Dose-response of deformable radiochromic dosimeters for spot scanning proton therapy

Simon V Jensen; Lia B Valdetaro; Per R Poulsen; Peter Balling; Jørgen B B Petersen; Ludvig P Muren

doi:10.1016/j.phro.2020.11.004

Dose-response of deformable radiochromic dosimeters for spot scanning proton therapy

Phys Imaging Radiat Oncol. 2020 Nov 20:16:134-137. doi: 10.1016/j.phro.2020.11.004. eCollection 2020 Oct.

Authors

Simon V Jensen¹, Lia B Valdetaro¹, Per R Poulsen¹, Peter Balling², Jørgen B B Petersen¹, Ludvig P Muren¹

Affiliations

¹ Danish Center for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark.
² Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark.

Abstract

Intrafractional motion and deformation influence proton therapy delivery for tumours in the thorax, abdomen and pelvis. This study aimed to test the dose-response of a compressively strained three-dimensional silicone-based radiochromic dosimeter during proton beam delivery. The dosimeter was read-out in its relaxed state using optical computed tomography and calibrated for the linear energy transfer, based on Monte Carlo simulations. A three-dimensional gamma analysis showed a 99.3% pass rate for 3%/3 mm and 93.9% for 2%/2 mm, for five superimposed measurements using deformation-including Monte Carlo dose calculations as reference. We conclude that the dosimeter's dose-response is unaffected by deformations.

Keywords: 3D dosimetry; Deformation; Monte Carlo; Proton therapy.