Validation of Automated Visual Evaluation (AVE) on Smartphone Images for Cervical Cancer Screening in a Prospective Study in Zambia

Abstract

I.AbstractObjectivesVisual inspection with acetic acid (VIA) is a low-cost approach for cervical cancer screening in most low- and middle-income countries (LMICs) but lacks objectivity and requires sustained training and quality assurance. We developed, trained, and validated an artificial-intelligence-based “Automated Visual Evaluation” (AVE) tool that can be adapted to run on smartphones to assess smartphone-captured images of the cervix and identify precancerous lesions, helping augment performance of VIA.DesignProspective study.SettinEight public health facilities in Zambia.Participants8,204 women aged 25-55.InterventionsCervical images captured on commonly used low-cost smartphone models were matched with key clinical information including human immunodeficiency virus (HIV) and human papillomavirus (HPV) status, plus histopathology analysis (where applicable), to develop and train an AVE algorithm and evaluate its performance for use as a primary screen and triage test for women who are HPV positive.Main outcome measuresArea under the receiver operating curve (AUC); sensitivity; specificity.ResultsAs a general population screening for cervical precancerous lesions, AVE identified cases of cervical precancerous and cancerous (CIN2+) lesions with high performance (AUC = 0.91, 95% confidence interval [CI] = 0.89 to 0.93), which translates to a sensitivity of 85% (95% CI = 81% to 90%) and specificity of 86% (95% CI = 84% to 88%) based on maximizing the Youden’s index. This represents a considerable improvement over VIA, which a meta-analysis by the World Health Organization (WHO) estimates to have sensitivity of 66% and specificity of 87%. For women living with HIV, the AUC of AVE was 0.91 (95% CI = 0.88 to 0.93), and among those testing positive for high-risk HPV types, the AUC was 0.87 (95% CI = 0.83 to 0.91).ConclusionsThese results demonstrate the feasibility of utilizing AVE on images captured using a commonly available smartphone and support our transition to clinical evaluation of AVE’s sensitivity, specificity, feasibility, and acceptability across a broader range of settings.