To evaluate the accuracy of dynamic versus static IMRT delivery using portal dosimetry
Clin. transl. oncol. (Print)
; 16(2): 208-212, feb. 2014. tab, ilus
Artigo
em Inglês
| IBECS
| ID: ibc-127726
Biblioteca responsável:
ES1.1
Localização: BNCS
ABSTRACT
INTRODUCTION:
To evaluate the delivery accuracy of dynamic (DMLC) and static (SMLC) intensity modulated radiation therapy (IMRT) techniques using portal dosimetry (PD) in Varian Eclipse Treatment Planning System. MATERIALS ANDMETHODS:
Seven DMLC IMRT Head and Neck plans were retrospectively generated for the study using SMLC mode at 20, 10 and 5 levels of intensity (SMLC20, SMLC10, SMLC5). Dosimetric verifications performed by PD on a total of 107 fields were evaluated using the gamma index (maximum (γmax), average (γavg), percentage of points with (γ%) ≤ 1). The images were acquired at a source-detector distance of 100 cm at gantry zero degree and also at clinically planned gantry angles.RESULTS:
For both modes, measurements are within acceptable criteria. (γ%) ≤ 1 improves by increasing SMLC levels (+3.4 % from SMLC5 to SMLC20, p < 0.001) and using DMLC (+3.9 % and +0.6 % compared to SMLC5 and SMLC20, respectively, p < 0.001). Also (γmax) parameter improves significantly by increasing SMLC levels (+22 % from SMLC5 to SMLC20) and using DMLC (+34 % and +16 % compared to SMLC5 and SMLC20, respectively). The effect of the gantry rotation influences the delivery accuracy by up to -7 % (p < 0.05). The effect of leaves travelling direction was almost negligible (1 %).CONCLUSIONS:
A good agreement between calculated and measured fluences was obtained for DMLC and SMLC techniques at higher intensity levels; however, DMLC delivery ensures the best reproduction of computed fluence maps. The gantry rotation influences the delivery accuracy in particular for SMLC modes at lower intensity levels (AU)RESUMEN
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Espanha
Base de dados:
IBECS
Assunto principal:
Radiometria
/
Planejamento da Radioterapia Assistida por Computador
/
Radioterapia de Intensidade Modulada
/
Radioterapia Guiada por Imagem
Tipo de estudo:
Estudo diagnóstico
/
Estudo de etiologia
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Estudo de avaliação
/
Estudo observacional
/
Fatores de risco
Limite:
Humanos
Idioma:
Inglês
Revista:
Clin. transl. oncol. (Print)
Ano de publicação:
2014
Tipo de documento:
Artigo
Instituição/País de afiliação:
Istituto di Ricovero e Cura a Carattere Scientifico Centro Regionale Oncologico Basilicata (IRCCS CROB)/Italy