Cost-effective device for locating and circumscribing superficial tumors with contrast enhancement and fluorescence quantification.

BACKGROUND: Two Bispectral contrast enhancement approaches for the fluorescence diagnosis with chlorine-e6 and a wide field-of-view imaging system with fluorescence excitation at 405 nm and time-resolved background suppression were analyzed and compared. METHODS: Two techniques for the contrast enhancement of a fluorescent video system (Red/Green (R/G) ratio and Red-Green (R-G)) with time-resolved background suppression for fluorescent diagnosis (FD) were tested in four patients with basal cell carcinoma (BCC). RESULTS: The results of both contrast enhancement methods were compared for the diagnostic efficiency for FD of BCC. Both techniques successfully determined the boundaries of the lesions and the fluorescence intensity. CONCLUSIONS: Both contrast enhancement modes have proven effective in identifying tumor borders in cases of low contrast in BCC FD with Ce6. While the Red/Green (R/G) mode provides sharper lesion borders, the Red minus Green (R-G) mode visualizes more fluorescent features and makes it easier to assess the lesion margins.

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).

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.

[A device for fluorescence diagnosis and photodynamic therapy of eye diseases, by using photosense].

By having a high photodynamic effectiveness and an ability of fluorescence, a Photosense photosensibilizer provides a way of combining photodynamic therapy (PDT) and monitoring its control within a session, which enhances the efficiency of treatment for the subretinal neovascular membrane. A slit lamp-based apparatus complex has been developed to employ the methods of fluorescence diagnosis (FD) and PDT, by applying this photosensitizer. The complex comprises an optical adapter that focusing laser radiation on the fundus of the eye in a range of 100-1000 microm, a video adapter that includes color and high-sensitive monochromic video cameras, as well as a personal computer and software that processes video information from the high-sensitive camera and displays the obtained images in real time. The original system of filters provides an image of the eye fundus in the fluorescent and usual color light at once during a FR procedure. The spatial resolution of the developed apparatus was tested on the test object specially devised for these purposes, which was 10 microm. The sensitivity of the complex is sufficient to record slightly fluorescent objects on the fundus of the eye.