Abstract
Thirteen children (1.8-15.8 years of age) with brain tumors were studied with [11C]l-methionine positron emission tomography (METPET). Patients were injected intravenously with tracer before a baseline PET scan was obtained. To assess the sensitivity of [11C]l-methionine uptake to competitive inhibition, 10 patients received oral l-phenylalanine (100 mg/kg); 1 hour later, a second METPET was obtained. Subjective assessment of [11C]l-methionine uptake closely paralleled results of quantitative examination (r = 0.81). [11C]l-methionine uptake in tumor-containing brain was increased in 11 patients (mean ratio of [11C] radioactivity in tumor to normal brain: 1.5 ± 0.57; range: 1.13-2.98). Increased tracer uptake occurred in ependymomas (3), medulloblastoma (1), and astrocytomas (5), but was less intense in low-grade tumors. l-phenylalanine reduced l-methionine uptake (25-69%) in 70% of studies. l-methionine uptake was not sensitive to competitive inhibition in brain radiation injury. Two-phase METPET is of potential value in difficult clinical situations evident in children with brain tumors, including the differential diagnosis of tumor recurrence and cerebral radiation injury.
Original language | English (US) |
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Pages (from-to) | 163-170 |
Number of pages | 8 |
Journal | Pediatric Neurology |
Volume | 6 |
Issue number | 3 |
DOIs | |
State | Published - 1990 |
ASJC Scopus subject areas
- Pediatrics, Perinatology, and Child Health
- Neurology
- Developmental Neuroscience
- Clinical Neurology