Assessing the role of positron emission tomography and bone scintigraphy in imaging of pleuropulmonary blastoma (PPB): A report from the International PPB/DICER1 Registry.

Abstract

Pleuropulmonary blastoma (PPB) is the most common primary lung neoplasm of infancy and early childhood. Given the rarity of PPB, the role of positron emission tomography (PET) and bone scintigraphy (bone scans) in diagnostic evaluation and surveillance has not been documented to date. Available PET and bone scan data are presented in this study. Patients with PPB enrolled in the International PPB/DICER1 Registry and available PET imaging and/or bone scan reports were retrospectively abstracted. On retrospective analysis, 133 patients with type II and III (advanced) PPB were identified with available report(s) (PET scan only=34, bone scan only=83, and both bone scan and PET=16). All advanced primary PPB (n=11) and recurrent (n=8) tumors prior to treatment presented with 18 F-fluorodeoxyglucose (FDG)-avid lesions, with median maximum standardized uptake values of 7.4 and 6.7, respectively. False positive FDG uptake in the thorax was noted during surveillance (specificity: 59%). Bone metastases were FDG-avid prior to treatment. Central nervous system metastases were not discernable on PET imaging. Sensitivity and specificity of bone scans for metastatic bone disease were 89% and 92%, respectively. Bone scans had a negative predictive value of 99%, although positive predictive value was 53%. Four patients with distant bone metastases had concordant true positive bone scan and PET. Primary, recurrent, and/or extracranial metastatic PPB presents with an FDG-avid lesion on PET imaging. Additional prospective studies are needed to fully assess the utility of nuclear medicine imaging in surveillance for patients with advanced PPB.