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

Alison L Salkeld; Jonathan Sykes; John Fernandez; Laura Murphy; Jennifer Chard; David I Thwaites

doi:10.1111/1754-9485.13721

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

J Med Imaging Radiat Oncol. 2024 Jul 15. doi: 10.1111/1754-9485.13721. Online ahead of print.

Authors

Alison L Salkeld^{1

2}, Jonathan Sykes^{1

2}, John Fernandez¹, Laura Murphy¹, Jennifer Chard¹, David I Thwaites^{1

2}

Affiliations

¹ Department of Radiation Oncology, Sydney West Radiation Oncology Network, Western Sydney Local Health District, Sydney, New South Wales, Australia.
² School of Physics, Institute of Medical Physics, University of Sydney NSW, Sydney, New South Wales, Australia.

PMID: 39008446
DOI: 10.1111/1754-9485.13721

Abstract

Introduction: Cranio-spinal radiotherapy (CSI) is used to treat central nervous system malignancies in paediatric, adolescent/young adult (AYA), and adult patients. Its delivery in the paediatric/AYA population is particularly challenging across different age groups. This study aims to assess the setup variations and dosimetric impact of CSI in paediatric and AYA patients.

Methods: This retrospective analysis included, 10 paediatric and AYA patients (aged 4-25) who underwent volumetric modulated arc therapy (VMAT) CSI between 2016 and 2022. Patient characteristics, diagnoses, prescribed CSI doses, and fractionation details were assessed. CT simulation and treatment planning followed standard protocols with setup errors were quantified by comparing daily treatment setup images with the planned position. The study evaluated the dosimetric impact on target volumes and organs at risk (OARs).

Results: The setup errors were identified, ranging from 0.5 to 6.2 mm in different directions, especially in the cranio-caudal direction. Despite these variations, there was minimal impact observed on the coverage of clinical target volumes (CTV) and doses to OARs (<1% relative change).

Conclusion: 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.

Keywords: cranio‐spinal radiotherapy; paediatric radiotherapy; peadiatrics; quality assurance; radiation oncology.