Providing a fast conversion of total dose to biological effective dose (BED) for hybrid seed brachytherapy.
J Appl Clin Med Phys
; 13(5): 3800, 2012 Sep 06.
Article
em En
| MEDLINE
| ID: mdl-22955644
ABSTRACT
Optimization of permanent seed implant brachytherapy plans for treatment of prostate cancer should be based on biological effective dose (BED) distributions, since dose does not accurately represent biological effects between different types of sources. Currently, biological optimization for these plans is not feasible due to the amount of time necessary to calculate the BED distribution. This study provides a fast calculation method, based on the total dose, to calculate the BED distribution. Distributions of various numbers of hybrid seeds were used to calculate total dose distributions, as well as BED distributions. Hybrid seeds are a mixture of different isotopes (in this study (125)I and (103)Pd). Three ratios of hybrid seeds were investigated 25/75, 50/50, and 75/25. The total dose and BED value from each voxel were coupled together to produce graphs of total dose vs. BED. Equations were then derived from these graphs. The study investigated four types of tissue bladder, rectum, prostate, and other normal tissue. Equations were derived from the total dose - BED correspondence. Accuracy of conversion from total dose to BED was within 2 Gy; however, accuracy of conversion was found to be better for high total dose regions as compared to lower dose regions. The method introduced in this paper allows one to perform fast conversion of total dose to BED for brachytherapy using hybrid seeds, which makes the BED-based plan optimization practical. The method defined here can be extended to other ratios, as well as other tissues that are affected by permanent seed implant brachytherapy (i.e., breast).
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Neoplasias da Próstata
/
Próteses e Implantes
/
Planejamento da Radioterapia Assistida por Computador
/
Braquiterapia
Limite:
Humans
/
Male
Idioma:
En
Revista:
J Appl Clin Med Phys
Assunto da revista:
BIOFISICA
Ano de publicação:
2012
Tipo de documento:
Article
País de afiliação:
Estados Unidos