The clinical impact of 18F-FDG PET/CT in extracranial pediatric germ cell tumors.

Abstract

Extracranial germ cell tumors are an uncommon pediatric malignancy with limited information on the clinical impact of 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in the literature. The purpose of this study was to evaluate and compare the clinical impact on management of 18F-FDG PET/CT with diagnostic computed tomography (CT) in pediatric extracranial germ cell tumor. The list of 18F-FDG PET/CT performed for extracranial germ cell tumor between May 2007 and November 2015 was obtained from the nuclear medicine database. 18F-FDG PET/CT and concurrent diagnostic CT were obtained and independently reviewed. Additionally, the patients' charts were reviewed for duration of follow-up and biopsy when available. The impact of 18F-FDG PET/CT compared with diagnostic CT on staging and patient management was demonstrated by chart review, imaging findings and follow-up studies. During the study period, 9 children (5 males and 4 females; age range: 1.6-17years, mode age: 14years) had 11 18F-FDG PET/CT studies for the evaluation of germ cell tumor. Diagnostic CTs were available for comparison in 8 patients (10 18F-FDG PET/CT studies). The average interval between diagnostic CT and PET/CT was 7.2days (range: 0-37days). In total, five lesions concerning for active malignancy were identified on diagnostic CT while seven were identified on PET/CT. Overall, 18F-FDG PET/CT resulted in a change in management in 3 of the 9 patients (33%). 18F-FDG PET/CT had a significant impact on the management of pediatric germ cell tumors in this retrospective study. Continued multicenter studies are required secondary to the rarity of this tumor to demonstrate the benefit of 18F-FDG PET/CT in particular clinical scenarios.