NMR Monitoring of Temperature and Its Biological Effects

描述(申请人提供)：无创体温监测在诊断和治疗中有许多直接用途。这些包括帮助使用热疗(HT)治疗癌症，检测和定位肿瘤，诊断代谢异常，以及研究肌肉锻炼和恢复。温度的非侵入性监测对于恶性肿瘤的高温治疗特别有用，在这种情况下，应用的热量取决于区域及其周围的实际温度。利用来自R21基金(R21 CA94040)的资金，我们开发了一种基于顺磁性稀土络合物TmDOTMA-超精细位移1H信号的温度依赖关系的非侵入性MR温度计。TmDOTMA-的1H化学位移对温度的敏感性大约是水信号的60倍，对组织微环境的变化不敏感，如pH和其他离子的浓度以及大分子的存在。我们的初步数据表明，基于TmDOTMA-质子化学位移的温度计为温度监测提供了灵敏而准确的方法。R33方案的总体目标是将开发的磁共振测温方法与其他多核磁共振测量相结合，以研究在治疗过程中对实验性肿瘤的代谢和生理影响。该提案的中心假设是，在高温治疗时，通过无创磁共振波谱和成像(MRS/MRI)测量的肿瘤的生物反应，提供了关于治疗结果的更准确和可靠的信息，因为不同的肿瘤或肿瘤区域对温度的脆弱性不同。为了验证这一假设，将开发稳健的MR方法，通过体内31P、23Na和1HMRS/MRI在磁体中传递受控射频(RF)HT，并同时监测/成像HT的代谢和生理效应。拟议的磁共振技术将提供创新的方法来监测治疗期间和治疗后的温度和代谢/生理反应。将所提出的技术应用于实验性肿瘤将加深我们对HT生物学的理解，这可能被证明在设计使肿瘤对HT和其他治疗方法敏感的方法方面有价值。动物实验将是将所提出的技术应用于人类患者进行核磁共振引导的高血压治疗的一步。

DESCRIPTION (provided by applicant): Noninvasive temperature monitoring has many direct uses in diagnosis and therapy. These include aiding in the use of hyperthermia (HT) for treatment of cancer, detection and localization of tumors, diagnosing metabolic abnormalities, and studying muscle exercise and recovery. Noninvasive monitoring of temperature is particularly useful for HT treatment of malignant tumors, where the amount of heat applied depends on the actual temperature in the region and its surroundings. Using the funding from a R21 grant (R21 CA94040) we have developed a noninvasive MR thermometer based on the temperature dependence of hyperfine shifted 1H signal of the paramagnetic lanthanide complex, TmDOTMA-. 1H chemical shifts of TmDOTMA- are approximately 60 times more sensitive to temperature than the water signal and are insensitive to changes in tissue microenvironment such as pH and concentration of other ions and presence of macromolecules. Our preliminary data show that the developed thermometer, based on the proton chemical shift of TmDOTMA-, provides sensitive and accurate methods for monitoring temperature. The overall goal of this R33 proposal is to combine the developed MR thermometry method with other multinuclear MR measurements to investigate the metabolic and physiologic effects HT in experimental tumors during the treatment. The central hypothesis of the proposal is that biological response of tumors, as measured by noninvasive MR spectroscopy and imaging (MRS/MRI) at the time of HT treatment, provides more accurate and reliable information about therapy outcome than HT temperature alone because different tumors or tumor regions have different vulnerability to temperature. To test this hypothesis, robust MR methods will be developed to deliver controlled radiofrequency (RF) HT in the magnet and simultaneously monitor/image the metabolic and physiological effects of HT by in vivo 31P, 23Na, and 1H MRS/MRI. The proposed MR techniques will provide innovative methods to monitor temperature and metabolic/physiologic response to HT treatment during and after the therapy. Application of the proposed techniques to experimental tumors will enhance our understanding of HT biology, which may prove valuable in designing methods to sensitize tumors to HT and other therapies. The animal experiments will be a step toward the application of the proposed techniques to human patients for MRI-guided HT treatment.