Photodynamic therapy with hematoporphyrin derivative in the treatment of superficial transitional-cell carcinoma of the bladder

Targeted Delivery of Catalase and Photosensitizer Ce6 by a Tumor-Specific Aptamer Is Effective against Bladder Cancer In Vivo

Photodynamic therapy (PDT) is often applied in a clinical setting to treat bladder cancer. However, current photosensitizers report drawbacks such as low efficacy, low selectivity, and numerous side effects, which have limited the clinical values of PDT for bladder cancer. Previously, we developed the first bladder cancer-specific aptamer that can selectively bind to and be internalized by bladder tumor cells versus normal uroepithelium cells. Here, we use an aptamer-based drug delivery system to deliver photosensitizer chlorine e6 (Ce6) into bladder tumor cells. In addition to Ce6, we also incorporate catalase into the drug complex to increase local oxygen levels in the tumor tissue. Compared with free Ce6, an aptamer-guided DNA nanotrain (NT) loaded with Ce6 and catalase (NT-Catalase-Ce6) can specifically recognize bladder cancer cells, produce oxygen locally, induce ROS in tumor cells, and cause mitochondrial apoptosis. In an orthotopic mouse model of bladder cancer, the intravesical instillation of NT-Catalase-Ce6 exhibits faster drug internalization and a longer drug retention time in tumor tissue compared with that in normal urothelium. Moreover, our modified PDT significantly inhibits tumor growth with fewer side effects such as cystitis than free Ce6. This aptamer-based photosensitizer delivery system can therefore improve the selectivity and efficacy and reduce the side effects of PDT treatment in mouse models of bladder cancer, bearing a great translational value for bladder cancer intravesical therapy.

Photodynamic Therapy: Current Trends and Potential Future Role in the Treatment of Bladder Cancer

Bladder cancer (BC) is the 10th most common cancer in the world. The therapeutic spectrum of BC is broad and is constantly expanding. Despite the wide clinical use of photodynamic diagnosis (PTD) for BC, PDT has not been sufficiently investigated in the treatment landscape of BC. We performed an online search of the PubMed database using these keywords: photodynamic therapy, bladder cancer, urothelial carcinoma, in vivo, in vitro, cell line, animal model. Reviews, case reports, and articles devoted to photodynamic diagnostics and the photodynamic therapy of tumors other than urothelial carcinoma were excluded. Of a total of 695 publications, we selected 20 articles with clinical data, 34 articles on in vivo PDT, and 106 articles on in vitro data. The results presented in animal models highlight the potential use of PDT in the neoadjuvant or adjuvant setting to reduce local recurrence in the bladder and upper urinary tracts. Possible regimens include the combination of PDT with intravesical chemotherapy for improved local tumor control or the integration of vascular-targeted PDT in combination with modern systemic drugs in order to boost local response. We summarize available evidence on the preclinical and clinical application of PDT for urothelial carcinoma in order to explain the current trends and future perspectives.

Critical PDT Theory VII: The Saga of Ruthenium

Recent studies involving photosensitizing agents containing ruthenium (Ru) are interpreted as an indication that this approach might be useful for treatment of bladder cancer. The absorbance spectrum of such agents tends to be limited to wavelengths < 600 nm. While this can spare underlying tissues from photodamage, this will limit applications to instances where only a thin layer of malignant cells is present. Among the more potentially interesting results is a protocol that uses only Ru nanoparticles. Other issues in Ru-based photodynamic therapy are discussed including the limited absorbance spectrum, questions relating to methodology and a general lack of details concerning localization and death pathways.

Advancements in nanoparticle-based treatment approaches for skin cancer therapy

Skin cancer has emerged as the fifth most commonly reported cancer in the world, causing a burden on global health and the economy. The enormously rising environmental changes, industrialization, and genetic modification have further exacerbated skin cancer statistics. Current treatment modalities such as surgery, radiotherapy, conventional chemotherapy, targeted therapy, and immunotherapy are facing several issues related to cost, toxicity, and bioavailability thereby leading to declined anti-skin cancer therapeutic efficacy and poor patient compliance. In the context of overcoming this limitation, several nanotechnological advancements have been witnessed so far. Among various nanomaterials, nanoparticles have endowed exorbitant advantages by acting as both therapeutic agents and drug carriers for the remarkable treatment of skin cancer. The small size and large surface area to volume ratio of nanoparticles escalate the skin tumor uptake through their leaky vasculature resulting in enhanced therapeutic efficacy. In this context, the present review provides up to date information about different types and pathology of skin cancer, followed by their current treatment modalities and associated drawbacks. Furthermore, it meticulously discusses the role of numerous inorganic, polymer, and lipid-based nanoparticles in skin cancer therapy with subsequent descriptions of their patents and clinical trials.

Advances in Management of Bladder Cancer-The Role of Photodynamic Therapy

Photodynamic therapy (PDT) is a non-invasive and modern form of therapy. It is used in the treatment of non-oncological diseases and more and more often in the treatment of various types of neoplasms in various locations including bladder cancer. The PDT method consists of local or systemic application of a photosensitizer, i.e., a photosensitive compound that accumulates in pathological tissue. Light of appropriate wavelength is absorbed by the photosensitizer molecules, which in turn transfers energy to oxygen or initiates radical processes that leads to selective destruction of diseased cells. The technique enables the selective destruction of malignant cells, as the photocytotoxicity reactions induced by the photosensitizer take place strictly within the pathological tissue. PDT is known to be well tolerated in a clinical setting in patients. In cited papers herein no new safety issues were identified. The development of anti-cancer PDT therapies has greatly accelerated over the last decade. There was no evidence of increased or cumulative toxic effects with each PDT treatment. Many modifications have been made to enhance the effects. Clinically, bladder cancer remains one of the deadliest urological diseases of the urinary system. The subject of this review is the anti-cancer use of PDT, its benefits and possible modifications that may lead to more effective treatments for bladder cancer. Bladder cancer, if localized, would seem to be a good candidate for PDT therapy since this does not involve the toxicity of systemic chemotherapy and can spare normal tissues from damage if properly carried out. It is clear that PDT deserves more investment in clinical research, especially for plant-based photosensitizers. Natural PS isolated from plants and other biological sources can be considered a green approach to PDT in cancer therapy. Currently, PDT is widely used in the treatment of skin cancer, but numerous studies show the advantages of related therapeutic strategies that can help eliminate various types of cancer, including bladder cancer. PDT for bladder cancer in which photosensitizer is locally activated and generates cytotoxic reactive oxygen species and causing cell death, is a modern treatment. Moreover, PDT is an innovative technique in oncologic urology.

Photodynamic therapy using self-assembled nanogels comprising chlorin e6-bearing pullulan

With minimal invasiveness and spatiotemporal therapeutic effects, photodynamic therapy is one of the most promising candidates for cancer treatment. Here, we developed a facile self-assembled nanogel using photosensitizer-grafted polysaccharides called chlorin e6-bearing pullulan. Chlorin e6 is used as a photosensitizer in cancer therapy. The anti-cancer effect of photodynamic therapy with our nanogel system was 780 times higher than that of the commercially available photosensitizer Photofrin. Finally, we demonstrated that actively growing cancer cell spheroids can be completely suppressed after treatment. Our system could efficiently induce tumor regression in tumor xenograft mice.

The Yin and Yang of PDT and PTT

In Chinese philosophy, yin and yang ("dark-bright," "negative-positive") describe how seemingly opposite or contrary forces may actually be complementary, interconnected and interdependent. This paper provides this perspective on photodynamic and photothermal therapies, with a focus on the treatment of solid tumors. The relative strengths and weaknesses of each modality, both current and emerging, are considered with respect to the underlying biophysics, the required technologies, the biological effects, their translation into clinical practice and the realized or potential clinical outcomes. For each specific clinical application, one or the other modality may be clearly preferred, or both are effectively equivalent in terms of the various scientific/technological/practical/clinical trade-offs involved. Alternatively, a combination may the best approach. Such combined approaches may be facilitated by the use of multifunctional nanoparticles. It is important to understand the many factors that go into the selection of the optimal approach and the objective of this paper is to provide guidance on this.

Tetrahydroporphyrin-tetratosylat (THPTS): A near-infrared photosensitizer for targeted and efficient photodynamic therapy (PDT) of human bladder carcinoma. An in vitro study

BACKGROUND

Efficacy of PDT in muscle-invasive bladder cancer is hampered by low tissue penetration of most photosensitizers by short excitation wavelength. THPTS is excitable at near-infrared (760nm) allowing tissue penetration up to 15mm. We examined the cellular effects of THPTS-PDT in human bladder cancer cells.

MATERIAL AND METHODS

We used four human transitional carcinoma cell lines, epithelial bladder progenitors (HBLAK) and bladder smooth muscle cells (HBSMC). We used flow cytometry to examine pharmacokinetics of THPTS, confocal laser scanning microscopy to analyze subcellular localization and production of reactive oxidative species (ROS), examined cytotoxicity and cell death pathways (qRT-PCR).

RESULTS

Total uptake varied between cell lines and was significantly high in HBLAK and HBSMC. Lysosomal localization was mainly seen in cancer cells and HBLAK, while THPTS was distributed throughout the cytoplasm in HBSMC. Significant ROS production was detected 30min after THPTS-PDT. Growth arrest occurred within 4h and resulted in apoptotic and necrotic cytotoxicity after 24h. Cytotoxicity was dose-dependent and specifically high in cancer cells and HBLAK and significantly low in HBSMC.

CONCLUSION

THPTS-PDT induces cellular mechanisms leading to cellular growth arrest, apoptosis and necrosis in human bladder cancer cells. These effects are only partly dependent on the total amount of THPTS uptake and rather dependent on its subcellular compartmentalization. HBSMC are hardly affected by THPTS-PDT confirming tumor specificity and safety. THPTS is a promising new photosensitizer with the unique advantage of deep tissue penetration allowing the treatment of solid tumors and warranting further animal studies.

Indocyanine Green Dye Enhanced Vascular Welding With the Near Infrared Diode Laser

For vascular anastomosis, use of topical photosensitizing dye enhances selec tive delivery of laser energy to target tissue, thus reducing the amount of collat eral thermal injury and threshold power required for welding. The authors compared the threshold power density needed to weld abdominal aortotomies in rabbits with and without photosensitizing dye. With continuous wave diode la ser energy, the threshold for welding using the dye indocyanine green (ICG) was 150 mW (power density 4.8 watts/cm2 at spot diameter of 2 mm). Without dye enhancement, tissue effects were not observed even at the highest energy output available from the laser (300 mW, power density 9.6 watts/cm2). Immediately after welding, the mean bursting pressure for the welds was 260 mm Hg. In survival studies, no anastomotic ruptures, thomboses, or aneurysms were iden tified. Use of photosensitizing dyes for tissue welding is feasible and may allow arterial welding with lower power laser systems and cause less thermal trauma by lowering threshold power levels.

Intravesical and alternative bladder-preservation therapies in the management of non-muscle-invasive bladder cancer unresponsive to bacillus Calmette-Guérin

Intravesical Bacillus Calmette-Guérin (BCG) remains the standard of care in the treatment of bladder carcinoma in situ and as adjuvant therapy after thorough transurethral resection of high-grade non-muscle-invasive bladder cancer. Despite BCG therapy, in up to 40% of patients it would recur and 60% to 70% of those would fail repeat BCG induction be deemed BCG unresponsive. For such patients, cystectomy remains the preferred treatment option per the American Urological Association and European Association of Urology, though some patients would be medically unfit or refuse radical surgery. Further intravesical therapy for bladder-preservation therapies may preserve quality of life in these patients and in some cases can be curative. There are numerous non-BCG intravesical salvage options available, including immunotherapy, single-agent chemotherapy, combination chemotherapy, and device-assisted chemotherapy. In addition, investigation of radiation-based treatment and other novel therapies including checkpoint inhibitors (programmed death-1/programmed death ligand-1), are currently underway. In this review, we examine the current status of alternatives to BCG in salvage therapy for bladder preservation.

Photoinactivation of Staphylococcus aureus using protoporphyrin IX: the role of haem-regulated transporter HrtA

Light- and photosensitiser-based antimicrobial photodynamic therapy is a very promising approach to the control of microbial infections. How the phenotypic features of a microorganism affect its response to photosensitiser-based photokilling represents an area of substantial research interest. To understand the mechanisms governing the phenomenon of a strain-dependent response to photodynamic inactivation (PDI), we analysed the possible role of the membrane-located haem transporter HrtA in Staphylococcus aureus. We used a S. aureus strains with an inactivated component of the haem-regulated transporter, HrtA, along with its wild-type counterpart to determine differences in PDI outcome and photosensitiser uptake between the studied isogenic strains. We observed that a lack of HrtA protein potentiates the phototoxic effect towards S. aureus but only when extracellular protoporphyrin IX is used. The observed effect may depend on the function of the HrtA transporter but is likely to result from changed membrane properties following the absence of the protein in the membrane. This indicates that disturbing the membrane properties is an attractive method for improving the efficacy of the photodynamic inactivation of microorganisms.

A Surgical View of Photodynamic Therapy in Oncology: A Review

Clinical photodynamic therapy (PDT) has existed for over 30 years, and its scientific basis has been known and investigated for well over 100 years. The scientific foundation of PDT is solid and its application to cancer treatment for many common neoplastic lesions has been the subject of a huge number of clinical trials and observational studies. Yet its acceptance by many clinicians has suffered from its absence from the undergraduate and/or postgraduate education curricula of surgeons, physicians, and oncologists. Surgeons in a variety of specialties many with years of experience who are familiar with PDT bear witness in many thousands of publications to its safety and efficacy as well as to the unique role that it can play in the treatment of cancer with its targeting precision, its lack of collateral damage to healthy structures surrounding the treated lesions, and its usage within minimal access therapy. PDT is closely related to the fluorescence phenomenon used in photodiagnosis. This review aspires both to inform and to present the clinical aspect of PDT as seen by a surgeon.

Highly specific in vivo gene delivery for p53-mediated apoptosis and genetic photodynamic therapies of tumour

Anticancer therapies are often compromised by nonspecific effects and challenged by tumour environments’ inherent physicochemical and biological characteristics. Often, therapeutic effect can be increased by addressing multiple parameters simultaneously. Here we report on exploiting extravasation due to inherent vascular leakiness for the delivery of a pH-sensitive polymer carrier. Tumours’ acidic microenvironment instigates a charge reversal that promotes cellular internalization where endosomes destabilize and gene delivery is achieved. We assess our carrier with an aggressive non-small cell lung carcinoma (NSCLC) in vivo model and achieve >30% transfection efficiency via systemic delivery. Rejuvenation of the p53 apoptotic pathway as well as expression of KillerRed protein for sensitization in photodynamic therapy (PDT) is accomplished. A single administration greatly suppresses tumour growth and extends median animal survival from 28 days in control subjects to 68 days. The carrier has capacity for multiple payloads for greater therapeutic response where inter-individual variability can compromise efficacy.

Alterations of p53 are associated with more than half of all human cancers. Here the authors present a new pH-sensitive nanoparticle that is delivered via systemic circulation and combines gene delivery to restore p53 with expression of Killerred protein to induce photosensitization.

Photodynamic therapy: oncologic horizons

Photodynamic therapy (PDT) is a light-based intervention with a long and successful clinical track record for both oncology and non-malignancies. In cancer patients, a photosensitizing agent is intravenously, orally or topically applied and allowed time to preferentially accumulate in the tumor region. Light of the appropriate wavelength and intensity to activate the particular photosensitizer employed is then introduced to the tumor bed. The light energy will activate the photosensitizer, which in the presence of oxygen should allow for creation of the toxic photodynamic reaction generating reactive oxygen species. The photodynamic reaction creates a cascading series of events including initiation of apoptotic and necrotic pathways both in tumor and neovasculature, leading to permanent lesion destruction often with upregulation of the immune system. Cutaneous phototoxicity from unintentional sunlight exposure remains the most common morbidity from PDT. This paper will highlight current research and outcomes from the basic science and clinical applications of oncologic PDT and interpret how these findings may lead to enhanced and refined future PDT.

The conjugates of gold nanorods and chlorin e6 for enhancing the fluorescence detection and photodynamic therapy of cancers

Gold nanorods (AuNRs) were conjugated with chlorin e6 (Ce6), a commonly used photosensitizer, to form AuNRs-Ce6 by electrostatic binding. Due to the strong surface plasmon resonance coupling, the fluorescence of conjugated Ce6 was enhanced 3-fold and the production of singlet oxygen was increased 1.4-fold. AuNRs-Ce6 were taken up by the HeLa and KB cell lines more easily than free Ce6, enhancing the intracellular delivery of Ce6. The increased cellular amount of Ce6 leads to a 3-fold more efficient photodynamic killing of these two cell lines. This demonstrates the potential of this approach to improve photodynamic detection and therapy of cancers.

Photodynamic therapy in urology: what can we do now and where are we heading?

BACKGROUND

Photodynamic therapy (PDT) is an innovative technique in oncologic urology. Its application appears increasingly realistic to all kind of cancers with technological progress made in treatment planning and light delivery associated with the emergence of novel photosensitizers. The aim of this study is to review applications of this technique in urology.

MATERIALS AND METHODS

We reviewed the literature on PDT for urological malignancies with the following key words: photodynamic therapy, prostate cancer, kidney cancer, urothelial cancer, penile cancer and then by cross-referencing from previously identified studies.

RESULTS

Focal therapy of prostate cancer is an application of PDT. Clinical studies are ongoing to determine PDT efficacy and safety. PDT as salvage treatment after radiotherapy has been tested. Oncologic results were promising but important side effects were reported. Individual dosimetric planning is necessary to avoid toxicity. PDT was tested to treat superficial bladder carcinoma with promising oncologic results. Serious side effects have limited use of first photosensitizers generation. Second generation of photosensitizer allowed reducing morbidity. For upper urinary tract carcinoma and urethra, data are limited. Few studies described PDT application in penile oncology for conservative management of carcinoma in situ and premalignant lesions. For renal cancer, PDT was only tested on preclinical model despite of its potential application. No data is available concerning PDT application for testicular cancer.

CONCLUSION

PDT clinical applications in urology have proved a kind of efficiency balanced with an important morbidity. Development of new photosensitizer generations and improvement in illumination protocols should permit to decrease side 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 and urothelial carcinoma]

PURPOSE

Photodynamic therapy (PDT) is an innovative therapeutic modality in urologic oncology.

MATERIAL AND METHODS

We reviewed the current literature on principles and modalities of PDT in urothelial and penile oncology.

RESULTS

PDT has been tested for the treatment recurrent superficial bladder tumors and in situ carcinoma. Carcinologic efficacy has been observed with first generation photosensitizer. The lack of selectivity for tumoral cells was responsible of serious adverse events. Development of selective photosensitizers has reduced the importance of side effects. Data concerning PDT for upper urinary tract and urethra carcinoma are still limited.

CONCLUSION

First PDT clinical applications in urothelial oncology have shown some effectiveness at the cost of significant morbidity. The development of selective photosensitizers should help to reduce side effects.

Cell damage and death by autoschizis in human bladder (RT4) carcinoma cells resulting from treatment with ascorbate and menadione

A human bladder carcinoma cell line RT4 was sham-treated with buffer or treated with ascorbate (VC) alone, menadione alone (VK(3)), or a combination of ascorbate:menadione (VC+VK(3)) for 1, 2, and 4 h. Cytotoxic damage was found to be treatment-dependent in this sequence: VC+VK(3)>VC>VK(3)>sham. The combined treatment induced the greatest oxidative stress, with early tumor cell injury affecting the cytoskeletal architecture and contributing to the self-excisions of pieces of cytoplasm freed from organelles. Additional damage, including a reduction in cell size, organelle alterations, nuclear damage, and nucleic acid degradation as well as compromised lysosome integrity, is caused by reactivation of DNases and the redox cycling of VC or VC+VK(3). In addition, cell death caused by VC+VK(3) treatment as well as by prolonged VC treatment is consistent with cell demise by autoschizis, not apoptosis. This report confirms and complements previous observations about this new mode of tumor cell death. It supports the contention that a combination of VC+VK(3), also named Apatone, could be co-administered as a nontoxic adjuvant with radiation and/or chemotherapies to kill bladder tumor cells and other cancer cells without any supplementary risk or side effects for patients.

The Intra-Vascular Stent as a Site-Specific Local Drug Delivery System

The current review focuses on utilization of a tubular structure (coated or uncoated, balloon expandable or self expanding) known as a "stent" for localized intravascular drug delivery. Emphasis of the review is on technologies currently employed for immobilization and coating for drug onto the stent prior to its placement in various lumen of the body. A brief discussion on stent design, comparison of angioplasty and coronary stenting, and market status complements the review for researchers new to this area.

Liver transplantation for hilar cholangiocarcinoma

Hilar cholangiocarcinoma was accepted as an indication for liver transplantation at the beginning of the transplantation era. Owing to disappointing long-term results for this indication, and in parallel, encouraging results in patients with benign disease, hilar cholangiocarcinoma has generally not been accepted as an indication for liver transplantation in recent years. To improve results, more aggressive approaches have been used: "abdominal organ cluster transplantation" and "extended bile duct resection", which lead to increased long-term survival rates. However, with improving results after conventional extrahepatic bile duct resection in combination with partial hepatectomy, extended procedures in combination with liver transplantation never became a real option in the treatment of hilar cholangiocarcinoma. However, new awareness of liver transplantation in the treatment of this cancer has been raised for patients with hilar cholangiocarcinoma in the context of underlying liver diseases such as primary sclerosing cholangitis, which preclude liver resection. Current results show increased survival figures, in particular in well-selected patients with early tumor stages. Further improvements in long-term survival may be reached with new adjuvant and neoadjuvant protocols. Patients with neoadjuvant radiochemotherapy show long-term results similar to those for liver transplantation for other indications. Also, photodynamic therapy and the use of new antiproliferative immunosuppressive agents may be an approach for further improvement of the long-term results. Currently, liver transplantation for the treatment of hilar cholangiocarcinoma should be restricted to centers with experience in the treatment of this cancer and should be taken into consideration in patients with contraindications to liver resection.

Photodynamic Therapy

ALA-PDT is a safe, well-tolerated, and effective treatment for many dermatologic conditions. Current data most strongly support its use in the treatment of actinic damage, but further investigation into alternative uses continues. Current efficacy is limited primarily by the depth of penetration of the photosensitizing agent and the activating light source. Even with this limitation, the potential applications of PDT are numerous. As new technology is developed to overcome current restraints, the future of PDT is wide open.

Neoadjuvant photodynamic therapy as a new approach to treating hilar cholangiocarcinoma: a phase II pilot study

BACKGROUND

Only 20-30% of patients with hilar cholangiocarcinomas (CC) are candidates for potentially curative resection. However, even after curative (R0) resection, these patients have a disease recurrence rate of up to 76%. The current prospective Phase II study investigated photodynamic therapy (PDT) as a neoadjuvant treatment for CC.

METHODS

Seven patients with advanced proximal bile duct carcinoma were evaluated. Patients were treated with PDT at the area of tumor infiltration and 2 cm beyond and underwent surgery after a median period of 6 weeks (range, 3-44 weeks).

RESULTS

One patient had a Bismuth-Corlette Type II tumor, two patients had Type IIIa, one patient had Type IIIb, and three patients had Type IV. Cholestasis parameters after PDT decreased significantly. No relevant adverse events from PDT occurred except for minor intraoperative phototoxicity in one patient. Three patients underwent right-sided liver resections, two patients underwent left-sided liver resections, and one patient received a combined hilar resection with partial pancreatoduodenectomy (PD) due to tumor extension into the distal bile duct. Liver transplantation and PD were performed in another patient. In all patients, R0 resection was achieved. Four patients developed minor surgical complications, even though the bilioenteric anastomoses were sewn to PDT-pretreated bile ducts. No viable tumor cells were found in the inner 4 mm layer of the surgical specimens. The PDT-pretreated epithelium of the tumor-free proximal resection margins exhibited only minimal inflammatory infiltration. Tumors recurred in 2 patients 6 and 19 months after surgery. The 1-year recurrence free survival rate was 83%.

CONCLUSIONS

Neoadjuvant PDT for hilar CC is a low-risk procedure with efficient selective destruction of the superficial 4 mm layer of bile duct tumor without complications exceeding series without neoadjuvant PDT. Neoadjuvant PDT should be evaluated prospectively to determine whether it reduces the rate of local disease recurrence after potentially curative resection.

Photodynamic therapy with intravesical instillation of 5-aminolevulinic acid for patients with recurrent superficial bladder cancer: a single-center study

OBJECTIVES

Photodynamic therapy (PDT) is an effective treatment option for patients with superficial bladder cancer uncontrolled by transurethral resection and/or intravesical bacille Calmette-Guérin (BCG) immunotherapy alone. We determined the efficacy and side effects of PDT in patients with recurrent superficial bladder cancer.

METHODS

Between April 1994 and July 2001, PDT was performed in 31 patients (23 men and 8 women). 5-Aminolevulinic acid (50 mL) in a 3% concentration was instilled intravesically. Patients were instructed to hold the solution as long as possible and were irradiated transurethrally with a mean light dose of 3.9 W using laser light emitting a wavelength of 633 nm for a mean time of 1260 seconds.

RESULTS

The mean patient age at the procedure was 70.2 years. At an average follow-up of 23.7 months (range 1 to 73), 16 patients were free of tumor recurrence; 15 patients had developed tumor recurrence after a mean of 8.3 months. Of 10 patients with prior BCG treatment, 4 were free of tumor recurrence. Treatment was well tolerated, with the only side effect being dysuria due to urinary tract infection in 4 patients and hematuria in 7 patients. No phototoxic skin reactions were observed.

CONCLUSIONS

PDT represents a safe, effective, and less-invasive treatment for patients with recurrent superficial bladder cancer. Because of the favorable side-effect profile, PDT can also be applied to patients with comorbidity precluding surgical treatment. Furthermore, PDT represents a second-line treatment for patients with tumor recurrence after BCG failure.

Photodynamic therapy of high-grade cervical intraepithelial neoplasia with 5-aminolevulinic acid

BACKGROUND AND OBJECTIVES

To determine the safety and efficacy of 5-aminolevulinic acid (ALA) as a topically applied photosensitizer for photodynamic therapy (PDT) of cervical intraepithelial neoplasia (CIN).

STUDY DESIGNS/MATERIALS AND METHODS

Forty women, who were at least 18 years old with persistent biopsy-proven CIN 2 and CIN 3 within the previous 3 months of enrollment, underwent PDT in a phase I and II design. Five escalating radiant energies (increments of 25 J/cm(2), beginning at 50-150 J/cm(2)) using a Coherent Dye Model 920 argon pumped dye laser providing light at 630 nm (maximum output 0.8 W) were used to perform PDT with a fixed dose of ALA (200 mg/ml). ALA was placed in a cervical cap fitted to the cervix. After 90 minutes, the cap was removed and the ectocervix was illuminated for 5-16 minutes, depending on the irradiance. Success was defined as the absence of CIN on Pap smear or colposcopic examination at 12-months. Patients were monitored for toxicity.

RESULTS

Thirty-two women (80%) completed the study with 1 year of follow-up. Sixty percent had CIN 3 and 40% CIN 2. Success rates at 4, 8, and 12 months were 51, 46, and 31%, respectively, and were not light-dose dependent. Three patients progressed from CIN 2 to CIN 3. Toxicity was tolerable and only consisted of spotting, vaginal discharge, mild cramping, and vaginal warmth. There was no apparent dose relationship to toxicity.

CONCLUSIONS

PDT at this light and ALA dose is well tolerated but has minimal activity in the treatment of CIN 2 and CIN 3. Other doses and schedules of light and ALA or novel photosensitizers may improve efficacy.

Changes produced in the urothelium by traditional and newer therapeutic procedures for bladder cancer

A handful of traditional and newer therapeutic procedures, such as chemotherapy, immunotherapy, radiotherapy, photodynamic and laser treatment, and gene therapy, are used to treat epithelial malignancies of bladder origin. These treatment modalities, used either intravesically or systemically, produce morphological changes in the urothelial mucosa that can be mistaken for carcinoma. The pathologist must be able to separate toxic and drug related alterations from tumour related changes. The clinical history is usually invaluable in this assessment.

Photodynamic therapy for superficial bladder cancer under local anaesthetic

OBJECTIVES

To evaluate the use of local anaesthesia (LA) in 5-aminolaevulinic acid (ALA) photodynamic therapy (PDT) for superficial transitional cell carcinoma (TCC) of the bladder, and to provide further toxicity and tolerability data on this new method within the context of a phase 1 trial.

PATIENTS AND METHODS

ALA PDT was administered to 19 patients with recurrent superficial TCC (stage Ta/carcinoma in situ, grades 1-3) using escalating doses of ALA (3-6%) and 633 nm laser light (25-50 J/cm2) under various LA (lignocaine) protocols. Pain was assessed using a linear analogue scale from 0 to 10. The endpoints of tolerability and toxicity were assessed for the different LA, light and ALA doses, with lignocaine levels.

RESULTS

ALA PDT is painful and requires some form of anaesthesia. The discomfort was immediate, associated with bladder spasm, and was a function of the ALA concentration rather than the total light dose given. Simple passive diffusion (PD) of 2% lignocaine instilled for 40 min before PDT gave adequate anaesthesia with 3% ALA (n=8; median pain score 1, range 0-2). With 6% ALA the pain was dramatically increased using PD (n=6; median pain score 8, range 5-10) and therefore the more potent LA technique of electromotive drug administration (EMDA) of 2% lignocaine was used, with excellent results (n=3; median pain score 1, range 0-2). All patients had transient bladder irritability that typically lasted 9-12 days, with no subjective/objective change in long-term bladder function. No other toxicity was reported. Serum lignocaine levels were minimal.

CONCLUSION

Bladder ALA PDT is both safe and feasible under LA. At a dose of 3% ALA, the procedure was well-tolerated using PD of lignocaine. At higher doses (6% ALA) more effective anaesthesia is required and this can be obtained satisfactorily with EMDA of lignocaine. With refinement, ALA PDT may be feasible as an outpatient treatment for superficial bladder TCC.

Medical management of patients with refractory carcinoma in situ of the bladder

Bladder cancer is a common genitourinary malignancy and carcinoma in situ (CIS) of the bladder exists as a potentially aggressive variant of the superficial form of the disease. Treatment must reflect the unpredictable nature of this disease entity. In 1976, the use of intravesical Bacillus Calmette-Guerin (BCG) was described for the management of early stage bladder cancer. A subsequent report demonstrated efficacy in a cohort of patients with CIS of the bladder. Since this time, intravesical BCG has been recognised as the initial therapy for CIS of the bladder. Although a 6-week treatment with intravesical BCG has been established as standard therapy in patients with CIS, there has been no consensus as to the subsequent treatment for patients in the setting of failure to initial management with BCG. In addition, a number of reports have demonstrated an increased potential of adverse effects after repeated treatment with intravesical BCG. A variety of alternative immunological and chemotherapeutic agents have been developed in response to the limitations of BCG for patients with refractory CIS of the bladder. At present, valrubicin remains the only agent that is approved by the US Food and Drug Administration for the specific indication of CIS of the bladder unresponsive to intravesical BCG. Although these agents appear promising, the most efficacious therapy remains to be determined. The specific treatment protocol for refractory CIS of the bladder remains elusive. It is ultimately the combined decision of the clinician and patient to determine which course of management is most beneficial.

The history of photodetection and photodynamic therapy

Light has been employed in the treatment of disease since antiquity. Many ancient civilizations utilized phototherapy, but it was not until early last century that this form of therapy reappeared. Following the scientific discoveries by early pioneers such as Finsen, Raab and Von Tappeiner, the combination of light and drug administration led to the emergence of photochemotherapy as a therapeutic tool. The isolation of porphyrins and the subsequent discovery of their tumor-localizing properties and phototoxic effects on tumor tissue led to the development of modern photodetection (PD) and photodynamic therapy (PDT). This review traces the origins and development of PD and PDT from antiquity to the present day.

The morphological changes in rat bladder after photodynamic therapy with 5-aminolaevulinic acid-induced protoporphyrin IX

OBJECTIVE

To assess the optimum light energy needed to induce only superficial bladder wall damage during photodynamic therapy (PDT) as a treatment for bladder cancer. Materials and methods The urinary bladder (with normal epithelium) of 64 female rats was treated with PDT using a continuous-wave argon-ion laser as an energy source and aminolaevulinic acid (ALA)-induced protoporphyrin IX photosensitizer. Four hours after the intravenous administration of ALA (300 mg/kg) the bladders were intravesically exposed to light fluences of 20-80 J/cm2. The control rats received no ALA and were exposed to 20 J/cm2 light. After 1, 3, 7 and 21 days the animals were killed and the morphological changes in bladder wall analysed both macroscopically and using light and scanning electron microscopy.

RESULTS

At the dose of ALA given, a fluence of 20-40 J/cm2 caused mainly superficial damage, whereas 80 J/cm2 produced full-thickness injuries to the bladder wall. The maximum effect of PDT occurred after 1 and 3 days of irradiation. After 3 weeks of PDT the histology showed few full-thickness injuries and only in those treated with 80 J/cm2 light.

CONCLUSION

These results indicate that PDT can be used to safely induce a selective superficial removal of bladder mucosa with no fibrotic effects on detrusor musculature, when optimum photosensitizing drug and fluences are used. These findings support the use of PDT in the therapy of superficial bladder cancer.

Neoadjuvant photodynamic therapy before curative resection of proximal bile duct carcinoma

BACKGROUND

Hilar bile duct carcinoma has an 80% probability of local recurrence after curative resection, which might be reduced if neoadjuvant photodynamic therapy is feasible. CASE AND TREATMENT: After intravenous injection of sodium porfimer we treated an adenocarcinoma of the proximal common bile duct (T2 N0 M0, Bismuth type II) in a 72-year-old man with red laser light (applied from the lumen at a dose 250 Joules/cm2), and the adjacent right and left hepatic and common bile duct at a dose of 125 Joules/cm2. After 23 days the tumor was completely resected (adenocarcinoma pT2 pNO; G2).

RESULTS

In the lumenal, 4-mm-thick layer the bile duct specimen exhibited complete tumor necrosis with pigmentation of photodegraded porfimer and no viable tumor cells, while in the outer layer of the wall (at 5-8-mm depth) viable cancer cell nests without degraded porfimer were seen. The bile duct tissue showed little damage. Eighteen months after surgery, neither tumor recurrence nor stricture formation was found at the pretreated bilioenteric anastomoses.

CONCLUSIONS

a) Photodynamic therapy with sodium porfimer seems to be confined to the superficial 4-mm layer of bile duct cancer. b) Neoadjuvant photodynamic therapy is feasible for hilar bile duct carcinoma.

The role of photodynamic therapy in the treatment of recurrent superficial bladder cancer

Photodynamic therapy is an exciting area of research for the treatment of superficial bladder cancer. Significant responses have been seen in patients resistant to standard intravesical treatments. New areas of research are focused on the development of new sensitizers and light distribution methods with less dermal and bladder toxicity.

Photodynamic therapy for advanced bile duct cancer: evidence for improved palliation and extended survival

Median survival time of nonresectable hilar bile duct cancer is only 4 to 6 months owing to tumor spread in the biliary tree, refractory cholestasis, and sepsis or liver failure. We explored whether local photodynamic therapy of nonresectable bile duct cancer could improve survival. A sample size of 23 patients is required to detect an increase in 6-month survival rate from less than 50% to greater than 70% in a single-arm phase-II trial with a statistical power of 80% (Fleming's single step procedure; alpha = 0.05). Twenty-three consecutive patients (8 women, 15 men; 67 +/- 14 years) with nonresectable bile duct cancer (Bismuth type III n = 2, type IV n = 21) were treated with photodynamic therapy and biliary endoprosthesis. Photofrin (QLT Pharmaceuticals, Vancouver, Canada) (2 mg/kg body weight intravenously) was photoactivated after 1 to 4 days with laser light (630 nm; 242 J/cm(2)) via endoscopic retrograde access. The 6-month survival rate was 91% after diagnosis and 74% after start of photodynamic therapy (30-day mortality rate was 4%) at a median follow-up time of 10.3 months after diagnosis. Causes of death were tumor progression (n = 9) and bacterial infections (n = 4). The median rate of local tumor response was 74%, 54%, 29%, and 67% after the first, second, third, fourth, and fifth photodynamic therapy. Time to progression ranged from 3 to 8 months. All patients, except 1 with diffuse liver metastases, improved in cholestasis, performance, and quality of life. Photodynamic therapy can prevent tumor occlusion of hilar bile ducts. The apparent benefit in survival time should be confirmed in a controlled trial versus palliation by endoprosthesis only.