Investigation of linear energy transfer (LET)-dependence behavior and dosimetric response of a flat-panel detector in pencil beam scanning proton therapy.
Phys Med
; 125: 104508, 2024 Sep.
Article
in En
| MEDLINE
| ID: mdl-39186892
ABSTRACT
PURPOSE:
This study aims to elucidate the dependence of the flat-panel detector's response on the linear energy transfer (LET) and evaluate the practical viability of employing flat-panel detectors in proton dosimetry applications through LET-dependent correction factors.METHODS:
The study assessed the flat-panel detector's response across varying depths using solid water and distinct 100, 150, and 200 MeV proton beams by comparing the flat-panel readings against reference doses measured with an ionization chamber. A Monte Carlo code was used to derive LET values, and an LET-dependent response correction factor was determined based on the ratio of the uncorrected flat-panel dose to the ionization chamber dose. The implications of this under-response correction were validated by applying it to a measurement involving a spread-out Bragg peak (SOBP), followed by a comparative analysis against doses calculated using the Monte Carlo code and MatriXX ONE measurement.RESULTS:
The association between LET and the flat-panel detector's under-response displayed a positive correlation that intensified with increasing LET values. Notably, with a 10 keV/µm LET value, the detector's under-response reached 50 %, while the measurement points in the SOBP demonstrated under-response greater than 20 %. However, post-correction, the adjusted flat-panel profile closely aligned with the Monte Carlo profile, yielding a 2-dimensional 3 %/3mm gamma passing rate of 100 % at various verification depths.CONCLUSION:
This study successfully defined the link between LET and the responsiveness of flat-panel detectors for proton dosimetric measurements and established a foundational framework for integrating flat-panel detectors in clinical proton dosimetry applications.Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Radiometry
/
Monte Carlo Method
/
Linear Energy Transfer
/
Proton Therapy
Language:
En
Journal:
Phys Med
Journal subject:
BIOFISICA
/
BIOLOGIA
/
MEDICINA
Year:
2024
Document type:
Article
Affiliation country:
Estados Unidos
Country of publication:
Italia