Out of Field dose measurements for 3D confromal and intensity modulated radiotherapy of paediatric brain tumour

Research output: Contribution to journalArticle

Authors

  • Marija Majer
  • Liliana Stolarczyk
  • Marijke De Saint-Hubert
  • Damian Kabat
  • Zeljka Knezevic
  • Saveta Miljanic
  • Natalia Mojz˙eszek
  • Roger Harrison

Institutes & Expert groups

  • Maria Skłodowska-Curie Institute of Oncology
  • Newcastle University - Institute of Health and Society
  • RBI - Ruđer Bošković Institute
  • Institute of Nuclear Physics PAN

Documents & links

DOI

Abstract

The purpose of this study was to measure out-of-field organ doses in clinical conditions in anthropomorphic paediatric phantoms which received a simulated treatment of a brain tumour with intensity modulated radiotherapy (IMRT) and 3D conformal radiotherapy (3D CRT). Organ doses measured with radiophotoluminescent and thermoluminescent dosemeters were on average 1.6 and 3.0 times higher for the 5 y-old than for the 10 y-old phantom for IMRT and 3D CRT, respectively. A larger 5-y to 10-y organ dose ratio for 3D CRT can be explained because the use of a mechanical wedge for the 5-y-old 3D CRT phantom treatment increased out-of-field doses. Due to different configurations of the radiation fields, for both phantoms, the IMRT technique resulted in a higher non-target brain dose and higher eye doses but lower thyroid doses compared to 3D CRT. For 3D CRT (which used a non-coplanar field configuration), eye doses were 3-6% and for IMRT (which used a coplanar field configuration) 27-30% of the treatment dose, respectively. For thyroid and more distant organs, doses were less than 1% of the treatment dose. Comparison of measured doses and doses calculated by the treatment planning system (TPS) showed that the TPS underestimated out-of-field doses both for IMRT and 3D CRT.

Details

Original languageEnglish
Pages (from-to)331-340
Number of pages10
JournalRadiation protection dosimetry
Volume176
Issue number3
DOIs
Publication statusPublished - 1 Nov 2017

Keywords

  • Radiotherapy, out-of-field dose, children, Brain tumor

ID: 2368080