FLUORESCENT DIAGNOSTICS OF MALIGNANT SKIN TUMORS WITH CHLORIN SERIES PHOTOSENSITIZERS

Abstract

The article shows possibilities in fluorescence imaging of malignant skin tumors with chlorin series photosensitizers (PS) photolon and fotoditazin. The regularities of photosensitizer accumulation from the data of local fluorescence spectroscopy depending on the PS and its dose, the clinical picture and the histological form of the malignant skin neoplasm is investigated. It is shown that the level and selectivity of PS accumulation in the tumor focus depends on the PS dose. In studies on 10 patients with basal cell skin cancer after the introduction of fotoditazin at a dose less than 1 mg/kg, fluorescent contrast between tumor and healthy tissue varied between 1.3 and 9.5, the average was 2.8±0.3; for patients who had the administered fotoditazin dose of 1 mg/kg, fluorescent contrast was 2.9±0.4, varying from 1.4 to 5. In a study with 127 patients after the introduction of photolon in the dose of 0.7-1 mg/kg, the average value of the fluorescence intensity in relative units in the intact skin was 6.9±0.3 (min 4.6, max 12.2), at a dose of 1.1 to 1.4 mg/kg – 8.0±0.3 (min 4.6, max 12.5), at a dose of 1.5-2 mg/kg – 9.9±0.7 (min 5.7, max 20.3). It is also shown that fluorescence intensity of malignant neoplasm of the skin with the same dose of the photosensitizer depends on the neoplasm’s clinical and histological forms. So, 3 hours after the introduction of photolon at a dose of 1.3 mg/kg the average fluorescent contrast in the surface type of skin cancer was 2.7±0.5, in the nodal form – 2.3±0.2, in erosive-ulcerative form – 3.6±0.3. In patients with nodular form of squamous skin cancer after the introduction of photolon at a dose of 1.3 mg/kg fluorescent contrast was significantly higher (p<0.05) (average of 2.8±0.2) than in the nodular form of basal cell carcinoma after the introduction of photolon at the same dose (average of 2.1±0.2).