Carter D L, MacFall J R, Clegg S T, Wan X, Prescott D M, Charles H C, Samulski T V
Department of Radiation Oncology, Duke University Medical Center, Durham, NC 27710, USA.
Int J Radiat Oncol Biol Phys. 1998 Mar 1;40(4):815-22. doi: 10.1016/s0360-3016(97)00855-9.
To determine the feasibility of measuring temperature noninvasively with magnetic resonance imaging during hyperthermia treatment of human tumors.
The proton chemical shift detected using phase-difference magnetic resonance imaging (MRI) was used to measure temperature in phantoms and human tumors during treatment with hyperthermia. Four adult patients having high-grade primary sarcoma tumors of the lower leg received 5 hyperthermia treatments in the MR scanner using an MRI-compatible radiofrequency heating applicator. Prior to each treatment, an average of 3 fiberoptic temperature probes were invasively placed into the tumor (or phantom). Hyperthermia was applied concurrent with MR thermometry. Following completion of the treatment, regions of interest (ROI) were defined on MR phase images at each temperature probe location, in bone marrow, and in gel standards placed outside the heated region. The median phase difference (compared to pretreatment baseline images) was calculated for each ROI. This phase difference was corrected for phase drift observed in standards and bone marrow. The observed phase difference, with and without corrections, was correlated with the fiberoptic temperature measurements.
The phase difference observed with MRI was found to correlate with temperature. Phantom measurements demonstrated a linear regression coefficient of 4.70 degrees phase difference per degree Celsius, with an R2 = 0.998. After human images with artifact were excluded, the linear regression demonstrated a correlation coefficient of 5.5 degrees phase difference per degree Celsius, with an R2 = 0.84. In both phantom and human treatments, temperature measured via corrected phase difference closely tracked measurements obtained with fiberoptic probes during the hyperthermia treatments.
Proton chemical shift imaging with current MRI and hyperthermia technology can be used to monitor and control temperature during treatment of large tumors in the distal lower extremity.
确定在人类肿瘤热疗过程中使用磁共振成像进行无创温度测量的可行性。
使用相差磁共振成像（MRI）检测的质子化学位移来测量热疗过程中模型和人类肿瘤的温度。四名患有小腿高级别原发性肉瘤肿瘤的成年患者在磁共振扫描仪中使用与MRI兼容的射频加热装置接受了5次热疗。每次治疗前，平均将3根光纤温度探头侵入性地放置到肿瘤（或模型）中。热疗与磁共振测温同时进行。治疗完成后，在每个温度探头位置、骨髓以及加热区域外放置的凝胶标准物的磁共振相位图像上定义感兴趣区域（ROI）。计算每个ROI的中位相差（与治疗前基线图像相比）。对在标准物和骨髓中观察到的相位漂移进行了该相差的校正。观察到的有无校正的相差与光纤温度测量值相关。
发现MRI观察到的相差与温度相关。模型测量显示每摄氏度的线性回归系数为4.70度相差，R2 = 0.998。在排除有伪影的人体图像后，线性回归显示每摄氏度的相关系数为5.5度相差，R2 = 0.84。在模型和人体治疗中，通过校正后的相差测量的温度在热疗过程中紧密跟踪光纤探头获得的测量值。
利用当前的MRI和热疗技术进行质子化学位移成像可用于监测和控制下肢远端大肿瘤治疗过程中的温度。
