title: 5-Aminolevulinic acid-based fluorescence diagnostics of cervical preinvasive changes.
abstract: The purpose of this article is to review the diagnostic possibilities of 5-aminolevulinic acid (5-ALA)-based fluorescence diagnosis of preinvasive cervical changes. Reviewed papers were selected from the PubMed database with keywords combining the terms individual cervical neoplasia and fluorescence diagnostics. The regular colposcopy procedure lacks specificity; therefore, new methods are continually sought for superior diagnosis of cervical pathology. 5-ALA-based fluorescence diagnostics is under investigation as an up-to-date diagnostic technique for cervical intraepithelial neoplasia (CIN). This method is grounded on the topical or systemic application of 5-ALA, which induces excess production of the endogenous photosensitizer protoporphyrin IX (PpIX) in tissues where carcinogenesis has begun. The conversion of PpIX to the heme is less efficient in tumors; therefore, higher amounts of PpIX tend to accumulate in premalignant and malignant tissues. Illumination with light of the appropriate wavelength initiates excitation of PpIX fluorescence, which in turn helps to localize PpIX-rich areas and identify potentially malignant tissues. A number of investigations suggest that because of its high selectivity for tumors and low toxicity to healthy tissues, 5-ALA-based diagnosis seems a promising tool for the noninvasive identification of cervical intraepithelial neoplasia.
authors.affiliation: Institute of Oncology of Vilnius University, Faculty of Medicine, Vilnius University, Vilnius, Lithuania.
authors.forename: Rasa
authors.initials: R
authors.lastname: Vansevičiūtė
authors.affiliation: Institute of Oncology of Vilnius University, Faculty of Medicine, Vilnius University, Vilnius, Lithuania.
authors.forename: Jonas
authors.initials: J
authors.lastname: Venius
authors.affiliation: Institute of Oncology of Vilnius University, Faculty of Medicine, Vilnius University, Vilnius, Lithuania. Electronic address: simona.letautiene@vuoi.lt.
authors.forename: Simona
authors.initials: S
authors.lastname: Letautienė
mesh_terms: D000622:Aminolevulinic Acid / Q000008:administration & dosage / Q000737:chemistry*; D005260:Female; D005453:Fluorescence; D006801:Humans; D017319:Photosensitizing Agents / Q000737:chemistry / Q000378:metabolism; D011524:Protoporphyrins / Q000096:biosynthesis / Q000737:chemistry; D012680:Sensitivity and Specificity; D002583:Uterine Cervical Neoplasms / Q000175:diagnosis*; D002578:Uterine Cervical Dysplasia / Q000175:diagnosis*
chemical_list: D017319:Photosensitizing Agents; D011524:Protoporphyrins; D000622:Aminolevulinic Acid; C028025:protoporphyrin IX
keywords: 5-Aminolevulinic acid; Cervical intraepithelial neoplasia; Fluorescence diagnostics; Photodynamic diagnostics; Photosensitizing agent