Quality assurance and other challenges in paediatric radiotherapy: Accurate delivery of craniospinal radiotherapy.

Ensuring precise setup in paediatric and AYA patients undergoing CSI is essential to maintain adequate CTV coverage. Although occasional substantial setup variations occurred during treatment, they had a limited impact on CTV coverage and OAR doses when infrequent. Appropriate planning target volume (PTV) margins can effectively compensate for occasional shifts. However, systematic errors could compromise treatment quality if undetected. Regular off-line review of patient set-up trends is recommended.