Detection of cervical intraepithelial neoplasia in vivo using confocal endomicroscopy

Abstract

Objective: A high resolution optical imaging device may offer a clinically useful adjunct to colposcopy for the diagnosis and assessment of cervical precancer. This study describes the clinical evaluation of a miniaturised confocal endomicroscope for the quantitative and qualitative assessment of cervical intraepithelial neoplasia (CIN) in vivo.

Design: A descriptive study (n = 25) was performed to assess the usability of confocal endomicroscopy to image the cervix. A prospective study (n = 15) then evaluated the diagnostic accuracy of the technique.

Setting and population: Patients undergoing colposcopy for treatment of CIN1-CIN3 were examined using confocal endomicroscopy.

Methods: A 5% solution of acetic acid was used to enhance the colposcopic features of the atypical region. Normal and abnormal regions of the cervix were then imaged following topical application of a fluorescent dye (acriflavine).

Main outcome measures: Confocal images were analysed to develop a scoring system to grade different levels of CIN. Microscopic features were correlated with histology from biopsy.

Results: Confocal endomicroscopy enabled microscopic imaging of cellular and subcellular structures in vivo at colposcopy. Imaging at increasing depth showed morphological features including dermal papillae, endocervical glands and the squamo-columnar junction. CIN was characterised by an increase in nuclear density, size and cellular atypia. The sensitivity for detection of CIN was 97%. The specificity for predicting the grade of abnormality was 80% for normal-CIN1 and 93% for CIN2-CIN3.

Conclusions: Confocal endomicroscopy is a sensitive imaging tool for detection and assessment of CIN. The technique enables in vivo imaging of cervical histology and the potential for 'see-and-treat' workflows.