Vanea Emilia S, Levêque Philippe, Abboud Fadi, Bol Anne, Denis Jean Marc, Kolbun Natallia, Vynckier Stefaan, Gallez Bernard
Biomedical Magnetic Resonance Unit, Université catholique de Louvain, Brussels, Belgium.
Magn Reson Med. 2009 May;61(5):1225-31. doi: 10.1002/mrm.21947.
Electron paramagnetic resonance (EPR) spectroscopy has been successfully employed to determine radiation dose using alanine. The EPR signal intensity reflects the number of stable free radicals produced, and provides a quantitative measurement of the absorbed dose. The aim of the present study was to explore whether this principle can be extended to provide information on spatial dose distribution using EPR imaging (EPRI). Lithium formate was selected because irradiation induces a single EPR line, a characteristic that is particularly convenient for imaging purposes. (125)I-brachytherapy seeds were inserted in tablets made of lithium formate. Images were acquired at 1.1 GHz. Monte Carlo (MC) calculations were used for comparison. The dose gradient can be determined using two-dimensional (2D) EPR images. Quantitative data correlated with the dose estimated by the MC simulations, although differences were observed. This study provides a first proof-of-concept that EPRI can be used to estimate the gradient dose distribution in phantoms after irradiation.
电子顺磁共振（EPR）光谱法已成功用于使用丙氨酸测定辐射剂量。EPR信号强度反映了产生的稳定自由基数量，并提供了吸收剂量的定量测量。本研究的目的是探讨这一原理是否可以扩展，以使用EPR成像（EPRI）提供空间剂量分布信息。选择甲酸锂是因为辐照会诱导出一条单一的EPR谱线，这一特性对于成像目的特别方便。将（125）I近距离放射治疗种子插入由甲酸锂制成的片剂中。在1.1 GHz下采集图像。使用蒙特卡罗（MC）计算进行比较。可以使用二维（2D）EPR图像确定剂量梯度。定量数据与MC模拟估计的剂量相关，尽管观察到了差异。本研究提供了第一个概念验证，即EPRI可用于估计辐照后体模中的梯度剂量分布。
