title: Protoporphyrin IX fluorescence contrast in invasive glioblastomas is linearly correlated with Gd enhanced magnetic resonance image contrast but has higher diagnostic accuracy.
abstract: The sensitivity and specificity of in vivo magnetic resonance (MR) imaging is compared with production of protoporphyrin IX (PpIX), determined ex vivo, in a diffusely infiltrating glioma. A human glioma transfected with green fluorescent protein, displaying diffuse, infiltrative growth, was implanted intracranially in athymic nude mice. Image contrast from corresponding regions of interest (ROIs) in in vivo MR and ex vivo fluorescence images was quantified. It was found that all tumor groups had statistically significant PpIX fluorescence contrast and that PpIX contrast demonstrated the best predictive power for tumor presence. Contrast from gadolinium enhanced T1-weighted (T1W+Gd) and absolute T2 images positively predicted the presence of a tumor, confirmed by the GFP positive (GFP+) and hematoxylin and eosin positive (H&E+) ROIs. However, only the absolute T2 images had predictive power from controls in ROIs that were GFP+ but H&E negative. Additionally, PpIX fluorescence and T1W+Gd image contrast were linearly correlated in both the GFP+ (r = 0.79, p<1×10(-8)) and H&E+ (r = 0.74, p<0.003) ROIs. The trace diffusion images did not have predictive power or significance from controls. This study indicates that gadolinium contrast enhanced MR images can predict the presence of diffuse tumors, but PpIX fluorescence is a better predictor regardless of tumor vascularity.
authors.affiliation: Dartmouth College, Thayer School of Engineering, Hanover New Hampshire 03755, USA. Kimberley.Samkoe@Dartmouth.edu
authors.forename: Kimberley S
authors.initials: KS
authors.lastname: Samkoe
authors.forename: Summer L
authors.initials: SL
authors.lastname: Gibbs-Strauss
authors.forename: Harold H
authors.initials: HH
authors.lastname: Yang
authors.forename: S
authors.initials: S
authors.lastname: Khan Hekmatyar
authors.forename: P
authors.initials: P
authors.lastname: Jack Hoopes
authors.forename: Julia A
authors.initials: JA
authors.lastname: O'Hara
authors.forename: Risto A
authors.initials: RA
authors.lastname: Kauppinen
authors.forename: Brian W
authors.initials: BW
authors.lastname: Pogue
mesh_terms: D000622:Aminolevulinic Acid / Q000737:chemistry; D000818:Animals; D019540:Area Under Curve; D045744:Cell Line, Tumor; D004058:Diffusion; D005682:Gadolinium / Q000737:chemistry*; D005909:Glioblastoma / Q000737:chemistry* / Q000378:metabolism; D006651:Histocytochemistry; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D051379:Mice; D008819:Mice, Nude; D011524:Protoporphyrins / Q000737:chemistry*; D012372:ROC Curve; D013050:Spectrometry, Fluorescence / Q000379:methods*
chemical_list: D011524:Protoporphyrins; D000622:Aminolevulinic Acid; D005682:Gadolinium; C028025:protoporphyrin IX