Diagnosis and Demarcation of Skin Malignancy Using Elastic Light Single-Scattering Spectroscopy: A Pilot Study

Prediction of the extent of germ cell loss utilising a noninvasive spectroscopy method in rat testicular damage model

The aim of this study is to investigate the efficiency of elastic light single-scattering spectroscopy system, a noninvasive method, to acquire spectra during testicular biopsy from normal and damaged seminiferous tubules with various degrees of germ cell loss. Adult control rats and doxorubicin-injected rats to achieve seminiferous germ cell loss (for 10 days [10D], 20 days [D20], 30 days [D30], 40 days [D40], and 50 days [D50]) were used. Spectroscopic measurements were acquired utilising a single-fibre optical probe, and histopathology of the biopsied testicular tissue samples were compared. Time-dependent testicular damage comprising various degrees of seminiferous tubule degeneration after doxorubicin-administration was observed. In D30, D40 and D50 groups, where significant germ cell loss was identified, elastic light single-scattering spectroscopy system signals were well correlated with disturbed spermatogenesis where significant differences in spectral signals were obtained. Our findings indicate that the elastic light single-scattering spectroscopy system has the potential to enable instant imaging of spermatogenesis in rats and could also be useful in humans for clinical applications, such as to increase sperm recovery success during micro-TESE for men with nonobstructive azoospermia.

The past, present, and prospective on UV-VIS-NIR skin photonics and spectroscopy-a wavelength guide

The study and applications of in vivo skin optics have been openly documented as early as the year 1954, or possibly earlier. To date, challenges in analyzing the complexities of this field remain, with wide scopes requiring more scrutiny. Recent advances in spectroscopic research and multivariate analytics allow a closer look into applications potentially for detecting or monitoring diseases. One of the challenges in this field is in establishing a reference for applications which correspond to certain bandwidths. This article reviews the scope on past research on skin spectroscopy, and the clinical aspects which have or may have applications on disease detection or enhancing diagnostics. A summary is supplied on the technicalities surrounding the measurements reported in literature, focused towards the wavelength-dependent applications in themes central to the respective research. Analytics on the topology of the papers' data cited in this work is also provided for a statistical perspective. In short, this paper strives to immediately inform the reader with possible applications via the spectroscopic devices at hand. Graphical Abstract .

Noninvasive assessment of oral lesions using elastic light single-scattering spectroscopy: a pilot study

PURPOSE

In the present study, we investigated the potential application of elastic light single-scattering spectroscopy (ELSSS) as a noninvasive, adjunctive tool to differentiate between malignant and benign oral lesions in vivo.

METHODS

ELSSS spectra were acquired from 52 oral lesions of 47 patients prior to surgical biopsy using a single optical fiber probe. The sign of the spectral slope was used as a diagnostic parameter and was compared to the histopathology findings to obtain sensitivity and specificity of the ELSSS system in differentiating between benign and malignant tissues.

RESULTS

The sign of the spectral slope was positive for the benign tissues and negative for the malignant tissues. Nine malignant lesions and one high-grade dysplasia were correctly classified as cancerous. Six out of the ten low-grade dysplasia were correctly classified as cancerous, and four of them were misclassified as benign. Thirty benign lesions were correctly classified as benign, and two were misclassified as malignant. Our results indicate that the sign of the spectral slope enables the differentiation between malignant and benign oral lesions with a sensitivity of 80% and specificity of 94%.

CONCLUSIONS

ELSSS has the potential to be developed as an adjunctive screening tool in the noninvasive evaluation of oral lesions in vivo. This new diagnostic system may reduce the number of unnecessary biopsies.

Differentiation of skin biopsies by light scattering spectroscopy

Introduction

Spectroscopic systems are medical tools that are used for the detection of cancerous tissues ex vivo and in vivo.

Aim

To differentiate inflammatory and benign skin lesions of excised biopsy samples via a combination of multivariate statistical analysis.

Material and methods

Spectral data were obtained from a total of 22 inflammatory and ten benign skin biopsy samples from 30 patients in the visible wavelength (450–750 nm) regions. Spectral data were compared with the dermatopathology results. Spectral data analyses of biopsy samples were performed via principal component analysis (PCA), followed by linear discriminant analysis (LDA). The differentiation performance was calculated with the receiver operating characteristic (ROC) curve analysis.

Results

The classification based on the discriminant function score provided a sensitivity of 90.9% and a specificity of 80% in discriminating benign from inflammatory lesions with an accuracy of 87.5%.

Conclusions

Our study revealed that light scattering spectroscopy could discriminate between inflammatory and benign skin lesions of excised biopsy samples with high sensitivity by using multivariate statistical analysis. It can be concluded that the high diagnostic accuracy of the optical spectroscopy method has the potential to use as a supplementary system to distinguish inflammatory skin lesions from benign during the pathological examination.

Fiber-based visible and near infrared optical coherence tomography (vnOCT) enables quantitative elastic light scattering spectroscopy in human retina

Elastic light scattering spectroscopy (ELSS) has been proven a powerful method in measuring tissue structures with exquisite nanoscale sensitivity. However, ELSS contrast in the living human retina has been relatively underexplored, primarily due to the lack of imaging tools with a large spectral bandwidth. Here, we report a simple all fiber-based setup to implement dual-channel visible and near infrared (NIR) optical coherence tomography (vnOCT) for human retinal imaging, bridging over a 300nm spectral gap. Remarkably, the fiber components in our vnOCT system support single-mode propagation for both visible and NIR light, both of which maintain excellent interference efficiencies with fringe visibility of 97% and 90%, respectively. The longitudinal chromatic aberration from the eye is corrected by a custom-designed achromatizing lens. The elegant fiber-based design enables simultaneous imaging for both channels and allows comprehensive ELSS analysis on several important anatomical layers, including nerve fiber layer, outer segment of the photoreceptors and retinal pigment epithelium. This vnOCT platform and method of ELSS analysis open new opportunities in understanding structure-function relationship in the human retina and in exploring new biomarkers for retinal diseases.

Noninvasive optical spectroscopy for identification of non-melanoma skin cancer: Pilot study

OBJECTIVE

Optical spectroscopy offers a noninvasive alternative to biopsy as a first-line screening tool for suspicious skin lesions. This study sought to define several optical parameters across malignant and benign tissue types.

STUDY DESIGN

Prospective pilot trial utilizing the Zenalux IM1 optical spectroscopy device from April 2016 to February 2017. For each skin lesion, provider pre-biopsy probability of malignancy was compared to histolopathologic diagnosis. Optical data were characterized across basal cell carcinoma (BCC; n = 9), squamous cell carcinoma (SCC; n = 5), actinic keratosis (AK; n = 4), scar tissue (n = 6), nevus (n = 2), and neurofibroma (NF; n = 1). Across all patients, agreement was determined between control measurements collected adjacent to the lesion and from the upper extremity.

METHODS

Prospective single center pilot study. The optical properties of 27 cutaneous lesions were collected from 18 adult patients presenting to Otolaryngology and Dermatology clinics with suspicious skin lesions warranting biopsy. Spectroscopy measurements were recorded for each lesion: two at the lesion site, two at an adjacent site (internal control), and one at the central medial upper extremity (arm control). Variables of interest included absolute oxygenated hemoglobin (Hb), Hb saturation, total Hb concentration, and Eumelanin concentration. For each lesion, internal control averages were subtracted from lesion averages to provide delta parameter values, and lesion averages were divided by internal control averages to provide ratio parameter values.

RESULTS

Mean percent difference between pre-biopsy probability of malignancy and histology was 29%, with a difference of 75% or greater seen in 5 of 25 lesions. Mean values for BCC, SCC, AK, and scar tissue varied most between extracted mean reduced scatter estimate (μa'; cm- ) delta values (BCC: -2.2 ± 3.8; SCC: -3.9 ± 2.0; AK: -3.3 ± 4.2, Scar: -1.7 ± 1.2) and total Hb (µM) ratio (BCC: 2.0 ± 3.3; SCC: 3.0 ± 1.3; AK: 1.1 ± 0.6; Scar: 1.4 ± 1.1). Agreement between local and arm controls was poor.

CONCLUSION

This pilot trial utilizes optical spectroscopy as a noninvasive method for determining cutaneous lesion histology. Effect sizes observed across optical parameters for benign and malignant tissue types will guide larger prospective studies that may ultimately lead to prediction of lesional histology without need for invasive biopsy. Lasers Surg. Med. 50:246-252, 2018. © 2018 Wiley Periodicals, Inc.

The Effect of Probe Pressure on In Vivo Single Fiber Reflectance Spectroscopy

Introduction: Single fiber reflectance spectroscopy (SFRS) is a noninvasive procedure to quantitate tissue absorption and scattering properties. It can be used to diagnose different diseases such as malignancy and pre-cancerous conditions. The measurement is done with a fiber optic probe in contact with the tissue surface. Herein, the effect of probe pressure on the extracted parameters from human lip spectra was studied. Methods: Thirty-three normal subjects were examined with three exerted pressure levels on the right, middle and left parts of their lips. Results: The results showed variation of spectroscopic parameters with different pressure levels. However, the effect was seen between a very mild contact (pressure 1) and the other reasonably practical pressure levels normally used in the medical centers. Conclusion: SFRS can be used as a reliable diagnostic tool in clinics.

Intraoperative assessment of laryngeal malignancy using elastic light single-scattering spectroscopy: A pilot study

OBJECTIVES/HYPOTHESIS

The elastic light single-scattering spectroscopy (ELSSS) system is a new tool for the real-time diagnosis of cancerous lesions. In the current study, we have employed ELSSS to investigate its ability in differentiation between normal and cancerous larynx tissues ex vivo.

STUDY DESIGN

Basic science study in assessment of laryngeal malignancy using spectroscopy.

METHODS

ELSSS spectra of the larynx tissue were acquired using a single-fiber optical probe. Ex vivo spectroscopic measurements were acquired on 95 laryngeal lesions of 40 patients. Average slopes of the spectra in the wavelength range of 450 to 750 nm were calculated. The signs of the spectral slopes were positive for benign and negative for cancerous larynx tissues. Histopathology results were used as a gold standard to define sensitivity and specificity.

RESULTS

The ELSSS system correctly defined 38 out of 41 malignant tissues as cancerous; three of them were misclassified as benign. All benign tissues were correctly classified. Moderate, severely dysplastic, and malignant tissues were correctly classified as cancerous. The system could not classify mild dysplastic tissues either benign or cancerous, whereas nearly half of them were classified as benign and the other half as malignant. The signs of the spectral slopes were used as a discrimination parameter between benign and cancerous (moderate, severely dysplastic, and malignant) lesions with a sensitivity and specificity of 94% and 100%, respectively.

CONCLUSIONS

The ELSSS system has the potential to be used as an adjunctive tool in the diagnosis of cancerous laryngeal tissues in real time and noninvasively. This new diagnostic technique may reduce the number of negative biopsies.

LEVEL OF EVIDENCE

NA Laryngoscope, 127:611-615, 2017.

Differentiating cancerous tissues from noncancerous tissues using single-fiber reflectance spectroscopy with different fiber diameters

Elastic light-scattering spectra acquired with single-fiber optical probes with diameters of 100, 200, 400, 600, 800, 1000, 1200, and 1500 μm were used to differentiate cancerous from noncancerous prostate tissues. The spectra were acquired ex vivo on 24 excised prostate tissue samples collected from four patients. For each probe, the spectra and histopathology results were compared in order to investigate the correlation between the core diameters of the single-fiber optical probe and successful differentiation between cancerous and noncancerous prostate tissues. The spectra acquired using probes with a fiber core diameter of 400 μm or smaller successfully differentiated cancerous from noncancerous prostate tissues. Next, the spectra were acquired from monosized polystyrene microspheres with a diameter of 5.00±0.01 μm to investigate the correlation between the core diameters of the probes and the Mie oscillations on the spectra. Monte Carlo simulations of the light distribution of the tissue phantoms were run to interrogate whether the light detected by the probes with different fiber core diameters was in the ballistic or diffusive regime. If the single-fiber optical probes detect light in the ballistic regime, the spectra can be used to differentiate between cancerous and noncancerous tissues.

Diagnosis of pelvic lymph node metastasis in prostate cancer using single optical fiber probe

Elastic light single-scattering spectroscopy system (ELSSS) is a biomedical tool which is used for detection of cancerous tissues ex-vivo. ELSSS spectra depend primarily on the size of scatterers in the tissue and are not directly related to changes in the absorption which are caused by variations of the biological macromolecules. In the present study, we aimed to detect metastasis in the pelvic lymph node by using combination of Principal Components Analysis (PCA) and Linear Discriminant Analysis (LDA). Single-scattering spectra in the 450-750nm wavelength regions were obtained from the total of 83 reactive lymph node and 12 metastatic lymph node samples from 10 prostatic cancer patients. The ELSSS spectral data were compared against the "gold standard" histopathology results. Data analyses were done via using PCA, followed by LDA. Receiver Operating Characteristic (ROC) curve analysis was employed for differentiating performance. The classification based on discriminant score provided sensitivity of 100% and specificity of 96.4%, in differentiating non-metastatic (reactive) from metastatic pelvic lymph nodes, with a Positive Predictive Value (PPV) of 0.8, a Negative Predictive Value (NPV) of 0.99 and the area under the ROC curve (AUC) of 0.99, respectively. In this study, it was shown that ELSSS system can accurately distinguish reactive and metastatic pelvic lymph nodes of prostate cancer with high PPV and NPV. It can be concluded that diagnostic accuracy of ELSSS system allows detecting metastatic tissues during operation.

Light Reflectance Spectroscopy to Detect Positive Surgical Margins on Prostate Cancer Specimens

PURPOSE

Intraoperative frozen section analysis is not routinely performed to determine positive surgical margins at radical prostatectomy due to time requirements and unproven clinical usefulness. Light reflectance spectroscopy, which measures light intensity reflected or backscattered from tissues, can be applied to differentiate malignant from benign tissue. We used a novel light reflectance spectroscopy probe to evaluate positive surgical margins on ex vivo radical prostatectomy specimens and correlate its findings with pathological examination.

MATERIALS AND METHODS

Patients with intermediate to high risk disease undergoing radical prostatectomy were enrolled. Light reflectance spectroscopy was performed on suspected malignant and benign prostate capsule immediately following organ extraction. Each light reflectance spectroscopy at 530 to 830 nm was analyzed and correlated with pathological results. A regression model and forward sequential selection algorithm were developed for optimal feature selection. Eighty percent of light reflectance spectroscopy data were selected to train a logistic regression model, which was evaluated by the remaining 20% data. This was repeated 5 times to calculate averaged sensitivity, specificity and accuracy.

RESULTS

Light reflectance spectroscopy analysis was performed on 17 ex vivo prostate specimens, on which a total of 11 histologically positive and 22 negative surgical margins were measured. Two select features from 700 to 830 nm were identified as unique to malignant tissue. Cross-validation when performing the predictive model showed that the optical probe predicted positive surgical margins with 85% sensitivity, 86% specificity, 86% accuracy and an AUC of 0.95.

CONCLUSIONS

Light reflectance spectroscopy can identify positive surgical margins accurately in fresh ex vivo radical prostatectomy specimens. Further study is required to determine whether such analysis may be used in real time to improve surgical decision making and decrease positive surgical margin rates.

Current concepts and future of noninvasive procedures for diagnosing oral squamous cell carcinoma--a systematic review

Background

Oral squamous cell carcinoma (OSCC) has a remarkably high incidence worldwide, and a fairly serious prognosis, encouraging further research into advanced technologies for noninvasive methods of making early diagnoses, ideally in primary care settings.

Objectives

Our purpose was to examine the validity of using advanced noninvasive technologies in diagnosis of OSCC by identifying and evaluating relevant published reports.

Data source

MEDLINE, EMBASE, and CINAHL were searched to identify clinical trials and other information published between 1990 and 10 June 2014; the searches of MEDLINE and EMBASE were updated to November 2014. Study selection: Studies of noninvasive methods of diagnosing OSCC, including oral brush biopsy, optical biopsy, saliva-based oral cancer diagnosis, and others were included.

Data extraction

Data were abstracted and evaluated in duplicate for possible relevance on two occasions at an interval of 2 months before being included or excluded.

Data synthesis

This study identified 163 studies of noninvasive methods for diagnosing OSCC that met the inclusion criteria. These included six studies of oral brush biopsy, 42 of saliva-based oral diagnosis, and 115 of optical biopsy. Sixty nine of these studies were assessed by the modified version of the QUADAS instrument. Saliva-based oral cancer diagnosis and optical biopsy were found to be promising noninvasive methods for diagnosing OSCC.

Limitation

The strength of evidence was rated low for accuracy outcomes because the studies did not report important details required to assess the risk for bias.

Conclusions

It is clear that screening for and early detection of cancer and pre-cancerous lesions have the potential to reduce the morbidity and mortality of this disease. Advances in technologies for saliva-based oral diagnosis and optical biopsy are promising pathways for the future development of more effective noninvasive methods for diagnosing OSCC that are easy to perform clinically in primary care settings.

Optical techniques for the noninvasive diagnosis of skin cancer

PURPOSE

The aim of this paper is to provide an overview of the most investigated optical diagnostic techniques: optical coherence tomography, fluorescence spectrometry, reflectance spectrometry, Raman spectroscopy, and confocal microscopy.

METHODS

A search of three databases was conducted using specific keywords and explicit inclusion and exclusion criteria for the analysis of the performances of these techniques in the pre- and postoperative diagnosis of skin cancers.

RESULTS

Optical coherence tomography has shown promising results in the assessment of deep margins of skin tumors and inflammatory skin diseases, but differentiating premalignant from malignant lesions proved to be less effective. Fluorescence spectroscopy proved to be effective in revealing the biochemical composition of tissue; early detection of malignant melanoma was reliable only with stepwise two-photon excitation of melanin, while tumoral margin assessment and differential diagnosis between malignant and non-malignant lesions showed some conflicting results. Characterization of the structural properties of tissue can be made using diffuse reflectance spectrometry, and the values of the specificity and sensitivity of this method are ranging between 72-92 % and 64-92 %, respectively. Raman spectroscopy proved to have better results both in carcinoma and melanoma diagnosis with sensitivities and specificities above 90 % and high above 50 %, respectively. Confocal microscopy is the closest technique to pathological examination and has gained the most clinical acceptance, despite the need for a standardization of the interpretation algorithm.

CONCLUSIONS

In conclusion, these optical techniques proved to be effective in the diagnosis of skin cancer, but further studies are needed in finding the appropriate method or combination of methods that can have wide clinical applications.