[Spectro-fluorescence analysis of ALA-induced protoporphyrin IX in differential diagnosis of stomach disease]

The results of examination of 47 patients with confirmed diagnosis of cancer of the stomach (21 patients) or 26 suspects were analyzed. 2-4 hours after oral taking of Alasence in the dose 5-10 mg/kg, gastroscopy with spectrofluorescence analysis of ALA-induced protoporphyrin IX was performed. There were no toxic complications due to Alasence taking. The standard spectrodetector LESA-7 was used for fluorescence record registration. The fluorescence spectra were recorded in the range of 650-850 nm. The specific for protoporphyrin IX peak at 700 nm wavelength was analyzed. Fluorescent endoscopic diagnosis allowed to confirm stomach cancer in 21 patients, and to detect cancer in 7 patients, including 2 cases of cancer in situ. The contrast of protoporphyrin IX accumulation (tumor/norm ratio) ranged from 2.5 to 18, that was enough for differential diagnosis in the majority of cases. In analysis of spectrograms for correct contrast calculation it is necessary to take into account the own fluorescence, with was high in some cases.