Hydrogels for Three-Dimensional Ionizing-Radiation Dosimetry
Open Access
- 21 June 2021
- Vol. 7 (2), 74
- https://doi.org/10.3390/gels7020074
Abstract
Radiation-sensitive gels are among the most recent and promising developments for radiation therapy (RT) dosimetry. RT dosimetry has the twofold goal of ensuring the quality of the treatment and the radiation protection of the patient. Benchmark dosimetry for acceptance testing and commissioning of RT systems is still based on ionization chambers. However, even the smallest chambers cannot resolve the steep dose gradients of up to 30–50% per mm generated with the most advanced techniques. While a multitude of systems based, e.g., on luminescence, silicon diodes and radiochromic materials have been developed, they do not allow the truly continuous 3D dose measurements offered by radiation-sensitive gels. The gels are tissue equivalent, so they also serve as phantoms, and their response is largely independent of radiation quality and dose rate. Some of them are infused with ferrous sulfate and rely on the radiation-induced oxidation of ferrous ions to ferric ions (Fricke-gels). Other formulations consist of monomers dispersed in a gelatinous medium (Polyacrylamide gels) and rely on radiation-induced polymerization, which creates a stable polymer structure. In both gel types, irradiation causes changes in proton relaxation rates that are proportional to locally absorbed dose and can be imaged using magnetic resonance imaging (MRI). Changes in color and/or opacification of the gels also occur upon irradiation, allowing the use of optical tomography techniques. In this work, we review both Fricke and polyacrylamide gels with emphasis on their chemical and physical properties and on their applications for radiation dosimetry.Keywords
This publication has 203 references indexed in Scilit:
- An evaluation of dosimetric characteristics of MAGIC gel modified by adding formaldehyde (MAGIC-f)Radiation Measurements, 2012
- Investigation of ultrasonic properties of MAGIC gels for pulse-echo gel dosimetryJournal of Physics: Conference Series, 2010
- Polymer gel dosimetryPhysics in Medicine & Biology, 2010
- The use of gel dosimetry to measure the 3D dose distribution of a90Sr/90Y intravascular brachytherapy seedPhysics in Medicine & Biology, 2009
- Removal of sodium acetate in poly(vinyl alcohol) and its quantification by 1H NMR spectroscopyJournal of Applied Polymer Science, 2007
- Dosimetric characteristics of a new unshielded silicon diode and its application in clinical photon and electron beamsMedical Physics, 2005
- Tissue-equivalent gel for non-invasive spatial radiation dose measurementsNuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2000
- Multiexponential relaxation in Fricke agarose gels: implications for NMR dosimetryPhysics in Medicine & Biology, 1996
- Chelator effect on ion diffusion in ferrous‐sulfate‐doped gelatin gel dosimeters as analyzed by MRIMedical Physics, 1996
- Dose-response curves for Fricke-infused agarose gels as obtained by nuclear magnetic resonancePhysics in Medicine & Biology, 1990