Detection of cervical lesions by multivariate analysis of diffuse reflectance spectra: a clinical study

Abstract

Diffuse reflectance (DR) spectroscopy is a non-invasive, real-time, and cost-effective tool for early detection of malignant changes in squamous epithelial tissues. The present study aims to evaluate the diagnostic power of diffuse reflectance spectroscopy for non-invasive discrimination of cervical lesions in vivo. A clinical trial was carried out on 48 sites in 34 patients by recording DR spectra using a point-monitoring device with white light illumination. The acquired data were analyzed and classified using multivariate statistical analysis based on principal component analysis (PCA) and linear discriminant analysis (LDA). Diagnostic accuracies were validated using random number generators. The receiver operating characteristic (ROC) curves were plotted for evaluating the discriminating power of the proposed statistical technique. An algorithm was developed and used to classify non-diseased (normal) from diseased sites (abnormal) with a sensitivity of 72 % and specificity of 87 %. While low-grade squamous intraepithelial lesion (LSIL) could be discriminated from normal with a sensitivity of 56 % and specificity of 80 %, and high-grade squamous intraepithelial lesion (HSIL) from normal with a sensitivity of 89 % and specificity of 97 %, LSIL could be discriminated from HSIL with 100 % sensitivity and specificity. The areas under the ROC curves were 0.993 (95 % confidence interval (CI) 0.0 to 1) and 1 (95 % CI 1) for the discrimination of HSIL from normal and HSIL from LSIL, respectively. The results of the study show that DR spectroscopy could be used along with multivariate analytical techniques as a non-invasive technique to monitor cervical disease status in real time.

Label-free, High-Resolution Optical Metabolic Imaging of Human Cervical Precancers Reveals Potential for Intraepithelial Neoplasia Diagnosis

“…49 .In fact, some studies have indicated that sampling normal-appearing regions of the cervix could increase HSIL detection by up to 30%. 50,51 However, punch biopsy of the human cervix is associated with the increased risk of bleeding and infection (as in all biopsies) and is typically performed without anesthesia, even though the frequency and duration of moderate to severe pain is high. 52 Unfortunately, topical anesthetics have proven ineffective in providing pain relief.…”

A comparative evaluation of diffuse reflectance and Raman spectroscopy in the detection of cervical cancer

“…Recently, Prabitha et al. has utilized PCA and LDA on the DR spectra recorded in vivo from 34 patients and reported a sensitivity of 89% and specificity of 97% for discriminating high‐grade SIL from normal and 100% sensitivity and specificity for discriminating HSIL from LSIL .…”

“…Prabitha et al. has recently carried out a clinical study by recording the diffuse reflectance (DR) images of cervix at the oxygenated haemoglobin absorption peaks of 545 nm and 575 nm . It was observed that the reflectance image intensity ratio R545/R575 could non‐invasively discriminate healthy tissue from premalignant and malignant lesions in real‐time.…”

Optical techniques for cervical neoplasia detection

“…Such difference in spectra detected by an optical sensor can be used in order to identify neoplastic lesions of the cervical epithelium. DRS is an indirect optical technique and may require either fitting of measured spectra with multi-parametric models describing the realistic optical properties of tissue [ 24 ] or using an efficient classification algorithm of optical spectra for the detection of HSIL [ 25 – 26 ]. The propagation of light in a scattering medium is usually modeled by the Monte Carlo algorithm.…”