We aimed to evaluate the diagnostic performance of F-FDG PET/CT for the detection of post-transplantation lymphoproliferative disorder (PTLD) in a pediatric population and explore its feasibility during response assessment. This retrospective study included 28 pediatric transplant recipients who underwent a total of 32 F-FDG PET/CT scans due to clinical suspicion of PTLD within an 8-year period. Pathology reports and 2-year follow-up were used as reference standard. Twenty-one response assessment F-FDG PET/CT scans were re-evaluated according to the Lugano criteria. The diagnosis of PTLD was established in 14 patients (49%). Sensitivity, specificity, positive predictive value, and negative predictive value of F-FDG PET/CT for the detection of PTLD in children with a clinical suspicion of this disease, was 50% (7/14), 100% (18/18), 100% (7/7), and 72% (18/25), respectively. False-negative results occurred in patients with PTLD in the Waldeyer’s ring, cervical lymph nodes or small bowel with either non-destructive or polymorphic PTLD. Two of 5 interim F-FDG PET/CT scans and 3 of 9 end-of-treatment F-FDG PET/CT scans were false-positive. F-FDG PET/CT had good specificity and positive predictive value but low to moderate sensitivity and negative predictive value for the detection of PTLD in a 28 pediatric patient cohort with a clinical suspicion of this disease. False-negative results were confirmed in the Waldeyer’s ring, cervical lymph nodes and small bowel with either non-destructive or polymorphic PTLD subtypes. F-FDG PET/CT appears to have a limited role in the response assessment setting of pediatric PTLD, given the observed high proportions of false-positives both at interim and end-of-treatment evaluations.
Copyright © 2020 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

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