Abstract

INTRODUCTION: Guidelines recommend true whole body (TWB) FDG-PET/CT scans from vertex to toes in paediatric lymphoma patients, although this suggestion has not been validated in large clinical trials. The objective of the study is to evaluate the incidence and clinical impact of lesions outside the "eyes to thighs" regular field of view (R-FOV) in FDG-PET/CT staging (sPET) and interim (iPET) scans in paediatric lymphoma patients. MATERIALS AND METHODS: TWB sPET and iPET scans were prospectively performed in paediatric lymphoma patients (11 worldwide centres). Expert panel central review of sPET and iPET scans were evaluated for lymphoma lesions outside the R-FOV, and clinical relevance of this findings. RESULTS: A total of 610 scans were performed in 305 patients. The sPET scans did not show lesions outside the R-FOV in 91.8% of the patients, while in 8.2% patients the sPET scans demonstrated lesions also outside the R-FOV (soft tissue, bone, bone marrow and skin); however, the presence of these lesions did not change the clinical stage of any patient and did not impact on treatment decision. Among the 305 iPET scans, there were no new positive FDG-avid lesions outside the R-FOV, when compared to their paired sPET scans. A single lesion outside the R-FOV on iPET occurred in one patient (0.3%) with the primary lesion diagnosed in the femur on sPET that persisted on iPET. CONCLUSION: The identification of additional lesions outside RFOV (eyes to thighs) FDG-PET/CT has no impact in the definition of the clinical stage of disease and minimal impact in the treatment definition of patients with pediatric lymphoma. As so, reduced field of view for both staging and interim FDG-PET/CT scans could be performed.

View details for PubMedID 30683766