title: New normoxic N-(Hydroxymethyl)acrylamide based polymer gel for 3D dosimetry in radiation therapy.
abstract: A novel composition of normoxic polymer gel dosimeters based on radiation-induced polymerization of N-(Hydroxymethyl)acrylamide (NHMA) is introduced in this study for 3D dosimetry for Quality Assurance (QA) in radiation therapy. Dosimeters were irradiated by 6, 10 and 18MV photon beams of a medical linear accelerator at various dose rates to doses of up to 20Gy. The dose response of polymer gel dosimeters was studied using nuclear magnetic resonance (NMR) spin-spin relaxation rate (R2) of hydrogen protons within the water molecule. Also, we measured gel response using absorption spectroscopy and found that this novel gel can be successfully utilized for both MRI- and OCT- (Optical Computed Tomography) based 3D dosimetry. We investigated dosimetric properties of six different compositions of the new NHMA-based gel in terms of dose rate, radiation beam quality and stability of dose-dependent polymerization after irradiation. We found no significant effects of these parameters on the novel gel dosimeter performance in both relaxation rate and absorbance measurements.
authors.affiliation: Radiation Technology Center, Atomic Energy Research Institute, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia; Medical Imaging Department, Faculty of Allied Health Sciences, Hashemite University, Zarqa, Jordan. Electronic address: khalid6d@yahoo.com.
authors.forename: Khalid A
authors.initials: KA
authors.lastname: Rabaeh
authors.affiliation: Radiation Technology Center, Atomic Energy Research Institute, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia.
authors.forename: Ahmed A
authors.initials: AA
authors.lastname: Basfar
authors.affiliation: Biomedical Physics Department, Research Center, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.
authors.forename: Akram A
authors.initials: AA
authors.lastname: Almousa
authors.affiliation: Medical Physics Unit, McGill University, Montréal, Québec, Canada.
authors.forename: Slobodan
authors.initials: S
authors.lastname: Devic
authors.affiliation: Biomedical Physics Department, Research Center, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia; Medical Physics Unit, McGill University, Montréal, Québec, Canada.
authors.forename: Belal
authors.initials: B
authors.lastname: Moftah
mesh_terms: D000178:Acrylamides / Q000737:chemistry*; D005782:Gels; D011108:Polymers / Q000737:chemistry*; D011874:Radiometry / Q000379:methods*
chemical_list: D000178:Acrylamides; D005782:Gels; D011108:Polymers; C066443:N-methylolacrylamide
keywords: Dosimeter; N-(Hydroxymethyl)acrylamide; Normoxic gel; Radiotherapy