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.

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.

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.