Experimental verification of IMPT treatment plans in an anthropomorphic phantom in the presence of delivery uncertainties.
Phys Med Biol
; 56(14): 4415-31, 2011 Jul 21.
Article
en En
| MEDLINE
| ID: mdl-21709345
Clinically relevant intensity modulated proton therapy (IMPT) treatment plans were measured in a newly developed anthropomorphic phantom (i) to assess plan accuracy in the presence of high heterogeneity and (ii) to measure plan robustness in the case of treatment uncertainties (range and spatial). The new phantom consists of five different tissue substitute materials simulating different tissue types and was cut into sagittal planes so as to facilitate the verification of co-planar proton fields. GafChromic films were positioned in the different planes of the phantom, and 3D-IMPT and distal edge tracking (DET) plans were delivered to a volume simulating a skull base chordoma. In addition, treatments planned on CTs of the phantom with HU units modified were delivered to simulate systematic range uncertainties (range-error treatments). Finally, plans were delivered with the phantom rotated to simulate spatial errors. Results show excellent agreement between the calculated and the measured dose distribution: >99% and 98% of points with a gamma value <1 (3%/3 mm) for the 3D-IMPT and the DET plan, respectively. For both range and spatial errors, the 3D-IMPT plan was more robust than the DET plan. Both plans were more robust to range than to the spatial uncertainties. Finally, for range error treatments, measured distributions were compared to a model for predicting delivery errors in the treatment planning system. Good agreement has been found between the model and the measurements for both types of IMPT plan.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Planificación de la Radioterapia Asistida por Computador
/
Fantasmas de Imagen
/
Incertidumbre
/
Radioterapia de Intensidad Modulada
/
Terapia de Protones
Tipo de estudio:
Prognostic_studies
Límite:
Humans
Idioma:
En
Revista:
Phys Med Biol
Año:
2011
Tipo del documento:
Article
País de afiliación:
Suiza
Pais de publicación:
Reino Unido