Ryan T P, Samulski T V, Lyons B E, Lee E, Holdren D, Fessenden P, Strohbehn J W
Dartmouth Medical Center, Dartmouth College, Hanover, NH 03755.
Int J Radiat Oncol Biol Phys. 1989 Jun;16(6):1557-64. doi: 10.1016/0360-3016(89)90962-0.
The smearing effects due to thermal conduction along various, nonenergized, interstitial devices were quantified in a flow cell-thermal step gradient. An insulated cylindrical flow cell with a high (ca 45 degrees C, 1.12 cm i.d., 1.6 cm o.d.) temperature region surrounded by a low (ca 37 degrees C) temperature region was used to compare temperature profiles measured with a thermocouple sensor inside a Stanford radiofrequency (RF) hyperthermia/brachytherapy catheter, a BSD instrumented microwave (MW) antenna (i.e., thermistor integrated into a dipole antenna) and a Dartmouth MW antenna with a juxtaposed optical sensor. Two parameters were used to quantify the thermal smearing of each interstitial device in the flow cell: (a) the maximum temperature difference (MTD) and (b) the full- width- half-maximum (FWHM) of the high temperature region. The "true" temperature maximum (45.4 degrees C) and distribution (FWHM = 1.65 +/- 0.06 cm) were measured with an optical sensor. These data indicate that the BSD instrumented MW antenna significantly smeared the true temperature profile (MTD = 2.7 degrees C, FWHM = 2.1 cm), as did the Dartmouth MW antenna (MTD = 1.5 degrees C, FWHM = 1.7 cm). The Stanford RF catheter, when insulated, resulted in minimal smearing (MTD = 0.3 degrees C, FWHM = 1.9 cm). Moreover, when the insulation was removed so the RF electrode was exposed to the thermal step gradient, smearing was again minimal (MTD = 0.3 degrees C, FWHM = 1.9 cm).
在流动池 - 热步梯度中对沿各种未通电的间质装置的热传导所导致的涂抹效应进行了量化。使用一个绝缘的圆柱形流动池，其具有一个高温区域（约45摄氏度，内径1.12厘米，外径1.6厘米）被一个低温区域（约37摄氏度）包围，以比较在斯坦福射频（RF）热疗/近距离治疗导管、BSD仪器化微波（MW）天线（即集成到偶极天线中的热敏电阻）以及带有并列光学传感器的达特茅斯MW天线内部用热电偶传感器测量的温度分布。使用两个参数来量化流动池中每个间质装置的热涂抹：（a）最大温差（MTD）和（b）高温区域的半高宽（FWHM）。用光学传感器测量“真实”的温度最大值（45.4摄氏度）和分布（FWHM = 1.65±0.06厘米）。这些数据表明，BSD仪器化MW天线显著涂抹了真实温度分布（MTD = 2.7摄氏度，FWHM = 2.1厘米），达特茅斯MW天线也是如此（MTD = 1.5摄氏度，FWHM = 1.7厘米）。斯坦福RF导管在绝缘时导致的涂抹最小（MTD = 0.3摄氏度，FWHM = 1.9厘米）。此外，当去除绝缘使得RF电极暴露于热步梯度时，涂抹再次最小（MTD = 0.3摄氏度，FWHM = 1.9厘米）。
