Adverse impact of multileaf collimator field shaping on lens dose in children with acute leukemia receiving cranial irradiation.
Int J Radiat Oncol Biol Phys
; 48(4): 1227-31, 2000 Nov 01.
Article
em En
| MEDLINE
| ID: mdl-11072182
ABSTRACT
PURPOSE:
This study was designed to investigate the impact of multileaf collimator (MLC) on lens dose in children with leukemia undergoing cranial irradiation. METHODS AND MATERIALS This is a prospective study utilizing three common cranial irradiation techniques. Technique A uses a half-beam, nondivergent radiation field. Technique B has the anterior divergent field edge at the lateral bony canthus. Technique C is similar to B, but with a field collimator angle. Thermoluminescent dosimeter (TLD) lens dose measurements were obtained in children and phantom with all three techniques.RESULTS:
Seventeen children were studied. Lens dose measurements were obtained in 14 children with technique A using MLC and blocks. In 7 of 14 children, dose measurements were obtained with MLC only. One child was treated with technique B and 2 children were treated with C, with MLC +/- blocks. In all 3 techniques, with MLC alone, the lens dose increased by 64%, 119%, and 72%, respectively. Similar results were obtained in phantom.CONCLUSION:
This study demonstrates that independent of irradiation technique, additional custom blocking is required to maximally protect the lens with MLC shaped fields. This is due to the lack of conformity between MLC and the desired field edge at the lateral bony canthus.
Buscar no Google
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Neoplasias Encefálicas
/
Irradiação Craniana
/
Cristalino
Tipo de estudo:
Observational_studies
Limite:
Adolescent
/
Adult
/
Child
/
Child, preschool
/
Humans
Idioma:
En
Revista:
Int J Radiat Oncol Biol Phys
Ano de publicação:
2000
Tipo de documento:
Article
País de afiliação:
Estados Unidos