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Dose profile establishment of new I-125 brachytherapy seed by radiochromic film
|dc.description||Due to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to email@example.com, referencing the URI of the item.||en|
|dc.description||Includes bibliographical references (leaves 62-63).||en|
|dc.description||Issued also on microfiche from Lange Micrographics.||en|
|dc.description.abstract||The dose profile of a prototype IS 125 I-125 brachytherapy seed was measured using MD-55 radiochromic film. Irradiated films were scanned by a document scanner and results were compared with results obtained when a densitometer was used. Images produced by a document scanner were converted to dose with several graphic related programs. Advantages of scanning the films with a document scanner versus with a densitometer include: no diffraction from the film holder used in densitometer scans, shorter scanning times and smaller experimental error. Experimental precision of 0.35 % relative standard deviation was obtained using the document scanner, but only 9 % could be achieved with the densitometer. As expected, the measured dose profiles showed this new brachytherapy seed to be similar to the commercially available model 6711 seed because of similar source geometry. Exposures with the seed embedded in a paraffin medium produced different profiles from when the seed was embedded in Plexiglas because of the difference of properties in these media. Unequal thickness at the two ends of the seed contributed to anisotropy in the dose distribution. Anisotropy in Plexiglas was a factor of 2 more than in paraffin for both longitudinal axes. Radial dose fall-off in paraffin was similar in shape to MCNP calculations out to 1 cm. The use of a document scanner for measurement of radiochromic film was shown to be an acceptable and convenient method for low-energy I-125 brachytherapy seed dosimetry. Further study is needed to evaluate the measurement of dose at extended distances from the seed, and to allow comparison to commercially available sources in accordance with AAPM TG43.||en|
|dc.publisher||Texas A&M University|
|dc.rights||This thesis was part of a retrospective digitization project authorized by the Texas A&M University Libraries in 2008. Copyright remains vested with the author(s). It is the user's responsibility to secure permission from the copyright holder(s) for re-use of the work beyond the provision of Fair Use.||en|
|dc.subject||Major health physics.||en|
|dc.title||Dose profile establishment of new I-125 brachytherapy seed by radiochromic film||en|
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