Multimodal fiber-probe spectroscopy as a clinical tool for diagnosing and classifying biological tissues

Year: 2017

Authors: Cicchi R., Anand S., Fantechi R., Giordano F., Gacci M., Conti V., Nesi G., Buccoliero AM., Carini M., Guerrini R., Pavone FS .

Autors Affiliation: National Institute of Optics, National Research Council (INO-CNR), Largo Enrico Fermi 6, Florence, 50125, Italy; European Laboratory for Non-Linear Spectroscopy (LENS), University of Florence, Via Nello Carrara 1, Sesto Fiorentino, 50019, Italy; Division of Urology, Department of Critical Care Medicine and Surgery, University of Florence, Viale Giovanni Battista Morgagni 85, Florence, 50134, Italy; Division of Neurosurgery, Department of Neuroscience I, A. Meyer Children’s Hospital, Viale Gaetano Pieraccini 24, Florence, 50141, Italy; Pediatric Neurology, Neurogenetics and Neurobiology Unit and Laboratories, Neuroscience Department, A. Meyer Children’s Hospital, University of Florence, Florence, Viale Gaetano Pieraccini 24, Florence, 50139, Italy; Division of Pathology, Department of Critical Care Medicine and Surgery, University of Florence, Viale Giovanni Battista Morgagni 85, Florence, 50134, Italy; Department of Physics, University of Florence, Via Giovanni Sansone 1, Sesto Fiorentino, 50019, Italy

Abstract: An optical fiber probe for multimodal spectroscopy was designed, developed and used for tissue diagnostics. The probe, based on a fiber bundle with optical fibers of various size and properties, allows performing spectroscopic measurements with different techniques, including fluorescence, Raman, and diffuse reflectance, using the same probe. Two visible laser diodes were used for fluorescence spectroscopy, a laser diode emitting in the NIR was used for Raman spectroscopy, and a fiber-coupled halogen lamp for diffuse reflectance. The developed probe was successfully employed for diagnostic purposes on various tissues, including brain and bladder. In particular, the device allowed discriminating healthy tissue from both tumor and dysplastic tissue as well as to perform tumor grading. The diagnostic capabilities of the method, determined using a cross-validation method with a leave-one-out approach, demonstrated high sensitivity and specificity for all the examined samples, as well as a good agreement with histopathological examination performed on the same samples. The obtained results demonstrated that the multimodal approach is crucial for improving diagnostic capabilities with respect to what can be obtained from individual techniques. The experimental setup presented here can improve diagnostic capabilities on a broad range of tissues and has the potential of being used clinically for guiding surgical resection in the near future.

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KeyWords: Diagnosis; Fibers; Fluorescence; Fluorescence spectroscopy; Grading; Histology; Optical fibers; Probes; Reflection; Semiconductor lasers; Spectroscopy; Tumors, Cross-validation methods; Diagnostic capabilities; Diffuse reflectance; Histopathological examinations; Multi-modal approach; Optical fiber probe; Spectroscopic measurements; Visible laser diodes, Tissue