Optimization of equivalent uniform dose using the L-curve criterion.
Phys Med Biol
; 52(19): 5973-84, 2007 Oct 07.
Article
en En
| MEDLINE
| ID: mdl-17881813
ABSTRACT
Optimization of equivalent uniform dose (EUD) in inverse planning for intensity-modulated radiation therapy (IMRT) prevents variation in radiobiological effect between different radiotherapy treatment plans, which is due to variation in the pattern of dose nonuniformity. For instance, the survival fraction of clonogens would be consistent with the prescription when the optimized EUD is equal to the prescribed EUD. One of the problems in the practical implementation of this approach is that the spatial dose distribution in EUD-based inverse planning would be underdetermined because an unlimited number of nonuniform dose distributions can be computed for a prescribed value of EUD. Together with ill-posedness of the underlying integral equation, this may significantly increase the dose nonuniformity. To optimize EUD and keep dose nonuniformity within reasonable limits, we implemented into an EUD-based objective function an additional criterion which ensures the smoothness of beam intensity functions. This approach is similar to the variational regularization technique which was previously studied for the dose-based least-squares optimization. We show that the variational regularization together with the L-curve criterion for the regularization parameter can significantly reduce dose nonuniformity in EUD-based inverse planning.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Garantía de la Calidad de Atención de Salud
/
Radiometría
/
Algoritmos
/
Planificación de la Radioterapia Asistida por Computador
/
Modelos Biológicos
/
Neoplasias
Tipo de estudio:
Diagnostic_studies
/
Evaluation_studies
/
Prognostic_studies
Límite:
Humans
Idioma:
En
Revista:
Phys Med Biol
Año:
2007
Tipo del documento:
Article
País de afiliación:
Estados Unidos