Characterization of a flat-panel detector for 2D dosimetry in scanned proton and carbon ion beams

Copyright © 2023 Associazione Italiana di Fisica Medica e Sanitaria. Published by Elsevier Ltd. All rights reserved..

PURPOSE: To fully characterize the flat panel detector of the new Sphinx Compact device with scanned proton and carbon ion beams.

MATERIALS AND METHODS: The Sphinx Compact is designed for daily QA in particle therapy. We tested its repeatability and dose rate dependence as well as its proportionality with an increasing number of particles and potential quenching effect. Potential radiation damage was evaluated. Finally, we compared the spot characterization (position and profile FWHM) with our radiochromic EBT3 film baseline.

RESULTS: The detector showed a repeatability of 1.7% and 0.9% for single spots of protons and carbon ions, respectively, while for small scanned fields it was inferior to 0.2% for both particles. The response was independent from the dose rate (difference from nominal value < 1.5%). We observed an under-response due to quenching effect for both particles, mostly for carbon ions. No radiation damage effects were observed after two months of weekly use and approximately 1350 Gy delivered to the detector. Good agreement was found between the Sphinx and EBT3 films for the spot position (central-axis deviation within 1 mm). The spot size measured with the Sphinx was larger compared to films. For protons, the average and maximum differences over different energies were 0.4 mm (3%) and 1 mm (7%); for carbon ions they were 0.2 mm (4%) and 0.4 mm (6%).

CONCLUSIONS: Despite the quenching effect the Sphinx Compact fulfills the requirements needed for constancy checks and could represent a time-saving tool for daily QA in scanned particle beams.

Medienart:

E-Artikel

Erscheinungsjahr:

2023

Erschienen:

2023

Enthalten in:

Zur Gesamtaufnahme - volume:107

Enthalten in:

Physica medica : PM : an international journal devoted to the applications of physics to medicine and biology : official journal of the Italian Association of Biomedical Physics (AIFB) - 107(2023) vom: 15. März, Seite 102561

Sprache:

Englisch

Beteiligte Personen:

Rossi, Eleonora [VerfasserIn]
Russo, Stefania [VerfasserIn]
Maestri, Davide [VerfasserIn]
Magro, Giuseppe [VerfasserIn]
Mirandola, Alfredo [VerfasserIn]
Molinelli, Silvia [VerfasserIn]
Vai, Alessandro [VerfasserIn]
Grevillot, Loïc [VerfasserIn]
Bolsa-Ferruz, Marta [VerfasserIn]
Rossomme, Séverine [VerfasserIn]
Ciocca, Mario [VerfasserIn]

Links:

Volltext

Themen:

7440-44-0
Carbon
Dosimetry
Ion therapy
Journal Article
Protons
Quality assurance

Anmerkungen:

Date Completed 20.03.2023

Date Revised 20.03.2023

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1016/j.ejmp.2023.102561

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM35403975X