Fluorescent diagnostics of keratoacantho

Keratoacanthoma (KA) is common benign epithelial tumor, in typical cases it spontaneously regresses, while in atypical cases it is transformed into squamous cells carcinoma with a frequency of up to 19%. Usually keratoacanthoma is removed surgically, by cryoablation, administration of interferon-alpha, and by other methods. In recent years for treatment of KA photodynamic therapy (PDT) is used, however, it does not prevent the relapse of the tumor. The preliminary fluorescent diagnostics (FD) that is non-invasive method without damaging tumors for obtaining more objective information improves the effectiveness of PDT. The purpose of the study was to develop new method for fluorescent diagnostics of the tumor with radachlorine photosensitizer. Patients with keratoacanthoma (30 persons) aged from 44 to 79 years, average age was 63 years, underwent FD. The clinical diagnosis of KA was confirmed by cytological and/or histological diagnoses. For fluorescence excitation Russian device for fluorescence imaging Biospec and diode laser source l 400-405 nm were used. Accumulation of Radachlorin in the tumor was monitored spectroscopically, therapeutic amount of the photosensitizer in the tumor exceeded its amount in the skin by 1.6-4.0 times. Fluorescence imaging with Radachlorin allows a physician to determine tumor boarders, evaluate accumulation of the photosensitizer in tissues and monitor performance of photodynamic therapy. In addition to that, simultaneous analysis of fluorescent tumor image and its spectrometry allows a physician to obtain more objective diagnosis because spectrometry gives quantitative parameters of fluorescence intensity, which can be used as diagnostic criterion and differential diagnosis.