Measurements and Monte Carlo calculations to determine the absolute detector response of radiochromic film for brachytherapy dosimetry.
Med Phys
; 28(2): 142-6, 2001 Feb.
Article
en En
| MEDLINE
| ID: mdl-11243336
GafChromic (MD-55-2) radiochromic film has become increasingly popular for medical applications and has proven to be useful for brachytherapy dosimetry. To measure the absolute dose near a brachytherapy source, the response of the proposed detector in the measurement conditions relative to the response of the detector in calibration conditions must be known. MD-55-2 radiochromic film has been exposed in four different photon beams, a 30 and 40 kVp tungsten anode x-ray beam, a 75 kVp orthovoltage therapy beam, and a 60Co teletherapy beam to measure the relative detector response. These measurements were combined with coupled photon/electron Monte Carlo transport calculations to determine the absolute detector response. The Los Alamos National Laboratory Monte Carlo transport code MCNP4B2 was used. The measured relative response of this batch of MD-55-2 film varies from 8.79 mOD/Gy, measured for the 60Co beam, by as much as 42% for the low-energy x-ray beams. However, the absolute detector response varies from 4.32 mOD/Gy for the 60Co beam by, at most, only 6.3%. In this work we demonstrate that the absolute detector response of MD-55-2 radiochromic film is a constant and independent of beam quality. Further, this work shows that MCNP4B2 accurately simulates the energy response and geometry artifacts of the radiochromic film.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Planificación de la Radioterapia Asistida por Computador
/
Braquiterapia
Tipo de estudio:
Health_economic_evaluation
Límite:
Humans
Idioma:
En
Revista:
Med Phys
Año:
2001
Tipo del documento:
Article
País de afiliación:
Estados Unidos
Pais de publicación:
Estados Unidos