Feature Of The Week 6/19/11: Optical Coherence Tomography as a Non-Invasive Imaging Technique for Examination of Cervical Tissue
Researchers from Ludwig Maximilians University Munich published on the important topic of using OCT for examination of cancerous cervical tissue. Below is a summary of their work.
Invasive cancer of the uterine cervix (ICC) is the second most frequent cancer in women worldwide accounting for 10% of all cancer-related deaths in women. Every year approximately 510,000 women are newly diagnosed with ICC and approximately 300,000 women die from the disease. Cervical intraepithelial neoplasia (CIN) precedes invasive cancer of the uterine cervix. Its detection and treatment can prevent the progression towards ICC. The implementation of screening programs has led to a decline in the number of cervical cancer related deaths. However, this requires a complex diagnostic infrastructure with overall high costs and major organizational effort. Therefore, the implementation of new imaging techniques that allow cheap, rapid and non-invasive evaluation of the cervix in real time would be a vast improvement. The purpose of this study was to evaluate the feasibility of optical coherence tomography (OCT) in the characterization of cervical dysplasia.
Colposcopy-guided OCT images were taken from unsuspicious and suspicious areas in women with suspected CIN. Each woman then underwent directed biopsies. All OCT images were separately evaluated by two blinded investigators and later compared to the corresponding histology based on a 6-grade classification (normal, inflammation, CIN 1,CIN 2,CIN 3, squamous carcinoma) Sensitivity and specificity of OCT in detecting CIN were determined. To assess the interobserver agreement, kappa coefficients were calculated from the ratings of each investigator for each OCT image seen.
210 OCT images were compared with the corresponding histology in 120 women undergoing colposcopy for suspected CIN. Sensitivity calculated for both investigators was 98% and 96% respectively with the threshold at CIN1 and 86% and 84% respectively with the threshold at CIN2. 39 (38) false positive results reduced the specificity to 39% and 41% respectively with the threshold at CIN1. Defining the threshold at CIN2 the specificity increased to 64% and 60% respectively. Unweighted kappa from a dichotomous classification with the threshold at CIN1 was 0.69 and 0.62 with the threshold at CIN2 showing substantial agreement between both investigators.
We conclude that optical coherence tomography is a rapid, easy-to-use modality that provides real-time, microarchitectural information of the cervical epithelium. Further refinement of this technology will lead to OCT systems with a significantly higher resolution and may result in a better differentiation of cancerous and precancerous lesions.
For more information see recent Article or click the tag Gynecology above. Courtesy Julia Gallwas.