Conventional in vivo irradiation procedures are insufficient to accurately determine tumor responses to non-uniform radiation fields.
Int J Radiat Biol
; 91(3): 257-61, 2015 Mar.
Article
em En
| MEDLINE
| ID: mdl-25347147
ABSTRACT
PURPOSE:
To determine differences in overall tumor responses measured by volumetric assessment and bioluminescence imaging (BLI) following exposure to uniform and non-uniform radiation fields in an ectopic prostate tumor model. MATERIALS ANDMETHODS:
Bioluminescent human prostate tumor xenografts were established by subcutaneous implantation into male mice. Tumors were irradiated with uniform or non-uniform field configurations using conventional in vivo irradiation procedures performed using a 225 kVp generator with custom lead shielding. Tumor responses were measured using Vernier calipers and by BLI using an in vivo imaging system. Survival was defined as the time to quadroupling of pre-treatment tumor volume.RESULTS:
The correlation between BLI and tumor volume measurements was found to be different for un-irradiated (R = 0.61), uniformly irradiated (R = 0.34) and partially irradiated (R = 0.30) tumors. Uniformly irradiated tumors resulted in an average tumor growth delay of 60 days with median survival of 75 days, compared to partially irradiated tumors which showed an average growth delay of 24 days and median survival of 38 days.CONCLUSIONS:
Correlation between BLI and tumor volume measurements is lower for partially irradiated tumors than those exposed to uniform dose distributions. The response of partially irradiated tumors suggests non-uniformity in response beyond physical dose distribution within the target volume. Dosimetric uncertainty associated with conventional in vivo irradiation procedures prohibits their ability to accurately determine tumor response to non-uniform radiation fields and stresses the need for image guided small animal radiation research platforms.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Neoplasias da Próstata
Tipo de estudo:
Diagnostic_studies
Limite:
Animals
/
Humans
/
Male
Idioma:
En
Revista:
Int J Radiat Biol
Assunto da revista:
RADIOLOGIA
Ano de publicação:
2015
Tipo de documento:
Article