title: Various shades of red-a systematic analysis of qualitative estimation of ALA-derived fluorescence in neurosurgery.
abstract: 5-Aminolevulinic acid (5-ALA)-fluorescence-guided resection is well established in many neuro-oncologic centers. Different classifications of 5-ALA-induced fluorescence have been reported. The aim of the systematic analysis was to evaluate the frequency of graduations, definitions, and designations of 5-ALA-induced fluorescence qualities. A systematic database search of PubMed was performed to identify studies reporting (1) on 5-ALA fluorescence-guided either spinal or cranial surgery, (2) on qualitative estimation and/or categorization of 5-ALA-induced fluorescence, (3) in English, and (4) were published as peer-reviewed original studies. Totally, 93 studies were identified. Different classification systems of 5-ALA-induced fluorescence were found. Over 60 % of the included studies used a dichotomized categorization of 5-ALA-induced fluorescence and 27.5 % of studies distinguished two different intensities of 5-ALA fluorescent tissue in addition to non-fluorescing tissue. More than 50 % of studies explicitly defined criteria for categorization of 5-ALA-induced fluorescence. The major limitation of the present analysis might be that it mainly comprises data from retrospective, uncontrolled, non-randomized trials. However, a precise definition of each 5-ALA-induced fluorescence quality is essential. Although dichotomized classification is the most common and simple graduation system, it may not be suitable for every clinical or scientific task. A three-level 5-ALA-induced fluorescence classification with precise definition of each fluorescence quality and their correlation with histological features would be more useful and reproducible in these cases.
authors.affiliation: Department of Neurosurgery, Medical Faculty, Heinrich Heine University Düsseldorf, Moorenstraße 5, 40225, Düsseldorf, Germany. marcelalexander.kamp@med.uni-duesseldorf.de.
authors.forename: Marcel A
authors.initials: MA
authors.lastname: Kamp
authors.affiliation: Department of Neurosurgery, Medical Faculty, Heinrich Heine University Düsseldorf, Moorenstraße 5, 40225, Düsseldorf, Germany.
authors.forename: Zarela
authors.initials: Z
authors.lastname: Krause Molle
authors.affiliation: Department of Neurosurgery, Medical Faculty, Heinrich Heine University Düsseldorf, Moorenstraße 5, 40225, Düsseldorf, Germany.
authors.forename: Christopher
authors.initials: C
authors.lastname: Munoz-Bendix
authors.affiliation: Department of Neurosurgery, Medical Faculty, Heinrich Heine University Düsseldorf, Moorenstraße 5, 40225, Düsseldorf, Germany.
authors.forename: Marion
authors.initials: M
authors.lastname: Rapp
authors.affiliation: Department of Neurosurgery, Medical Faculty, Heinrich Heine University Düsseldorf, Moorenstraße 5, 40225, Düsseldorf, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Sabel
authors.affiliation: Department of Neurosurgery, Medical Faculty, Heinrich Heine University Düsseldorf, Moorenstraße 5, 40225, Düsseldorf, Germany.
authors.forename: Hans-Jakob
authors.initials: HJ
authors.lastname: Steiger
authors.affiliation: Department of Neurosurgery, Medical Faculty, Heinrich Heine University Düsseldorf, Moorenstraße 5, 40225, Düsseldorf, Germany. Cornelius@med.uni-duesseldorf.de.
authors.forename: Jan F
authors.initials: JF
authors.lastname: Cornelius
mesh_terms: D001932:Brain Neoplasms / Q000145:classification / Q000601:surgery*; D003116:Color; D005069:Evaluation Studies as Topic; D005453:Fluorescence; D005456:Fluorescent Dyes; D005910:Glioma / Q000145:classification / Q000601:surgery*; D006801:Humans; D007982:Levulinic Acids; D019635:Neurosurgical Procedures / Q000379:methods*; D012189:Retrospective Studies; D013120:Spinal Cord Neoplasms / Q000145:classification / Q000601:surgery*; D000622:Aminolevulinic Acid
chemical_list: D005456:Fluorescent Dyes; D007982:Levulinic Acids; D000622:Aminolevulinic Acid
keywords: 5-ALA fluorescence; Glioma; Meningioma; Metastases; Spinal