[Clinical value of amino acid imaging in paediatric brain tumours. Comparison with MRI].
OBJECTIVE
To evaluate single photon emission computed tomography (SPECT) using the amino acid l-3-[123I]-alpha-methyl tyrosine (IMT) and contrast enhanced magnetic resonance imaging (MRI) as diagnostic tools in primary paediatric brain tumours in respect of non-invasive tumour grading. Patients, materials, methods: 45 children with primary brain tumours were retrospectively evaluated. IMT uptake was quantified as tumour/nontumour-ratio, a 4-value-scale was used to measure gadolinium enhancement on contrast enhanced MRI. Statistical analyses were performed to evaluate IMT uptake and gadolinium enhancement in low (WHO I/II) and high (WHO III/IV) grade tumours and to disclose a potential relationship of IMT uptake to disruption of blood brain barrier as measured in corresponding MRI scans.


RESULTS
IMT uptake above background level was observed in 35 of 45 patients. IMT uptake was slightly higher in high grade tumours but the difference failed to attain statistical significance. Grading of individual tumours was neither possible by IMT SPECT nor by gadolinium enhanced MRI.


CONCLUSIONS
IMT is accumulated in most brain tumours in children. Tumour grading was not possible using IMT or contrast enhancement as determined by MRI. Neither morphological nor functional imaging can replace histology in paediatric brain tumours.
Lang
K
K
Leitender Oberarzt, Klinik und Poliklinik für Nuklearmedizin, Westfälische Wilhelms-Universität, Albert-Schweitzer-Str. 33, 48149 Münster. m.weckesser@uni-muenster.de
Kloska
S
S
Straeter
R
R
Rickert
C H
CH
Goder
G
G
Kurlemann
G
G
Brentrup
A
A
Schober
O
O
Weckesser
M
M
D000293:Adolescent; D000596:Amino Acids; D001932:Brain Neoplasms / Q000145:classification / Q000175:diagnosis* / Q000000981:diagnostic imaging; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D049268:Positron-Emission Tomography; D015899:Tomography, Emission-Computed, Single-Photon
D000596:Amino Acids