Quality assurance and other challenges in paediatric radiotherapy: Accurate delivery of craniospinal radiotherapy
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Published on: February 6, 2019
Alison L Salkeld1,2, Jonathan Sykes1,2, John Fernandez1
1Department of Radiation Oncology, Sydney West Radiation Oncology Network, Western Sydney Local Health District, Sydney, New South Wales, Australia.
Insights
Setup variations in cranio-spinal radiotherapy (CSI) for paediatric and adolescent/young adult (AYA) patients had minimal dosimetric impact. Appropriate planning target volume (PTV) margins can compensate for occasional shifts, but systematic errors require regular review.
Area of Science:
- Radiation Oncology
- Paediatric Oncology
- Medical Physics
Background:
- Cranio-spinal radiotherapy (CSI) is crucial for central nervous system malignancies in paediatric, adolescent/young adult (AYA), and adult patients.
- Delivering CSI in paediatric and AYA populations presents unique challenges across different age groups.
- Accurate patient setup is vital for effective CSI treatment delivery.
Purpose of the Study:
- To assess setup variations during CSI in paediatric and AYA patients.
- To evaluate the dosimetric impact of these setup variations on target volumes and organs at risk (OARs).
Main Methods:
- Retrospective analysis of 10 paediatric and AYA patients (aged 4-25) treated with volumetric modulated arc therapy (VMAT) CSI.
- Quantification of setup errors by comparing daily treatment images with planned positions.
- Evaluation of dosimetric impact on clinical target volumes (CTV) and OARs.
Main Results:
- Setup errors ranged from 0.5 to 6.2 mm, particularly in the cranio-caudal direction.
- Despite setup variations, minimal impact (<1% relative change) was observed on CTV coverage and OAR doses.
- Occasional substantial setup variations had limited dosimetric consequences.
Conclusions:
- Precise patient setup is essential for adequate CTV coverage in paediatric and AYA CSI.
- Planning target volume (PTV) margins can effectively mitigate the impact of occasional setup variations.
- Regular off-line review of setup trends is recommended to detect and address systematic errors, ensuring treatment quality.
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.
