A smartphone-based standalone fluorescence spectroscopy tool for cervical precancer diagnosis in clinical conditions

Real-time prediction about the severity of noncommunicable diseases like cancers is a boon for early diagnosis and timely cure. Optical techniques due to their minimally invasive nature provide better alternatives in this context than the conventional techniques. The present study talks about a standalone, field portable smartphone-based device which can classify different grades of cervical cancer on the basis of the spectral differences captured in their intrinsic fluorescence spectra with the help of AI/ML technique. In this study, a total number of 75 patients and volunteers, from hospitals at different geographical locations of India, have been tested and classified with this device. A classification approach employing a hybrid mutual information long short-term memory model has been applied to categorize various subject groups, resulting in an average accuracy, specificity, and sensitivity of 96.56%, 96.76%, and 94.37%, respectively using 10-fold cross-validation. This exploratory study demonstrates the potential of combining smartphone-based technology with fluorescence spectroscopy and artificial intelligence as a diagnostic screening approach which could enhance the detection and screening of cervical cancer.

High-definition FT-IR reveals a synergistic effect on lipid accumulation in prostate cancer cells induced by a combination of X-rays and radiosensitizing drugs

Radiotherapy is one of the most commonly used cancer therapies with many benefits including low toxicity to healthy tissues. However, a major problem in radiotherapy is cancer radioresistance. To enhance the effect of this kind of therapy several approaches have been proposed such as the use of radiosensitizers. A combined treatment of radiotherapy and radiosensitizing drugs leads to a greater effect on cancer cells than anticipated from the addition of both responses (synergism). In this study, high-definition FT-IR imaging was applied to follow lipid accumulation in prostate cancer cells as a response to X-ray irradiation, radiosensitizing drugs, and a combined treatment of X-rays and the drugs. Lipid accumulation induced in the cells by an increasing X-ray dose and the presence of the drugs was analyzed using Principal Component Analysis and lipid staining. Finally, the synergistic effect of the combined therapy (X-rays and radiosensitizers) was confirmed by calculations of the integral intensity of the 2850 cm-1 band.

Raman Spectroscopy for Early Detection of Cervical Cancer, a Global Women’s Health Issue—A Review

This review focuses on recent advances and future perspectives in the use of Raman spectroscopy for cervical cancer, a global women’s health issue. Cervical cancer is the fourth most common women’s cancer in the world, and unfortunately mainly affects younger women. However, when detected at the early precancer stage, it is highly treatable. High-quality cervical screening programmes and the introduction of the human papillomavirus (HPV) vaccine are reducing the incidence of cervical cancer in many countries, but screening is still essential for all women. Current gold standard methods include HPV testing and cytology for screening, followed by colposcopy and histopathology for diagnosis. However, these methods are limited in terms of sensitivity/specificity, cost, and time. New methods are required to aid clinicians in the early detection of cervical precancer. Over the past 20 years, the potential of Raman spectroscopy together with multivariate statistical analysis has been shown for the detection of cervical cancer. This review discusses the research to date on Raman spectroscopic approaches for cervical cancer using exfoliated cells, biofluid samples, and tissue ex vivo and in vivo.

A micro-Raman spectroscopy study of inflammatory condition of human cervix: Probing of Tissues and blood plasma samples

The present study explores the application of the micro-Raman spectroscopy technique to discriminate normal and cervicitis condition from cervical malignancy by analyzing the Raman signatures of tissues and plasma samples of the same subjects. The Raman peaks from tissue samples at 1026 cm^-1,1298 cm^-1 and 1243 cm^-1 are attributed to glycogen, fatty acids and collagen and are found to be reliable signatures capable of identifying cervicitis and normal condition from cervical cancer. The Raman signatures from plasma samples belonging to carbohydrates (578 cm^-1), lipids (1059 cm^-1) and nucleic acids (1077 cm^-1,1341 cm^-1 and 1357 cm^-1) are quite useful to classify various stages of cervix at par with tissue based diagnosis. The PCA-SVM based classification of the spectral data indicates the potential of Raman spectroscopy based liquid biopsy to rule out false diagnosis of cervicitis as cervical malignancy.

Detection of cervical intraepithelial neoplasia by using optical coherence tomography in combination with microscopy

Optical coherence tomography (OCT) is a noninvasive high-resolution imaging technique that permits the detection of cancerous and precancerous lesions of the uterine cervix. The purpose of this study was to evaluate a new system that integrates an OCT device into a microscope. OCT images were taken from loop electrosurgical excision procedure (LEEP) specimens under microscopic guidance. The images were blinded with respect to their origin within the microscopic image and analyzed independently by two investigators using initially defined criteria and later compared to the corresponding histology. Sensitivity and specificity were calculated with respect to the correct identification of high-grade squamous intraepithelial lesions (HSIL). The interinvestigator agreement was assessed by using Cohen’s kappa statistics. About 160 OCT images were obtained from 20 LEEP specimens. Sixty randomly chosen images were used to define reproducible criteria for evaluation. The assessment of the remaining 100 images showed a sensitivity of 88% (second investigator 84%) and a specificity of 69% (65%) in detecting HSIL. Surgical microscopy-guided OCT appears to be a promising technique for immediate assessment of microanatomical changes. In the gynecological setting, the combination of OCT with a colposcope may improve the detection of high-grade squamous intraepithelial lesions.

The Use of a Novel Optical Algorithm in the Diagnosis of Cervical Pre-Invasive Pathology - A Preliminary Proof of Principal Study

OBJECTIVE

To develop a novel optical probe monitoring cervical tissues in real-time and to compare the new imaging technique to actual cervical pathologic findings on resected cone biopsy specimens.

METHODS

A loop electro-excisional procedure was performed on 15 women with a biopsy diagnosis of dysplasia. The conization specimen was then assessed with the novel optical system and results recorded. The 'normal' and 'abnormal' areas were tested by the optical setup at several points. Extracted parameters were used as the input of the classifier function of a logistic regression algorithm model to assess for system accuracy vs. clinical examination.

RESULTS

Ninety-seven samples were taken - forty-five samples from 'abnormal zones' and 42 samples from 'normal zones', as defined by the surgeon. The pathologist diagnosed 58 samples as dysplastic and 39 samples as normal. The novel optical method predicted 58 sample points as abnormal and 39 points as normal. The sensitivity of the system was 90% with a specificity of 77%. The probability of correct differentiation of dysplastic cervical tissue from normal cervical tissue was 85%.

CONCLUSIONS

The optical probe and the algorithms of image processing in combination with the logistic regression algorithm correlated well with pathology results for cervical dysplasia ex-vivo.

Ex vivo investigations on the potential of optical coherence tomography (OCT) as a diagnostic tool for reproductive medicine in a bovine model

Routine infertility investigations in the male and female include imaging techniques such as ultrasonography and endoscopy (fertiloscopy). However, these techniques lack the resolution to localize vital sperm or to reveal detailed morphological analysis of the oviduct which is often the cause of infertility in females. Therefore we set out to evaluate the efficiency of optical coherence tomography (OCT) as a diagnostic imaging tool for micron-scale visualization of the male and female genital tract. Using the bovine as a model, the optical features of the Telesto(TM) , Ganymede(TM) (both Thorlabs) and Niris(TM) (Imalux) OCT imaging systems were compared.

Effect of optical clearing agents on optical coherence tomography images of cervical epithelium

Optical coherence tomography (OCT) can be used as an adjunct to colposcopy in order to detect precancerous and cancerous cervical lesions. Optical clearing agents (OCAs) temporarily reduce the optical scattering of biological tissues. The purpose of this study was to investigate their influence on OCT imaging. OCT images were taken from unsuspicious and suspicious areas of fresh conization specimens immediately after resection and 5, 10, and 20 min after application of dimethyl sulfoxide (DMSO) or polyethylene glycol (PEG). Corresponding histologies were obtained from all sites. The images taken 5, 10, and 20 min after application of OCA were compared to the initial images with respect to changes in brightness, contrast, and scanning depth using a standard nonparametric test of differences of proportions. Further, mean intensity backscattering curves were calculated from all OCT images in the histological groups CIN2, CIN3, inflammation, and normal epithelium. Mean difference profiles within each of these groups were determined, reflecting the mean differences between the condition before the application of OCA and the exposure times 5, 10, and 20 min, respectively. The null hypothesis was tested employing the Dicky-Fuller-test, Hotelings-test and run test. The visual analysis of 434 OCT images from 109 different sites of 24 conization specimens showed a statistically significant increase in brightness and contrast for normal and dysplastic epithelium after application of DMSO or PEG. Further, the analysis of mean intensity profiles suggests the existence of an increased backscattering intensity after application of DMSO or PEG. DMSO and PEG contribute substantially to optical clearing in cervical squamous epithelium and therefore influence OCT imaging in a positive way. With further refinement of the OCT technology, the observed changes may be beneficial in interpreting the tissue microstructure and identifying cervical intraepithelial neoplasia.

Progress in Fourier Transform Infrared Spectroscopic Imaging Applied to Venereal Cancer Diagnosis

Fourier transform infrared imaging spectroscopy is a powerful technique that provides molecular and spatial information at the single-cell level. We report on the progress of this technology in the field of cancer research, focusing on human cervical cancer because of the inherent difficulty in grading this type of cancer and as a model for venereal cancers in dogs. Using a suite of multivariate imaging processing techniques, we demonstrate the potential of this technique to identify histologic features in the normal epithelium and cervical intraepithelial neoplasia stages I and III. We highlight the advantages and detail the barriers that need to be overcome before implementation of this technology in the clinical environment.

Validation of an ex vivo human cervical tissue model for optical imaging studies

OBJECTIVE

To establish and validate an ex vivo human cervical tissue model for optical coherence tomography (OCT) studies with special emphasis on investigating time dependent structural changes of the epithelium.

METHODS

Four hundred OCT images were taken from 80 unsuspicious and suspicious areas of 18 fresh conisation specimens immediately after resection (0 hour) and 1, 2, 3, and 4 hours, referred to as waiting times in the following, postoperatively and compared to the corresponding histology. For each 2D-OCT-image, a 1D-intensity profile was generated. The profiles were analyzed with respect to systematic differences which may result from different waiting times, employing discriminant analysis (DA).

RESULTS

The different waiting times do not appear to imply significant differences among the corresponding OCT-images as represented by the intensity profiles.

CONCLUSION

We conclude that the proposed cervical tissue model appears to be applicable for ex vivo OCT studies.

Diagnostic efficacy of backscattering intensity measurements in optical coherence tomography of cervical intraepithelial dysplasia

BACKGROUND AND OBJECTIVES

The aim of this study was to determine the diagnostic efficacy of backscattering intensity measurements in optical coherence tomography in identifying different grades of cervical intraepithelial dysplasia.

STUDY DESIGN/MATERIALS AND METHODS

OCT images were taken from 153 unsuspicious and suspicious areas of 30 fresh conisation and hysterectomy specimens, evaluated by two blinded investigators using a six-grade classification (normal, inflammation, CIN1, CIN2, CIN3, squamous carcinoma) and later compared to the corresponding histology. Differences between judgments based on either the histology or the OCT images were investigated employing Correspondence Analysis (CA). Further, we explored the extent as to which backscattering intensity profiles of OCT images contained the essential information required for a reliable and valid diagnosis, using Linear Discriminant Analysis (LDA).

RESULTS

The CA of histology- and OCT-based judgments suggests that the diagnostic process may be characterized in terms of two stochastically independent underlying ("latent") variables, the first of them reflecting the definiteness with which CIN classes are identified, the second reflecting a bias towards diagnosing inflammation on the side of the OCT-based judgments. This finding is supported by the results of LDAs, where histology and OCT categorizations differ in particular with respect to the positions of inflammation and CIN1. Possibly, a second canonical variable has to be assumed accounting for the evaluation of carcinoma.

CONCLUSIONS

The systematic differences between histology-based and OCT-based diagnoses suggest that the use of available information is influenced by perceptual and/or cognitive biases. Apart from this it seems that the profiles appear to provide a remarkably large amount of information determining the main course of the diagnostic process.

Role of optical spectroscopy using endogenous contrasts in clinical cancer diagnosis

Optical spectroscopy has been intensively studied for cancer management in the past two decades. This review paper first introduces the background of optical spectroscopy for cancer management, which includes the advantages of optical techniques compared to other established techniques, the principle of optical spectroscopy and the typical setup of instrumentation. Then the recent progress in optical spectroscopy for cancer diagnosis in the following organs is reviewed: the brain, breast, cervix, lung, stomach, colon, prostate and the skin. Reviewed papers were selected from the PubMed database with keywords combining the terms of individual optical spectroscopy techniques and cancers. The primary focus is on the in vivo applications of optical spectroscopy in clinical studies. Ex vivo studies are also included for some organs to highlight special applications or when there are few in vivo results in the literature. Practical considerations of applying optical spectroscopy in clinical settings such as the speed, cost, complexity of operation, accuracy and clinical value are discussed. A few commercially available clinical instruments that are based on optical spectroscopy techniques are presented. Finally several technical challenges and standard issues are discussed and firm conclusions are made.

Optical coherence tomography as a non-invasive imaging technique for preinvasive and invasive neoplasia of the uterine cervix

OBJECTIVE

Optical coherence tomography (OCT) is a non-invasive high-resolution imaging technique that permits characterization of microarchitectural features of tissue up to 2 mm in depth in real time. The purpose of this study was to evaluate the feasibility of OCT for the identification of precancerous (cervical intraepithelial neoplasia (CIN)) and cancerous lesions of the uterine cervix.

METHODS

We conducted a prospective study on the use of OCT in women with suspected CIN. OCT images were obtained on colposcopy from non-suspicious and suspicious areas, and were evaluated independently by two investigators and later compared with the corresponding histology. The sensitivity, specificity, negative and positive predictive values and accuracy of the new technique in identifying CIN or carcinoma were calculated.

RESULTS

Of a total of 610 OCT images, 97 from suspicious areas in 60 women were compared with the corresponding histology. Sixty-three of 67 CIN lesions and four invasive carcinomas were diagnosed correctly on evaluation of the OCT images by the first observer. There were 69 true-positive, 11 true-negative, 13 false-positive and four false-negative results, giving a sensitivity of 95% and a specificity of 46%.

CONCLUSION

OCT is a rapid, easy-to-use modality that provides real-time, microarchitectural information of the cervical epithelium. Further refinement of this technology will lead to OCT systems with a significantly higher resolution and may result in better differentiation of cancerous and precancerous lesions.