title: Laser-induced autofluorescence spectroscopy: can it be of importance in detection of bladder lesions?
abstract: BACKGROUND
  Non-muscle invasive bladder cancer can be missed during white light endoscopy in up to 50% of cases. We aimed to test whether or not we could find a difference between benign and cancerous tissue wavelengths using laser induced autofluorescence spectroscopy can increase cancer detection.
  
  
  METHODS
  We analysed 67 tissue samples using spectral analysis. The WavSTAT (Spectra Science) optical biopsy device was used to record fluorescence spectra from biopsied tissue enabling calculation of an AUC for each spectrum, a measure of the mean spectral wavelength (λ¯ (nm)) and a dimensionless fluorescence ratio. Mann-Whitney test was used to compare the two groups.
  
  
  RESULTS
  We found that 49.3% (33/67) of the tissue was benign, 44.8% (30/67) was CIS/cancerous tissue, and the remaining 4/67 samples were atypia (2) and dysplasia (2). The median AUC for the benign tissue was 19.53 (interquartile range [IQR]: 5.35-30.39) and that for CIS/cancerous tissue was 7.05 (IQR: 2.89-14.24) (P=0.002). The median wavelengths for the benign tissue and malignant tissue were 502.4nm (IQR: 500.3-504.3nm) and 505.2nm (IQR: 502.1-513.2nm), respectively (P=0.003). The median fluorescence ratio was 0.080 (IQR: 0.070-0.088) for benign tissue and 0.096 (IQR: 0.079-0.221) for CIS/cancerous tissue (P=0.002).
  
  
  CONCLUSIONS
  We found statistical differences between the median AUC calculations and median wavelengths for the benign and cancerous tissue. We also found a statistical difference between the fluorescence ratios between the two tissue types. There seems to be a role for optical spectroscopy in verifying bladder lesions.
authors.affiliation: Department of Urology, Ninewells Hospital and Medical School, Dundee, UK; Department of Urology, Royal Gwent Hospital, Newport, Wales, UK; Islamic Universities of Gaza, College of Medicine, Gaza, Palestine. Electronic address: aboumarzouk@gmail.com.
authors.forename: Omar
authors.initials: O
authors.lastname: Aboumarzouk
authors.affiliation: The Photobiology Unit, University of Dundee, Ninewells Hospital & Medical School, Dundee, UK; The Scottish Photodynamic Therapy Centre, Ninewells Hospital & Medical School, Dundee, UK.
authors.forename: Ronan
authors.initials: R
authors.lastname: Valentine
authors.affiliation: The Photobiology Unit, University of Dundee, Ninewells Hospital & Medical School, Dundee, UK; The Scottish Photodynamic Therapy Centre, Ninewells Hospital & Medical School, Dundee, UK.
authors.forename: Ron
authors.initials: R
authors.lastname: Buist
authors.affiliation: Department of Urology, Ninewells Hospital and Medical School, Dundee, UK.
authors.forename: Sarfraz
authors.initials: S
authors.lastname: Ahmad
authors.affiliation: Academic Urology Unit of the Medical Research Institute of University of Dundee, UK.
authors.forename: Ghulam
authors.initials: G
authors.lastname: Nabi
authors.affiliation: The Photobiology Unit, University of Dundee, Ninewells Hospital & Medical School, Dundee, UK.
authors.forename: Sam
authors.initials: S
authors.lastname: Eljamel
authors.affiliation: The Photobiology Unit, University of Dundee, Ninewells Hospital & Medical School, Dundee, UK; The Scottish Photodynamic Therapy Centre, Ninewells Hospital & Medical School, Dundee, UK.
authors.forename: Harry
authors.initials: H
authors.lastname: Moseley
authors.affiliation: Department of Urology, Ninewells Hospital and Medical School, Dundee, UK.
authors.forename: Slawomir Grzegorz
authors.initials: SG
authors.lastname: Kata
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D007834:Lasers; D008875:Middle Aged; D061848:Optical Imaging / Q000379:methods*; D017319:Photosensitizing Agents / Q000032:analysis; D011524:Protoporphyrins / Q000032:analysis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence / Q000379:methods*; D001749:Urinary Bladder Neoplasms / Q000737:chemistry / Q000175:diagnosis*
chemical_list: D017319:Photosensitizing Agents; D011524:Protoporphyrins; C028025:protoporphyrin IX
keywords: Autofluorescence; Bladder cancer; Laser; Optical biopsy; Optical spectrometry; Spectroscopy