Tissue classification and diagnostics using a fiber probe for combined Raman and fluorescence spectroscopy

Year: 2015

Authors: Cicchi R., Anand S., Rossari S., Sturiale A., Giordano F., De Giorgi V., Maio V., Massi D., Nesi G., Buccoliero AM., Tonelli F., Guerrini R., Pimpinelli N., Pavone FS.

Autors Affiliation: National Institute of Optics, National Research Council (INO-CNR), Largo Enrico Fermi 6 – 50125, Florence, Italy;
European Laboratory for Non-Linear Spectroscopy (LENS), University of Florence, Via Nello Carrara, 1 – 50019, Sesto Fiorentino, Italy;
Division of Clinical, Preventive and Oncology Dermatology, Department of Critical Care Medicine and Surgery, University of Florence, Piazza Indipendenza 11 – 50129, Florence, Italy;

Department of Clinical Physiopathology, Surgical Unit, University of Florence, Florence, Viale Giovanni Battista Morgagni 85 – 50134, Florence, Italy;

Division of Neurosurgery, Department of Neuroscience I, “Anna Meyer” Pediatric Hospital, Viale Gaetano Pieraccini 24 – 50141, Florence, Italy;

Division of Pathology, Department of Critical Care Medicine and Surgery, University of Florence, Viale Giovanni Battista Morgagni 85 – 50134, Florence, Italy;

Abstract: Two different optical fiber probes for combined Raman and fluorescence spectroscopic measurements were designed, developed and used for tissue diagnostics. Two visible laser diodes were used for fluorescence spectroscopy, whereas a laser diode emitting in the NIR was used for Raman spectroscopy. The two probes were based on fiber bundles with a central multimode optical fiber, used for delivering light to the tissue, and 24 surrounding optical fibers for signal collection. Both fluorescence and Raman spectra were acquired using the same detection unit, based on a cooled CCD camera, connected to a spectrograph. The two probes were successfully employed for diagnostic purposes on various tissues in a good agreement with common routine histology. This study included skin, brain and bladder tissues and in particular the classification of: malignant melanoma against melanocytic lesions and healthy skin; urothelial carcinoma against healthy bladder mucosa; brain tumor against dysplastic brain tissue. The diagnostic capabilities were determined using a cross-validation method with a leave-one-out approach, finding very high sensitivity and specificity for all the examined tissues. The obtained results demonstrated that the multimodal approach is crucial for improving diagnostic capabilities. The system presented here can improve diagnostic capabilities on a broad range of tissues and has the potential of being used for endoscopic inspections in the near future.

Conference title: Photonics West – BIOS 2015

KeyWords: Biopsy; Brain; CCD cameras; Diagnosis; Fibers; Fluorescence; Fluorescence spectroscopy; Histology; Multimode fibers; Optical fibers; Probes; Semiconductor lasers, Cross-validation methods; Diagnostic capabilities; Fluorescence and luminescence; Multimode optical fibers; Raman; Spectroscopic measurements; Tissue characterization; Tissue classification, Tissue