Proton magnetic resonance spectroscopic imaging in children with recurrentprimary brain tumors

Purpose: Proton magnetic resonance spectroscopic imaging (H-1-MRSI) is a no ninvasive technique for spatial characterization of biochemical markers in tissues. We measured the relative tumor concentrations of these biochemical markers in children with recurrent brain tumors and evaluated their potent ial prognostic significance. Patients and Methods: H-1-MRSI was performed on 27 children with recurrent primary brain tumors referred to our institution for investigational drug t rials, Diagnoses included high-grade glioma (n = 10), brainstem glioma (n = 7), medulloblastoma/peripheral neuroectodermal tumor (n = 6), ependymoma ( n = 3), and pineal germinoma (n = 1). H-1-MRSI was performed on 1.5-T magne tic resonance imagers before treatment. The concentrations of choline (Cho) and N-acetyl-aspartate (NAA) in the tumor and normal brain were quantified using a multislice multivoxel method, and the maximum Cho:NAA ratio was de termined for each patient's tumor. Results: The maximum Cho:NAA ratio ranged from 1.1 to 13.2 (median, 4.5); t he Cho:NAA ratio in areas of normal-appearing brain tissue was less than 1. 0, The maximum Cho:NAA ratio for each histologic subtype varied considerabl y; approximately equal numbers of patients within each tumor type had maxim um Cho: NAA ratios above and below the median. Patients with a maximum Cho: NAA ratio greater than 4.5 had a median survival of 22 weeks, and all 13 pa tients died by 63 weeks. Patients with a Cho:NAA ratio less than or equal t o 4.5 had a projected survival of more than 50% at 63 weeks. The difference was statistically significant (P = .0067, log-rank test). Conclusion: The maximum tumor Cho:NAA ratio seems to be predictive of outco me in children with recurrent primary brain tumors and should be evaluated as a prognostic indicator in newly diagnosed childhood brain tumors. J Clin Oncol 18:1020-1026, (C) 2000 by American Society of Clinical Oncology.