Akademik Veri Yönetim Sistemi
Annual Congress of the European Association of Nuclear Medicine (EANM'25), Barcelona, İspanya, 4 - 08 Ekim 2025, ss.118, (Özet Bildiri)
Aim/Introduction: Non-ossifying fibromas (NOFs) are common benign bone lesions frequently encountered in radiological practice. Typically arising during childhood, they are often (~75%) detected incidentally in the second decade of life. NOFs are usually located in the metaphyseal-diaphyseal regions of the femur or tibia and may show increased FDG uptake on PET/ CT, mimicking bone metastases. This study aims to evaluate the visual and quantitative features of incidentally detected NOFs in pediatric patients undergoing F-18 FDG PET/CT. Materials and Methods: F-18 FDG PET/CT scans performed in pediatric patients (≤18 years old) at our clinic between 2015 and 2024 were retrospectively analyzed. Patients were categorized based on clinical indications. Lesion localization and size were recorded. Mean and maximum standardized uptake values (SUVmax and SUVmean) were calculated and compared with the mediastinal blood pool, the liver (right lobe), and, if present, the primary tumor. Results: Among 1,500 pediatric FDG PET/CT scans, 40 lesions from 32 patients (mean age: 15 years (6-18); 62% male) were retrospectively evaluated. Clinical details are summarized in Table 1. Regarding the localization of the NOF lesions: 24 were located in the distal femur, 2 in the femoral head region, 11 in the proximal tibia, 1 in the distal tibia, and single cases in the humerus and iliac bone. The mean craniocaudal length of the lesions was 14.2 mm (8-70 mm). The average SUVmax and SUVmean were 2.9 (0.5-19.9) and 1.1 (0.2-4.0) respectively. Reference average SUVmax values were 2.1 (0.6-3.4) for the liver and 1.5 (0.4-3.4) for the mediastinal blood pool. Among 24 patients with malignancy, 6 had undergone surgery. In the remaining 18, the average SUVmax of the primary malignant lesions was 11,9 (3,3-24,5). SUVmax exceeded liver and mediastinal reference values in 48% (n:19) and 60% (n:24) of NOF lesions, respectively. In two patients, the NOF lesions demonstrated higher SUVmax values than the primary tumor (4.7 vs. 3.3 and 19.9 vs. 6.7). In this subgroup, the average NOF SUVmax was calculated as 4.4. Conclusion: Non-ossifying fibromas (NOFs) are common benign bone lesions typically asymptomatic in nature. However, their variable metabolic activity on FDG PET/ CT can lead to misinterpretation as a malignant lesion, potentially impacting disease staging and clinical management. Therefore, the morphological clues from the CT component of PET/CT and, lesion localization are essential for accurate diagnosis and to avoid diagnostic pitfalls due to FDG uptake.