Brain and brain tumor uptake of L-3-(123I)iodo-alpha-methyl tyrosine: competition with natural L-amino acids

Journal Article · Sat Jun 01 00:00:00 EDT 1991 · Journal of Nuclear Medicine; (United States)

OSTI ID:5594452

Langen, K J; Roosen, N; Coenen, H H; Kuikka, J T; Kuwert, T; Herzog, H; Stoecklin, G F; Feinendegen, L E ^[1]

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1. Institute of Medicine, Research Center Juelich (Germany)

SPECT studies with L-3-(123I)iodo-alpha-methyl tyrosine (IMT) were carried out in 10 patients with different types of brain tumors--first under fasting conditions (basal) and a week later during intravenous infusion of a mixture of naturally-occurring L-amino acids (AA load). An uptake index (UI) was calculated by dividing tissue count rates by the integral of plasma count rates. The UI decreased by 45.6% {plus minus} 15.4% (n = 10, p less than 0.001) for normal brain and by 53.2% {plus minus} 14.1% for gliomas (n = 5, p less than 0.01) during AA load compared to basal conditions, while two meningiomas and a metastasis showed only a minor decrease (23.9 {plus minus} 5.7%, n.s.). Two pituitary adenomas could not be delineated on the SPECT scans. These data indicate that IMT competes with naturally-occurring L-amino acids for transport into normal brain and gliomas. Transport characteristics of IMT into tumors of nonglial origin appear to be different from those of gliomas. For both types of tumors, it is advisable to perform IMT-SPECT under fasting conditions.

• OSTI ID: 5594452
• Journal Information: Journal of Nuclear Medicine; (United States), Journal Name: Journal of Nuclear Medicine; (United States) Vol. 32:6; ISSN 0161-5505; ISSN JNMEA
• Country of Publication: United States
• Language: English

Related Subjects

550601* -- Medicine-- Unsealed Radionuclides in Diagnostics
62 RADIOLOGY AND NUCLEAR MEDICINE
AMINO ACIDS
BETA DECAY RADIOISOTOPES
BODY
BRAIN
CARBOXYLIC ACIDS
CENTRAL NERVOUS SYSTEM
COMPUTERIZED TOMOGRAPHY
DIAGNOSIS
DIAGNOSTIC TECHNIQUES
DISEASES
DRUGS
ELECTRON CAPTURE RADIOISOTOPES
EMISSION COMPUTED TOMOGRAPHY
FASTING
HOURS LIVING RADIOISOTOPES
INTERMEDIATE MASS NUCLEI
IODINE 123
IODINE ISOTOPES
ISOTOPES
LABELLED COMPOUNDS
MEMBRANE TRANSPORT
NEOPLASMS
NERVOUS SYSTEM
NUCLEI
ODD-EVEN NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANS
PATIENTS
RADIOISOTOPES
RADIOPHARMACEUTICALS
SINGLE PHOTON EMISSION COMPUTED TOMOGRAPHY
TOMOGRAPHY
UPTAKE