Cosolvent-free polymer gel dosimeters with improved dose sensitivity and resolution for x-ray CT dose response.
Phys Med Biol
; 56(7): 2091-102, 2011 Apr 07.
Article
in En
| MEDLINE
| ID: mdl-21386143
ABSTRACT
This study reports new N-isopropylacrylamide (NIPAM) polymer gel recipes with increased dose sensitivity and improved dose resolution for x-ray CT readout. NIPAM can be used to increase the solubility of N, N'-methylenebisacrylamide (Bis) in aqueous solutions from approximately 3% to 5.5% by weight, enabling the manufacture of dosimeters containing up to 19.5%T, which is the total concentration of NIPAM and Bis by weight. Gelatin is shown to have a mild influence on dose sensitivity when gels are imaged using x-ray CT, and a stronger influence when gels are imaged optically. Phantoms that contain only 3% gelatin and 5 mM tetrakis hydroxymethyl phosphonium chloride are sufficiently stiff for dosimetry applications. The best cosolvent-free gel formulation has a dose sensitivity in the linear range (~0.88 H Gy(-1)) that is a small improvement compared to the best NIPAM-based gels that incorporate isopropanol as a cosolvent (~0.80 H Gy(-1)). This new gel formulation results in enhanced dose resolution (~0.052 Gy) for x-ray CT readout, making clinical applications of this imaging modality more feasible.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Polymers
/
Radiation Dosage
/
Radiometry
/
Tomography, X-Ray Computed
Type of study:
Diagnostic_studies
Language:
En
Journal:
Phys Med Biol
Year:
2011
Document type:
Article
Affiliation country:
Canadá