Photodynamic therapy: Palliation and endoscopic technique in cholangiocarcinoma

Transarterial Delivery of a Biodegradable Single-Agent Theranostic Nanoprobe for Liver Tumor Imaging and Combinatorial Phototherapy

PURPOSE

To assess selective accumulation of biodegradable nanoparticles within hepatic tumors after transarterial delivery for in vivo localization and combinatorial phototherapy.

MATERIALS AND METHODS

A VX2 hepatic tumor model was used in New Zealand white rabbits. Transarterial delivery of silicon naphthalocyanine biodegradable nanoparticles was performed using a microcatheter via the proper hepatic artery. Tumors were exposed via laparotomy, and nanoparticles were observed by near-infrared (NIR) fluorescence imaging. For phototherapy, a handheld NIR laser (785 nm) at 0.6 W/cm² was used to expose tumor or background liver, and tissue temperatures were assessed with a fiberoptic temperature probe. Intratumoral reactive oxygen species formation was assessed using a fluorophore (2',7'-dichlorodihydrofluorescein diacetate).

RESULTS

Nanoparticles selectively accumulated within viable tumor by NIR fluorescence. Necrotic portions of tumor did not accumulate nanoparticles, consistent with a vascular distribution. NIR-dependent heat generation was observed with nanoparticle-containing tumors, but not in background liver. No heat was generated in the absence of NIR laser light. Reactive oxygen species were formed in nanoparticle-containing tumors exposed to NIR laser light, but not in background liver treated with NIR laser or in tumors in the absence of NIR light.

CONCLUSIONS

Biodegradable nanoparticle delivery to liver tumors from a transarterial approach enabled selective in vivo tumor imaging and combinatorial phototherapy.

Digital Pancreaticocholangioscopy for Mapping of Pancreaticobiliary Neoplasia: Can We Alter the Surgical Resection Margin?

INTRODUCTION

In patients with pancreaticobiliary lesions anticipating surgical resection, digital pancreaticocholangioscopy can be used to identify the extent of disease. This presurgical"mapping" could change the surgical plan and optimize patient care.

MATERIALS AND METHODS

Patients with pancreaticobiliary lesions anticipating surgery who underwent endoscopic retrograde cholangiopancreatography with digital pancreaticocholangioscopy from 9 international centers were included. Primary outcome was whether pancreaticocholangioscopy altered the surgical plan. Secondary outcome was correlation between surgical and endoscopic histology and adverse events.

RESULTS

A total of 118 patients were included (64% male, mean age 69 y): cholangioscopy in 105 patients (89%), pancreatoscopy in 13 patients (11%). Pancreaticocholangioscopy changed the surgical plan in 39 (34%) of patients: 8 of 13 in the pancreatic duct, 32 of 105 in the bile duct. In the bile duct, 6 patients (5%) had less extensive surgery, 26 patients (25%) avoided surgery. In the pancreatic duct, 4 patients (31%) had more extensive surgery and 4 patients (31%) had less extensive surgery. Four patients with downstaged surgery had positive margins on surgical resection; 1 required additional surgical intervention. Overall correlation between endoscopy and surgical histology was 88%. Adverse events included post endoscopic retrograde cholangiopancreatography pancreatitis in 3 patients (2.5%).

CONCLUSION

Digital pancreaticocholangioscopy can be effectively used as a mapping tool to delineate the degree of involvement of biliary lesions before surgical resection, in some cases altering the surgical plan. Prospective studies are needed, especially when downstaging surgery.

Endoscopic palliation of malignant biliary strictures

Malignant biliary strictures often present late after the window for curative resection has elapsed. In such patients, the goal of therapy is typically focused on palliation. While historically, palliative measures were performed surgically, the advent of endoscopic intervention offers minimally invasive options to provide relief of symptoms, improve quality of life, and in some cases, increase survival of these patients. Some of these therapies, such as endoscopic biliary decompression, have become mainstays of treatment for decades, whereas newer modalities, including radiofrequency ablation, and photodynamic therapy offer additional options for patients with incurable biliary malignancies.

Efficacy and safety of photodynamic therapy for unresectable cholangiocarcinoma: A meta-analysis

BACKGROUND

Photodynamic therapy with the placement of a biliary stent may improve the prognosis in patients with unresectable cholangiocarcinoma. The aim of this research is to determine the hazard ratio of photodynamic therapy with stent compared to biliary stenting alone or other therapies for the treatment of cholangiocarcinoma.

METHODS

Several databases were searched from inception to December 31 2013 for trials comparing photodynamic therapy+stent vs. stent-only or other treatments for cholangiocarcinoma. The outcomes of interest included patient survival, the changes of serum bilirubin levels, the quality of life (Karnofsky performance status), and adverse events. The hazard ratios (HR) were extracted from the survival curves using Tierney's Method. LnHR and its variance were pooled using an inverse variance-weighted average. Inconsistency was quantified using I(2) statistics.

RESULTS

In all, 8 trials comparing PDT+stent with other therapeutic methods were selected. We made a meta-analysis based on the 7 trials, which compared the result of PDT+stent and the stent-only group. HR summarizes the survival for the two groups. Overall survival was significantly better in patients who received photodynamic therapy than those who did not [HR=0.49, 95% confidence interval (CI), 0.33∼0.73, P=0.0005]. Among the 8 trials (642 subjects), 5 assessed the changes of serum bilirubin levels, and/or Karnofsky performance status, as other indications for improvement. In all, the incidence for phototoxic reaction is 11.11%. The incidence for other events in photodynamic therapy and the stent-only group was 13.64% and 12.79%, respectively.

CONCLUSION

The palliative treatment of cholangiocarcinoma, with photodynamic therapy, is associated with an increased survival benefit, an improved biliary drainage, and a better quality of life. However, the quality of this evidence is low.

Defensive mechanism in cholangiocarcinoma cells against oxidative stress induced by chlorin e6-based photodynamic therapy

In this study, the effect of chlorin e6-based photodynamic therapy (Ce6-PDT) was investigated in human intrahepatic (HuCC-T1) and extrahepatic (SNU1196) cholangiocarcinoma (CCA) cells. The amount of intracellular Ce6 increased with increasing Ce6 concentration administered, or with incubation time, in both cell lines. The ability to take up Ce6 and generate reactive oxygen species after irradiation at 1.0 J/cm² did not significantly differ between the two CCA cell types. However, after irradiation, marked differences were observed for photodamage and apoptotic/necrotic signals. HuCC-T1 cells are more sensitive to Ce6-PDT than SNU1196 cells. Total glutathione (GSH) levels, glutathione peroxidase and glutathione reductase activities in SNU1196 cells were significantly higher than in HuCC-T1 cells. With inhibition of enzyme activity or addition of GSH, the phototoxic effect could be controlled in CCA cells. The intracellular level of GSH is the most important determining factor in the curative action of Ce6-PDT against tumor cells.

Prototype of biliary drug-eluting stent with photodynamic and chemotherapy using electrospinning

Background

The combination of biliary stent with photodynamic and chemotherapy seemed to be a beneficial palliative treatment of unresectable cholangiocarcinoma. However, by intravenous delivery to the target tumor the distribution of the drug had its limitations and caused serious side effect on non-target organs. Therefore, in this study, we are going to develop a localized eluting stent, named PDT-chemo stent, covered with gemcitabine (GEM) and hematoporphyrin (HP).

Methods

The prototype of PDT-chemo stent was made through electrospinning and electrospraying dual-processes with an electrical charge to cover the stent with a drug-storing membrane from polymer liquid. The design of prototype used PU as the material of the backing layer, and PCL/PEG blends in different molar ratio of 9:1 and of 1:4 were used in two drug-storing layers with GEM and HP loaded respectively.

Results

The optical microscopy revealed that the backing layer was formed in fine fibers from electrospinning, while drug-storing layers, attributed to the droplets from electrospraying process. The covered membrane, the morphology of which was observed by scanning electron microscopy (SEM), covered the stent surface homogeneously without crack appearances. The GEM had almost 100% of electrosprayed efficiency than 70% HP loaded on the covered membrane due to the different solubility of drug in PEG/PCL blends. Drug release study confirmed the two-phased drug release pattern by regulating in different molar ratio of PEG/PCL blends polymer.

Conclusions

The result proves that the PDT-chemo stent is composed of a first burst-releasing phase from HP and a later slow-releasing phase from GEM eluting. This two-phase of drug eluting stent may provide a new prospect of localized and controlled release treatment for cholangiocarcinoma disease.

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.

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.

5-aminolevulinic acid-incorporated poly(vinyl alcohol) nanofiber-coated metal stent for application in photodynamic therapy

Background

The study investigated the use of combined photodynamic therapy (PDT) and stent placement for the treatment of cholangiocarcinoma (CC). For this purpose, 5-aminolevulinic acid (ALA) was incorporated into poly(vinyl alcohol) (PVA) nanofiber, and coated onto metal stents. Their efficacy was assessed in PDT towards HuCC-T1 CC cells.

Methods

Fabrication of ALA-PVA nanofiber, and simultaneous coating onto metal stents, was performed through electrospinning. The dark-toxicity, generation of protoporphyrin IX (PpIX), and PDT effect of ALA and ALA-PVA nanofiber were studied in vitro, using HuCC-T1 CC cells.

Results

The ALA-PVA nanofibers were coated onto metal stents less than 1000 nm in diameter. ALA-only displayed marginal cytotoxicity; ALA-PVA nanofiber showed less cytotoxicity. PpIX generation was not sigficantly different between ALA and ALA-PVA nanofiber treatments. PVA itself did not generate PpIX in tumor cells. ALA and ALA-PVA nanofiber displayed a similar PDT effect on tumor cells. Cell viability was decreased, dose-dependently, until ALA concentration reached 100 μg/mL. Necrosis and apoptosis of tumor cells occurred similarly for ALA and ALA- PVA nanofiber treatments.

Conclusion

The ALA-PVA nanofiber-coated stent is a promising candidate for therapeutic use with cholangiocarcinoma.

Reversal of Jaundice in Two Patients with Inoperable Cholangiocarcinoma Treated with Cisplatin and Gemcitabine Combination

Two patients are presented with severe jaundice, due to inoperable cholangiocarcinoma. The chemotherapeutic approach in patients with severe jaundice is discussed. Many schedules of chemotherapy were developed in this tumor type with normal serum bilirubin. We report here the first successful use of cisplatin and gemcitabine combination chemotherapy in these patients. Tolerability was good and liver function tests gradually improved.