Task group: completed projects

Survey on the spleen as an organ at risk in paediatric radiotherapy

PI: Mark Gaze
Status: survey closed, project completed 

A subgroup formed of SIOPE-Radiation Oncology Working Group members, and colleagues from University College London Hospitals, has been working to gauge the level of understanding of the risk of mortality from overwhelming post-splenectomy infection arising from incidental irradiation of the spleen in paediatric radiotherapy practice, and to develop straightforward evidence-based guidance to mitigate this risk.

The following recommendations have been made:

  • Paediatric radiation oncologists should delineate the spleen and record the dose received as the standard of care, and communicate this and the level of risk to other relevant clinicians.
  • Clinical trial protocols and radiotherapy guidelines should mandate contouring of the spleen and give a dose objective of ALARA or ideally a mean <10 Gy, if this can be achieved without compromise to target volume coverage.
  • To reduce the risk of mortality from OPSI, a mean spleen dose ≥10 Gy should be regarded as significant, and the need to recommend prophylaxis should be considered.
  • Professional organisations should work to increase awareness of the risks associated with incidental irradiation of the spleen through new or revised evidence-based guidelines and continuing professional development activities.
  • Information for parents and patients should explicitly mention the risk and the recommendation for prophylaxis above a defined spleen dose.
  • Recently, a manuscript based on this work has been published in the European Journal of Cancer (see “Recent Publications”).


Management of vertebral radiotherapy dose in paediatric patients with cancer: consensus recommendations from the SIOPE radiotherapy working group

PI: Bianca Hoeben, Geert Janssens
Status: project closed

Inhomogeneous radiotherapy dose distribution over the vertebrae in children can cause long-term spinal problems, including kyphosis, lordosis, scoliosis, and hypoplasia. Risk of involuntary inhomogeneous doses over the vertebrae is higher with highly-conformal radiotherapy techniques as are used today.

The aim of the project was to gather information regarding normal vertebral development in childhood and the disruptive influence of radiotherapy on vertebral growth, and to establish recommendations for modern radiotherapy techniques.

After a survey that was distributed among SIOPE-affiliated centres, results were discussed alongside the evidence from literature in a group of paediatric radiation oncologists from 27 leading centres in 11 European countries. The group produced consensus recommendations on how to approach dose coverage for target volumes that are adjacent to vertebrae to minimise the risk of long-term spinal problems (Hoeben et al. Lancet Oncology 2019;20(3):e155-166 and doi: 10.1016/S1470-2045(19)30034-8.).

Future multicenter studies regarding the effects of conformal radiotherapy techniques on vertebral growth will provide more data to re-evaluate and update these recommendations.