MONITORING TUMOR-ACTIVITY IN LOW-GRADE GLIOMA OF CHILDHOOD

Chemotherapeutic or radiotherapeutic regimens are being increasingly u sed in low grade glioma of childhood. These protocols require methods to monitor tumor activity. We report our experience in eleven patients . The tumors were localized in the optic pathway (3), cerebral cortex (4) and thalamus/hypothalamus (4). Histological diagnoses included low grade astrocytoma (6), gliofibroma (1) and ganglioglioma (2). Two chi ldren with neurofibromatosis type 1 (NF-1) and typical optical tumors were not biopsied. 13 episodes of progression were noted including 3 a ltered diagnoses. This was evident from clinical symptoms in 11/13 epi sodes, computed tomography (CT) or magnetic resonance imaging (MRI) in 10/13 situations, iodine-123-alpha-methyltyrosine (I-123-IMT) single- photon emission computed tomography (SPECT) in 10/10 situations, fluor ine-18 fluorodesoxyglucose (F-18-FDG) positron emission tomography (PE T) in 0/3 and thallium-201 (Tl-201) SPECT in 1/1. Seven responses to c hemotherapy were recorded. Clinical symptoms indicated this in 7/7 sit uations, MRI in 5/7, I-123-IMT SPECT in 1/2 and Tl-201 SPECT in 1/1. T hese data suggest that I-123-LMT SPECT is a valuable addition to low g rade glioma diagnostic and stress the need for a prospective study.