Photodynamic therapy for unresectable cholangiocarcinoma: contribution of single operator cholangioscopy for targeted treatment

The Role of Cholangioscopy in Biliary Diseases

Endoscopy plays a central role in diagnostic and therapeutic approaches to biliary disease in both benign and malignant conditions. A cholangioscope is an endoscopic instrument that allows for the direct exploration of the biliary tree. Over the years, technology has improved endoscopic image quality and allowed for the development of an operative procedure that can be performed during cholangioscopy. Different types of instruments are available in this context, and they can be used in different anatomical access points according to the most appropriate clinical indication. The direct visualization of biliary mucosa is essential in the presence of biliary strictures of unknown significance, allowing for the appropriate allocation of patients to surgery or conservative treatments. Cholangioscopy has demonstrated excellent performance in discriminating malignant conditions (such as colangiocarcinoma) from benign inflammatory strictures, and more recent advances (e.g., artificial intelligence and confocal laser endomicroscopy) could further increase its diagnostic accuracy. Cholangioscopy also plays a primary role in the treatment of benign conditions such as difficult bile stones (DBSs). In this case, it may not be possible to achieve complete biliary drainage using standard ERCP. Therapeutic cholangioscopy-guided lithotripsy allows for stone fragmentation and complete biliary drainage. Indeed, other complex clinical situations, such as patients with intra-hepatic lithiasis and patients with an altered anatomy, could benefit from the therapeutic role of cholangioscopy. The aim of the present review is to explore the most recent diagnostic and therapeutic advances in the roles of cholangioscopy in the management of biliary diseases.

Drug Self-delivery Nanorods Enhance Photodynamic Therapy of Triple-Negative Breast Cancer by inhibiting Oxidative Phosphorylation

Photodynamic therapy (PDT) shows very high potential for the clinical treatment of triple-negative breast cancer. However, the efficacy of PDT is significantly weakened by tumor hypoxia, the relatively high intracellular glutathione levels and the active proliferation of cancer cells. To address these issues, we developed a novel drug self-delivery nanorod (defined as AINRs) through the hydrophobic interaction among the mitochondrial complex III inhibitor (atovaquone, ATO), the photosensitizer (indocyanine green, ICG) and the dispersion stabilizer (distearoyl phosphoethanolamine-polyethylene glycol 2000, DSPE-PEG 2000). The AINRs showed a rod-like morphology with a mean diameter of 120.6 ± 5.4 nm, a zeta potential of -26.35 ± 1.63 mV and a significantly high drug loading rate of 93.48%. The results of in vitro cell experiments involving triple-negative breast cancer cell lines (4T1 cells and MDA-MB-231 cells) indicated that the AINRs could effectively block the oxidative phosphorylation of cancer cells through the inhibition of mitochondrial complex III, which results in the reduction of endogenous oxygen consumption and the decrease of the intracellular ATP level. The reduction of ATP content further inhibited the glutathione synthesis and arrested the cell cycle at the S-phase, which results in enhanced in vitro PDT efficacy of ICG. The results of in vivo antitumor activity in 4T1-bearing mice showed that the tumor growth inhibition rate of the AINRs with near-infrared laser irradiation (NIR) was 90%, whereas the tumor growth inhibition rates of the AINRs without NIR, ICG with NIR and doxorubicin (3 mg/kg) were only 31.68%, 61.15% and 24.59%, respectively. In addition, the results of safety studies, including body weights, biochemical indicators and H&E staining images of the main organs demonstrated the security of the AINRs. In summary, this study showed that the oxidative phosphorylation inhibition of triple-negative breast cancer was a safe and effective method to enhance its PDT efficacy.

Peroral cholangioscopy: Update on the state-of-the-art

Peroral cholangioscopy (POC) is an endoscopic procedure that allows direct intraductal visualization of the biliary tract. POC has emerged as a vital tool for indeterminate biliary stricture evaluation and treatment of difficult biliary stones. Over several generations of devices, POC has fulfilled additional clinical needs where other diagnostic or therapeutic modalities have been inadequate. With adverse event rates comparable to standard endoscopic retrograde cholangioscopy and unique technical attributes, the role of POC is likely to continue expand. In this frontiers article, we highlight the existing and growing clinical applications of POC as well as areas of ongoing research.

Effect of Photodynamic Therapy on Gemcitabine-Resistant Cholangiocarcinoma in vitro and in vivo Through KLF10 and EGFR

Cholangiocarcinoma is a relatively rare neoplasm with increasing incidence. Although chemotherapeutic agent such as gemcitabine has long been used as standard treatment for cholangiocarcinoma, the interindividual variability in target and drug sensitivity and specificity may lead to therapeutic resistance. In the present study, we found that photodynamic therapy (PDT) treatment inhibited gemcitabine-resistant cholangiocarcinoma cells via repressing cell viability, enhancing cell apoptosis, and eliciting G1 cell cycle arrest through modulating Cyclin D1 and caspase 3 cleavage. In vivo, PDT treatment significantly inhibited the growth of gemcitabine-resistant cholangiocarcinoma cell-derived tumors. Online data mining and experimental analyses indicate that KLF10 expression was induced, whereas EGFR expression was downregulated by PDT treatment; KLF10 targeted the EGFR promoter region to inhibit EGFR transcription. Under PDT treatment, EGFR overexpression and KLF10 silencing attenuated the anti-cancer effects of PDT on gemcitabine-resistant cholangiocarcinoma cells by promoting cell viability, inhibiting apoptosis, and increasing S phase cell proportion. Importantly, under PDT treatment, the effects of KLF10 silencing were significantly reversed by EGFR silencing. In conclusion, PDT treatment induces KLF10 expression and downregulates EGFR expression. KLF10 binds to EGFR promoter region to inhibit EGFR transcription. The KLF10/EGFR axis participates in the process of the inhibition of PDT on gemcitabine-resistant cholangiocarcinoma cells.

Percutaneous transhepatic cholangioscopy using a single-operator cholangioscope (pSOC), a retrospective, observational, multicenter study

BACKGROUND AND AIMS

Percutaneous cholangioscopy (PC) is more complex and invasive than a transpapillary approach, with the need for a large percutaneous tract of 16 French (Fr) on average in order to advance standard percutaneous cholangioscopes. The aim of this study was to investigate whether percutaneous single-operator cholangioscopy (pSOC) using the SpyGlass^™ DS system is feasible, safe, and effective in PC for diagnostic and therapeutic indications.

MATERIALS AND METHODS

The data of 28 patients who underwent pSOC in 4 tertiary referral centers were retrospectively analyzed. Technical and clinical success for therapeutic procedures was assessed as well as diagnostic accuracy of pSOC-guided biopsies and visualization. Adverse events and the required number and size of dilatations were reviewed.

RESULTS

25/28 (89%) patients had a post-surgical altered anatomy. The average number of percutaneous dilatations prior to pSOC was 1.25 with a mean dilatation size of 11 French. Histopathology showed a 100% accuracy. Visual impression showed an overall accuracy of 96.4%. Technical and clinical success was achieved in 27/28 (96%) of cases. Adverse events occurred in 3/28 (10.7%) cases.

CONCLUSION

pSOC is a feasible, safe, and effective technique for diagnostic and therapeutic indications. It may be considered an alternative approach in clinical cases where gastrointestinal anatomy is altered. It has the potential to reduce peri-procedural adverse events and costs. Prospective randomized-controlled trials are necessary to confirm the previously collected data.

Photodynamic therapy of extrahepatic cholangiocarcinoma using digital cholangioscopy

Background:

Cholangiocarcinoma is an aggressive neoplasm that usually requires palliative biliary drainage. Photodynamic therapy (PDT) has been described as a successful adjunct treatment to malignant biliary obstruction.

Aim:

To describe the use of digital cholangioscope to help provide laser light during biliary PDT session using locally developed light source.

Method:

Patient receives intravenous photosensitizer 24 h before the procedure. It starts with a regular duodenoscopy. After identification of the major papilla and retrograde cannulation, the digital cholangioscope is introduced into the common bile duct. Then, the cholangioscopic examination helps to identify the neoplastic stricture. Under direct visualization lighting catheter is advanced through the cholangioscope. Repositioning is recommended every centimeter to cover all strictured area. At the end of the procedure, a final cholangioscopy assesses the bile duct for the immediate result and adverse events.

Result:

This procedure was applied in one 82-year-old male due to obstructive jaundice in the last two months. EUS and ERCP revealed a severe dilation of the common bile duct associated with choledocholithiasis. Besides, was revealed dilation of hepatic duct up to a well-circumscribed hypoechoic solid mass measuring 1.8x2 cm compressing the common hepatic duct. The mass was deemed unresectable and the patient was referred for palliative treatment with PDT. He remained asymptomatic for three months. He perished due to complications 15 months after the PDT session.

Conclusion:

Digital cholangioscopy-guided biliary PDT is feasible and seems safe and effective as an adjunct modality in the palliation of extrahepatic cholangiocarcinoma.

Endoscopic retrograde cholangiopancreatography, lights and shadows: Handle with care

The role of endoscopic retrograde cholangiopancreatography (ERCP) has dramatically changed in the last years, mainly into that of a therapeutic procedure. The treatment of benign biliary disease, like “difficult” choledocolithiasis, with endoscopic papillary large balloon dilation combined with endoscopic sphinterotomy has proven an effective and safe technique. Moreover, safety in ERCP has improved as well, with the prevention of post-ERCP pancreatitis and patient-to-patient transmission of infections. The advent of self-expandable metal stenting has radically changed the management of biliopancreatic malignant strictures, while the role for therapy of benign strictures is still controversial. In addition, cholangioscopy (though the direct visualization of the biliopancreatic ductal system) has allowed for characterization of indeterminate biliary strictures and facilitated rescue therapy of large biliary stones deemed removable. Encouraging data from tissue ablation techniques, such as photodynamic therapy and radiofrequency ablation, need to be confirmed by large sample size clinical controlled trials. On the other hand, we have no drug-coated stents yet available to implant and evidence for the use of biodegradable stents is still weak. The competency and privileging of ERCP and endoscopic ultrasonography have been analyzed longer but the switch between the two procedures, at the same time, is becoming ordinary; as such, the endoscopist interested in this field should undergo parallel edification through training plans. Finally, the American Society for Gastrointestinal Endoscopy’s statement on non-anesthesiologist administration of propofol for gastrointestinal endoscopy is not actually endorsed by the European Society of Anaesthesiology, having many medical-legal implications in some European countries.

Physically-triggered nanosystems based on two-dimensional materials for cancer theranostics

There is an increasing demand to develop effective methods for treating malignant diseases to improve healthcare in our society. Stimuli-responsive nanosystems, which can respond to internal or external stimuli are promising in cancer therapy and diagnosis due to their functionality and versatility. As a newly emerging class of nanomaterials, two-dimensional (2D) nanomaterials have attracted huge interest in many different fields including biomedicine due to their unique physical and chemical properties. In the past decade, stimuli-responsive nanosystems based on 2D nanomaterials have been widely studied, showing promising applications in cancer therapy and diagnosis, including phototherapies, magnetic therapy, drug and gene delivery, and non-invasive imaging. Here, we will focus our attention on the state-of-the-art of physically-triggered nanosystems based on graphene and two-dimensional nanomaterials for cancer therapy and diagnosis. The physical triggers include light, temperature, magnetic and electric fields.

Mitochondrial-targeted multifunctional mesoporous Au@Pt nanoparticles for dual-mode photodynamic and photothermal therapy of cancers

In the conventional non-invasive cancer treatments, such as photodynamic therapy (PDT) and photothermal therapy (PTT), light irradiation is precisely focused on tumors to induce apoptosis via the generation of reactive oxygen species (ROS) or localized heating. However, overconsumption of oxygen and restricted diffusion distance of ROS limit the therapeutic effects on hypoxic tumors. Herein, we developed a platform for the rapid uptake of multifunctionalized Au@Pt nanoparticles (NPs) by mitochondria in cancer cells. The mesoporous Au@Pt nanoparticles were labeled with a cell-targeting ligand (folic acid), a mitochondria-targeting group (triphenylphosphine (TPP)), and a photosensitizer (Ce6). This led to significant improvement of the PDT efficacy due to an enhanced cellular uptake, an effective mitochondrial ROS burst, and a rapid intelligent release of oxygen. Moreover, Au@Pt NPs can convert laser radiation into heat, resulting in thermally induced cell damage. This nanosystem could be used as a dual-mode phototherapeutic agent for enhanced cancer therapy and molecular targets associated with disease progression. We achieved a mitochondria-targeted multifunctional therapy strategy (a combination of PDT and PTT) to substantially improve the therapeutic efficiency.

Recent developments in choledochoscopy: technical and clinical advances

Peroral cholangioscopy has become an important tool in the diagnosis and treatment of a variety of biliary diseases, ranging from indeterminate biliary strictures to bile duct stones. Although the first cholangioscopy was performed in the 1970s, recent technological advances have provided us with cholangioscopes that yield high-resolution images, possess single-operator capability, and have ultrathin design to allow easier maneuverability and detailed imaging of the biliary tract. We review here the currently available devices for peroral cholangioscopy, their clinical applications, limitations, and complications.

Photodynamic Therapy in Patients with Advanced Hilar Cholangiocarcinoma: Percutaneous Cholangioscopic Versus Peroral Transpapillary Approach

OBJECTIVE

This study aimed to compare the clinical outcomes of patients with advanced hilar cholangiocarcinoma (CC) who underwent photodynamic therapy (PDT) with either percutaneous transhepatic cholangioscopy (PTCS) or endoscopic retrograde cholangiopancreatography (ERCP).

BACKGROUND DATA

PDT has been proposed as a promising therapy for treatment of unresectable hilar CC that is resistant to conventional standard treatment. However, few studies have compared the delivery methods of PDT in unresectable hilar CC patients.

METHODS

Thirty-seven adult patients with advanced hilar CC were included in this study. Twenty-four patients treated with PTCS-directed PDT and 13 patients treated with ERCP-directed PDT were analyzed retrospectively.

RESULTS

The PTCS- and ERCP-directed PDT groups were comparable with respect to age, gender, health status, pretreatment bilirubin levels, Bismuth type, and hilar CC stage. The length of hospital stay differed significantly (p < 0.001) between the two groups, with a median hospital stay of 37 days (range, 13-77 days) in the ERCP-directed PDT group versus 63 days (range, 23-125 days) in the PTCS-directed group. PTCS-directed PDT patients demonstrated an overall survival similar to that of ERCP-directed PDT patients, with a median survival of 11.6 versus 9.5 months, respectively (p = 0.96). Only lower pre-PDT bilirubin levels (p = 0.002) were a significant predictor of improved survival in all patients who underwent PDT, as determined by multivariate analysis. Median metal stent patency was similar between the groups [PTCS-directed PDT group (n = 8), 6.2 months; ERCP-directed PDT group (n = 7), 7.2 months; p = 0.642]. Survival after PTCS- or ERCP-directed PDT was not statistically different in patients with advanced hilar CC.

CONCLUSIONS

Lower pre-PDT bilirubin levels were associated with longer survival in all patients.

A graphene oxide based smart drug delivery system for tumor mitochondria-targeting photodynamic therapy

Subcellular organelles play critical roles in cell survival. In this work, a novel photodynamic therapy (PDT) drug delivery and phototoxicity on/off nano-system based on graphene oxide (NGO) as the carrier is developed to implement subcellular targeting and attacking. To construct the nanodrug (PPa-NGO-mAb), NGO is modified with the integrin αvβ3 monoclonal antibody (mAb) for tumor targeting. Pyropheophorbide-a (PPa) conjugated with polyethylene-glycol is used to cover the surface of the NGO to induce phototoxicity. Polyethylene-glycol phospholipid is loaded to enhance water solubility. The results show that the phototoxicity of PPa on NGO can be switched on and off in organic and aqueous environments, respectively. The PPa-NGO-mAb assembly is able to effectively target the αvβ3-positive tumor cells with surface ligand and receptor recognition; once endocytosized by the cells, they are observed escaping from lysosomes and subsequently transferring to the mitochondria. In the mitochondria, the 'on' state PPa-NGO-mAb performs its effective phototoxicity to kill cells. The biological and physical dual selections and on/off control of PPa-NGO-mAb significantly enhance mitochondria-mediated apoptosis of PDT. This smart system offers a potential alternative to drug delivery systems for cancer therapy.

Biliary Tumor Ablation with Photodynamic Therapy and Radiofrequency Ablation

Within the past two decades, major progress has been made in biliary endoscopy both with stenting and with ablative therapy. A primary goal in patients with malignant biliary lesions who are not candidates for surgery is to provide localized and efficient necrosis of the lesions. This article summarizes the current literature on biliary tumor ablation with photodynamic therapy and radiofrequency ablation. Prognosis, treatment technique, potential complications, treatment efficacy, and controversies are discussed.

Advances in endoscopic retrograde cholangiopancreatography for the treatment of cholangiocarcinoma

Cholangiocarcinoma (CCA) is a malignancy of the bile ducts that carries high morbidity and mortality. Patients with CCA typically present with obstructive jaundice, and associated complications of CCA include cholangitis and biliary sepsis. Endoscopic retrograde cholangiopancreatography (ERCP) is a valuable treatment modality for patients with CCA, as it enables internal drainage of blocked bile ducts and hepatic segments by using plastic or metal stents. While there remains debate as to if bilateral (or multi-segmental) hepatic drainage is required and/or superior to unilateral drainage, the underlying tenant of draining any persistently opacified bile ducts is paramount to good ERCP practice and good clinical outcomes. Endoscopic therapy for malignant biliary strictures from CCA has advanced to include ablative therapies via ERCP-directed photodynamic therapy (PDT) or radiofrequency ablation (RFA). While ERCP techniques cannot cure CCA, advancements in the field of ERCP have enabled us to improve upon the quality of life of patients with inoperable and incurable disease. ERCP-directed PDT has been used in lieu of brachytherapy to provide neoadjuvant local tumor control in patients with CCA who are awaiting liver transplantation. Lastly, mounting evidence suggests that palliative ERCP-directed PDT, and probably ERCP-directed RFA as well, offer a survival advantage to patients with this difficult-to-treat malignancy.

Chlorin e6 Conjugated Poly(dopamine) Nanospheres as PDT/PTT Dual-Modal Therapeutic Agents for Enhanced Cancer Therapy

Photodynamic therapy (PDT), using a combination of chemical photosensitizers (PS) and light, has been successfully applied as a noninvasive therapeutic procedure to treat tumors by inducing apoptosis or necrosis of cancer cells. However, most current clinically used PS have suffered from the instability in physiological conditions which lead to low photodynamic therapy efficacy. Herein, a highly biocompatible poly(dopamine) (PDA) nanoparticle conjugated with Chlorin e6 (referenced as the PDA-Ce6 nanosphere) was designed as a nanotherapeutic agent to achieve simultaneous photodynamic/photothermal therapy (PDT/PTT). Compared to the free Ce6, the PDA-Ce6 nanosphere exhibited significantly higher PDT efficacy against tumor cells, because of the enhanced cellular uptake and subsequently greater reactive oxygen species (ROS) production upon laser irradiation at 670 nm. Meanwhile, the PDA-Ce6 nanosphere could be also used as a photoabsorbing agent for PTT, because of the excellent photothermal conversion ability of PDA nanoparticle under laser irradiation at 808 nm. Moreover, our prepared nanosphere had extremely low dark toxicity, while excellent phototoxicity under the combination laser irradiation of 670 and 808 nm, both in vitro and in vivo, compared to any single laser irradiation alone. Therefore, our prepared PDA-Ce6 nanosphere could be applied as a very promising dual-modal phototherapeutic agent for enhanced cancer therapy in future clinical applications.

Role of photodynamic therapy and intraductal radiofrequency ablation in cholangiocarcinoma

Cholangiocarcinoma comprises 3% of all gastrointestinal malignancies. Prognosis is poor as the disease is locally advanced at the time of its presentation. Biliary endoprosthesis are widely used for biliary decompression, however, they only provides temporary relief. Photodynamic therapy and Radiofrequency ablation are two innovative approaches performed endoscopically to locally destruct the malignant tissue. This chapter focuses on their application and appropriate use along with their benefits and complications.

Endoscopic treatment options for cholangiocarcinoma

Cholangiocarcinomas are often locally advanced or have metastasized, and at the time of diagnosis individuals often have a poor prognosis. Endoscopic treatment options traditionally include biliary decompression via stenting to allow for systemic chemotherapy and radiotherapy, with self-expanding metal biliary stents being preferred. Recent developments in locoregional therapy delivered endoscopically, such as photodynamic therapy and radiofrequency abalation, have shown promising results in improving patient survival.

Biliary stenting for cholangiocarcinoma: An update

Cholangiocarcinoma (bile duct cancer) is the most common malignant tumor of the biliary tree. This devastating malignancy presents late, and is notoriously difficult to diagnose, thus resulting a high mortality. The majority of cholangiocarcinoma patients present with an unresectable disease, and survive less than 12 mo following diagnosis. Biliary stent placement is an effective palliative therapy for malignant biliary obstruction, which can significantly improve the quality of life, and extend the survival time of patients. Different biliary stent placement methods would closely affect the prognosis of patients. The purpose of this article is to review the treatment efficacy, insertion paths and types of biliary stents. This paper also covers emerging biliary stents including drug stents, and biliary stent combination local therapy.

Endoscopic treatment options for cholangiocarcinomas

Cholangiocellular carcinoma (CCC) is a very aggressive tumor, which remains highly resistant to current chemoradiation therapies. Death is usually caused by the tumor burden. However, biliary obstruction, which leads to cholangitis and liver failure, is also a cause of death. Therefore, relief of biliary obstruction is one of the key palliative treatment options for patients with hilar or distal CCC. Radiologic or endoscopic insertions of stents (plastic or self-expanding metal) are definite biliary drainage options. Whereas stents alone can help achieve relief of bile duct obstruction, endoscopic ablative interventions with photodynamic therapy or radiofrequency ablation are also useful in destroying intraluminal tumor. Destroying the tumor leads to an increase in the luminal diameter of the obstructed bile duct, allowing for placement of more or larger diameter stents, and thus improving bile flow. Besides decreasing morbidity associated with obstruction, ablative therapies such as photodynamic therapy have also been associated with improved survival in a sub-group of patients with CCC and should therefore be incorporated into the treatment algorithm of any center treating patients with CCC.

Photodynamic therapy in unresectable cholangiocarcinoma: not for the uncommitted

Background/Aims

Photodynamic therapy (PDT) in unresectable cholangiocarcinoma has been associated with improved survival. We report a single tertiary care center experience over the past 6 years.

Methods

Fifty-five patients with unresectable cholangiocarcinoma received PDT between 2004 and 2010. Plastic stents were placed after PDT to prevent cholangitis.

Results

Twenty-seven patients (49%) showed Bismuth type IV, 22 (41%) showed Bismuth type III, and six (10%) showed Bismuth type I and II. Twenty patients (37%) received chemotherapy and radiation therapy, five (9%) received chemotherapy only; and one (2%) received radiation therapy only. Mean number of PDT sessions was 1.9±1.5 sessions (range, 1 to 9). Mean survival duration was 293±266 days (median, 190; range, 25 to 1,332). PDT related complications included three (5%) facial burn, three (5%) photosensitivity, and two (3%) rash. Kaplan-Meier analysis comparing the survival means of patients who received PDT and chemotherapy/radiation therapy (median survival 257 days; 95% confidence interval [CI], 166 to 528) versus who received PDT only (median survival 183 days; 95% CI, 129 to 224) showed no significant difference (log-rank p=0.20).

Conclusions

PDT has a measurable impact on survival in unresectable cholangiocarcinoma but requires aggressive stenting posttherapy.