Comparison of sensitivity and specificity of PDD, colposcopy and cytology in the detection of cervical neoplastic lesions

Abstract

Abstract Objectives: Photodynamic diagnosis (PDD) is based on the phenomenon of selective accumulation of a photosensitizer in the tissues where carcinogenesis has started. The change may be identified by fluorescence which takes place when a photosensitizer is activated by the light of an appropriate wave length. The aim of this study was: 1. Evaluation of photodynamic diagnosis in detection and precise location of cervical neoplastic lesions. 2. Comparison of sensitivity and specificity of PDD, colposcopy and cytology in detection of cervical neoplastic lesions. Material: The study was carried out between October 2006 and December 2007 and included 73 women, patients of Gynecologic Oncology Division of the Poznan University of Medical Sciences Hospital. The examined patients were divided into two groups: the first consisted of 43 women with neoplastic lesions and the second, consisting of 30 patients with no oncologic changes of uterine cervix, comprised the control group. Methods: Each patient had PDD, cytological smear and colposcopy performed. For PDD 3% 5-d-aminolevulinic acid (5-ALA) gel was used as a photosensitizer, applied on cervical surface 4 hours before the examination. To activate fluorescence of the areas with highest accumulation of the photosensitizer, the cervix was exposed to the light of 405 nm wave length. Results and conclusions: 1. Photodynamic diagnosis with 3% 5-ALA enables the detection of cervical intraepithelial neoplasia with higher sensitivity than colposcopy and higher specificity than cytological diagnosis 2. Fluorescence allows for precise location of a cervical neoplastic change as well as its extension, borders or multifocal character 3. Location of the change indicated by fluorescence may facilitate the choice of the place for direct biopsy as well as the extension of the therapy