Systematic review: photodynamic therapy for unresectable cholangiocarcinoma

Advantages of laserphyrin compared with photofrin in photodynamic therapy for bile duct carcinoma

BACKGROUND

The aim of this study was to compare the effects of laserphyrin-PDT (L-PDT) on biliary cancer with those of the conventional photosensitizer, photofrin-PDT (P-PDT).

METHODS

An animal tumor model was established by inoculation of NOZ cells in 4-week-old male BALB/c mice. The laser light wavelength was set at 630 nm for P-PDT and 660 nm for L-PDT, at a frequency of 10 Hz. Each group received a total energy flux of 60 J/cm(2). The proportion of TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling)-positive cells, expression of VEGF (vascular endothelial growth factor) and the PCNA (proliferating cell nuclear antigen)-labeling index (LI) were assessed after PDT.

RESULTS

L-PDT had significantly more potent apoptotic effects at 48 and 72 h after light exposure compared with P-PDT (P < 0.001). The mean PCNA-LI was significantly lower in the L-PDT group than the P-PDT group and the index was significantly lower at several time points after PDT (6, 12, 24, 48 and 72 h after laser light exposure) in the L-PDT than P-PDT (P < 0.001 vs. control). The cell proliferative activity was significantly decreased at 12 and 24 h after P-PDT compared with the control (P < 0.001). VEGF expression was significantly higher at 3 h after L-PDT compared with the control (P < 0.05), whereas it was significantly higher at many time points after P-PDT (3, 6, 48 and 72 h; P < 0.05 vs. control).

CONCLUSIONS

L-PDT is a better approach for biliary cancer than the conventional P-PDT, based on its potent apoptotic and cytostatic effects.

Photodynamic therapy of cancer: an update

Photodynamic therapy (PDT) is a clinically approved, minimally invasive therapeutic procedure that can exert a selective cytotoxic activity toward malignant cells. The procedure involves administration of a photosensitizing agent followed by irradiation at a wavelength corresponding to an absorbance band of the sensitizer. In the presence of oxygen, a series of events lead to direct tumor cell death, damage to the microvasculature, and induction of a local inflammatory reaction. Clinical studies revealed that PDT can be curative, particularly in early stage tumors. It can prolong survival in patients with inoperable cancers and significantly improve quality of life. Minimal normal tissue toxicity, negligible systemic effects, greatly reduced long-term morbidity, lack of intrinsic or acquired resistance mechanisms, and excellent cosmetic as well as organ function-sparing effects of this treatment make it a valuable therapeutic option for combination treatments. With a number of recent technological improvements, PDT has the potential to become integrated into the mainstream of cancer treatment.

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

Photodynamic therapy (PDT) for unresectable cholangiocarcinoma is associated with improvement in cholestasis and survival. Single operator cholangioscopy (SOC) has been used for targeted laser illumination. We analyzed our growing experience of SOC with direct PDT. This is a retrospective analysis of a consecutive series of patients prospectively entered into a registry. Forty-five patients (24 male, aged 67.3 ± 10.6 years) were treated with PDT for cholangiocarcinoma during a five-year period. Thirty-two patients were treated with ERCP and PDT alone, and 13 were treated with ERCP and PDT using SOC. The two groups were then compared to observe any statistically significant difference in regards to age, gender, serum bilirubin, MELD score, adverse effects, or survival. An overall median of 1 PDT session per patient (range: 1-9) was performed. Twenty-six total sessions of PDT using SOC were performed in 13 patients with a median of 2.0 sessions per patient (range: 1-6). Median global survival was 168 days (range: 26-1353). Median survival for the PDT-only group was 200 days, and median survival for the PDT-with-SOC group was 386 days (p = 0.45). There was a statistically significant difference (p < 0.0001) between the two groups in regards to fluoroscopy time, with the PDT-only group having a median time of 21.1 min and the PDT-with-SOC group having a median time of 11.1 min. PDT related complications included 7 cases of mild phototoxicity and one case of moderate phototoxicity requiring hospitalization. SOC permits targeted therapy during PDT and can be successfully performed without adverse events while simultaneously reducing exposure to radiation.

Cholangiocarcinoma--controversies and challenges

Cholangiocarcinomas are a diverse group of tumors that are presumed to originate from the biliary tract epithelium either within the liver or the biliary tract. These cancers are often difficult to diagnose, their pathogenesis is poorly understood, and their dismal prognosis has resulted in a nihilistic approach to their management. The two major clinical phenotypes are intrahepatic, mass-forming tumors and large ductal tumors. Among the ductal cancers, lesions at the liver hilum are most prevalent. The risk factors, clinical presentation, natural history and management of these two types of cholangiocarcinoma are distinct. Efforts to improve outcomes for patients with these diseases are affected by several challenges to effective management. For example, designations based on anatomical characteristics have been inconsistently applied, which has confounded analysis of epidemiological trends and assessment of risk factors. The evaluation of therapeutic options, particularly systemic therapies, has been limited by a lack of appreciation of the different phenotypes. Controversies exist regarding the appropriate workup and choice of management approach. However, new and emerging tools for improved diagnosis, expanded indications for surgical approaches, an emerging role for locoregional and intrabiliary therapies and improved systemic therapies provide optimism and hope for improved outcomes in the future.

Clinical feasibility of direct peroral cholangioscopy-guided photodynamic therapy for inoperable cholangiocarcinoma performed by using an ultra-slim upper endoscope (with videos)

BACKGROUND

Photodynamic therapy (PDT) has emerged as a promising palliative treatment for inoperable cholangiocarcinoma. Cholangioscopy-guided PDT can be useful for identification of tumor margins, determination of the appropriate location for placement of the diffuser, and evaluation of the patient's response to therapy.

OBJECTIVE

To evaluate the feasibility of PDT under direct peroral cholangioscopy (POC) by using an ultra-slim upper endoscope in patients with inoperable cholangiocarcinoma.

DESIGN

Prospective, observational, pilot study.

SETTING

Single tertiary-care referral center.

PATIENTS

This study involved 9 patients with inoperable extrahepatic cholangiocarcinoma.

INTERVENTION

Photofrin II was administered intravenously 48 hours before PDT. Additional PDT was performed up to 48 hours after the initial application of therapy. A successful direct POC-guided PDT was defined as advancement of the endoscope into the distal margin of the tumor and maintenance of endoscope position until PDT was completed.

MAIN OUTCOME MEASUREMENTS

The clinical feasibility, usefulness, and complications of direct POC for PDT.

RESULTS

Seventeen sessions of direct POC for PDT were performed in 9 patients. PDT was performed successfully in 15 of 17 sessions (88.2%) and 7 of 9 patients (77.8%). Biliary drainage under direct POC, if necessary after PDT, was possible in 100% of patients (7/7). Follow-up direct POC confirmed significant tumor ablation after PDT in 5 patients. One patient reported mild skin redness; no major procedure-related complications were observed.

LIMITATIONS

Small sample size, pilot study.

CONCLUSION

Direct POC-guided PDT by using an ultra-slim upper endoscope seems to be both feasible and safe in select patients with inoperable extrahepatic cholangiocarcinoma.

Advances in photodynamic therapy for the treatment of hilar biliary tract cancer

The prognosis of patients with nonresectable hilar biliary tract cancer (hBTC) is poor. Responsiveness to chemotherapy or radiochemotherapy is moderate at best, and patients are at a high risk of dying early from complications of local tumor infiltration (e.g., cholestasis, septic cholangitis, empyema or liver failure) rather than systemic disease. Therefore, palliative local therapy for the prevention of tumor complications plays a central role and still yields the longest survival times. Photodynamic therapy (PDT) is a local-ablative, tumor tissue-specific treatment currently representing the standard of care for nonresectable hBTC. Throughout the literature, PDT plus biliary drainage achieves median survival times in the range of 9-21 months (average 14-16 months), compared with approximately 6 months for drainage only. This article summarizes the recent advances in preclinical and clinical experience of PDT for hBTC, including experimental in vitro and in vivo studies, clinical studies and an overview of the ongoing clinical trials.

Cholangiocarcinoma: an endoscopist's perspective

The incidence of cholangiocarcinoma is on the rise. This may be related in part to higher detection rates secondary to sophisticated endoscopic modalities. These tumors pose a significant diagnostic dilemma. High index of suspicion, careful interpretation of serum markers and utilization of endoscopic techniques, including endoscopic retrograde cholangiopancreatography and endoscopic ultrasound, help to establish the diagnosis. Imaging modalities are crucial in the evaluation of these tumors. They help to define the extent of the native lesion, which may dictate its resectability, as well as evaluate for metastasis. Therapeutic options are somewhat limited, short of surgical resection. Newer chemotherapeutic agents, as well as endoscopy-targeted therapy, may improve the overall treatment success rate, although experience is somewhat limited at this time. Endoscopic intervention is essential for palliation.

Photodynamic therapy for cholangiocarcinoma

Cholangiocarcinoma is the primary malignancy arising from the biliary epithelium, and it presents as jaundice, cholestasis, and cholangitis. Over 50 percent of patients present with advanced-stage disease, and the prognosis is poor with the survival measured in months even after biliary decompression. Palliative management has become the standard of care for unresectable disease, and this involves an endoscopic approach. Photodynamic therapy (PDT) involves the administration of a photosensitizer followed by local irradiation with laser therapy. The use of PDT for palliation of bile-duct tumors has produced promising results. Several studies conducted in Europe and the United States have shown that PDT produces a marked improvement in the symptoms of cholestasis, survival, and quality of life. This chapter summarizes the principle of PDT, the technique employed, and the published experience regarding PDT for cholangiocarcinoma.