Background: The principal aim of this study was to identify the lowest nodule diameter and the SUV max capable of characterizing lung nodules in pediatric patients with bone sarcoma. Procedure: Eighteen consecutive bone sarcoma patients (M/F=11:7; mean age 14 years) with suspicious lung lesions at CT were enrolled. Overall, 63 lung nodules with a mean diameter of 3.35mm (range 1.2-39.8mm) were investigated. 18F-FDG PET was performed according to standard procedure using a hybrid PET/CT system and results were compared with histology and/or clinical/radiological follow-up. For each lesion, we evaluated SUV max, SUV ratio to the mediastinal blood pool and maximum nodule diameter. Results: Of the 63 nodules, 32 proved to be benign and 31 malignant. On a visual basis, 18F-FDG PET had an accuracy of 88.9%, a sensitivity of 90.3%, a specificity of 87.5%, a PPV of 87.5%, and a NPV of 90.3%. ROC curve analysis of SUV max for all nodules showed a value around 1 (>1.09) to be capable of differentiating metastases from benign lesions: sensitivity and specificity were 90.3% and 93.8%, respectively (accuracy 92.1%). Similar analysis revealed a cut-off value around 1 (>0.83) for SUV ratio (sensitivity and specificity were 90.3% and 90.6%, respectively) and a cut-off value of ca. 6mm (>5.8mm) for nodule diameter (sensitivity and specificity of 90.3% and 81.3%, respectively). Conclusions: 18F-FDG PET/CT is an accurate modality for the metabolic characterization of lung nodules in the pediatric population with bone sarcoma, and a SUV max (or SUV ratio) >1 is capable of discriminating malignant from benign lesions.
- Lung nodule
- Pediatric sarcoma
ASJC Scopus subject areas
- Pediatrics, Perinatology, and Child Health