Dynamic Spectral Imaging for Post-Treatment Triage
Poster Presentation at IFCPC (London, 2014)
Poster 237 – Dr Christina Founta : Dynamic Spectral Imaging for Post-Treatment Triage.
The UK NHSCSP (National Health Service Cervical Screening Programme) recently implemented “test-of-cure” for patients treated for Cervical Intraepithelial Neoplasia (CIN), moving the management decision to colposcopy.
To assess the accuracy of colposcopy with and without the adjunctive aid of the cervical aceto-whitening map of the DYSIS digital colposcope [DYSIS Medical Ltd, Livingston, UK] in detecting CIN2+ in patients with a post-treatment negative smear who are high-risk (HR) HPV positive. They represent a significant proportion of the test-of-cure population and are a newly introduced challenging group.
This is an observational ongoing study, including women with a post-treatment negative smear who are high-risk (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 81 women. In 57 (70.3%) histology was available and these are analyzed. Colposcopic impression before the DYSISmap was seen was High-Grade (HG) in 3 cases (5.2%), none of which had a histologically confirmed CIN2+ lesion. In contrast, the DYSISmap identified as potential CIN2+ 30 cases (53%), in 4 of which histology showed HG CIN. Overall, 5 (8.8%) women had HG histology. The sensitivity of standard colposcopy for CIN2+ was 0% improving to 80% with the incorporation of the DYSISmap. Specificity was 94% and 45% 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 96%.
Albeit numbers are still small, there is a clear trend showing that incorporating the DYSISmap as an adjunct to standard colposcopy improves the sensitivity of colposcopy to predict CIN2+ on normal cytology / HR HPV positive patients after treatment for CIN.