Radiation Dose, Outcomes, and Trends of CT-Guided Osteoid Osteoma Ablation in Pediatric Patients: An Analysis of the Registry of the German Society for Interventional Radiology and Minimally Invasive Therapy

PURPOSE: This study evaluated radiation dose parameters, clinical outcomes, and national trends in conventional CT-guided pediatric osteoid osteoma ablation. MATERIALS AND METHODS: We retrospectively analyzed data from the German Society for Interventional Radiology and Minimally Invasive Therapy (DeGIR) registry (2019-2024). Patients ≤ 18 years with available Dose Length Product were included. Radiation dose, clinical outcome, and ablation modality were assessed. Benchmarks were defined using percentiles stratified by age and anatomical location. RESULTS: A total of 166 pediatric patients (mean age 13.45 years; 59 female) were included. The median Dose Length Product was 132.00 (Q1: 53, Q3: 314) mGycm, 222.00 (Q1: 64.50, Q3: 485) mGycm for axial skeleton, and 124.00 (Q1: 51, Q3: 297) mGycm for extremity ablations. Technical success was 99.4% (partial technical success 0.60%), early clinical success was 58.43% (39.76% not assessable, 1.81% no improvement), and the complication rate was 1.81%. After additional age stratification and exclusion of very small groups (n < 5), Dose Length Product Q1; Q3 values were: axial skeleton 10-14 years 53; 504 mGycm (n = 6), 15-18 years 71; 483 mGycm (n = 17); extremities 5-9 years 55; 184 mGycm (n = 19), 10-14 years 43; 256 mGycm (n = 58), 15-18 years 50; 370 mGycm (n = 61). Radiofrequency ablation was most frequently applied (71.08%), followed by microwave ablation (26.51%), cryoablation (1.81%), and others (0.60%). CONCLUSION: This multicenter analysis provides proposed pediatric benchmarks for radiation exposure during conventional CT-guided osteoid osteoma ablation, which demonstrated excellent safety and technical success, supporting its role as standard therapy.