Dynamic Spectral Imaging for triage of Low Grades
Poster Presentation at IFCPC (London, 2014)
Women with Low-Grade (LG) smears who are high-risk (HR) HPV positive have a 16% chance of underlying CIN2+. In addition, data from the sentinel sites and the ATLS study showed that for these women, the 3-year risk for CIN2+ after a negative colposcopy is triple compared to the general population and that colposcopy failed to identify which aceto-white lesions represent High Grade (HG) disease and should be biopsied.
To assess the adjunctive aid of the cervical aceto-whitening map of the DySIS digital colposcope [DySIS Medical Ltd, Livingston, UK] in detecting or excluding CIN2+ for LG / HR HPV positive referrals.
This is an observational ongoing study, including women referred for colposcopy with LG smears who are HR HPV positive. Patients are examined using the DySIS digital colposcope. Initial colposcopic impression and potential biopsy sites are recorded before and after the appearance of the DySISmap. Biopsies are performed at the discretion of the colposcopist and histology is used to interpret results. Final outcomes include sensitivity, specificity and negative predictive value (NPV) for CIN2+ after the application of the DySISmap.
The study currently includes 93 women. In 70 (75.2%) of them histology is available and these are analyzed. Colposcopic impression before the DySISmap was seen, was HG in 8 cases (11.4%), 2 of which had a histologically confirmed CIN2+ lesion.
In contrast, the DySISmap identified as potential CIN2+ 43 cases (61.4%) in 12 of which histology was HG. Overall, 15 (21.7%) women had a CIN2+ histological result.
The sensitivity of standard colposcopy for CIN2+ was 13% improving to 80% with the incorporation of the DySISmap. Specificity was 89% and 40% respectively.
Although NPV cannot be accurately assessed, using directed biopsy histological results the combined NPV of colposcopy and DySISmap for CIN2+ in this population was 88%.
Incorporating the DySISmap as an adjunct to standard colposcopy seems to significantly improve the sensitivity of colposcopy for CIN2+ among LG smear, HR HPV positive referrals. Larger patient numbers are needed to reach safe conclusions.