The impact of using electrical impedance spectroscopy (ZedScan) on the performance of colposcopy in diagnosing high grade squamous lesions of the cervix

Abstract : Objectives. - To determine the efficacy of colposcopy plus ZedScan, which measures changes in tissue electrical impedance, for detecting intraepithelial high-grade lesions compared to colposcopy alone. Methods. - A prospective study conducted at a university hospital colposcopy clinic. Patients referred following abnormal cervical cytology or colposcopic follow up were examined by colposcopy plus ZedScan to assess the cervix. The results of ZedScan directed and colposcopically directed biopsies were compared. Results. - Ninety-one patients were included in this study. The median age was 33 years. Eighty (88%) were referred with abnormal cytology; LSIL 45%, ASCUS 27%, ACS-H8%, HSIL7%, AGC1% and 12% follow-up postconisation or colposcopic follow up. Colposcopy alone detected 18 high-grade lesions with 64 women undergoing biopsy with a total of 115 biopsies being taken with a sensitivity of 60% and NPV estimated at 81.7%. ZedScan with colposcopy increased the detection of high-grade lesions by 47.3%, identifying 27 high-grade lesions and one case of invasive cancer. Sensitivity was 93.1% and NPV estimated at 91.3%. A combination of normal colposcopy practice and ZedScan had a sensitivity and NPV of 100%. Conclusion. - ZedScan used in conjunction with the colposcopy improves sensitivity in detecting highgrade lesions at the expense of a moderate increase in the number of biopsies. Crown Copyright (C) 2017 Published by Elsevier Masson SAS. All rights reserved.