The ability of optical coherence tomography (OCT) to produce highly sensitive, noninvasive cross-sectional images has proven useful for diagnosing cervical cancer—even though its low specificity for cervical cancer leads to a high number of false positives. Julia K.S. Gallwas of Ludwig Maximilian University Munich (Germany), and colleagues investigated the accuracy and reproducibility of OCT in characterizing and grading cervical intraepithelial neoplasia (CIN), using equipment supplied by Imalux. OCT images were taken from suspicious and unsuspicious areas in 120 women undergoing colposcopy for suspected CIN. Each woman also underwent biopsy. 1
Two blinded investigators (one of whom disclosed a financial relationship with Imalux) evaluated the OCT imagery separately, and then compared the images with the histology based on standard grading: normal, inflammation, CIN1, CIN2, CIN3, squamous carcinoma. The study measured sensitivity and specificity of OCT in detecting CIN, as well as interobserver agreement.
The researchers found that, depending on the chosen threshold, the sensitivity of OCT compared well with the expert colposcopy results. With the threshold at CIN1, the sensitivity was 98 and 96 percent for both investigators, respectively, and the specificity was 39 and 41 percent, respectively, due to a large number of false positive results. With the threshold at CIN2, sensitivity was 86 and 94 percent and specificity increased to 64 and 60 percent, respectively. Interobserver agreement measures were high.
The study determined that, “OCT is highly sensitive in identifying pre-invasive and invasive cancer of the uterine cervix. At present, OCT is not capable to replace colposcopy but it can be used as an adjunct either to guide biopsies or to define the extent of the lesions.”
1. J.K.S. Gallwas et al., Lasers in Surgery and Medicine 43 (3), 206–212 (2011).