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Normoxic polymer gel dosimetry using less toxic monomer of N-isopropyl acrylamide and X-ray computed tomography for radiation therapy applications
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Abstract
Background
Polymer gel dosimetry has been used extensively in radiation therapy for its capability in depicting a three dimensional view of absorbed dose distribution. However, more studies are required to find less toxic and more efficient polymers for application in radiotherapy dosimetry.
Aim
The purpose of this work was to evaluate the N-isopropyl acrylamide (NIPAM) gel dosimetric characteristics and optimize the protocol for X-ray computed tomography (CT) imaging of gel dosimeters for radiation therapy application.
Material and methods
A polymer gel dosimeter based on NIPAM monomer was prepared and irradiated with 60Co photons. The CT number changes following irradiation were extracted from CT images obtained with different sets of imaging parameters.
Results
The results showed the dose sensitivity of ΔNCT (H)[[ce:hsp sp="0.25"/]]=[[ce:hsp sp="0.25"/]]0.282[[ce:hsp sp="0.25"/]]±[[ce:hsp sp="0.25"/]]0.018 (H[[ce:hsp sp="0.25"/]]Gy−1) for NIPAM gel dosimeter. The optimized set of imaging exposure parameters was 120[[ce:hsp sp="0.25"/]]kVp and 200[[ce:hsp sp="0.25"/]]mA with the 10[[ce:hsp sp="0.25"/]]mm slice thickness. Results of the depth dose measurement with gel dosimeter showed a great discrepancy with the actual depth dose data.
Conclusion
According to the current study, NIPAM-based gel dosimetry with X-ray CT imaging needs more technical development and formulation refinement to be used for radiation therapy application.
Abstract
Background
Polymer gel dosimetry has been used extensively in radiation therapy for its capability in depicting a three dimensional view of absorbed dose distribution. However, more studies are required to find less toxic and more efficient polymers for application in radiotherapy dosimetry.
Aim
The purpose of this work was to evaluate the N-isopropyl acrylamide (NIPAM) gel dosimetric characteristics and optimize the protocol for X-ray computed tomography (CT) imaging of gel dosimeters for radiation therapy application.
Material and methods
A polymer gel dosimeter based on NIPAM monomer was prepared and irradiated with 60Co photons. The CT number changes following irradiation were extracted from CT images obtained with different sets of imaging parameters.
Results
The results showed the dose sensitivity of ΔNCT (H)[[ce:hsp sp="0.25"/]]=[[ce:hsp sp="0.25"/]]0.282[[ce:hsp sp="0.25"/]]±[[ce:hsp sp="0.25"/]]0.018 (H[[ce:hsp sp="0.25"/]]Gy−1) for NIPAM gel dosimeter. The optimized set of imaging exposure parameters was 120[[ce:hsp sp="0.25"/]]kVp and 200[[ce:hsp sp="0.25"/]]mA with the 10[[ce:hsp sp="0.25"/]]mm slice thickness. Results of the depth dose measurement with gel dosimeter showed a great discrepancy with the actual depth dose data.
Conclusion
According to the current study, NIPAM-based gel dosimetry with X-ray CT imaging needs more technical development and formulation refinement to be used for radiation therapy application.
Keywords
Polymer gel dosimetry; X-ray computed tomography; Radiation therapy
About this articleTitle
Normoxic polymer gel dosimetry using less toxic monomer of N-isopropyl acrylamide and X-ray computed tomography for radiation therapy applications
Journal
Reports of Practical Oncology and Radiotherapy
Issue
Pages
172-175
Published online
2010-11-01
DOI
10.1016/j.rpor.2010.10.001
Bibliographic record
Rep Pract Oncol Radiother 2010;15(6):172-175.
Keywords
Polymer gel dosimetry
X-ray computed tomography
Radiation therapy
Authors
Seyed-Mostafa Ghavami
Asghar Mesbahi
Ismaeel Pesianian
Abbas Shafaee
Mohammad-Reza Aliparasti