The usefulness of dynamic O-(2-18F-fluoroethyl)-L-tyrosine PET in the clinical evaluation of brain tumors in children and adolescents
Veronika Dunkl, Corvin Cleff, Gabriele Stoffels, Natalie Judov, Sevgi Sarikaya-Seiwert, Ian Law, Lars Bøgeskov, Karsten Nysom, Sofie B Andersen, Hans-Jakob Steiger, Gereon R Fink, Guido Reifenberger, Nadim J Shah, Heinz H Coenen, Karl-Josef Langen, Norbert Galldiks, Veronika Dunkl, Corvin Cleff, Gabriele Stoffels, Natalie Judov, Sevgi Sarikaya-Seiwert, Ian Law, Lars Bøgeskov, Karsten Nysom, Sofie B Andersen, Hans-Jakob Steiger, Gereon R Fink, Guido Reifenberger, Nadim J Shah, Heinz H Coenen, Karl-Josef Langen, Norbert Galldiks
Abstract
Experience regarding O-(2-(18)F-fluoroethyl)-L-tyrosine ((18)F-FET) PET in children and adolescents with brain tumors is limited.
Methods: Sixty-nine (18)F-FET PET scans of 48 children and adolescents (median age, 13 y; range, 1-18 y) were analyzed retrospectively. Twenty-six scans to assess newly diagnosed cerebral lesions, 24 scans for diagnosing tumor progression or recurrence, 8 scans for monitoring of chemotherapy effects, and 11 scans for the detection of residual tumor after resection were obtained. Maximum and mean tumor-to-brain ratios (TBRs) were determined at 20-40 min after injection, and time-activity curves of (18)F-FET uptake were assigned to 3 different patterns: constant increase; peak at greater than 20-40 min after injection, followed by a plateau; and early peak (≤ 20 min), followed by a constant descent. The diagnostic accuracy of (18)F-FET PET was assessed by receiver-operating-characteristic curve analyses using histology or clinical course as a reference.
Results: In patients with newly diagnosed cerebral lesions, the highest accuracy (77%) to detect neoplastic tissue (19/26 patients) was obtained when the maximum TBR was 1.7 or greater (area under the curve, 0.80 ± 0.09; sensitivity, 79%; specificity, 71%; positive predictive value, 88%; P = 0.02). For diagnosing tumor progression or recurrence, the highest accuracy (82%) was obtained when curve patterns 2 or 3 were present (area under the curve, 0.80 ± 0.11; sensitivity, 75%; specificity, 90%; positive predictive value, 90%; P = 0.02). During chemotherapy, a decrease of TBRs was associated with a stable clinical course, and in 2 patients PET detected residual tumor after presumably complete tumor resection.
Conclusion: Our findings suggest that (18)F-FET PET can add valuable information for clinical decision making in pediatric brain tumor patients.
Keywords: FET PET; children; contrast-enhanced MRI; glioma; kinetic pattern of 18FF-FET uptake; metabolic imaging.
© 2015 by the Society of Nuclear Medicine and Molecular Imaging, Inc.
Source: PubMed