Brachytherapy in the treatment of bile duct cancer - a tough challenge. J Contemp Brachytherapy. 2017;9:187-195. [PMID: 28533809 PMCID: PMC5437079 DOI: 10.5114/jcb.2017.66893]

Role of intraluminal brachytherapy in palliation of biliary obstruction in cholangiocarcinoma: A brief review

Surgery is the only curative treatment for cholangiocarcinoma. However, most patients present with advanced disease, and hence are unresectable. Thus, the intent of treatment shifts from curative to palliative in the majority of cases. Biliary drainage with intraluminal brachytherapy is an effective means of relieving the malignant biliary obstruction. In this review, we discuss the role of brachytherapy in the palliation of obstructive symptoms in extrahepatic cholangiocarcinoma.

Ablative therapies of the biliary tree

Cholangiocarcinoma, a malignancy of the epithelial cells in the intrahepatic or extrahepatic biliary tree, is often diagnosed at later stages. Median survival duration ranges from 3 to 9 months with a less than ten percent 5-year survival rate. Thus, often treatment strategies are aimed more towards palliation instead of cure. With the majority of patients presenting with unresectable disease at the time of diagnosis, surgical intervention is not feasible, making less invasive endoscopic therapies more suitable. Initially, biliary stents were utilized for biliary decompression to mitigate cholestatic symptoms and prevent cholangitis; however, this strategy did not prove to provide significant survival benefit. Therefore, efforts to treat the tumor burden itself in addition to maintaining biliary patency became a focus of innovation and research in the endoscopic field. This study has led to the advent of therapies such as photodynamic therapy, radiofrequency ablation, and intraluminal brachytherapy. These options combined with biliary stenting have shown to not only offer the benefit of biliary decompression, but also to potentially improve stent patency and survival. Further, there is an anti-tumor effect of each of these modalities, portending an additional benefit in this subset of patients. Despite numerous retrospective and prospective studies assessing these ablative therapies, there is still a paucity of appropriately powered randomized controlled trials, and further research has yet to be done in the field. This review details the current literature entailing endobiliary ablative strategies.

Extrahepatic cholangiocarcinoma: Current status of endoscopic approach and additional therapies

The prognosis of patients with advanced or unresectable extrahepatic cholangiocarcinoma is poor. More than 50% of patients with jaundice are inoperable at the time of first diagnosis. Endoscopic treatment in patients with obstructive jaundice ensures bile duct drainage in preoperative or palliative settings. Relief of symptoms (pain, pruritus, jaundice) and improvement in quality of life are the aims of palliative therapy. Stent implantation by endoscopic retrograde cholangiopancreatography is generally preferred for long-term palliation. There is a vast variety of plastic and metal stents, covered or uncovered. The stent choice depends on the expected length of survival, quality of life, costs and physician expertise. This review will provide the framework for the endoscopic minimally invasive therapy in extrahepatic cholangiocarcinoma. Moreover, additional therapies, such as brachytherapy, photodynamic therapy, radiofrequency ablation, chemotherapy, molecular-targeted therapy and/or immunotherapy by the endoscopic approach, are the nonsurgical methods associated with survival improvement rate and/or local symptom palliation.

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.

Percutaneous Intraductal Microwave Ablation and Self-expandable Metallic Stenting: A New Treatment Method for Malignant Extrahepatic Biliary Obstruction

PURPOSE

To evaluate the patency and clinical efficacy of percutaneous intraductal microwave ablation (PIMWA) and uncovered self-expandable metallic stents (USEMs) in inoperable malignant extrahepatic biliary obstruction.

MATERIALS AND METHODS

The procedures to be performed on patients with malignant inoperable extrahepatic biliary obstruction were decided by a multidisciplinary team including an interventional radiologist. In our study, 141 patients were evaluated retrospectively. Twenty-one patients who underwent PIMWA + USEMs with the MedWaves AveCure microwave system (AveCure^® Intelligent Controller and Super-Flex Smart Catheter) and met the inclusion criteria were included in the study. Complications related to the intervention, stent patency, survival time, serum bilirubin levels, and the general condition of the patients were noted.

RESULTS

The median stent patency and the median survival time were 108 and 143 days, respectively. The rates of 30-day, 2-month, 6-month and 8-month survival were 95.2%, 85.7%, 38.1%, and 14.3%, respectively.

CONCLUSION

The PIMWA + USEMs procedure is a safe, effective, and minimally invasive alternative palliative treatment method in patients with malignant inoperable extrahepatic biliary obstruction.

A guide to curriculum inquiry for brachytherapy simulation-based medical education

PURPOSE

Brachytherapy is a required clinical competency within radiation oncology training but decreased utilization and volume have limited trainee exposure. Simulation-based medical education is an established educational tool that allows learners to engage in higher-order learning in a safe space and has unique application in brachytherapy instruction.

METHODS AND MATERIALS

We reviewed best practices in curriculum development for simulation-based medical education in brachytherapy, current works in brachytherapy simulation, and identify areas for future development.

RESULTS

The systematic curriculum inquiry method as it relates to brachytherapy was described using the "six-step approach" of problem identification and general needs assessment, targeted needs assessment, goals and objectives, educational strategies, implementation, and evaluation and feedback. Best practices in simulation identified several features of effective learning, including feedback, repetitive practice, and curriculum integration. A review of current simulation-based medical education brachytherapy publications revealed five manuscripts to date with a focus on feasibility across a variety of disease sites, including the prostate, cervical, breast, and head and neck. Potential areas of future development include curricular quality improvement, long-term outcomes, objectives that scale to the learner's competencies, and expansion beyond psychomotor skills.

CONCLUSIONS

Brachytherapy is an essential modality in radiation oncology. Simulation-based medical education provides a powerful opportunity to improve brachytherapy training effectively.

Patterns of Failure and the Need for Biliary Intervention in Resected Biliary Tract Cancers After Chemoradiation

BACKGROUND

This study assessed patterns of failure and rates of subsequent biliary intervention among patients with resected biliary tract cancers (BTCs) including gallbladder carcinoma (GBC) and extra- and intrahepatic cholangiocarcinoma (eCCA and iCCA) treated with adjuvant chemoradiation therapy (CRT).

METHODS

In this single-institution retrospective analysis of 80 patients who had GBC (n = 29), eCCA (n = 43), or iCCA (n = 8) treated with curative-intent resection and adjuvant CRT from 2007 to 2017, the median radiation dose was 50.4 Gy (range 36-65 Gy) with concurrent 5-fluorouracil (5-FU) chemotherapy. All but two of the patients received adjuvant chemotherapy. The 2-year locoregional failure (LRF), 2-year recurrence-free survival (RFS), and 2-year overall survival (OS), and univariate predictors of LRF, RFS, and OS were calculated for the entire cohort and for a subgroup excluding patients with iCCA (n = 72). The predictors of biliary interventions also were assessed.

RESULTS

Of the 80 patients (median follow-up period, 30.5 months; median OS, 33.9 months), 54.4% had American Joint Committee on Cancer (AJCC) stage 1 or 2 disease, 57.1% were lymph node-positive, and 66.3% underwent margin-negative resection. For the entire cohort, 2-year LRF was 23.8%, 2-year RFS was  43.7%, and 2-year OS was 62.1%.  When patients with iCCA were excluded, the 2-year LRF was 22.6%, the 2-year RFS was 43.9%, and the 2-year OS was 59.2%. In the overall and subgroup univariate analyses, lymph node positivity was associated with greater LRF, whereas resection margin was not. Biliary intervention was required for 12 (63.2%) of the 19 patients with LRF versus 11 (18%) of the 61 patients without LRF (P < 0.001). Of the 12 patients with LRF who required biliary intervention, 4 died of biliary complications.

CONCLUSIONS

The LRF rates remained significant despite adjuvant CRT. Lymph node positivity may be associated with increased risk of LRF. Positive margins were not associated with greater LRF, suggesting that CRT may mitigate LRF risk for this group. An association between LRF and higher rates of subsequent biliary interventions was observed, which may yield significant morbidity. Novel strategies to decrease the rates of LRF should be considered.

microRNA-329 suppresses epithelial-to-mesenchymal transition and lymph node metastasis in bile duct cancer by inhibiting laminin subunit beta 3

Bile duct cancer (BDC), also known as cholangiocarcinoma, is a highly desmoplastic cancer with a growth pattern characterized by periductal extension and infiltration. Studies have suggested that microRNAs (miRNAs) play an important role in BDC progression. Here we aim at investigating the effects of miR-329 on BDC development, focusing especially on epithelial-to-mesenchymal transition (EMT) in vitro and lymph node metastasis in vivo. Expression microarrays associated with BDC tissues were collected and differentially expressed genes were analyzed, followed by miRNA target prediction and verification. The role miR-329 played in BDC was examined using gain-of-function and loss-of-function methods. The expressions of miR-329, laminin subunit beta 3 (LAMB3), and EMT markers, in addition to cell proliferation, migration, and invasion were evaluated. Furthermore, nude mice models of BDC were established to observe tumor growth and metastatic lymph nodes. The LAMB3 was identified as an upregulated gene based on the GSE77984 and GSE45001 microarray analysis. LAMB3 was also predicted and confirmed to be a target gene of miR-329 by dual-luciferase reporter assay. Through further cell experiments, the EMT process was reversed, cell proliferation, invasion, and migration were suppressed, when miR-329 was upregulated. Furthermore, in vivo experiments exhibited that the overexpression of miR-329 inhibited tumor growth and the number of metastatic lymph nodes. This study provides in vivo and in vitro evidence that miR-329 inhibits BDC progression through translational repression of LAMB3. Therefore, the obtained results may aid as an experimental basis for improving prognosis of BDC.

Endoscopic Retrograde Cholangiopancreatography-Guided Ablation for Cholangiocarcinoma

Most patients with perihilar cholangiocarcinoma present with surgically unresectable disease owing to the insidious nature of this malignancy. Relief of malignant perihilar biliary obstruction is a key aspect of cholangiocarcinoma. Although palliative stenting using uncovered metal stents has been advocated in patients with unresectable malignant perihilar biliary strictures, several endoscopic retrograde cholangiopancreatography-guided ablative modalities have emerged. Palliative photodynamic therapy, radiofrequency ablation, and intraluminal brachytherapy have been associated with improved stent patency and survival, although the ideal treatment approach remains unclear. This article reviews the published evidence for using each of these endobiliary ablative modalities in this difficult-to-treat patient population.

Technique for the administration of high-dose-rate brachytherapy to the bile duct using a nasobiliary catheter

PURPOSE

Cholangiocarcinoma patients who are potential candidates for liver transplantation may be treated with high-dose-rate (HDR) brachytherapy using a minimally invasive nasobiliary catheter in an effort to escalate the radiotherapy dose to the tumor and maximize local control rates. This work describes the equipment, procedures, and quality assurance (QA) that enables successful administration.

METHODS AND MATERIALS

This work describes the nasobiliary catheter placement, simulation, treatment planning, treatment delivery, and QA. In addition, a chart review was performed of all patients who received endoscopic retrograde cholangiopancreatography for HDR bile duct brachytherapy at our institution from 2007 to 2017. The review evaluated how many patients were treated and the number of patients who could not be treated because of anatomic and/or equipment limitations.

RESULTS

From 2007 to 2017, 122 cholangiocarcinoma patients have been treated with HDR brachytherapy using a nasobiliary catheter. Three patients underwent catheter placement but did not receive brachytherapy treatment due to catheter migration between placement and treatment or because the HDR afterloader was unable to extend the source wire into the treatment site. Periodic QA is recommended for ensuring whether the HDR afterloader is capable of extending the source wire through an extensive and curved path.

CONCLUSIONS

Intraluminal HDR brachytherapy with a nasobiliary catheter can be successfully administered. Procedures and QA are described for ensuring safety and overcoming technical challenges.

Age Is Not a Limiting Factor in Interventional Radiotherapy (Brachytherapy) for Patients with Localized Cancer

This review examines the role of interventional radiotherapy (IRT otherwise known as brachytherapy) in cancer treatment for elderly patients. Despite their advanced age and associated comorbidities, elderly patients should receive definitive cancer therapies, including surgery and radiotherapy (RT). In fact, RT becomes first-line option for patients who are not eligible for surgery (due to comorbidities, anticoagulant drugs, and risk of disfigurement) or those who refuse it. It emerged from this review of the literature as effective, simple, safe, and comfortable and was associated with good local control, low toxicity rates, and excellent cosmesis and provided a cost benefit. IRT may be used as sole treatment for small cancers or as a useful adjunct to surgery or external beam radiotherapy (EBRT) in more advanced (or lymph node positive) cases, especially when the aim is local control with adequate preservation of normal tissue function. As palliative treatment, IRT preserves quality of life and/or improves survival. It is to be hoped that this review will serve as a helpful guide for members of multidisciplinary teams that are involved in treating elderly patients with cancer.

Current status of brachytherapy in cancer treatment - short overview

Cancer incidence and mortality depend on a number of factors, including age, socio-economic status and geographical location, and its prevalence is growing around the world. Most of cancer treatments include external beam radiotherapy or brachytherapy. Brachytherapy, a type of radiotherapy with energy from radionuclides inserted directly into the tumor, is increasingly used in cancer treatment. For cervical and skin cancers, it has become a standard therapy for more than 100 years as well as an important part of the treatment guidelines for other malignancies, including head and neck, skin, breast, and prostate cancers. Compared to external beam radiotherapy, brachytherapy has the potential to deliver an ablative radiation dose over a short period of time directly to the altered tissue area with the advantage of a rapid fall-off in dose, and consequently, sparing of adjacent organs. As a result, the patient is able to complete the treatment earlier, and the risks of occurrence of another cancer are lower than in conventional radiotherapy treatment. Brachytherapy has increased its use as a radical or palliative treatment, and become more advanced with the spread of pulsed-dose-rate and high-dose-rate afterloading machines; the use of new 3D/4D planning systems has additionally improved the quality of the treatment. The aim of the present study was to present short summaries of current studies on brachytherapy for the most frequently diagnosed tumors. Data presented in this manuscript should help especially young physicians or physicists to explore and introduce brachytherapy in cancer treatments.