer Center Korea Practice Guidelines for the Management of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common cancer globally and the fourth most common cancer in men in Korea, where the prevalence of chronic hepatitis B infection is high in middle-aged and elderly patients. These practice guidelines will provide useful and constructive advice for the clinical management of patients with HCC. A total of 44 experts in hepatology, oncology, surgery, radiology, and radiation oncology in the Korean Liver Cancer Association-National Cancer Center Korea Practice Guideline Revision Committee revised the 2014 Korean guidelines and developed new recommendations that integrate the most up-to-date research findings and expert opinions.

2018 Korean Liver Cancer Association-National Cancer Center Korea Practice Guidelines for the Management of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common cancer globally and the fourth most common cancer in men in Korea, where the prevalence of chronic hepatitis B infection is high in middle-aged and elderly patients. These practice guidelines will provide useful and constructive advice for the clinical management of patients with HCC. A total of 44 experts in hepatology, oncology, surgery, radiology and radiation oncology in the Korean Liver Cancer Association-National Cancer Center Korea Practice Guideline Revision Committee revised the 2014 Korean guidelines and developed new recommendations that integrate the most up-to-date research findings and expert opinions.

Predictors of Radiation-Induced Liver Disease in Eastern and Western Patients With Hepatocellular Carcinoma Undergoing Proton Beam Therapy

PURPOSE

To identify predictors of radiation-induced liver disease (RILD) in patients with hepatocellular carcinoma (HCC) treated with proton beam therapy (PBT).

METHODS

This multicenter study included 136 patients with HCC (eastern, n = 102; western, n = 34) without evidence of intrahepatic tumor progression after PBT. The RILD was defined as ascites with alkaline-phosphatase abnormality, grade ≥3 hepatic toxicity, or Child-Pugh score worsening by ≥2 within 4 months after PBT completion. The proton doses were converted to equivalent doses in 2-GyE fractions. The unirradiated liver volume (ULV) was defined as the absolute liver volume (LV) receiving <1 GyE; the standard liver volume (SLV) was calculated using body surface area. Possible correlations of clinicodosimetric parameters with RILD were examined.

RESULTS

The mean pretreatment LV was 85% of SLV, and patients with a history of hepatectomy (P < .001) or hepatitis B virus infection (P = .035) had significantly smaller LV/SLV. Nineteen (14%) patients developed RILD. Multivariate logistic regression analysis identified ULV/SLV (P = .001), gross tumor volume (P = .001), and Child-Pugh classification (P = .002) as independent RILD predictors, and mean liver dose and target-delivered dose were not associated with RILD occurrence. A "volume-response" relationship between ULV/SLV and RILD was consistently observed in both eastern and western cohorts. In Child-Pugh class-A patients whose ULV/SLV were ≥50%, 49.9%-40%, 39.9%-30% and <30%, the RILD incidences were 0%, 6%, 16%, and 39% (P < .001), respectively. For the Child-Pugh class-B group, the RILD incidences in patients with ≥60%, 59.9%-40%, and <40% of ULV/SLV were 0%, 14%, and 83% (P = .006), respectively.

CONCLUSIONS

The ULV/SLV, not mean liver dose, independently predicts RILD in patients with HCC undergoing PBT. The relative and absolute contraindications for Child-Pugh class-A patient's ULV/SLV are <50% and <30%, and <60% and <40% for Child-Pugh class-B patients, respectively. Our results indicate that the likelihood of hepatic complications for PBT is dictated by similar metrics as that for surgery.

Does Risk-Adapted Proton Beam Therapy Have a Role as a Complementary or Alternative Therapeutic Option for Hepatocellular Carcinoma?

To evaluate the role of risk-adapted proton beam therapy (PBT) in hepatocellular carcinoma (HCC) patients, a total of 243 HCC patients receiving risk-adapted PBT with three dose-fractionation regimens (regimen A [n = 40], B [n = 60], and C [n = 143]) according to the proximity of their gastrointestinal organs (<1 cm, 1–1.9 cm, and ≥2 cm, respectively) were reviewed: The prescribed doses to planning target volume 1 (PTV1) were 50 gray equivalents (GyE) (EQD2 [equivalent dose in 2 Gy fractions], 62.5 GyE₁₀), 60 GyE (EQD2, 80 GyE₁₀), and 66 GyE (EQD2, 91.3 GyE₁₀) in 10 fractions, respectively, and those of PTV2 were 30 GyE (EQD2, 32.5 GyE₁₀) in 10 fractions. In all patients, the five-year local recurrence-free survival (LRFS) and overall survival (OS) rates were 87.5% and 48.1%, respectively, with grade ≥3 toxicity of 0.4%. In regimens A, B, and C, the five-year LRFS and OS rates were 54.6%, 94.7%, and 92.4% (p < 0.001), and 16.7%, 39.2%, and 67.9% (p < 0.001), respectively. The five-year OS rates of the patients with the Modified Union for International Cancer Control (mUICC) stages I, II, III, and IVA and Barcelona Clinic Liver Cancer (BCLC) stages A, B, and C were 69.2%, 65.4%, 43.8%, and 26.6% (p < 0.001), respectively, and 65.1%, 40%, and 32.2% (p < 0.001), respectively. PBT could achieve promising long-term tumor control and have a potential role as a complementary or alternative therapeutic option across all stages of HCC.

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 beam therapy for cancer in the era of precision medicine

Precision radiotherapy, which accurately delivers the dose on a tumor and confers little or no irradiation to the surrounding normal tissue and organs, results in maximum tumor control and decreases the toxicity to the utmost extent. Proton beam therapy (PBT) provides superior dose distributions and has a dosimetric advantage over photon beam therapy. Initially, the clinical practice and study of proton beam therapy focused on ocular tumor, skull base, paraspinal tumors (chondrosarcoma and chordoma), and unresectable sarcomas, which responded poorly when treated with photon radiotherapy. Then, it is widely regarded as an ideal mode for reirradiation and pediatrics due to reducing unwanted side effects by lessening the dose to normal tissue. During the past decade, the application of PBT has been rapidly increasing worldwide and gradually expanding for the treatment of various malignancies. However, to date, the role of PBT in clinical settings is still controversial, and there are considerable challenges in its application. We systematically review the latest advances of PBT and the challenges for patient treatment in the era of precision medicine.

Effectiveness and Safety of Simultaneous Integrated Boost-Proton Beam Therapy for Localized Pancreatic Cancer

Purpose:

To evaluate the clinical effectiveness and feasibility of simultaneous integrated boost-proton beam therapy in patients with localized pancreatic cancer.

Methods:

Thirty-seven patients with localized pancreatic cancer underwent simultaneous integrated boost-proton beam therapy, and 8 (21.6%) patients received induction chemotherapy. The internal target volume was obtained by summing the gross tumor volumes in exhalation phase computed tomography images. Planning target volume 1 included internal target volume plus 3 to 5 mm margins, excluding the 5 mm expanded volume of gastrointestinal structures, and planning target volume 2 included the internal target volume plus 7 to 12 mm margins. The prescribed doses to planning target volume 1 and planning target volume 2 were 45 GyE (equivalent dose in 2 Gy, 54.4 GyE₁₀) and 30 GyE (equivalent dose in 2 Gy, 32.5 GyE₁₀) in 10 fractions, respectively.

Results:

Overall, treatment was well tolerated, with no grade of toxicity ≥3. Median overall survival was 19.3 months, and 1-year local progression-free survival, relapse-free survival, and overall survival rates were 64.8%, 33.2%, and 75.7%, respectively. Patients treated with simultaneous integrated boost-proton beam therapy after induction chemotherapy had a significantly higher median overall survival time compared to those with simultaneous integrated boost-proton beam therapy alone (21.6 months vs 16.7 months, P = .031). Multivariate analysis showed that induction chemotherapy was a significant factor for overall survival (P < .05).

Conclusions:

Simultaneous integrated boost-proton beam therapy could be feasible and promising for patients with localized pancreatic cancer.

Validation of fast motion-including dose reconstruction for proton scanning therapy in the liver

This study validates a method of fast motion-including dose reconstruction for proton pencil beam scanning in the liver. The method utilizes a commercial treatment planning system (TPS) and calculates the delivered dose for any translational 3D target motion. Data from ten liver patients previously treated with photon radiotherapy with intrafraction tumour motion monitoring were used. The dose reconstruction method utilises an in-house developed program to incorporate beam's-eye-view tumour motion by shifting each spot in the opposite direction of the tumour and in-depth motion as beam energy changes for each spot. The doses are then calculated on a single CT phase in the TPS. Two aspects of the dose reconstruction were assessed: (1) The accuracy of reconstruction, by comparing dose reconstructions created using 4DCT motion with ground truth doses obtained by calculating phase specific doses in all 4DCT phases and summing up these partial doses. (2) The error caused by assuming 4DCT motion, by comparing reconstructions with 4DCT motion and actual tumour motion. The CTV homogeneity index (HI) and the root-mean-square (rms) dose error for all dose points receiving  >70%, >80% and  >90% of the prescribed dose were calculated. The dose reconstruction resulted in mean (range) absolute CTV HI errors of 1.0% (0.0-3.0)% and rms dose errors of 2.5% (1.0%-5.3%), 2.1% (0.9%-4.5%), and 1.8% (0.7%-3.7%) for  >70%, >80% and  >90% doses, respectively, when compared with the ground truth. The assumption of 4DCT motion resulted in mean (range) absolute CTV HI errors of 5.9% (0.0-15.0)% and rms dose errors of 6.3% (3.9%-12.6%), 5.9% (3.4%-12.5%), and 5.4% (2.6%-12.1%) for  >70%, >80% and  >90% doses, respectively. The investigated method allows tumour dose reconstruction with the actual tumour motion and results in significantly smaller dose errors than those caused by assuming that motion at treatment is identical to the 4DCT motion.

Stereotactic body radiotherapy based treatment for hepatocellular carcinoma with extensive portal vein tumor thrombosis

BACKGROUND

There is currently no worldwide consensus for the management of hepatocellular carcinoma (HCC) with portal vein tumor thrombus (PVTT). We evaluated the efficacy of stereotactic body radiotherapy (SBRT) as the initial treatment for HCC with extensive PVTT based on a relatively large number of patients.

METHODS

In our multidisciplinary approach for patients with hepatobiliary tumors, SBRT is recommended for unresectable HCC with PVTT or those with contraindication for transarterial chemoembolization (TACE). The aim is to shrink the tumor thrombus and preserve adequate portal venous flow, thus facilitating subsequent treatments such as TACE and tumor resection. In the present study, 70 continuous cases of HCC patients with extensive PVTT initially treated with SBRT were studied. The median follow-up period was 9.5 months (range, 1.0-21.0 months). The dynamic changes of tumor thrombosis with time after SBRT were also analyzed.

RESULTS

The median survival time for the whole group was 10.0 months (95% CI, 7.7-12.3 months), with a 6- and 12-month overall survival (OS) rate of 67.3%, and 40.0% respectively. Patients who received combined SBRT and TACE showed significantly longer OS than those without indication for TACE after SBRT (12.0 ± 1.6 vs. 3.0 ± 1.0 months). Patients with good response to radiation usually had better survival. SBRT was well tolerated in our patient series.

CONCLUSIONS

In conclusion, SBRT used as the initial treatment for HCC patients with extensive PVTT originally unsuitable for resection or TACE can achieve adequate thrombus shrinkage and portal vein flow restoration in the majority of cases. It could thus offer the patients an opportunity to undergo further treatment such as resection or TACE procedure. Such therapeutic strategy may result in survival advantage, especially for those who do receive combined modality with SBRT.

Venous invasion by hepatic tumors: imaging appearance and implications for management

Venous invasion by hepatic tumors most commonly occurs with hepatocellular carcinoma and is associated with worse patient prognosis. Imaging plays an important role in the diagnosis of tumor thrombus in the liver. Moreover, differentiating between bland and tumor thrombus in the liver has important diagnostic, staging, therapeutic, and prognostic implications and may require a multimodal imaging approach including ultrasound, computed tomography, and/or magnetic resonance imaging. Treatment of hepatic malignancies with associated tumor thrombus is dependent on tumor type, disease extent within the liver, liver hemodynamics, and underlying liver function. Treatment of such tumors may involve surgical, locoregional and/or systemic therapies. The current review will focus on the imaging characteristics of venous invasion by hepatic tumors. The imaging findings most useful for differentiating hepatic venous tumor thrombus and bland thrombus will be highlighted and demonstrated with imaging examples. Imaging findings with implications for subsequent patient management will be described.

Strategic application of radiotherapy for hepatocellular carcinoma

With increasing clinical use, radiotherapy (RT) has been considered reliable and effective method for hepatocellular carcinoma (HCC) treatment, depending on extent of disease and patient characteristics. RT for HCC can improve therapeutic outcomes through excellent local control, downstaging, conversion from unresectable to resectable status, and treatments of unresectable HCCs with vessel invasion or multiple intrahepatic metastases. In addition, further development of modern RT technologies, including image-guided radiotherapy (IGRT), intensity-modulated radiotherapy (IMRT), and stereotactic body radiotherapy, has expanded the indication of RT. An essential feature of IGRT is that it allows image guidance therapy through in-room images obtained during radiation delivery. Compared with 3D-conformal RT, distinctions of IMRT are inverse treatment planning process and use of a large number of treatment fields or subfields, which provide high precision and exquisitely conformal dose distribution. These modern RT techniques allow more precise treatment by reducing inter- and intra-fractional errors resulting from daily changes and irradiated dose at surrounding normal tissues. More recently, particle therapy has been actively investigated to improve effectiveness of RT. This review discusses modern RT strategies for HCC, as well as optimal selection of RT in multimodal approach for HCC.

Optimal time of tumour response evaluation and effectiveness of hypofractionated proton beam therapy for inoperable or recurrent hepatocellular carcinoma

Objective

To evaluate the optimal time of tumour response and effectiveness of hypofractionated proton beam therapy (PBT) for hepatocellular carcinoma (HCC).

Results

Overall, treatment was well tolerated with no grade toxicity ≥3. Of 71 patients, 66 patients (93%) eventually reached complete response (CR) after PBT: 93.9% (62 of 66) of patients who reached CR within 12 months, and the remaining 4 patients (6.1%) reached CR at 12.5, 16.2, 19.1 and 21.7 months, respectively. The three-year local progression-free survival (LPFS), relapse-free survival (RFS) and OS rates were 89.9%, 26.8%, and 74.4%, respectively. Multivariate analysis revealed that the tumour response was an independent prognostic factor for LPFS, RFS, and OS.

Conclusion

Most CR was achieved within 1 year after PBT and further salvage treatments in PBT field might be postponed up to approximately 18–24 months. Hypofractionated PBT could be good alternative for HCC patients who are unsuitable for surgical or invasive treatments with curative intent.

Materials and Methods

Seventy-one inoperable or recurrent HCC patients underwent hypofractionated PBT using 66 GyE in 10 fractions. The tumour responses were defined as the maximal tumour response observed during the follow-up period using the modified Response Evaluation Criteria in Solid Tumors criteria.

Prognostic group stratification and nomogram for predicting overall survival in patients who received radiotherapy for abdominal lymph node metastasis from hepatocellular carcinoma: a multi-institutional retrospective study (KROG 15-02)

OBJECTIVE

To develop a prognostic model for overall survival (OS) in hepatocellular carcinoma (HCC) patients receiving radiotherapy (RT) to metastatic abdominal lymph nodes (LNs).

MATERIALS AND METHODS

Two hundred twenty-eight patients treated with RT to metastatic abdominal LNs were retrospectively reviewed.

RESULTS

Median OS in all patients was 11.1 months. LN responders had significantly higher median OS than non-responders (14.2 months vs. 7.5 months, p<0.05). On multivariate analysis, Child-Pugh classification, status of intrahepatic tumor, presence of distant metastasis, number and location of metastatic LNs, serum level of alpha fetoprotein (AFP), and the LN response to RT were significant prognostic factors for OS (p < 0.05 each). Based on the results of multivariate analysis, prognostic group stratification according to the number of pre-treatment risk factors was a significant predictor of OS, and median OS in patients with ≥ 4, 3, 2, 1, and 0 risk factors were 2.9, 5.5, 10.3, 13.6, and 27.8 months, respectively (p<0.05). A nomogram was formulated by integrating the different prognostic contribution of each factor, and it showed good accuracy for predicting 2-year OS with a concordance index of 0.72.

CONCLUSION

Prognostic group stratification and nomogram could be useful prognostic and therapeutic indicators in selecting treatment strategies.

A systematic review of publications on charged particle therapy for hepatocellular carcinoma

Charged particle therapy (proton beam therapy and carbon ion therapy) is a form of radiotherapy which has the unique characteristic of superior depth dose distribution, and has been used for the treatment of hepatocellular carcinoma (HCC) in a limited number of patients, especially in Japan. We undertook a systematic review to define the clinical utility of charged particle therapy for patients with HCC. We searched the MEDLINE database from 1983 to June 2016 to identify clinical studies on charged particle therapy for HCC. Primary outcomes of interest were local control, overall survival, and late radiation morbidities. A total of 13 cohorts from 11 papers were selected from an initial dataset of 78 papers. They included a randomized controlled trial comparing proton beam therapy with transarterial chemoembolization, 9 phase I or II trials and 2 retrospective studies. The reported actuarial local control rates ranged from 71.4-95% at 3 years, and the overall survival rates ranged from 25-42.3% at 5 years. Late severe radiation morbidities were uncommon, and a total of 18 patients with grade ≥3 late adverse events were reported among the 787 patients included in this analysis. Charged particle therapy for HCC was associated with good local control with limited probability of severe morbidities. The cost-effectiveness and the distinctive clinical advantages of charged particle therapies should be clarified in order to become a socially accepted treatment modality for HCC.

The treatment of intermediate stage tumours beyond TACE: From surgery to systemic therapy

Treatment of hepatocellular carcinoma (HCC) is dependent on the stage of the disease. Intermediate stage HCC encompasses the largest subgroup of patients with the disease, and is characterized by substantial heterogeneity. The standard therapeutic approach, transarterial chemoembolization (TACE), is probably over-used and may not be appropriate for all patients with intermediate stage HCC. In patients with extensive tumour bulk, multi-nodular spread or impaired liver function, TACE may not be optimal and other treatments can be considered as a first-line treatment. These include surgery, percutaneous ablation, radioembolization or systemic treatment. In addition, patients who do not achieve complete or partial necrosis (TACE failure) and patients with early recurrence after TACE, should be managed individually, considering systemic treatments usually reserved for advanced disease. In selected cases and in patients who achieve downstaging, radical approaches such as hepatic resection or even liver transplantation can be considered. In this review, we evaluate the current literature for the treatment strategies for patients with intermediate Barcelona Clinic Liver Cancer (BCLC) B stage HCC.

New Evidence and Perspectives on the Management of Hepatocellular Carcinoma with Portal Vein Tumor Thrombus

Portal vein tumor thrombosis (PVTT) is an intractable condition but common phenomenon in hepatocellular carcinoma (HCC). HCC patients with PVTT may have worse liver function, a higher chance of comorbidity related to portal hypertension, lower tolerance to treatment and poorer prognoses. In Western guidelines, patients are offered palliative treatment with sorafenib or other systemic agents because HCC with PVTT is grouped together with metastatic HCC during the planning of its management. In recent years, various treatment options have become available for patients with HCC and PVTT. Therapy has also shifted toward evidence-based treatment. However, policies for the management of HCC with PVTT have not been established. This comprehensive literature review aims to present current and available management options for patients with HCC and PVTT. Evidence is mainly based on studies published after 2010.

Treatment of hepatocellular carcinoma with portal vein tumor thrombus: advances and challenges

Portal vein tumor thrombus is a frequent, challenging complication in hepatocellular carcinoma. Hepatocellular carcinoma patients with portal vein tumor thrombus may show worse liver function, less treatment tolerance and worse prognosis than patients without portal vein tumor thrombus, and they may be at higher risk of comorbidity related to portal hypertension. Western and some Asian guidelines stratify hepatocellular carcinoma with portal vein tumor thrombus together with metastatic hepatocellular carcinoma and therefore recommend only palliative treatment with sorafenib or other systemic agents. In recent years, more treatment options have become available for hepatocellular carcinoma patients with portal vein tumor thrombus, and an evidence-based approach to optimizing disease management and treatment has become more widespread. Nevertheless, consensus policies for managing hepatocellular carcinoma with portal vein tumor thrombus have not been established. This comprehensive literature review, drawing primarily on studies published after 2010, examines currently available management options for patients with hepatocellular carcinoma and portal vein tumor thrombus.

Risk-adapted simultaneous integrated boost-proton beam therapy (SIB-PBT) for advanced hepatocellular carcinoma with tumour vascular thrombosis

PURPOSE

To evaluate clinical effectiveness and safety of simultaneous integrated boost-proton beam therapy (SIB-PBT) in hepatocellular carcinoma (HCC) patients with tumour vascular thrombosis (TVT).

MATERIAL AND METHODS

Forty-one HCC patients with TVT underwent SIB-PBT using three dose-fractionation schemes: if gross tumour volume <1cm (n=27), 1-1.9cm (n=7), and ⩾2cm (n=7) from gastrointestinal structures, 50GyE (EQD2, 62.5GyE₁₀), 60Gy (EQD2, 80GyE₁₀), 66Gy (EQD2, 91.3GyE₁₀), respectively, in 10 fractions was prescribed to planning target volume 1 (PTV1), and 30GyE (EQD2, 32.5GyE₁₀) in 10 fractions was prescribed to PTV2.

RESULTS

Overall, treatment was well tolerated, with no grade toxicity ⩾3. Median overall survival (OS) was 34.4months and 2-year local progression-free survival (LPFS), relapse free survival (RFS), and OS rates were 88.1%, 25%, and 51.1%, respectively. Patients treated with EQD2 of ⩾80GyE₁₀ tended to show better TVT response (92.8% vs. 55.5%, p=0.002) 2-year LPFS (92.9% vs. 82.5%, p=0.463), RFS (28.8% vs. 19%, p=0.545), and OS (58.4% vs. 46.8%, p=0.428) rates than those with EQD2 of <80GyE₁₀. Multivariate analysis showed that TVT response and Child Pugh classification were independent prognostic factors for OS.

CONCLUSIONS

SIB-PBT is feasible and promising for HCC patients with TVT.

Clinical outcomes and toxicities of proton radiotherapy for gastrointestinal neoplasms: a systematic review

BACKGROUND

Proton beam radiotherapy (PBT) is frequently shown to be dosimetrically superior to photon radiotherapy (RT), though supporting data for clinical benefit are severely limited. Because of the potential for toxicity reduction in gastrointestinal (GI) malignancies, we systematically reviewed the literature on clinical outcomes (survival/toxicity) of PBT.

METHODS

A systematic search of PubMed, EMBASE, abstracts from meetings of the American Society for Radiation Oncology, Particle Therapy Co-Operative Group, and American Society of Clinical Oncology was conducted for publications from 2000-2015. Thirty-eight original investigations were analyzed.

RESULTS

Although results of PBT are not directly comparable to historical data, outcomes roughly mirror previous data, generally with reduced toxicities for PBT in some neoplasms. For esophageal cancer, PBT is associated with reduced toxicities, postoperative complications, and hospital stay as compared to photon radiation, while achieving comparable local control (LC) and overall survival (OS). In pancreatic cancer, numerical survival for resected/unresected cases is also similar to existing photon data, whereas grade ≥3 nausea/emesis and post-operative complications are numerically lower than those reported with photon RT. The strongest data in support of PBT for HCC comes from phase II trials demonstrating very low toxicities, and a phase III trial of PBT versus transarterial chemoembolization demonstrating trends towards improved LC and progression-free survival (PFS) with PBT, along with fewer post-treatment hospitalizations. Survival and toxicity data for cholangiocarcinoma, liver metastases, and retroperitoneal sarcoma are also roughly equivalent to historical photon controls. There are two small reports for gastric cancer and three for anorectal cancer; these are not addressed further.

CONCLUSIONS

Limited quality (and quantity) of data hamper direct comparisons and conclusions. However, the available data, despite the inherent caveats and limitations, suggest that PBT offers the potential to achieve significant reduction in treatment-related toxicities without compromising survival or LC for multiple GI malignancies. Several randomized comparative trials are underway that will provide more definitive answers.

Radiotherapy as valid modality for hepatocellular carcinoma with portal vein tumor thrombosis

Although the current standard treatment for hepatocellular carcinoma (HCC) with portal vein tumor thrombosis (PVTT) is sorafenib, many previous studies have established the need for a reliable local modality for PVTT control, which is a major cause of liver function deterioration and metastasis. Additionally, there is growing evidence for the prognostic significance of PVTT classification according to the location of tumor thrombosis. Favorable outcomes can be obtained by applying local modalities, including surgery or transarterial chemoembolization, especially in second-order or distal branch PVTT. Rapid control of PVTT could maintain or improve liver function and reduce intrahepatic as well as distant metastasis. Radiotherapy (RT) is one of the main locoregional treatment modalities in oncologic fields, but has rarely been used in HCC because of concerns regarding hepatic toxicity. However, with the development of advanced techniques, RT has been increasingly applied in HCC management. Randomized studies have yet to definitively prove the benefit of RT, but several comparative studies have justified the application of RT in HCC. The value of RT is especially noticeable in HCC with PVTT; several prospective and retrospective studies have reported favorable outcomes, including a 40% to 60% objective response rate and median overall survival of 15 mo to 20 mo in responders. In this review, we evaluate the role of RT as an alternative local modality in HCC with PVTT.