OBJECT The aim of the study was to document postoperative cerebral glucose 
distribution before proton therapy using F-18 fluorodeoxyglucose positron 
emission tomography (FDG PET) in children with craniopharyngioma. METHODS 
Between August 2011 and April 2014, 50 patients (20 males, 30 females) enrolled 
in a prospective trial for craniopharyngioma underwent FDG PET imaging before 
proton therapy. Proton therapy was delivered using doublescattered beams with a 
total prescribed dose of 54 cobalt gray equivalent. Tracer uptake in each of 63 
anatomical regions was computed after warping PET images to a 3D reference 
template in Talairach coordinates. Regional uptake was deemed significantly low 
or high if it exceeded age-corresponding 95% prediction intervals of the normal 
population. The reference group included 132 children with non-CNS-related 
diseases and normal-appearing cerebral FDG PET scans. RESULTS Median patient age 
at diagnosis was 8.5 years (range 2-18 years). Forty-eight patients underwent 
1-4 tumor-related surgeries before proton therapy, including placement of an 
Ommaya reservoir in 14 patients. Sixteen patients had symptomatic hydrocephalus 
that was treated with temporary (external ventricular drain, n = 16) or 
permanent CSF shunting (ventriculoperitoneal shunt, n = 1). The most commonly 
seen PET abnormalities in patients before proton therapy were significantly 
reduced uptake in subregions of the frontal lobe (often involving more than 1 
gyrus), medial and ventral portions of the temporal lobe, cingulate gyrus, and 
caudate nucleus. A significantly high uptake was frequently observed on the 
contralateral side, including the superior, medial, and inferior temporal gyri 
and a large portion of the parietal lobe. Statistically significant predictor 
variables identified in the multivariate analysis for the extent of 
hypometabolism were sex (p = 0.005), hydrocephalus (p = 0.026), and the number 
of tumor-related surgeries (p = 0.017). CONCLUSIONS Postoperative FDG PET of 
patients with craniopharyngioma revealed metabolic abnormalities in specific 
regions of the brain. The ability to identify anatomical metabolic defects in 
individual patients facilitates the investigation of brain injury in children 
with craniopharyngioma.