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

Thallium-201 chloride single photon emission computed tomography (Tl-2 01 SPECT) has been proposed as a diagnostic tool in the assessment of patients with brain tumors. We performed SPECT scans coupled with magn etic resonance imaging (MRI) in children with brain tumors to determin e 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-20 1 uptake was imaged with triple-headed SPECT in 20/24 (83%) histologic ally and anatomically diverse neoplasms with MRI-measurable residual d isease, including 13/16 (80%) posterior fossa tumors. Tl-201 SPECT dem onstrated 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 fe atures: gadolinium enhancement, necrosis, exophytic, unicentric and mu lticentric. Tl-201 uptake was not detectable in patients with tumors o f maldevelopmentaI origin or radionecrosis. It is suggested that Tl-20 1 SPECT is an important imaging adjunct in the assessment of children with brain tumors.