PT - JOURNAL ARTICLE AU - Montes de Jesus, Filipe AU - Glaudemans, Andor W.J.M. AU - Tissing, Wim AU - Dierckx, Rudi A. AU - Rosati, Stefano AU - Diepstra, Arjan AU - Noordzij, Walter AU - Kwee, Thomas C. TI - <sup>18</sup>F-FDG PET/CT in the Diagnostic and Treatment Evaluation of Pediatric Post-transplant Lymphoproliferative Disorders AID - 10.2967/jnumed.119.239624 DP - 2020 Jan 01 TA - Journal of Nuclear Medicine PG - jnumed.119.239624 4099 - http://jnm.snmjournals.org/content/early/2020/01/16/jnumed.119.239624.short 4100 - http://jnm.snmjournals.org/content/early/2020/01/16/jnumed.119.239624.full AB - We aimed to evaluate the diagnostic performance of 18F-FDG PET/CT for the detection of post-transplantation lymphoproliferative disorder (PTLD) in a pediatric population and explore its feasibility during response assessment. Methods: This retrospective study included 28 pediatric transplant recipients who underwent a total of 32 18F-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 18F-FDG PET/CT scans were re-evaluated according to the Lugano criteria. Results: The diagnosis of PTLD was established in 14 patients (49%). Sensitivity, specificity, positive predictive value, and negative predictive value of 18F-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 18F-FDG PET/CT scans and 3 of 9 end-of-treatment 18F-FDG PET/CT scans were false-positive. Conclusion: 18F-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. 18F-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.