Photodynamic therapy for cholangiocarcinoma

Effect of topical 5-aminolevulinic acid photodynamic therapy versus therapy combined with CO2 laser pretreatment for patients with cervical high-grade squamous intraepithelial lesions

OBJECTIVE

To evaluate the effect of 5-aminolevulinic acid photodynamic therapy (ALA-PDT) combined with CO2 laser pretreatment (Laser+ALA-PDT) on patients with cervical high-grade squamous intraepithelial lesions (HSILs).

METHODS

A total of 114 patients treated by ALA-PDT or Laser+ALA-PDT at 3 centers were retrospectively reviewed. The effective rate, cure rate of lesions as well as high-risk human papillomavirus (HR-HPV) regression rate and persistent infection rate in the 2 groups were compared according to 3-6 month and 9-12 months follow-ups. The characteristics and risk factors for ineffective cases were evaluated by regression analysis.

RESULTS

At the 3-6month follow-up, the effective rate was significantly higher in the Laser+ALA-PDT group than in the ALA-PDT group (96.6% vs. 81.3%, p = 0.048). A total of 79.3% of the laser+ALA-PDT patients achieved cure rate compared with 61.3% of the ALA-PDT patients (p = 0.082). In the Laser+ALA-PDT group, the HR-HPV-negative rate was significantly higher (72.4% vs. 50.7%, p = 0.045), while the persistence rate was significantly lower (20.7% vs. 42.7%, p = 0.037). At the 9-12month follow-up, the cure rate was 83% in the ALA-PDT group, 17% lower than that in the Laser+ALA-PDT group (p = 0.055). A total of 20.8% of patients in the ALA-PDT group and 5.3% in the Laser+ALA-PDT group showed persistent HR-HPV infection (p = 0.120). Pretreatment HR-HPV type, multiple infections and treatment modality were relevant factors for PDT outcome.

CONCLUSIONS

For patients with cervical HSIL, laser+ALA-PDT shows better efficiency and HPV regression compared with ALA-PDT. HPV16/18 and multi-infection may be risk factors for ineffective treatment with ALA-PDT.

Comparison of current guidelines and consensus on the management of patients with cholangiocarcinoma: 2022 update

As a consequence of breakthroughs in the area of guidelines research, the therapy for cholangiocarcinoma has significantly improved the efficacy rate of diagnosis and survival outcomes. We compared the most recently updated clinical practice guidelines and consensus to provide recommendations based on the diagnostic and therapeutic equipment available in various countries. Following a systematic review, we discovered that these guidelines and consensus had both similarities and differences in terms of what organizations or groups drafted the guidelines and the approach, applicability, content and recent updates of the guidelines as well as in terms of diagnostic and treatment algorithms. The disparities could be attributable to a variety of etiological factors, high risk patients, health resources, medical technology, treatment options, and income levels. Additionally, while complete adoption of guidelines may benefit physicians, patients, and authorities, there remains a disconnect between expected goals and implementation.

Photodynamic Therapy: A Compendium of Latest Reviews

Photodynamic therapy (PDT) is a promising therapy against cancer. Even though it has been investigated for more than 100 years, scientific publications have grown exponentially in the last two decades. For this reason, we present a brief compendium of reviews of the last two decades classified under different topics, namely, overviews, reviews about specific cancers, and meta-analyses of photosensitisers, PDT mechanisms, dosimetry, and light sources. The key issues and main conclusions are summarized, including ways and means to improve therapy and outcomes. Due to the broad scope of this work and it being the first time that a compendium of the latest reviews has been performed for PDT, it may be of interest to a wide audience.

Photodynamic therapy of extrahepatic cholangiocarcinoma using digital cholangioscopy

BACKGROUND

Photodynamic therapy (PDT) of an extrahepatic cholangiocarcinoma using a digital cholangioscopy to deliver the laser.

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.

Photodynamic therapy of cancer of large duodenal papilla and extrahepatic bile ducts

The problem of treating patients with malignant neoplasms of the extrahepatic bile ducts and the large duodenal papilla remains relevant due to the growing incidence, high mortality, and a pronounced decrease in the quality of life of patients, despite the radical surgery. The purpose of this study was to evaluate the effectiveness of photodynamic therapy (PDT) in inoperable patients with malignant tumors of these localizations.

The study is based on the treatment of 79 patients with adenocarcinoma of large duodenal papilla and extrahepatic bile ducts. 29 patients received palliative bile drainage operations with PDT. 50 patients in the control group only had palliative bile drainage operations. Patients in the study group received from 1 to 3 PDT courses in a year. In total, 29 patients received 52 PDT courses. The tolerance to the method and the life expectancy of patients were evaluated. The median survival of patients who underwent PDT was 18 months (11–60 months); in the control group – 11.5 months. PDT, in combination with bile drainage operation, is an effective method for the treatment of inoperable patients with malignant neoplasms of the extrahepatic bile ducts and the large duodenal papilla in the absence of severe complications and with easy tolerance to therapy by patients. For the treatment and prolongation of life of patients whose radical surgical treatment is associated with a high risk of death, PDT seems to be the best treatment option. Results of PDT treatment for cancer of this localization are comparable with the results of radical surgeries and exceed those for palliative surgeries.

Near Infrared Photoimmunotherapy with Combined Exposure of External and Interstitial Light Sources

Near infrared photoimmunotherapy (NIR-PIT) is a new target-cell-specific cancer treatment that induces highly selective necrotic/immunogenic cell death after systemic administration of a photoabsorber antibody conjugate and subsequent NIR light exposure. However, the depth of NIR light penetration in tissue (approximately 2 cm) with external light sources limits the therapeutic effects of NIR-PIT. Interstitial light exposure using cylindrical diffusing optical fibers can overcome this limitation. The purpose in this study was to compare three NIR light delivery methods for treating tumors with NIR-PIT using a NIR laser system at an identical light energy; external exposure alone, interstitial exposure alone, and the combination. Panitumumab conjugated with the photoabsorber IRDye-700DX (pan-IR700) was intravenously administered to mice with A431-luc xenografts which are epithelial growth factor receptor (EGFR) positive. One and 2 days later, NIR light was administered to the tumors using one of three methods. Interstitial exposure alone and in combination with external sources showed the greatest decrease in bioluminescence signal intensity. Additionally, the combination of external and interstitial NIR light exposure showed significantly greater tumor size reduction and prolonged survival after NIR-PIT compared to external exposure alone. This result suggested that the combination of external and interstitial NIR light exposure was more effective than externally applied light alone. Although external exposure is the least invasive means of delivering light, the combination of external and interstitial exposures produces superior therapeutic efficacy in tumors greater than 2 cm in depth from the tissue surface.

Photofrin® photodynamic therapy with intratumor photosensitizer injection provides similar tumor response while reducing systemic skin photosensitivity: Pilot murine study

OBJECTIVES

The goal of this study was to compare tumor response to Photofrin^® photodynamic therapy using intravenous and intratumoral injection of photosensitizer. Systemic skin photosensitivity and photosensitizer distribution were also compared between the two delivery methods.

METHODS

SCCVII tumors were initiated in the hind legs of female C3H mice and grown to a volume of ∼1,000 mm³ . Photofrin^® was delivered intravenously via the tail vein at a concentration of 2 mg/kg or intratumorally at concentrations ranging from 0.5-2 mg/kg. A 630 nm laser illumination was delivered via interstitial diffuser placement at a fluence rate of 400 mW/cm and fluence of 100 J/cm. Mice were maintained under normal room lighting for 24 hours after treatment, at which point photographs were captured for assessment of skin photosensitivity. Animals were then sacrificed, and their tumors were excised, sectioned, imaged, and stained with hematoxylin and eosin (H&E). H&E slides were imaged to assess necrosis post-PDT, and skin photographs were evaluated by two blinded reviewers for quantification of skin photosensitivity. Whole-body fluorescence imaging was performed before and after photodynamic therapy.

RESULTS

Tumor necrosis was not significantly different based on treatment group (P = 0.33), while skin photosensitivity was significantly reduced in animals that received Photofrin^® intratumorally (P = 0.0005). Fluorescence imaging revealed similar photosensitizer fluorescence in excised tumors for intratumor and intravenous injection of Photofrin^® (P = 0.48), although fluorescence decreased significantly with decreasing intratumor injection concentration (P= 0.01).

CONCLUSIONS

This pilot study shows that intratumoral administration of Photofrin^® has the potential to produce similar tumor outcomes, while reducing systemic skin photosensitivity. Further studies are warranted to characterize and optimize intratumor delivery. Lasers Surg. 50:476-482, 2018. © 2017 Wiley Periodicals, Inc.

Polymeric Nanoparticles for Cancer Photodynamic Therapy

In chemotherapy a fine balance between therapeutic and toxic effects needs to be found for each patient, adapting standard combination protocols each time. Nanotherapeutics has been introduced into clinical practice for treating tumors with the aim of improving the therapeutic outcome of conventional therapies and of alleviating their toxicity and overcoming multidrug resistance. Photodynamic therapy (PDT) is a clinically approved, minimally invasive procedure emerging in cancer treatment. It involves the administration of a photosensitizer (PS) which, under light irradiation and in the presence of molecular oxygen, produces cytotoxic species. Unfortunately, most PSs lack specificity for tumor cells and are poorly soluble in aqueous media, where they can form aggregates with low photoactivity. Nanotechnological approaches in PDT (nanoPDT) can offer a valid option to deliver PSs in the body and to solve at least some of these issues. Currently, polymeric nanoparticles (NPs) are emerging as nanoPDT system because their features (size, surface properties, and release rate) can be readily manipulated by selecting appropriate materials in a vast range of possible candidates commercially available and by synthesizing novel tailor-made materials. Delivery of PSs through NPs offers a great opportunity to overcome PDT drawbacks based on the concept that a nanocarrier can drive therapeutic concentrations of PS to the tumor cells without generating any harmful effect in non-target tissues. Furthermore, carriers for nanoPDT can surmount solubility issues and the tendency of PS to aggregate, which can severely affect photophysical, chemical, and biological properties. Finally, multimodal NPs carrying different drugs/bioactive species with complementary mechanisms of cancer cell killing and incorporating an imaging agent can be developed. In the following, we describe the principles of PDT use in cancer and the pillars of rational design of nanoPDT carriers dictated by tumor and PS features. Then we illustrate the main nanoPDT systems demonstrating potential in preclinical models together with emerging concepts for their advanced design.

Comparison of flat cleaved and cylindrical diffusing fibers as treatment sources for interstitial photodynamic therapy

PURPOSE

For interstitial photodynamic therapy (iPDT) of bulky tumors, careful treatment planning is required in order to ensure that a therapeutic dose is delivered to the tumor, while minimizing damage to surrounding normal tissue. In clinical contexts, iPDT has typically been performed with either flat cleaved or cylindrical diffusing optical fibers as light sources. Here, the authors directly compare these two source geometries in terms of the number of fibers and duration of treatment required to deliver a prescribed light dose to a tumor volume.

METHODS

Treatment planning software for iPDT was developed based on graphics processing unit enhanced Monte Carlo simulations. This software was used to optimize the number of fibers, total energy delivered by each fiber, and the position of individual fibers in order to deliver a target light dose (D90) to 90% of the tumor volume. Treatment plans were developed using both flat cleaved and cylindrical diffusing fibers, based on tissue volumes derived from CT data from a head and neck cancer patient. Plans were created for four cases: fixed energy per fiber, fixed number of fibers, and in cases where both or neither of these factors were fixed.

RESULTS

When the number of source fibers was fixed at eight, treatment plans based on flat cleaved fibers required each to deliver 7180-8080 J in order to deposit 90 J/cm(2) in 90% of the tumor volume. For diffusers, each fiber was required to deliver 2270-2350 J (333-1178 J/cm) in order to achieve this same result. For the case of fibers delivering a fixed 900 J, 13 diffusers or 19 flat cleaved fibers at a spacing of 1 cm were required to deliver the desired dose. With energy per fiber fixed at 2400 J and the number of fibers fixed at eight, diffuser fibers delivered the desired dose to 93% of the tumor volume, while flat cleaved fibers delivered this dose to 79%. With both energy and number of fibers allowed to vary, six diffusers delivering 3485-3600 J were required, compared to ten flat cleaved fibers delivering 2780-3600 J.

CONCLUSIONS

For the same number of fibers, cylindrical diffusers allow for a shorter treatment duration compared to flat cleaved fibers. For the same energy delivered per fiber, diffusers allow for the insertion of fewer fibers in order to deliver the same light dose to a target volume.

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.

Apoptosis in cancer cells induced by photodynamic treatment – a methodological approach

Photodynamic therapy (PDT) is approved for clinical indications including several (pre-) cancers of the skin and solid tumors of the brain and the gastrointestinal tract. It operates by an acute cellular response caused by oxidation of cell components following light-induced and photosensitizer-mediated generation of reactive oxygen species. By this, PDT is capable of inducing the major types of cytotoxic responses: autophagy, apoptosis, and necrosis. As excited photosensitizer molecules react rather non-specifically with neighboring molecules, we suggest that with PDT and most (if not any) cell-localizing photosensitizers, all kinds of cellular responses can be provoked — following a strict dose-dependency, i.e. a transition from survival, over apoptosis to necrosis depending on the applied photosensitizer concentration or light dose. In this review, we briefly discuss (i) the types of cell death induced by PDT focusing on apoptosis induction, (ii) a simple experimental approach to quickly assess the dose-dependent phototoxic responses based on viability assays, and (iii) an overview of in vitro apoptosis detection methods for further in depth analyses. With this conceptual framework, we attempt to provide a rational experimental approach for initial in vitro, cell-based characterization of newly synthesized photosensitizers or formulations thereof — thus to plug the gap between subsequent in vivo evaluation and the preceding fundamental (physico-)chemical work devoted to the improvement of photosensitizing drugs based on mainly porphyrins, phthalocyanines and their derivatives.

Photodynamic therapy for cholangiocarcinoma using low dose mTHPC (Foscan(®))

BACKGROUND

Photodynamic therapy (PDT) combined with stenting is an effective treatment modality for palliation of nonresectable cholangiocarcinoma (CC). A drawback of standard PDT using Photofrin(®) as photosensitizer is the long lasting skin photosensitivity of up to 3 months. The aim of this study was to show the outcome of PDT of CC, potential side effects and to determine the best drug light interval (DLI) using mTHPC (Foscan(®)) at a low dose.

METHODS

13 patients with nonresectable CC were treated with stenting and PDT (3mg Foscan(®) per treatment, 0.032-0.063 mg/kg body weight, 652 nm, 50 J/cm). Fluorescence measurements were performed with a single bare fiber for 5/13 patients prior to PDT at the tumor site to determine the fluorescence contrast. For another 7/13 patients, long-term fluorescence-kinetics were measured on the oral mucosa to determine the time of maximal relative fluorescence intensity.

RESULTS

The results so far indicate a median survival time of 13 months. Side effects such as perforations or skin phototoxicity could not be observed. Foscan(®) fluorescence within the tumor site was clearly detectable but a significant fluorescence contrast of tumor to adjacent healthy tissue could not be found. The fluorescence kinetics measured in the oral mucosa showed a maximum at 3.85 days (median) after drug administration.

CONCLUSION

Combined stenting and PDT performed with a low Foscan(®) dose results in equal and potentially longer survival times compared to standard Photofrin(®) PDT, while lowering the risk of side effects strongly. Thus it may improve the quality of life.

Safety and long term efficacy of porfimer sodium photodynamic therapy in locally advanced biliary tract carcinoma

BACKGROUND

In patients with unresectable cholangiocarcinoma, photodynamic therapy (PDT) with porfimer sodium promotes biliary drainage and may improve survival and quality of life.

AIM

To prospectively evaluate the safety and efficacy of PDT in patients with locally advanced biliary tract carcinoma.

METHODS

Eligible patients had unresectable, histologically confirmed disease, a Karnofsky performance status of ≥30% and life expectancy >12 weeks. Patients received 2mg/kg i.v. of porfimer sodium, followed by endobiliary laser activation and stent replacement 48 h later. Patients were assessed clinically and radiologically before treatment and on day 28, and followed up thereafter at three-monthly intervals until death.

RESULTS

36 patients were entered over an 18 months period: 14 males, 22 females, with a median age of 65 (30-79)yr and performance status of 80 (50-100). PDT was technically successful in all cases and was generally well tolerated; there was no grade 4 toxicity and no treatment-associated mortality. The median survival was 12 (1-84) months.

CONCLUSIONS

Porfimer sodium PDT can be delivered safely to patients with biliary tract cancer and is suitable for testing in phase III studies (UKCRN ID 1218).