Fluorescence diagnosis of cervical squamous intraepithelial lesions: A clinical feasability study

The potential of fluorescence diagnosis (FD) is still undeveloped in gynaecology. In order to diagnose and localize squamous intraepithelial lesion (SIL) of the cervix, a new method improving the low specificity of colposcopy, would be useful.

The goal of this study was to assess the feasability and safety of colposcopic FD of SIL after topicaly application of methyl aminolevulinate (MAL).

Patients with histologic proved cervical intraepithelial neoplasia (CIN) and planned for loop electrosurgical excision procedure (LEEP) under general anesthesia, were included in a prospective study. Before general anesthesia, a thick layer of MAL (Metvix(®)-160mg/mL cream) was applied on the cervix for 35-150min. Fluorescent colposcopic inspection of the cervix was performed using a rigid 10-mm laparoscope inserted in the vaginal cavity and connected to D-light AF system (Karl Storz Endoskope, Tuttlingen Germany). In order to confirm neoplasic status, fluorescent foci underwent directed punch biopsy(ies).

Fourteen patients were included in the study. Colposcopic fluorescence imaging revealed red fluorescent foci in 71.4% of cases (10/14) (neoplasic status of fluorescent foci was confirmed in 80%). Concerning ME-ALA, the mean of application time was 73min (35-150). Two cases presented a false-positive fluorescence and four cases of false-negative fluorescence. For all cases of false-negative fluorescence, application time of MAL was less than 60min. We observed no systemic or local toxicity of MAL application in any of the groups.

Using topical application of MAL to the cervix, we demonstrated that FD of SIL is feasible. This study justifies the further development of fluorescence imaging that combines classical white light colposcopy with the use of a photosensitizer.