TY  - JOUR
AU  - Höfel, Sebastian
AU  - Zwicker, Felix
AU  - Fix, Michael K
AU  - Drescher, Malte
TI  - Towards liquid EPR dosimetry using nitroxides in aqueous solution.
JO  - Physics in medicine and biology
VL  - 69
IS  - 5
SN  - 0031-9155
CY  - Bristol
PB  - IOP Publ.
M1  - DKFZ-2024-00439
SP  - 055026
PY  - 2024
AB  - Objective. Water-equivalent dosimeters are desirable for dosimetry in radiotherapy. The present work investigates basic characteristics of novel aqueous detector materials and presents a signal loss approach for electron paramagnetic resonance (EPR) dosimetry.Approach. The proposed principle is based on the radiation dose dependent annihilation of EPR active nitroxides (NO·) in aqueous solutions. Stable nitroxide radicals (3-Maleimido-2,2,5,5-tetramethyl-1-pyrrolidinyloxy (MmP), 3-Carbamoyl-2,2,5,5-tetramethyl-1-pyrrolidinyloxy (CmP)) in aqueous solutions containing dimethyl sulfoxide (DMSO) as an additive were filled in glass capillaries for irradiation and EPR readout. Radiation doses ranging from 1 to 64 Gy were applied with a clinical 6 MV flattening filter free photon beam. EPR readout was then performed with a X-band benchtop spectrometer. The dose response, temporal stability and reproducibility of the samples' EPR signal amplitudes as well as the influence of the nitroxide concentration between 10 and 160μM on the absolute signal loss were investigated using MmP. CmP was used to examine the dependence of the dose response on DMSO concentration between 0 and 10 vol
KW  - Electron Spin Resonance Spectroscopy: methods
KW  - Reproducibility of Results
KW  - Dimethyl Sulfoxide
KW  - Radiometry: methods
KW  - Water
KW  - Nitrogen Oxides
KW  - EPR dosimetry (Other)
KW  - dimethyl sulfoxide (Other)
KW  - nitroxide (Other)
KW  - radiotherapy (Other)
KW  - water equivalence (Other)
KW  - nitroxyl (NLM Chemicals)
KW  - Dimethyl Sulfoxide (NLM Chemicals)
KW  - Water (NLM Chemicals)
KW  - Nitrogen Oxides (NLM Chemicals)
LB  - PUB:(DE-HGF)16
C6  - pmid:38306975
DO  - DOI:10.1088/1361-6560/ad25c4
UR  - https://inrepo02.dkfz.de/record/288730
ER  -