Photodynamic therapy for preinvasive vaginal cancer.

Abstract

5592 Background: Photodynamic therapy (PDT) is an effective method for the treatment of various cancers resulting in apoptosis, autophagy and ischemic necrosis of irradiated tissues. The purpose of the study was to analyze the efficacy of PDT for pre-invasive vaginal cancer treatment. Methods: PDT results were studied in 20 patients aged 32-65 years with verified pre-invasive vaginal cancer. All patients received PDT with the Latus diode laser and Photolon or Photolan photosensitizers. The effect was evaluated with extended colposcopy. The criteria for efficiency included normalization of the colposcopic picture and the absence of atypical cells. The sizes of the irradiation fields varied from 1.5 to 2 cm, the number of fields - from 1 to 4, the power density - from 0.1 to 0.17 W/cm2, the light dose - from 40 to 100 J/cm2. The duration of a PDT session varied from 10 to 30 min, depending on the number of irradiation fields. The irradiation field necessarily included an area of normal tissue 3-5 mm surrounding the lesion. 4 to 6 sessions were required to restore the normal layer of stratified squamous epithelium. The antitumor efficacy of PDT was evaluated based on the results of visual observation of changes in the area of the treated pathological foci and information on the presence or absence of clinical symptoms of the disease 1 and 3 months after the treatment (WHO criteria). Results: Complete regression was registered in 100% of patients after 3 months. Repeated courses of PDT were required in cases with a wide spread of pathological foci and the impossibility of their simultaneous irradiation. At follow-up after 1 month, 3 of 20 patients (15%) showed local foci of atypical changes in the epithelium managed with repeated PDT courses. In 6 months, stable remission of the disease clinical symptoms in the treated pathological foci was registered. The results of the cytological study performed 3 months after PDT were normal in 100% patients; no negative changes were registered 6 and 12 months after PDT. Conclusions: The results of PDT in the treatment of patients with pre-invasive vaginal cancer demonstrated its high therapeutic efficacy and a minimal number of adverse reactions, which allows recommending PDT in the treatment of pre-invasive vaginal cancer.