title: Laser-induced fluorescence: experimental intraoperative delineation of tumor resection margins.
abstract: The ability of laser-induced fluorescence spectroscopy to delineate tumor margins intraoperatively was studied using a rat intracerebral glioma model. A fluorescent dye, chloro-aluminum phthalocyanine tetrasulfonate (ClAlPcS4), was injected intravenously 24 hours before tumor resection. The animals underwent tumor resection under the operating microscope, guided by laser-induced fluorescence measurement in one group (Group 1) and visual assessment in the other (Group 2). The Group 1 rats had a significantly reduced volume of residual tumor following resection (0.5 +/- 0.2 cu mm vs. 13.7 +/- 4.0 cu mm, mean +/- standard error of the mean, p less than 0.02). Three of the nine animals in Group 1 were tumor-free at 2 weeks following resection, compared with none of the 10 rats in Group 2 (p less than 0.05). Interference from brain autofluorescence was minimized using spectrally resolved detection and the ClAlPcS4 dye, which has a 680-nm fluorescence peak significantly higher than the 470-nm autofluorescence peak of normal brain. Contrast ratios of up to 40:1 were found for glioma:normal brain fluorescence signals. Spatially-resolved spectra were acquired in approximately 5 seconds using a fiberoptic probe. This study demonstrates the ability of an intraoperative laser-induced fluorescence system to detect tumor margins that could not be identified with the operating microscope.
authors.affiliation: Department of Surgery (Neurosurgery), Massachusetts General Hospital, Harvard Medical School, Boston.
authors.forename: W S
authors.initials: WS
authors.lastname: Poon
authors.forename: K T
authors.initials: KT
authors.lastname: Schomacker
authors.forename: T F
authors.initials: TF
authors.lastname: Deutsch
authors.forename: R L
authors.initials: RL
authors.lastname: Martuza
mesh_terms: D000818:Animals; D001932:Brain Neoplasms / Q000473:pathology / Q000601:surgery*; D005456:Fluorescent Dyes / Q000493:pharmacokinetics; D005910:Glioma / Q000473:pathology / Q000601:surgery*; D007211:Indoles / Q000493:pharmacokinetics; D007834:Lasers; D008297:Male; D009942:Organometallic Compounds / Q000493:pharmacokinetics; D051381:Rats; D011916:Rats, Inbred F344; D013050:Spectrometry, Fluorescence / Q000379:methods*
chemical_list: D005456:Fluorescent Dyes; D007211:Indoles; D009942:Organometallic Compounds; C052736:chloroaluminum tetrasulfophthalocyanine