Adjustment of treatment parameters for photodynamic therapy of cervical pre-cancer and cancer

• Main Authors: I. P. Aminodova, S. A. Aminodov
• Format: Article
• Language: Russian
• Published: Non-profit partnership for development of domestic photodynamic therapy and photodiagnosis "Russian Photodynamic Association" 2015-06-01
• Series: Biomedical Photonics
• Subjects: cervical cancer; fl uorescence diagnosis; photodynamic therapy; fotoditazin
• Online Access: https://www.pdt-journal.com/jour/article/view/57

Comprehensive study for optimization of parameters of photodynamic action with fotoditazin in patients with tumor and pre-tumor cervical diseases was conducted. The study included 52 female patients: pre-invasive cervical diseases were diagnosed in 34 (CIN I – in 9, CIN II – in 13, CIN III – in 12), cervical cancer – in 11 (8 had squamous cell cancer, 3 – adenocarcinoma of cervical canal), chronic cervicitis – in 7. The study agent in the form of 0,5% gel was applied on cervix in dose of 1 ml. To detect optimal interval between gel application and conduction of photodynamic therapy dynamics of accumulation and elimination of photosensitizer by means of its fl uorescence was studied. Fotoditazin was shown to have good accumulation in pathological tissues. The maximal agent accumulation was noticed in 30 min, continued about 15 min, and then gradually decreased. Maximal fl uorescence of photosensitizer was observed in foci of malignant tumor and severe intraepithelial neoplasia. To detect optimal light dose for irradiation cytological study of cell smear from specimen after light exposure with different light doses was performed. The minimal light dose necessary for activation of photochemical reaction pathway was 100 J/cm2, and optimal – 250 J/cm2. This dose allowed to destroy all atypical cells in the area of light exposure after application of gel fotoditazin. According to obtain data we suppose that the most effi cient regimen of photodynamic therapy with local application of fotoditazin-gel for treating dysplasia and pre-invasive cervical cancer was a dose of laser irradiation of 250 J/cm2 with duration of application of 30–45 min.