[(18)F]FET-PET in children and adolescents with central nervous system tumors: does it support difficult clinical decision-making?

PURPOSE: Positron emission tomography (PET) with O-(2-[(18)F]fluoroethyl)-L-tyrosine ([(18)F]FET) is a well-established tool for non-invasive assessment of adult central nervous system (CNS) tumors. However, data on its diagnostic utility and impact on clinical management in children and adolescents are limited. METHODS: Twenty-one children and young adults (13 males; mean age, 8.6 ± 5.2 years; range, 1–19 at initial diagnosis) with either newly diagnosed (n = 5) or pretreated (n = 16) CNS tumors were retrospectively analyzed. All patients had previously undergone neuro-oncological work-up including cranial magnetic resonance imaging. In all cases, [(18)F]FET-PET was indicated in a multidisciplinary team conference. The impact of PET imaging on clinical decision-making was assessed. Histopathology (n = 12) and/or clinical and imaging follow-up (n = 9) served as the standard of reference. RESULTS: The addition of [(18)F]FET-PET to the available information had an impact on further patient management in 14 out of 21 subjects, with avoidance of invasive surgery or biopsy in four patients, biopsy guidance in four patients, change of further treatment in another five patients, and confirmation of diagnosis in one patient. CONCLUSION: [(18)F]FET-PET may provide important additional information for treatment guidance in pediatric and adolescent patients with CNS tumors. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00259-023-06114-6.