NMR relaxometry measurements of Fricke gel dosimeters exposed to neutrons

作者：Marrale Maurizio^*; Brai Maria; Longo Anna; Gallo Salvatore; Tomarchio Elio; Tranchina Luigi; Gagliardo Cesare; D' Errico Francesco

来源：Radiation Physics and Chemistry, 2014, 104: 424-428.

DOI：10.1016/j.radphyschem.2014.05.049

• Gel dosimeter
• Fricke method
• Nuclear magnetic resonance relaxometry
• Magnetic resonance imaging
• Neutron beam

Fricke infused gel matrices offer several features making them suitable for dosimetric applications; among these there are tissue equivalence, low cost and ease of preparation. Their nuclear magnetic resonance (NMR) relaxation properties can be used as a radiation detector for the dosimetry of beams used in cancer therapy. In recent years neutron capture therapy has been resumed for the treatment of various types of cancer and it requires three-dimensional mapping of the neutron fields. In this work, we investigated this particular application through NMR relaxometry and MR imaging of Fricke gels exposed to neutrons. We analyzed both the R-1 and R-2 relaxation rates, which relate to the longitudinal T-1 and transversal T-2 relaxation times. In particular, we found that the relaxation rate R-2 does not depend on the neutron fluence, whereas the relaxation rate R-1 increases linearly with the fluence. The magnetic resonance imaging acquisitions showed that T-1-weighted images allow the characterization of samples exposed to different neutron fluences.

• 出版日期2014-11