VALUE OF TL-201 SPECT IMAGING IN CHILDHOOD BRAIN-TUMORS

Thallium-201 chloride single photon emission computed tomography (Tl-201 SPECT) has been proposed as a diagnostic tool in the assessment of patients with brain tumors. We performed SPECT scans coupled with magnetic resonance imaging (MRI) in children with brain tumors to determine the sensitivity and potential value of SPECT in neuro-oncology. Each patient was injected with 2.5-3.0 mCi of thallium chloride, followed by technetium-99m HMPAO (5-15 mCi) to assess cerebral perfusion. Tl-201 uptake was imaged with triple-headed SPECT in 20/24 (83%) histologically and anatomically diverse neoplasms with MRI-measurable residual disease, including 13/16 (80%) posterior fossa tumors. Tl-201 SPECT demonstrated uptake in tumors with MRI volumes ranging from 0.03 to 60 cm(3). Tl-201 SPECT imaging was not correlated with the following MRI features: gadolinium enhancement, necrosis, exophytic, unicentric and multicentric. Tl-201 uptake was not detectable in patients with tumors of maldevelopmentaI origin or radionecrosis. It is suggested that Tl-201 SPECT is an important imaging adjunct in the assessment of children with brain tumors.