title: Thallium-201 versus technetium-99m-MIBI SPECT in evaluation of childhood brain tumors: a within-subject comparison.
abstract: We previously found that 201TI SPECT is a highly specific agent for detection of metabolic activity of childhood brain tumors. To compare the relative diagnostic accuracy of 201TI and a technetium-based tumor-avid agent, we have obtained SPECT in 19 children using 201TI (37-111 MBq) followed immediately by 99mTc-methoxyisobutylisonitrile (MIBI) (370-740 MBq) intravenously. Moderate to intense focal uptake of both tracers characterized true positive cases (n = 6). Lesion boundaries were better defined by MIBI. Uptake of MIBI by choroid plexus occurred despite pretreatment with potassium perchlorate (6 mg/kg) and complicated interpretation of deep/paraventricular lesions. Preliminary assessment indicated sensitivity approximately 67% (TI and MIBI); specificity approximately 91% (TI); approximately 100% (MIBI). Two tumors (medulloblastoma, dysgerminoma) were TI/MIBI nonavid. Semi-quantitative assessment of tracer uptake was made using a ratio of radioactivity in tumor-containing areas compared to uninvolved brain. Ratio values were (mean +/- s.d.) 7.88 +/- 7.70 (TI) and 27.1 +/- 36.41 (MIBI). The spectrum of tumor avidity is similar for TI and MIBI. Clearer identification of boundaries by MIBI may be an advantage in applications, e.g., radiotherapy port planning.
authors.affiliation: Department of Radiology Division of Nuclear Medicine, Children's Hospital, Boston, MA 02115.
authors.forename: L A
authors.initials: LA
authors.lastname: O'Tuama
authors.forename: S T
authors.initials: ST
authors.lastname: Treves
authors.forename: J N
authors.initials: JN
authors.lastname: Larar
authors.forename: A B
authors.initials: AB
authors.lastname: Packard
authors.forename: A J
authors.initials: AJ
authors.lastname: Kwan
authors.forename: P D
authors.initials: PD
authors.lastname: Barnes
authors.forename: R M
authors.initials: RM
authors.lastname: Scott
authors.forename: P M
authors.initials: PM
authors.lastname: Black
authors.forename: J R
authors.initials: JR
authors.lastname: Madsen
authors.forename: L C
authors.initials: LC
authors.lastname: Goumnerova
mesh_terms: D001932:Brain Neoplasms / Q000175:diagnosis / Q000000981:diagnostic imaging*; D002648:Child; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis / Q000000981:diagnostic imaging*; D012680:Sensitivity and Specificity; D017256:Technetium Tc 99m Sestamibi; D013794:Thallium Radioisotopes; D015899:Tomography, Emission-Computed, Single-Photon; D014057:Tomography, X-Ray Computed
chemical_list: D013794:Thallium Radioisotopes; D017256:Technetium Tc 99m Sestamibi