Proton beam therapy for unresectable intrahepatic cholangiocarcinoma

Combined High-Dose Radiotherapy with Sequential Gemcitabine-Cisplatin Based Chemotherapy Increase the Resectability and Survival in Locally Advanced Unresectable Intrahepatic Cholangiocarcinoma: A Multi-institutional Cohort Study

PURPOSE

The locally advanced unresectable intrahepatic cholangiocarcinoma (ICC) has detrimental oncological outcomes. In this study, we aimed to investigate the efficacy of radiotherapy in patients with locally advanced unresectable ICC.

MATERIALS AND METHODS

Between 2001 and 2021, 116 patients were identified through medical record who underwent radiotherapy for locally advanced unresectable ICC. The resectability of ICC is determined by the multidisciplinary team at each institution. Overall survival (OS) were analyzed using the Kaplan-Meier method, and prognostic factors were analyzed using the Cox proportional hazards model.

RESULTS

The median equivalent radiotherapy dose in 2 Gy fractions (EQD2) was 52 Gy (range, 30 to 110 Gy). Forty-seven patients (40.5%) received sequential gemcitabine-cisplatin based chemotherapy (GEM-CIS CTx). Multivariate analysis identified two risk factors, EQD2 of ≥ 60 Gy and application of sequential GEM-CIS CTx for OS. Patients were grouped by these two risk factors: group 1, EQD2 ≥ 60 Gy with sequential GEM-CIS CTx (n=25); group 2, EQD2 < 60 Gy with sequential GEM-CIS CTx or fluoropyrimidine-based concurrent chemoradiotherapy (n=70); and group 3, radiotherapy alone (n=21). Curative resection was more frequently undergone in group 1 than in groups 2 or 3 (28% vs. 8.6% vs. 0%, respectively). Consequently, OS was significantly better in group 1 than in groups 2 and 3 (p < 0.05).

CONCLUSION

Combined high-dose radiotherapy with sequential GEM-CIS CTx improved oncologic outcomes in patients with locally advanced unresectable ICC. Further prospective studies are required to validate these findings.

Proton Beam Therapy for Intrahepatic Cholangiocarcinoma: A Multicenter Prospective Registry Study in Japan

Introduction

Intrahepatic cholangiocarcinoma (ICC) can be treated with chemotherapy in unresectable cases, but outcomes are poor. Proton beam therapy (PBT) may provide an alternative treatment and has good dose concentration that may improve local control.

Methods

Fifty-nine patients who received initial PBT for ICC from May 2016 to June 2018 at nine centers were included in the study. The treatment protocol was based on the policy of the Japanese Society for Radiation Oncology. Forty patients received 72.6-76 Gy (RBE) in 20-22 fr, 13 received 74.0-76.0 Gy (RBE) in 37-38 fr, and 6 received 60-70.2 Gy (RBE) in 20-30 fr. Overall survival (OS) and progression-free survival (PFS) were estimated by Kaplan-Meier analysis.

Results

The 59 patients (35 men, 24 women; median age: 71 years; range: 41-91 years) had PS of 0 (n = 47), 1 (n = 10), and 2 (n = 2). Nine patients had hepatitis and all 59 cases were considered inoperable. The Child-Pugh class was A (n = 46), B (n = 7), and unknown (n = 6); the median maximum tumor diameter was 5.0 cm (range 2.0-15.2 cm); and the clinical stage was I (n = 12), II (n = 19), III (n = 10), and IV (n = 18). At the last follow-up, 17 patients were alive (median follow-up: 36.7 months; range: 24.1-49.9 months) and 42 had died. The median OS was 21.7 months (95% CI: 14.8-34.4 months). At the last follow-up, 37 cases had recurrence, including 10 with local recurrence. The median PFS was 7.5 months (95% CI: 6.1-11.3 months). In multivariable analyses, Child-Pugh class was significantly associated with OS and PFS, and Child-Pugh class and hepatitis were significantly associated with local recurrence. Four patients (6.8%) had late adverse events of grade 3 or higher.

Conclusion

PBT gives favorable treatment outcomes for unresectable ICC without distant metastasis and may be particularly effective in cases with large tumors.

Interventional Radiology Locoregional Therapies for Intrahepatic Cholangiocarcinoma

Surgical resection remains the cornerstone of curative treatment for intrahepatic cholangiocarcinoma (iCCA), but this option is only available to a small percentage of patients. For patients with unresectable iCCA, systemic therapy with gemcitabine and platinum-based agents represents the mainstay of treatment; however, the armamentarium has grown to include targeted molecular therapies (e.g., FGFR2 inhibitors), use of adjuvant therapy, liver transplantation in select cases, immunotherapy, and locoregional liver-directed therapies. Despite advances, iCCA remains a challenge due to the advanced stage of many patients at diagnosis. Furthermore, given the improving options for systemic therapy and the fact that the majority of iCCA patients succumb to disease progression in the liver, the role of locoregional therapies has increased. This review will focus on the expanding role of interventional radiology and liver-directed therapies in the treatment of iCCA.

Locoregional Treatment in Intrahepatic Cholangiocarcinoma: Which Treatment for Which Patient?

For unresectable intrahepatic cholangiocarcinoma (iCC), different locoregional treatments (LRT) could be proposed to patients, including radiofrequency ablation (RFA) and microwave ablation (MWA), external beam radiotherapy (EBRT) or transarterial treatments, depending on patient and tumor characteristics and local expertise. These different techniques of LRT have not been compared in a randomized clinical trial; most of the relevant studies are retrospective and not comparative. The aim of this narrative review is to help clinicians in their everyday practice discuss the pros and cons of each LRT, depending on the individual characteristics of their patients.

Proton beam therapy for extrahepatic biliary tract cancer: Analysis with prospective multi-institutional patients' registration database, Proton-Net

Background and purpose

To examine the role of proton beam therapy (PBT) in the treatment of extrahepatic biliary tract cancer (EBC).

Methods and materials

We analyzed the data accumulated in the Proton-Net database, which prospectively registered all individual patient data treated with PBT in all Japanese proton institutions from May 2016 to June 2019. The primary endpoint was overall survival (OS), and the secondary endpoints were local control (LC), progression-free survival (PFS), and toxicity.

Results

Ninety-three patients with unresectable and/or recurrent EBC were treated with PBT using a median prescribed dose of 67.5 Gy (RBE) (range, 50-72.6 Gy) in 25 (22-30 fractions). With a median follow-up of 16.3 months, the median survival time was 20.1 months and the 2-year OS was 37.8%. Two-year PFS and LC rates were 20.6% and 66.5%, respectively. Poor liver function (Child-Pugh B, C), a narrower distance between the tumor and digestive tract (2 cm >), and a larger tumor diameter (2 cm <) were identified as poor prognostic factors for OS. PBT-related grade 3 ≤ acute and late adverse events occurred in 5.4% and 4.3% of patients, respectively, including one gastrointestinal late toxicity (duodenal ulcer).

Conclusions

This is the largest prospectively accumulated series of PBT for EBC, and PBT showed favorable outcomes with acceptable toxicity profiles.

The multidisciplinary management of cholangiocarcinoma

Cholangiocarcinoma is a lethal malignancy of the biliary epithelium that can arise anywhere along the biliary tract. Surgical resection confers the greatest likelihood of long-term survivability. However, its insidious onset, difficult diagnostics, and resultant advanced presentation render the majority of patients unresectable, highlighting the importance of early detection with novel biomarkers. Developing liver-directed therapies and emerging targeted therapeutics may offer improved survivability for patients with unresectable or advanced disease. In this article, the authors review the current multidisciplinary standards of care in resectable and unresectable cholangiocarcinoma, with an emphasis on novel biomarkers for early detection and nonsurgical locoregional therapy options.

Locoregional Approaches in Cholangiocarcinoma Treatment

Cholangiocarcinoma (CCA) is a rare hepatic malignant tumor with poor prognosis due to late detection and anatomic factors limiting the applicability of surgical resection. Without surgical resection, palliation is the most common approach. In non-surgical cases contained within the liver, locoregional therapies provide the best chance for increased survival and disease control. The most common methods, transarterial chemoembolization and transarterial radioembolization, target tumors by embolizing their blood supply and limiting the tumor's ability to metabolize. Other treatments induce direct damage via thermal ablation to tumor tissue to mediate their anti-tumor efficacy. Recent studies have begun to explore roles for these therapies outside their previous role of palliation. This review will outline the mechanisms of each of these treatments, along with their effects on overall survival, while comparing these to non-locoregional therapies.

Particle Beam Therapy for Intrahepatic and Extrahepatic Biliary Duct Carcinoma: A Multi-Institutional Retrospective Data Analysis

To examine the efficacy and toxicity of particle beam therapy (PT) for biliary duct carcinoma (BDC) and compare the outcomes between extrahepatic BDC (eBDC) and intrahepatic BDC (iBDC). We analyzed multi-institutional data from May 2009 to December 2019. The primary endpoint was overall survival (OS), and the secondary endpoints were local control (LC), progression-free survival (PFS) and toxicity. We included 150 patients with unresectable BDC treated with PT using a median prescribed dose of 70.2 GyRBE (range, 44-77 GyRBE) in 25 fractions (range, 10-38 fractions). With a median follow-up of 13.0 months, median survival time (MST) was 21 months, and 2-year OS was 44.8%. For eBDC and iBDC, the MSTs were 20 and 23 months, respectively. Two-year PFS and LC rates were 20.6% and 66.5%, respectively. Vascular invasion, prescribed dose and serum tumor marker level (carcinoembryonic antigen: CEA) were identified as poor prognostic factors for OS. A higher radiation dose EQD2 ≥ 67 Gy showed superior OS, with a hazard ratio of 0.341. The radiation dose of PT is an important predisposing factor for overall survival. The MST for patients with eBDC given a higher radiation dose was 25 months, compared to 15 months for those given the lower dose and 23 months for patients with iBDC (all iBDC given higher doses). iBDC and eBDC duct carcinomas showed equivalent outcomes with PT, especially when treated with a high radiation dose. In detailed analysis, baseline CEA level in iBDC, and radiation dose and GTV in eBDC were statistically significant predicators for OS. Acute and late toxicity grade ≥3 occurred in 2.2% and 2.7% of patients, respectively, including two late grade-5 toxicities. In conclusion, PT showed good efficacy for BDC, both eBDC and iBDC, with a low incidence of severe toxicity.

Intrahepatic cholangiocarcinoma: The role of liver transplantation, adjunctive treatments, and prognostic biomarkers

Intrahepatic cholangiocarcinoma (iCCA) is a primary epithelial cell malignancy of the liver with rising incidence rate globally. Its insidious presentation, heterogeneous and aggressive biology, and recalcitrance to current therapies results in unacceptably high morbidity and mortality. This has spurred research efforts in the last decade to better characterize it molecularly with translation to improved diagnostic tools and treatments. Much of this has been driven by patient advocacy. This has renewed interest in orthotopic liver transplantation (LT) with adjunctive therapies for iCCA, which was historically disparaged due to poor recipient outcomes and donor organ scarcity. However, the optimal use of LT as a treatment for iCCA care remains unclear. Here, we review the epidemiology of iCCA, the history of LT as a treatment modality, alternative approaches to iCCA local control, the evidence for peri-operative systemic therapies, and the potential roles of biomarkers and targeted agents. In doing so, we hope to prioritize areas for continued research and identify areas where multidisciplinary care can improve outcomes.

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.

Progress in Radiotherapy for Cholangiocarcinoma

Cholangiocarcinoma (CCA) originates from the epithelium of the bile duct and is highly malignant with a poor prognosis. Radical resection is the only treatment option to completely cure primary CCA. Due to the insidious onset of CCA, most patients are already in an advanced stage at the time of the initial diagnosis and may lose the chance of radical surgery. Radiotherapy is an important method of local treatment, which plays a crucial role in preoperative neoadjuvant therapy, postoperative adjuvant therapy, and palliative treatment of locally advanced lesions. However, there is still no unified and clear recommendation on the timing, delineating the range of target area, and the radiotherapy dose for CCA. This article reviews recent clinical studies on CCA, including the timing of radiotherapy, delineation of the target area, and dose of radiotherapy. Further, we summarize large fraction radiotherapy (stereotactic body radiotherapy [SBRT]; proton therapy) in CCA and the development of immunotherapy and the use of targeted drugs combined with radiotherapy.

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.

Locoregional Treatments in Cholangiocarcinoma and Combined Hepatocellular Cholangiocarcinoma

Cholangiocarcinoma (CCA) is a primary and aggressive cancer of the biliary tree. Combined hepatocellular cholangiocarcinoma (CHC) is a distinctive primary liver malignancy which has properties of both hepatocytic and cholangiocytic differentiation. CHC appears to have a worse prognosis compared to hepatocellular carcinoma, and similar to that of intrahepatic CCA. While significant advances have been made in understanding the pathophysiology and treatment of these two tumor types, their prognosis remains poor. Currently, liver resection is the primary treatment modality; however, only a minority of patients are eligible for surgery. However, the use of locoregional therapies proves an alternative approach to treating locally advanced disease with the aim of converting to resectability or even transplantation. Locoregional therapies such as transarterial chemoembolization (TACE), selective internal radiation therapy (SIRT), radiofrequency ablation (RFA), and photodynamic therapy (PDT) can provide patients with tumor control and increase the chances of survival. In this review, we appraise the evidence surrounding the use of locoregional therapies in treating patients with CCA and CHC.

Management of Intrahepatic Cholangiocarcinoma

Cholangiocarcinoma is a tumor that arises as a result of differentiation of the cholangiocytes and can develop from anywhere in the biliary tree. Subtypes of cholangiocarcinoma are differentiated based on their location in the biliary tree. If diagnosed early these can be resected, but most cases of intrahepatic cholangiocarcinoma present late in the disease course where surgical resection is not an option. In these patients who are poor candidates for resection, a combination of chemotherapy, locoregional therapies like ablation, transarterial chemo and radioembolization, and in very advanced and metastatic disease, external radiation are the available options. These modalities can improve overall disease-free and progression-free survival chances. In this review, we will discuss the risk factors and clinical presentation of intrahepatic cholangiocarcinoma, diagnosis, available therapeutic options, and future directions for management options.

Recurrent cholangiocarcinoma with long-term survival by multimodal treatment: A case report

Long-term outcomes after surgical resection of bile duct cancer remain unsatisfactory, and survival, particularly after tumor recurrence, is poor. Gemcitabine and cisplatin combination (GC) therapy is the standard first-line treatment; however, second-line approaches are yet to be established. Radiotherapy may prolong the survival of patients with advanced biliary tract cancer, and particle radiotherapy delivers a more concentrated dose than conventional radiotherapy to deeper tumors. The present report describes the long-term survival of a 65-year-old man with distal bile duct cancer of pathological stage IIA (T2N0M0; depth of invasion, 5.5 mm) following multimodal treatment. Following subtotal stomach-preserving pancreatoduodenectomy, multiple hepatic recurrences were identified 9 months later, and GC therapy was initiated. The tumors were no longer evident 18 months later, and GC therapy was discontinued at the patient's request. A computed tomography (CT) scan performed 30 months after surgery identified a new solitary hepatic recurrence and duke pancreatic monoclonal antigen type-2 (DUPAN-2) levels were increased. Further GC therapy was declined. Carbon ion radiotherapy (CIRT) at a dose of 60 Gy [relative biological effectiveness (RBE)-weighted absorbed dose] was then delivered in four fractions over 4 days [15 Gy (RBE)/day]. Tumor size decreased on CT, and fluorodeoxyglucose-positron emission tomography/CT revealed a decline in the standardized uptake value of the tumor after 2 months, with decreased DUPAN-2 levels. Following regrowth of the hepatic recurrence, CIRT was repeated at a dose of 66 Gy (RBE) in four fractions over 4 days [16.5 Gy (RBE)/day] and stable disease was maintained for 19 months. After 19 months, CT revealed tumor regrowth and another new metastatic lesion was identified in the left kidney. The patient received systematic chemotherapy again and died of the disease 81 months after the initial surgery. In conclusion, CIRT is a potential treatment option to control solitary recurrence of biliary tract cancer.

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.

Clinical Outcomes of Patients With Unresectable Cholangiocarcinoma Treated With Proton Beam Therapy

OBJECTIVE

To investigate the clinical outcomes and failure patterns of patients with unresectable cholangiocarcinoma (CC) who had been treated with proton beam therapy (PBT).

METHODS

The authors retrospectively examined 30 patients with unresectable CC who had undergone PBT between November 2015 and December 2017. Survival curves were plotted with the Kaplan-Meier method. Independent predictors of survival were identified by multivariate Cox proportional hazard regression analyses. Complications were assessed using the Common Terminology Criteria for Adverse Events v4.0.

RESULTS

The median tumor size was 7 cm. Seventeen patients (56.7%) had regional lymph node metastases. The median radiation dose was 72.6 cobalt gray equivalents, and 23 patients (76.7%) received concurrent chemotherapy. The 1-year local control, regional control, and distant metastases-free rates were 88%, 86%, and 68%, respectively. The median overall survival and progression-free survival were 19.3 and 10.4 months, respectively. The median jaundice-free survival was 13 months, with a 1-year biliary tract infection (BTI)-free rate of 58%. Patients who received concurrent chemotherapy had a better median progression-free survival (12.1 vs. 4.7 mo). The most common form of acute toxicity from PBT was acute skin reactions which were rarely severe (grade III: 7% of patients). Three and 2 patients had grade III-IV toxicities and radiation-induced liver disease. There were no deaths caused by PBT or concurrent chemotherapy.

CONCLUSIONS

PBT is clinically useful in patients with unresectable CC, even in the presence of large tumors or regional nodal metastases. Its use may induce durable symptom relief, without increasing acute or late toxicity.

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 in Liver Malignancies

PURPOSE OF REVIEW

Proton beam therapy (PBT) allows for improved sparing of surrounding normal tissues compared with X-ray-based radiation therapy. This is especially important in the setting of liver malignancies, where an increase in integral dose leads to a higher risk of radiation-induced liver disease (RILD) as well as close proximity to vital gastrointestinal (GI) organs.

RECENT FINDINGS

We have data from multiple centers demonstrating that PBT can safely deliver high, ablative doses of radiation therapy conferring excellent local control with good tolerance of treatment. PBT is an effective treatment with longstanding evidence of efficacy that is increasing in availability.

Clinical outcomes of previously untreated patients with unresectable intrahepatic cholangiocarcinoma following proton beam therapy

BACKGROUND

The effectiveness of proton beam therapy (PBT) as initial treatment for patients with unresectable intrahepatic cholangiocarcinoma (ICC) is unclear, particularly as related to ICC histological subtypes. We performed this study to address this gap in knowledge.

METHODS

Thirty-seven patients with unresectable ICC who underwent PBT as their initial treatment were evaluated. Twenty-seven patients had Child-Pugh class A liver function, 11 exhibited jaundice, and 10 had multiple tumors. Nineteen, 7, and 11 tumors were classified as mass forming (MF), periductal infiltrating (PI), and intraductal growth (IG) types, respectively, based on gross appearance in imaging studies. Patients were classified into the curative group (n = 25) and palliative group (n = 12) depending on whether the planning target volume covered all the macroscopic tumors.

RESULTS

The 1- and 2-year overall survival rates were 60.3, and 41.4%, respectively; the median survival time (MST) was 15 months for all patients. The MSTs for curative and palliative groups were 25 and 7 months, respectively. Curative treatment and adjuvant chemotherapy significantly improved overall survival, while the presence of periductal infiltrating type tumors was a negative prognostic factor. In the curative group, the 1- and 2-year local control rates were 100 and 71.5%, respectively, while the 1-, and 2-year progression-free survival rates were 58.5, and 37.6%, respectively. No severe acute toxicities were observed. Three patients experienced grade 3 biliary tract infection, although it was unclear whether this was radiotherapy-related.

CONCLUSION

PBT may yield to improve survival and local tumor control among patients with unresectable ICC.

Hypofractionated Radiation Therapy for Unresectable/Locally Recurrent Intrahepatic Cholangiocarcinoma

OBJECTIVE

The aim of this study was to evaluate outcomes for patients with unresectable intrahepatic cholangiocarcinoma (ICC) treated with hypofractionated proton or photon radiation therapy (HF-RT).

METHODS

We retrospectively identified 66 patients with ICC who were treated with HF-RT from 2008 to 2018. Median age at RT was 76 years (range 30-92), including 27 patients (41%) aged ≥ 80 years. Median RT dose was 58.05 Gy (range 37.5-67.5), all delivered in 15 daily fractions. Thirty-two patients received proton RT and 34 patients received photon RT.

RESULTS

Median follow-up times from diagnosis and RT start were 21 months and 14 months, respectively. In total, five patients (7.6%) developed local failure. The 2-year outcomes were 84% local control (LC) and 58% OS. Among the 51 patients treated with definitive intent, the 2-year LC rate was 93% and the OS rate was 62%. On multivariate analysis for LC, older age was associated with a lower risk of local failure [hazard ratio (HR) 0.91; p = 0.02], while prior surgery (HR 16.5; p = 0.04) and macrovascular invasion (HR 123.93; p = 0.02) were independently associated with an increased risk of local failure. On multivariate analysis for OS, female sex (HR 0.33; p = 0.001) and prior chemotherapy (HR 0.38; p = 0.003) remained significantly associated with OS. On multivariate analysis for OS, compared with photon RT, there was a trend towards improved survival with proton RT (HR 0.50; p = 0.05). The rate of overall grade 3 + toxicity was 11%. One patient developed radiation-induced liver disease and was treated with corticosteroids.

CONCLUSIONS

HF-RT yields high rates of local control and is an effective modality to optimize biliary control for unresectable/locally recurrent ICC.

Carbon-ion radiotherapy for cholangiocarcinoma: a multi-institutional study by and the Japan carbon-ion radiation oncology study group (J-CROS)

To evaluate the safety and efficacy of carbon-ion radiotherapy (CIRT) for cholangiocarcinoma via a multicenter retrospective study. Clinical data were collected from patients with cholangiocarcinoma who had received CIRT at one of four treating institutions in Japan. Of 56 eligible patients, none received surgery for cholangiocarcinoma before or after CIRT. The primary endpoint was overall survival (OS). Based on the tumor site, the 56 cases were categorized as intrahepatic cholangiocarcinoma (IHC) (n=27) or perihilar cholangiocarcinoma (PHC) (n=29). In all patients, the median tumor size was 37 (range, 15‒110) mm, and the most commonly prescribed dose was 76 Gy (relative biological effectiveness) in 20 fractions. The median survival was 14.8 (range, 2.1-129.2) months, and the 1- and 2-year OS rates were 69.7% and 40.9%, respectively. The median survival times of the patients with IHC and those with PHC were 23.8 and 12.6 months, respectively. Both univariate and multivariate analyses revealed that cholangitis pre-CIRT and Child‒Pugh class B were significant prognostic factors for an unfavorable OS. Of four patients who died of liver failure, one with IHC was suspected to have radiation-induced liver disease because of newly developed ascites, and died at 4.3 months post-CIRT. Grade 3 CIRT-related bile duct stenosis was observed in one IHC case. No other CIRT-related severe adverse events, including gastrointestinal events, were observed. These results suggest that CIRT yields relatively favorable treatment outcomes, especially for patients with IHC, and acceptable toxicities were observed in patients with cholangiocarcinoma who did not receive surgery.

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.

A feasibility study of high-dose hypofractionated carbon ion radiation therapy using four fractions for localized hepatocellular carcinoma measuring 3 cm or larger

BACKGROUND AND PURPOSE

To evaluate the safety of carbon-ion radiotherapy (C-ion RT) using 60 Gy (relative biological effectiveness, RBE) in four fractions for patients with hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

The primary outcome was acute toxicities within 90 days. The secondary outcomes were late toxicities, local control, and progression-free survival and overall survival rates. The key inclusion criteria were as follows: (1) 3 cm or larger HCC without major vascular invasion and not adjacent to the alimentary tract; (2) Child-Pugh's grade A/B; and (3) without extrahepatic metastasis.

RESULTS

A total of 21 cases were analyzed between October 2012 and April 2016. The median follow-up period among the 17 survivors was 24.2 (range: 6.3-43.7) months. Grade 3 or higher acute toxicity was not observed, while three (14.3%) of the 21 patients experienced grade 3 late toxicities. The 1- and 2-year local control, progression-free survival, and overall survival rates were 100% and 92.3%, 81.0% and 50.0%, and 90.5% and 80.0%, respectively.

CONCLUSION

C-ion RT using 60 Gy (RBE) in four fractions was safe and achieved promising local tumor control.

Proton beam therapy for gastrointestinal cancers: past, present, and future

Despite the conformality of modern X-ray therapy limiting high dose received by normal tissues the physical properties of X-rays make it impossible to avoid dose being delivered distal to the target. This "exit dose" is likely clinically significant especially for patients with gastrointestinal (GI) cancers when considering that even low dose received by the heart, lungs, bowel, and other radiosensitive structures can lead to morbidity and even may affect long-term tumor control. In contrast, proton beam therapy (PBT) delivers no "exit dose" and a growing body of literature suggests that this may improve clinical outcomes by reducing toxicity and even allowing for safe dose intensification to enhance tumor control. While there are not yet robust prospective data demonstrating the role of PBT for GI cancers, emerging retrospective data provide a strong rationale for continued study of how PBT may improve the therapeutic ratio for these patients. Here we review these data as well as discuss ongoing clinical trials of PBT for GI cancers.

Locoregional therapies in cholangiocarcinoma

Cholangiocarcinoma is a rare and aggressive malignancy of the biliary tract. Complete surgical resection can be curative, but the majority of patients are diagnosed with advanced disease and usually die within a year of diagnosis. Most deaths are attributable to local disease progression rather than distant metastases, supporting the use of locoregional therapies. There is evidence that locoregional therapies can provide local tumor control resulting in increased survival while avoiding some of the side effects of systemic treatments, increasing potential treatment options for patients who may be unsuitable for systemic palliative treatments. This review considers the evidence for locoregional therapies in cholangiocarcinoma, which can be classified into endoscopic, vascular, percutaneous and radiation oncological therapies. Current guidelines do not recommend the routine use of locoregional therapies due to a lack of prospective data, but the results of ongoing trials are likely to increase the evidence base and impact on clinical practice.

Proton beam therapy for hepatocellular carcinoma

INTRODUCTION

Radiation therapy is an effective treatment option for hepatocellular carcinoma (HCC) patients. However, radiotherapy for HCC still has limited recognition as a standard treatment option in international consensus guidelines due to a paucity of randomized controlled trials and the risk of hepatotoxicity, which is primarily mediated by baseline liver function and dose delivered to non-tumor liver cells. Proton beam therapy (PBT) may offer advantages over photon-based radiation treatments through its dosimetric characteristic of sparing more liver volume at low to moderate doses. PBT has the potential to reduce radiation-related hepatotoxicity and allow for tumor dose escalation. Areas covered: This article reviews the clinical rationale for using PBT for HCC patients and clinical outcome and toxicity data from retrospective and prospective studies. PBT-specific technical challenges for these tumors and appropriate selection of patients to be treated with PBT are discussed. Expert commentary: Local control, overall survival, and toxicity results are promising for liver PBT. Future studies, including ongoing randomized cooperative group trials, will aim to determine the incremental benefit of PBT over photons and which patients are most suitable for PBT.

External radiotherapy and brachytherapy in the management of extrahepatic and intrahepatic cholangiocarcinoma: available evidence

This review aims to summarize the currently available evidence for the role of external radiotherapy and brachytherapy in the management of cholangiocarcinoma. High locoregional disease recurrence rates after surgical resection alone for both the extrahepatic cholangiocarcinoma (EHCC) and intrahepatic cholangiocarcinoma (IHCC) provide a rationale for using adjuvant radiotherapy with chemotherapy. We performed a literature search related to radiotherapy in cholangiocarcinoma published between 2000 and 2016. The role of radiation is discussed in the adjuvant, neoadjuvant, definitive and the palliative setting. Evidence from Phase II trials have demonstrated efficacy of adjuvant chemoradiation in combination with chemotherapy in EHCC. Locally advanced cholangiocarcinoma may be treated with neoadjuvant chemoradiotherapy. In the case of downsizing, assessment for resection may be considered. Brachytherapy offers dose escalation after external radiotherapy. Selected unresectable cases of cholangiocarcinoma may be considered for stereotactic body radiation therapy with neoadjuvant and/or concurrent chemotherapy. Liver transplantation is a treatment option in selected patients with EHCC and IHCC after neoadjuvant chemoradiation. Stenting in combination with palliative external radiotherapy and/or brachytherapy provides improved stent patency and survival. Newer advanced radiation techniques provide a scope for achieving better disease control with reduced morbidity. Effective multimodality treatment incorporating radiotherapy is the way forward for improving survival in patients with cholangiocarcinoma.

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.

Proton beams in cancer treatments: Clinical outcomes and dosimetric comparisons with photon therapy

PURPOSE

To review current evidence of the role of proton therapy (PT) in other tumors than skull base, sinusal/parasinusal, spinal and pediatric tumors; to determine medico-economic aspects raised by PT.

MATERIAL AND METHODS

A systematic review on Medline was performed with the following keywords: proton therapy, proton beam, protontherapy, cancer; publications with comparison between PT and photon-therapy were also selected.

RESULTS

In silico studies have shown superiority (better dose delivery to the target and/or to organs at risk) of PT toward photon-therapy in most of thoracic and abdominal malignant tumors. Potential benefits of PT could be: reduction of toxicities (including radiation-induced cancer), increase of tumor control through a dose-escalation approach, hypofractionation. Cost of treatment is always cited as an issue which actually can be managed by a precise patient selection making PT a cost-effective procedure. Comparison plan with photon therapy may be useful to determine the dosimetric and clinical advantages of PT (Normal Tissue Complications Probability).

CONCLUSION

PT may be associated with a great advantage compared to the best photon-therapies in various types of cancers. Accumulation of clinical data is on-going and will challenge the in silico data analysis. Some indications are associated with strong superiority of PT and may be discussed as a new standard within prospective observational studies.

Multi-Institutional Phase II Study of High-Dose Hypofractionated Proton Beam Therapy in Patients With Localized, Unresectable Hepatocellular Carcinoma and Intrahepatic Cholangiocarcinoma

PURPOSE

To evaluate the efficacy and safety of high-dose, hypofractionated proton beam therapy for hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC).

MATERIALS AND METHODS

In this single-arm, phase II, multi-institutional study, 92 patients with biopsy-confirmed HCC or ICC, determined to be unresectable by multidisciplinary review, with a Child-Turcotte-Pugh score (CTP) of A or B, ECOG performance status of 0 to 2, no extrahepatic disease, and no prior radiation received 15 fractions of proton therapy to a maximum total dose of 67.5 Gy equivalent. Sample size was calculated to demonstrate > 80% local control (LC) defined by Response Evaluation Criteria in Solid Tumors (RECIST) 1.0 criteria at 2 years for HCC patients, with the parallel goal of obtaining acceptable precision for estimating outcomes for ICC.

RESULTS

Eighty-three patients were evaluable: 44 with HCC, 37 with ICC, and two with mixed HCC/ICC. The CTP score was A for 79.5% of patients and B for 15.7%; 4.8% of patients had no cirrhosis. Prior treatment had been given to 31.8% of HCC patients and 61.5% of ICC patients. The median maximum dimension was 5.0 cm (range, 1.9 to 12.0 cm) for HCC patients and 6.0 cm (range, 2.2 to 10.9 cm) for ICC patients. Multiple tumors were present in 27.3% of HCC patients and in 12.8% of ICC patients. Tumor vascular thrombosis was present in 29.5% of HCC patients and in 28.2% of ICC patients. The median dose delivered to both HCC and ICC patients was 58.0 Gy. With a median follow-up among survivors of 19.5 months, the LC rate at 2 years was 94.8% for HCC and 94.1% for ICC. The overall survival rate at 2 years was 63.2% for HCC and 46.5% ICC.

CONCLUSION

High-dose hypofractionated proton therapy demonstrated high LC rates for HCC and ICC safely, supporting ongoing phase III trials of radiation in HCC and ICC.