ESTRO 2025 - Abstract Book

S2522

Physics - Autosegmentation

ESTRO 2025

adjusted if necessary. Landmarks were used to measure the anterior and posterior heights of 5169 individual vertebrae in 359 paediatric CT images, with ages ranging from 0.5 to 16.5 years.

Results: Inclusion of paediatric scans during training improved performance of the model, achieving DSC above 0.85 for each vertebra (Figure 2), comparable to expert inter-observer variation. The accuracy of the selected landmarks was dependent on the image resolution and contour quality with 10% of landmarks requiring manual corrections. The relationship between age and vertebral height was best described using linear regression models (R2>0.75). The lumbar vertebrae were found to have the highest growth-rates (1.08-1.16 mm/y), followed by the thoracic (0.67-1.03 mm/y), and cervical vertebrae (0.48-0.66 mm/y).