Open this publication in new window or tab >>2014 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]
Lithium formate has shown to be a material with properties suitable for electron paramagnetic resonance (EPR) dosimetry, among them up to 7 times higher sensitivity compared to alanine, which is a well-established EPR detector material for dose determinations in radiotherapy.
The aim of this thesis was to further investigate the properties of lithium formate and develop the dosimetry system towards applications in radiotherapy. The intrinsic efficiency for energies of relevance to brachytherapy and the signal stability were investigated. The dosimetry system was expanded to include a smaller dosimeter model, suitable for measurements in dose gradient regions. An individual sensitivity correction method was applied to the smaller dosimeters to be able to perform dose determinations with the same precision as for the larger ones. EPR dosimetry in general is time consuming and effort was spent to optimize the signal readout procedure regarding measurement time and measurement precision.
The system was applied in two clinical applications chosen for their high demands on the dosimetry system: 1) a dosimetry audit for external photon beam therapy and 2) dose verification measurements around a low energy HDR brachytherapy source.
The conclusions drawn from this thesis were: dose determinations can be performed with a standard uncertainty of 1.8-2.5% using both the original size dosimeters and the new developed smaller ones. The dosimetry system is robust and useful for applications when high measurement precision and accuracy is prioritized. It is a good candidate for dosimetry audits, both in external beam therapy and brachytherapy.
Place, publisher, year, edition, pages
Linköping: Linköping University Electronic Press, 2014. p. 51
Series
Linköping University Medical Dissertations, ISSN 0345-0082 ; 1417
National Category
Radiology, Nuclear Medicine and Medical Imaging
Identifiers
urn:nbn:se:liu:diva-111091 (URN)10.3384/diss.diva-111091 (DOI)978-91-7519-246-8 (ISBN)
Public defence
2014-11-06, Eken, ingång 65, plan 9, Campus US, Linköpings universitet, Linköping, 09:00 (English)
Opponent
Supervisors
2014-10-072014-10-072021-10-13Bibliographically approved