Miniaturized microdosimeters as LET monitors: First comparison of calculated and experimental data performed at the 62 MeV/u 12C beam of INFN-LNS with four different detectors

Research output: Contribution to journalArticle

Authors

  • Paolo Colautti
  • Valeria Conte
  • Anna Selva
  • Sabina Chiriotti Alvarez
  • Andrea Pola
  • Davide Bortot
  • Laure De Nardo
  • Claudio Verona
  • Gianluca Verona Rinati
  • Giulio Magrin
  • Pablo (G.A.P) Cirrone
  • Francesco Romano

Institutes & Expert groups

  • INFN - Instituto Nazionale di Fisica Nucleare
  • POLIMI - Politecnico di Milano
  • University of Padova - Physics and Astronomy Department
  • University of Roma Tor Vergata, via del Politecnico 1, Roma 00133
  • EBG GmbH MedAustron
  • ELI-Beamlines

Documents & links

Abstract

Purpose: The aim of this paper is to investigate the limits of LET monitoring of therapeutic carbon ion beams with miniaturized microdosimetric detectors. Methods: Four different miniaturized microdosimeters have been used at the 62 MeV/u 12C beam of INFN Southern National Laboratory (LNS) of Catania for this purpose, i.e. a mini-TEPC and a GEM-microdosimeter, both filled with propane gas, and a silicon and a diamond microdosimeter. The −yD (dose-mean lineal energy) values, measured at different depths in a PMMA phantom, have been compared withLE¯TD (dose-mean LET) values in water, calculated at the same water-equivalent depth with a Monte Carlo simulation setup based on the GEANT4 toolkit. Results: In these first measurements, no detector was found to be significantly better than the others as a LET monitor. The −yD relative standard deviation has been assessed to be 13% for all the detectors. On average, the ratio between −yD and LE¯TD values is 0.9 ± 0.3, spanning from 0.73 ± 0.08 (in the proximal edge and Bragg peak region) to 1.1 ± 0.3 at the distal edge. Conclusions: All the four microdosimeters are able to monitor the dose-mean LET with the 11% precision up to the distal edge. In the distal edge region, the ratio of −yD to LE¯TD changes. Such variability is possibly due to a dependence of the detector response on depth, since the particle mean-path length inside the detectors can vary, especially in the distal edge region.

Details

Original languageEnglish
Pages (from-to)113-121
Number of pages9
JournalPhysica Medica
Volume52
Issue number113-121
DOIs
Publication statusPublished - 18 Jul 2018

Keywords

  • LET , Monte Carlo, Ione beam therapy

ID: 4985882