title: Spectral fluorescence lifetime detection and selective melanin imaging by multiphoton laser tomography for melanoma diagnosis.
abstract: Multiphoton excited tissue fluorescence summarises the emission of all naturally occurring endogenous fluorescent bio-molecules with their often overlapping fluorescence spectra. Common fluorescence intensity measurements could not be utilised to distinguish between different fluorophores or metabolic states. To overcome this limitation, we investigated new procedures of selective melanin imaging and spectral fluorescence lifetime imaging in combination with high resolution multiphoton laser tomography. Overall 46 melanocytic lesions of human skin were analysed. We suggested that fluorescence light, detected in such a way, may yield additional information for melanoma diagnostics. Remarkable differences in lifetime behaviour of keratinocytes in contrast to melanocytes were observed. Fluorescence lifetime distribution was found in correlation with the intracellular amount of melanin. Spectral analysis of melanoma revealed a main fluorescence peak around 470 nm in combination with an additional peak close to 550 nm throughout all epidermal layers. Excitation at 800 nm shows a selectively observable fluorescence of melanin containing cells and offers the possibility of cell classification. Procedures of selective imaging as well as spectral fluorescence lifetime imaging by means of multiphoton laser tomography support diagnostic decisions and may improve the process of non-invasive early detection of melanoma.
authors.affiliation: Department of Dermatology and Allergology, University Hospital, Jena, Germany.
authors.forename: Enrico
authors.initials: E
authors.lastname: Dimitrow
authors.forename: Iris
authors.initials: I
authors.lastname: Riemann
authors.forename: Alexander
authors.initials: A
authors.lastname: Ehlers
authors.forename: Martin Johannes
authors.initials: MJ
authors.lastname: Koehler
authors.forename: Johannes
authors.initials: J
authors.lastname: Norgauer
authors.forename: Peter
authors.initials: P
authors.lastname: Elsner
authors.forename: Karsten
authors.initials: K
authors.lastname: König
authors.forename: Martin
authors.initials: M
authors.lastname: Kaatz
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003937:Diagnosis, Differential; D004867:Equipment Design; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods; D008297:Male; D008543:Melanins / Q000032:analysis* / Q000737:chemistry; D008545:Melanoma / Q000175:diagnosis*; D018613:Microscopy, Confocal / Q000295:instrumentation / Q000379:methods*; D036641:Microscopy, Fluorescence, Multiphoton / Q000295:instrumentation / Q000379:methods*; D008875:Middle Aged; D009508:Nevus, Pigmented / Q000175:diagnosis*; D012680:Sensitivity and Specificity; D012878:Skin Neoplasms / Q000175:diagnosis*; D013050:Spectrometry, Fluorescence / Q000379:methods*; D014054:Tomography / Q000295:instrumentation / Q000379:methods*; D055815:Young Adult
chemical_list: D008543:Melanins