Development and evaluation of dose management system for paediatric image-guided radiotherapy

Abstract Paediatric patients exhibit highened sensitivity to radiation compared to adults during image-guided radiation therapy, underscring the need for careful dose management, even for minimal exposures. This study aims to develop and evaluate a system for efficiently recording and managing imaging doses. Monte Carlo (MC) simulations were employed to accurately model the radiation dose from the cone-beam computed tomography (CBCT) system utilized in this study. Additionally, a custom detector was designed for image processing. The full-pan mode was chosen to reconstruct images for paediatric patients from data acquired through a 200 ∘ rotation. In the dosimetric analysis, the tissue-absorbed doses were calculated using MC simulations within a computerizsed anatomical phantom tailored for paediatric use. The study utilized hybrid anthropomorphic phantom representing ages 0, 1, 5, 10, 15, and 30 years to compute and record organ doses. The developed system accounted for offsets generated during the image verification after patient examinations and treatments, applying these adjustments to image dose calculations. Finalized results were stored on a server, maintaining a record of daily imaging doses for each patient. The simulation process required approximately 20 hours per inspection, with results converted to the Digital Imaging and Communications in Medicine (DICOM) format and analysed using the Eclipse treatment planning system. Among all age groups, the 0-year-old phantom received the highest radiation doses across all organs due to minimal attenuation before reaching the target organs. The greatest dose variation based on rotation angle was observed in the eyes and lens. This study successfully developed and evaluated a retrospective system for managing and optimizing CBCT image doses in paediatric radiotherapy, demonstrating its potential for improving radiation safety and dose tracking in young patients.