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Diffuse reflectance spectroscopy: diagnostic accuracy of a non-invasive screening technique for early detection of malignant changes in the oral cavity
  1. J L Jayanthi1,
  2. G U Nisha1,
  3. S Manju2,
  4. E K Philip2,
  5. P Jeemon3,
  6. K V Baiju4,
  7. V T Beena2,
  8. N Subhash1
  1. 1Biophotonics Laboratory, Centre for Earth Science Studies, Akkulam, Trivandrum, India
  2. 2Department of Oral & Maxillofacial Pathology, Government Dental College, Trivandrum, India
  3. 3Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, UK
  4. 4Department of Statistics, Sree Narayana College, Chempazhanthy, Trivandrum, India
  1. Correspondence to N Subhash; subhash{at}


Background Strong proof-of-principle for utilisation of diffuse reflectance spectroscopy, a non-invasive tool for early detection of malignant changes, has emerged recently. The potential of this technique in distinguishing normal tissue from hyperplastic and dysplastic tissues was explored.

Methods Diffuse reflectance (DR) spectra in the 400–700 nm region were obtained from the buccal mucosa of 96 patients and 34 healthy volunteers. The DR spectral data were compared against the gold standard biopsy and histopathology results. A principal-component analysis was performed for dimensional reduction in the normalised spectral data with linear discriminant analysis as the classifying technique. The receiver operator characteristic curve technique was employed for evaluating the performance of the diagnostic test.

Results DR spectral features for different lesions, such as normal/healthy, hyperplastic, dysplastic and squamous cell carcinoma (SCC), varied significantly according to the intensity of oxygenated haemoglobin absorption. While the classification based on discriminant scores provided an overall sensitivity of 98.5% and specificity of 96.0% for distinguishing SCC from dysplasia, they were 100.0% and 95.0%, respectively, for distinguishing dysplasia from hyperplasia. Similarly, the analysis yielded a sensitivity of 95.0% and specificity of 100.0% for distinguishing hyperplasia from healthy tissue. The areas under the receiver operator characteristic curves were 0.98 (95% CI 0.95 to 1.00) and 0.95 (95% CI 0.90 to 1.00) for distinguishing dysplasia from SCC and hyperplasia from dysplasia, respectively.

Conclusion DR spectral data efficiently discriminate healthy tissue from oral malignant lesions. Diagnostic accuracies obtained in this study highlight the potential use of this method for routine clinical practice.

  • Diffuse reflectance spectroscopy
  • oral lesions classification
  • principal components
  • ROC curves
  • discriminant scores
  • diagnostic performance
  • cardiac epidemiology
  • diabetes and endocrinology
  • lipid disorders
  • epidemiology
  • hepatobiliary tumours
  • epidemiology
  • adult oncology

This is an open-access article distributed under the terms of the Creative Commons Attribution Non-commercial License, which permits use, distribution, and reproduction in any medium, provided the original work is properly cited, the use is non commercial and is otherwise in compliance with the license. See: and

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  • To cite: Jayanthi JL, Nisha GU, Manju S, et al. Diffuse reflectance spectroscopy: diagnostic accuracy of a non-invasive screening technique for early detection of malignant changes in the oral cavity. BMJ Open 2011;1:e000071. doi:10.1136/bmjopen-2011-000071

  • Funding This work was supported by carried out with grants from the Department of Science & Technology, Government of India (SP/S2/L-19/1999) and the Centre for Earth Science Studies Plan-223 project. JJL acknowledges Council of Scientific and Industrial Research (CSIR), New Delhi for her senior research fellowship. PJ is supported by the Wellcome Trust Capacity Strengthening Strategic Award to the Public Health Foundation of India and a consortium of UK universities.

  • Competing interests None.

  • Ethics approval Ethics approval was provided by the scientific and ethics committee of Government Dental College, Trivandrum, Kerala, India.

  • Contributors JLJ and NS developed the DRS system. JLJ, NS, SM, EKP, PJ and VTB developed the protocol of the study. JLJ, NGU, SM and EKP conducted the study and obtained the data. VTB monitored data collection for the whole study and revised the paper. NGU, KVB, PJ, JLJ and NS wrote the statistical analysis plan, cleaned and analysed the data, and drafted and revised the paper. SM and EKP performed the biopsy, prepared the slides for histopathology and revised the paper.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Data sharing statement Only aggregate data are presented in the paper. The complete data set is available from the corresponding author.

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