Tumor-tracking radiotherapy of moving targets; verification using 3D polymer gel, 2D ion-chamber array and biplanar diode array

Research output: Contribution to journalArticle

Abstract

The aim of this study was to carry out a dosimetric verification of a dynamic multileaf collimator (DMLC)-based tumor-tracking delivery during respiratory-like motion. The advantage of tumor-tracking radiation delivery is the ability to allow a tighter margin around the target by continuously following and adapting the dose delivery to its motion. However, there are geometric and dosimetric uncertainties associated with beam delivery system constraints and output variations, and several investigations have to be accomplished before a clinical integration of this tracking technique. Two types of delivery were investigated in this study I) a single beam perpendicular to a target with a one dimensional motion parallel to the MLC moving direction, and II) an intensity modulated arc delivery (RapidArc®) with a target motion diagonal to the MLC moving direction. The feasibility study (I) was made using an 2D ionisation chamber array and a true 3D polymer gel. The arc delivery (II) was verified using polymer gel and a biplanar diode array. Good agreement in absorbed dose was found between delivery to a static target and to a moving target with DMLC tracking using all three detector systems. However, due to the limited spatial resolution of the 2D array a detailed comparison was not possible. The RapidArc® plan delivery was successfully verified using the biplanar diode array and true 3D polymer gel, and both detector systems could verify that the DMLC-based tumor-tracking delivery system has a very good ability to account for respiratory target motion.

Details

Authors
  • Sofie Ceberg
  • Per Munck Af Rosenschöld
  • Herbert Cattell
  • Helen Gustafsson
  • Paul Keall
  • Stine S. Korreman
  • Joakim Medin
  • Fredrik Nordström
  • Gitte Persson
  • Amit Sawant
  • Michelle Svatos
  • Jens Zimmerman
  • Sven Å J. Bäck
  • Marianne Falk
Organisations
External organisations
  • Varian Medical Systems
  • ACT Health
  • Stanford University
  • Niels Bohr Institute
  • University of Wisconsin-Madison
  • Copenhagen University Hospital
  • Skåne University Hospital
  • Finsen Laboratory, Rigshospitalet, Copenhagen
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Radiology, Nuclear Medicine and Medical Imaging
Original languageEnglish
Article number012051
Pages (from-to)235-239
Number of pages5
JournalJournal of Physics: Conference Series
Volume250
Issue number1
Publication statusPublished - 2010 Jan
Publication categoryResearch
Peer-reviewedYes