Comparative study of treatment efficacy in severe intraepithelial squamous cell lesions and preinvasive cervical cancer by conization and chlorin e6-mediated fluorescence-assisted systemic photodynamic therapy.

BACKGROUND: Cervical cancer (CC) occupies a leading position in incidence among young women of reproductive age. In this connection, it is urgent to search for the most effective approaches to the diagnosis and treatment of this pathology. The purpose of the study was to evaluate the effectiveness of the PDT method using Cе6 with the control of the photobleaching using video and spectral fluorescence diagnostic methods, to develop the method of fluorescence-assisted systemic photodynamic therapy mediated with chlorin e6 for treatment CIN 3 and CIS. MATERIALS AND METHODS: A randomized comparative clinical study was conducted involving 94 women aged 18 to 49 years with histologically verified severe intraepithelial squamous cell lesions of the cervix or preinvasive cervical cancer. The patients were included in 2 groups: in the first group conization of the cervix was performed with curettage of the remaining part of the cervical canal; patients in the second group underwent the chlorin e6-mediated fluorescence-assisted systemic photodynamic therapy. RESULTS: The absolute majority of patients in the main group after the first course of chlorin e6-mediated fluorescence-assisted systemic photodynamic therapy showed normalization of cytological parameters and colposcopic picture, while women from the comparison group showed signs of cervical lesions statistically significantly more often. These changes corresponded to the dynamics of the proliferation markers expression in the cells of intraepithelial squamous cell lesions. Also, patients of the second group who were planning a pregnancy had better reproductive outcomes after treatment compared to those of the first group. CONCLUSION: In general, higher clinical efficacy and safety of the use of the chlorin e6-mediated fluorescence-assisted systemic photodynamic therapy in the treatment of intraepithelial squamous cell lesions and preinvasive cervical cancer have been established compared to the use of standard treatment methods.

Preliminary low-dose photodynamic exposure to skin cancer with chlorin e6 photosensitizer.

BACKGROUND: The study aimed to investigate the chlorin e6 photosensitizer distribution in the tumor and tumor border (5 mm) during low-dose photodynamic treatment and to increase the effectiveness of the therapy for skin neoplasms. METHODS: Sensitized boundaries of neoplasms were evaluated by video fluorescence imaging. The study of changes in the chlorin e6 distribution before/after photodynamic therapy and in the process of low-dose photodynamic exposure was carried out by the method of spectral fluorescence diagnostics. RESULTS: All 19 patients with basal-cell skin cancer had a contrast of chlorin e6 accumulation compared to normal tissues. 3 hours after intravenous administration of the photosensitizer at a dose of 1 mg/kg, the chlorin e6 concentration was: in normal tissues - 0.18 mg/kg, in the tumor - 1.26 mg/kg, in the tumor border - 0.63 mg/kg. In most cases, the fluorescence indices of chlorin e6 in tumor tissues after low-dose photodynamic therapy increased and exceeded the values before light exposure. CONCLUSION: Low-dose photodynamic therapy seems to be an optimal method for treating select skin neoplasms, which does not cause severe pain in patients during the light exposure and allows for local increase of the photosensitizer concentration in tumor tissues. This method of photodynamic therapy can improve the effectiveness of thе treatment.

Photodynamic therapy of classic Kaposi's sarcoma with video-fluorescence control.

BACKGROUND: Kaposi's sarcoma (multiple idiopathic hemorrhagic sarcoma, Kaposi's angiosarcoma) is an angioproliferative neoplasm of endothelial origin associated with human herpes virus 8 (HHV - 8) and human immunodeficiency virus (HIV). The incidence of the classical form of Kaposi's sarcoma (КS) varies significantly in different geographical areas from 0.14/1 million people (both men and women) to 10.5 per 1 million men and 2.7 per 1 million women. The onset of КS is typical at the age of 35-39 in men and 25-39 years in women. CASE REPORT: A case of successful treatment of a recurrent non-HIV and non-HHV-8 Kaposi's sarcoma with PDT in a 79-year old man. RESULTS: After the recieved photodynamic treatment, complete pathologic response was achieved, i.e., Grade 5 tumor response according to Miller-Payne histological grading system (1999). The overall condition has significantly improved with no clinical tumor signs. CONCLUSION: This report describes a good outcome with PDT in the treatment of Kaposi's sarcoma. The results obtained are initial, but encouraging, demonstrating good tolerance, safety and high efficacy of PDT in classical КS. The successful use of PDT in cutaneous manifestations of HIV-associated KS is also described in literature.

Laser-induced fluorescent visualization and photodynamic therapy in surgical treatment of glial brain tumors.

High-grade gliomas have a diffuse and infiltrative nature of the growth of tumor cells, due to which the achievement of radical resection is difficult. Surgical resection completeness of brain tumors is an important factor in prolonging the life of patients. An accurate definition of tumor boundaries and residual fluorescent regions is impossible due to imperfections of the equipment used for fluorescent imaging. 5-aminolevulinic acid (5-ALA) is a precursor of protoporphyrin IX (PpIX) in humans and is clinically used to detect and treat tumors. Currently, fluorescence-guided surgery with PpIX used a surgical microscope with an excitation wavelength in the blue spectrum range. Because of its low ability to penetrate into biological tissue, blue light is ineffective for providing high-quality fluorescent navigation. Also, when performing an operation using radiation in the blue spectrum range, the photosensitizer's surface layer (PS) often bleaches out, which leads to frequent errors. The use of red light emission makes it possible to slow down the PS bleaches out due to the absorption properties of PpIX, but this task is technically more complicated and requires highly sensitive cameras and specialized optical filters. The new two-channel video system for fluorescent navigation has a radiation source in the red range of the spectrum, the penetration depth of which is greater than the blue light, which makes it possible to increase the depth of probing into biological tissues. The study's clinical part involved 5 patients with high grade glioma and 1 patient with low grade glioma: grade III oligodendrogliomas (2), grade IV glioblastomas (3), and grade II diffusion astrocytoma (1).

Sublingual administration of 5-aminolevulinic acid for laser-induced photodiagnostics and photodynamic therapy of oral cavity and larynx cancers.

BACKGROUND: The study aimed to develop a method for sublingual administration of 5-aminolevulinic acid to patients and evaluate its effectiveness in fluorescence diagnostics and photodynamic therapy of neoplasms of the oral cavity and larynx. METHODS: The boundaries of the neoplasms were established by the video-fluorescence diagnostics and clarified using spectral-fluorescent diagnosis before and after photodynamic therapy. RESULTS: The fluorescence diagnostics demonstrated a high accumulation of protoporphyrin IX, induced by sublingual administration of 5-aminolevulinic acid to patients before the photodynamic therapy and photobleaching of protoporphyrin IX in pathologically altered tissues after the photodynamic therapy. Glucose contained in the sublingual dose supports active transport of 5-ALA into the cells. It increases the PpIX accumulation in the cells, therefore improving the PD and PDT efficacy. CONCLUSION: The study and the initially obtained results demonstrated the possibility and effectiveness of laser-induced photodiagnostics and photodynamic therapy with sublingual administration of 5-ALA to patients with premalignant lesions of the oral cavity and larynx. It can eliminate the threat of the transformation of these diseases into malignant tumors and prevent the need for surgical treatment.

Correlation of synovial caspase-3 concentration and the photodynamic effectiveness in osteoarthritis treatment.

BACKGROUND: The present study focuses on investigation of Intra-articular PDT mechanisms for OA treatment. Also, a search for determination of the most effective dose of chlorin e6 (Ce6) for anti-inflammatory PDT of OA was carried out. METHODS: The study was carried out on laboratory animals (11 Chinchilla rabbits, 1 year, 2.5 kg) with a gonarthritis model of post-traumatic OA. According to the instructions for using Photoditazin (Ce6 based PS) for PDT of human oncological and non-oncological diseases, the recommended dose is 0.7-1.2 mg/kg. For studies on rabbits, taking into account the conversion coefficient (3.2), the PS doses of 2.4, 3.2 and 6.4 mg/kg were selected. Fluorescence spectra were measured intra-articular before and after PDT using spectrometer with fiber-optic probe. The intrajoint PDT was carried out using a laser (662 ± 10 nm) and a fiber-optic catheter with a cylindrical diffuser inside a sapphire needle for a uniform distribution of the laser radiation. The immunohistochemical study was carried out by staining the samples with caspase-3. RESULTS: Histological and immunohistochemical analysis showed that the best PS dose for intravenous administration for PDT of rabbit gonarthritis is 3.2 mg/kg. The PS concentration directly in the synovial tissue was 0.5 mg/kg, and this was enough to achieve the most positive results to reduce the caspase-3 level. CONCLUSION: The caspase-3 level correlates well with other signs of inflammation in the synovial membrane (edema, etc.). Therefore, to assess the PDT effectiveness in the treatment of gonarthritis accompanied by synovitis, it is sufficient to analyze only for caspase-3. The efficacy of PDT with Ce6 showed that 3.2 mg/kg PS dose (1 mg/kg for a human) is the most effective.

Novel Polycationic Photosensitizers for Antibacterial Photodynamic Therapy.

Antibacterial photodynamic therapy (APDT) is a promising method of treating local infected foci, in particular, surgical and burn wounds, trophic and diabetic ulcers. Photodynamic inactivation (PDI) is able to effectively destroy bacterial cells without them developing resistance in response to treatment.This work was dedicated to the study of photophysical and antibacterial properties of new photosensitizers (PS) based on polycationic phthalocyanines and synthetic bacteriochlorins for photodynamic inactivation of P. aeruginosa bacteria and their biofilms. Gram-negative bacteria P. aeruginosa are often found in infected wounds, presumably in biofilm state and are characterized by rather low susceptibility to APDT, which is a problem. PS were studied for possible aggregation at various concentrations by means of absorption and fluorescence spectroscopy. The results of studies of the ZnPcChol8, (3-PyHp)4BCBr4 and (3-PyEBr)4BCBr4 in water and serum confirm the assumption of a low degree of their aggregation at high concentrations.Consequently, their photodynamic efficiency is high enabling to use these PS at high concentrations to sensitize pathological foci for APDT.It was shown that all the investigated PS had a high efficiency of photodynamic inactivation of Gram-negative bacteria P. aeruginosa, as well as their biofilms. Tetracationic hydrophilic near-infrared photosensitizer (3-PyEBr)4BCBr4 with reduced molecule size had significantly higher efficacy of photodynamic inactivation of P. aeruginosa biofilms compared with other studied photosensitizers.

Combined treatment of nonresectable cholangiocarcinoma complicated by obstructive jaundice.

BACKGROUND: The five-year survival rate for successful surgical treatment of cholangiocellular cancer is only 20-40%, and in the case of an unresectable tumor, the life expectancy does not usually exceed 6 months. Survival decreases with the presence of jaundice, due to the spread of the tumor process along the bile ducts, leading to their obstruction. We report outcomes of patients with nonresectable bile duct carcinoma complicated by obstructive jaundice treated with Photodynamic Therapy (PDT). METHODS: Combined diagnosis and treatment included percutaneous cholangiostomy, intraductal video fluorescence diagnostics, photodynamic therapy, and bile duct stenting. All patients were treated at the Sechenov University Oncology Center in Moscow. The results of treatment of 33 patients have been presented. The intraductal diagnosis of malignant bile duct lesions was performed after cholangiostomy using the endovideofluorescence module for minimally invasive surgery and endoscopy. With the use of this method, it is the first time in Russia that it has become possible to obtain a videofluorescent image of the tumor and to determine the high level of photosensitizer accumulation in all cholangiocarcinoma patients. The preparations Photolon, Radachlorin, and Photosens were employed as photosensitizers (PS). Intraductal photodynamic therapy was used to achieve the antitumor effect. Laser power density was about 200 mW/cm2. RESULTS: We present initial results, improved the diagnostic possibilities in this difficult localization of carcinoma, and demonstrated the feasibility of prolongation of life without significant deterioration of its quality. The average survival time in the treatment group is 9.5 months. CONCLUSION: The treatment of patients with nonresectable cholangiocarcinoma with Photodynamic Therapy should be an available option. In this context, the additional use of intraductal endovideofluorescence diagnostics is a highly specific technique that allows reliable detection of the photosensitizer accumulation predominantly by the tumor tissue and appears promising. As shown by our experience, flourescent localization followed by Photodynamic Therapy, enabled us to improve diagnostic techniques and treat the tumor with improved outcome.

Theoretical and experimental modeling of interstitial laser hyperthermia with surface cooling device using Nd3+-doped nanoparticles.

To improve methods of laser hyperthermia for the treatment of bulk malignant neoplasms, an urgent task is the development of techniques and devices that automatically control heating at a given tissue depth and ensure its uniformity. The article proposes the concept of a system for performing hyperthermia with real-time spectroscopic temperature control and surface cooling, which allows to record spectra of diffusely scattered radiation and fluorescent signal from various depths of biological tissues by the means of the variation of the angle and distance between the fiber source of laser radiation and the receiving fiber. Theoretical and experimental modeling of the spatial distribution of diffusely scattered radiation and temperature inside the tissue with a fiber optic device providing surface cooling of the irradiated tissue, and recording spectral information from a given depth in real time, is presented. Simulation of radiation propagation in biological tissues, depending on the distance between the source and the receiver and the angle of their tilt, was carried out using the Monte Carlo method. Modeling of the temperature distribution inside the tissues was carried out by means of a numerical solution of the heat conduction equation. Experimental modeling was carried out on phantoms of biological tissues simulating their scattering properties as well as accumulation of the investigated nanoparticles doped with Nd3+ ions. It was shown that inorganic nanoparticles doped with rare-earth Nd3+ ions can be used as temperature labels for feedback to the therapeutic laser. According to the results of the theoretical simulation, optimal configurations of the relative arrangement of the fibers were chosen, as well as the optimum surface cooling temperatures for the given power densities. The heating of the phantom of the neoplasm containing the investigated nanoparticles doped with Nd3+ ions by laser radiation with an 805-nm wavelength and power density of 1 W/cm2 up to 42 °C at a depth of 1 cm while maintaining the surface temperature within the limits of the norm was demonstrated.

Gonarthritis photodynamic therapy with chlorin e6 derivatives.

BACKGROUND: The new methods of osteoarthritis treatment are in constant demand due to the complexity of the early diagnosis and therapy. Specific features of Сhlorin e6 derivative (Ce6) accumulation in knee joint tissues and the efficiency of photodynamic therapy (PDT) of gonarthritis were studied. METHODS: The experimental research was conducted on the model of posttraumatic gonarthritis on rabbits. The analysis of dynamics of change of Ce6 concentration in tissues of a knee joint was carried out by the method of fluorescent diagnostics. The intra-joint PDT was carried out using 662nm laser with energy density of 120-150J/cm(2) and a sapphire diffuser. An analysis of slices was conducted to confirm the anti-inflammatory effect through apoptosis. RESULTS: The method of fluorescent spectroscopy revealed that the highest amount of Ce6 was accumulated in the synovial membrane of a damaged knee joint 2.5h after its intravenous introduction. On 14th day after gonarthritis modeling but before PDT the synovial membrane showed signs of synovitis. On 21st day after PDT the synovial membrane possessed noticeable villous structure, and no cells of inflammatory nature were observed. CONCLUSION: Fluorescent diagnostics in knee joint tissues can be used in clinical practice of gonarthritis before, during and after PDT for monitoring the Ce6 accumulation and for treatment control. Optimal radiation energy density was determined to be 150J/cm(2). In the studied time intervals (5-25min) no dependency of PDT effect on irradiation time at the same energy density was observed. The analysis of results of clinical and morphological research shows that PDT is a low-invasive method of gonarthritis treatment with a high degree of efficiency and selectivity.

Laser biospectroscopy and 5-ALA fluorescence navigation as a helpful tool in the meningioma resection.

5-aminolevulinic acid (5-ALA) is a natural precursor of protoporphyrin IX (PP IX), which possesses fluorescent properties and is more intensively accumulated in tumor cells than in normal tissue. Therefore, the use of 5-ALA in the surgical treatment of intracranial tumors, particularly gliomas, has gained popularity in the last years, whereas its use in other intracranial pathological entities including meningiomas has been reported occasionally. This study describes a series of 28 patients with intracranial meningiomas, who were administered 5-ALA for a better visualization of tumor boundaries. Twelve patients underwent also laser spectroscopic analysis in order to confirm the visual impression of tumor tissue visualization. Bone infiltration was readily demonstrated. In one case, the tumor recurrence could have been prevented by removal of a tumor remnant, which would possibly have been better recognized if spectroscopic analysis had been used. Fluorescent navigation (FN) is a useful method for maximizing the radicality of meningioma surgery, particularly if the tumor infiltrates the bone, the skull base, and/or the surrounding structures.

Evaluation of blood oxygen saturation in vivo from diffuse reflectance spectra.

A simple method to evaluate the hemoglobin oxygen saturation and relative hemoglobin concentration in a tissue from diffuse reflectance spectra in the visible wavelength range is put forward in this paper. It was assumed that while oxygenated and deoxygenated hemoglobin contributions to light attenuation are strongly variable functions of wavelength, all other contributions to the attenuation including scattering are smooth wavelength functions and can be approximated by Taylor series expansion. Based on this assumption, a simple, robust algorithm suitable for real time monitoring of the hemoglobin oxygen saturation in the tissue has been derived. This algorithm can be used with different fiber probe configurations for delivering and collecting light passed through the tissue. An experimental technique using this algorithm has been developed for in vivo monitoring during artery occlusion and in vitro monitoring of blood samples. The experimental results obtained are presented in the paper.