INVESTIGATION OF THE KINETICS OF PROTOPORPHYRIN IX ACCUMULATION IN VULVAR TISSUES AFTER ORAL ADMINISTRATION OF 5-AMINOLEVULINIC ACID

Objective. To study the kinetics of 5-aminolevulinic acid-induced protoporphyrin IX in the vulvar skin, mucosa, and condylomata acuminata (CA) of women after oral administration of alasens solution and to choose optimal time regimens for the fluorescence diagnosis and photodynamic therapy of vulvar CA. Subjects and methods. The study covered 14 patients with CA. Alasens was orally given in a dose of 25 mg/kg body weight. A Spectr-Cluster computerized fluorescence spectral diagnostic system was used to measure spectra before and 1, 2, 3, 5, 7 hours after oral administration of alasens. To estimate tissue protoporphyrin accumulation, the authors employed the index D f that was determined from the integral intensity of the spectrum recorded in the area of the maximum protoporphyrin IX autofluorescence (620— 660 nm) in reference to that (470—520 nm). The mean values of D f in the vulvar skin, mucosa, and CA were calculated for each patient. The resultant mean values were used to estimate the mean values of D f for each time point in all the patients. The fluorescence contrast (C) of CA in the surrounding intact tissue was determined from the averaged (for all the patients) value of D f for CA with respect to that in intact tissue. Results. Local fluorescence spectroscopy has shown that the optimal time for the fluorescence diagnosis of vulvar CA is 3 to 7 hours after use of alasens solution. Photodynamic therapy may be performed in the above period, by causing minimal damage to the surrounding intact tissues.

fluorescence diagnosis, local fluorescence spectroscopy, 5-aminolevulinic acid, protoporphyrin IX, vulvar condylomata acuminate