title: MR characterization of brain and brain tumor response to radiotherapy.
abstract: This paper describes our experience in using the T1 and T2 relaxation times for quantitative evaluation of brain and brain tumor response to radiation therapy. Twenty-two computed T1 and 22 computed T2 images were obtained from 66 routine inversion-recovery and spin-echo magnetic resonance (MR) brain scans. The relaxation times of the brain tissues, determined from the computed images, were examined as a function of the absorbed dose. Statistical evaluation of the results showed no significant difference between the relaxation times of irradiated and not irradiated tissues, including tumor and normal white matter. Influence of the magnetic field strength and imaging techniques on the computed T1 and T2 values was confirmed. We conclude that the relaxation time values, as obtained today using conventional MR scanner and standard software, are not specific enough to warrant a correct assessment of the acute radiation effect on the brain tissues.
authors.affiliation: Department of Radiation Oncology, University of Miami School of Medicine, FL.
authors.forename: P V
authors.initials: PV
authors.lastname: Houdek
authors.forename: H J
authors.initials: HJ
authors.lastname: Landy
authors.forename: R M
authors.initials: RM
authors.lastname: Quencer
authors.forename: W
authors.initials: W
authors.lastname: Sattin
authors.forename: C A
authors.initials: CA
authors.lastname: Poole
authors.forename: B A
authors.initials: BA
authors.lastname: Green
authors.forename: C A
authors.initials: CA
authors.lastname: Harmon
authors.forename: V
authors.initials: V
authors.lastname: Pisciotta
authors.forename: J G
authors.initials: JG
authors.lastname: Schwade
mesh_terms: D000293:Adolescent; D000328:Adult; D001921:Brain / Q000528:radiation effects*; D001932:Brain Neoplasms / Q000532:radiotherapy*; D002648:Child; D006801:Humans; D008279:Magnetic Resonance Imaging; D008875:Middle Aged