Mayrovitz H N, Weingrad D N, Lopez L
Lymphology. 2016 Mar;49(1):27-35.
Previous work showed tissue dielectric constant (TDC) measurements at 300 MHz useful to evaluate local skin water and then a hand-held compact version provided values similar to the original multi-probe system when assessed in healthy subjects. Our current goals were to use the compact portable device to determine: 1) its utility in assessing agerelated differences between younger healthy women vs. women with breast cancer (BC); 2) upper-arm site differences in women with BC and 3) its utility and limitations of a single measurement vs. averaging triplicate measurements. A total of 84 women were included; 42 were young (24.0 ± 2.4 years) self-described healthy women (group A) and 42 were older (65.5 ± 1.6 years) women with recently diagnosed BC who were awaiting surgery (group B). In both groups TDC values were assessed on the anterior forearm and in group B at the hand, forearm and biceps with all measurements bilateral and in triplicate Results showed the following. 1) Forearm TDC values are similar for younger and older groups with no significant differences (NSD) between groups or between dominant and nondominant sides or inter-arm ratios. 2) Hand TDC values are about 21% greater than forearm and biceps values but inter-arm ratios (at-risk/contralateral) are NSD among sites with values for hand, forearm and biceps of 1.027 ± 0.180, 0.997 ± 0.066 and 1.010 ± 0.075 respectively. 3) Based on limits of agreement analyses, single TDC measurements are adequate for most forearm and biceps evaluations but multiple measurements are likely needed for hand measurements. 4) Theoretical detection thresholds for nilateral lymphedema using a 3SD limit of inter-arm ratios are 1.57, 1.20 and 1.24 for and, forearm and biceps. These ratios indicate likely useful forearm and biceps thresholds but a less useful ratio at the hand due primarily to the large variance in hand TDC values among patients.
先前的研究表明，在300兆赫下测量组织介电常数（TDC）有助于评估局部皮肤水分，随后一种手持式紧凑型设备在健康受试者中进行评估时，所提供的值与原始多探头系统相似。我们当前的目标是使用这种紧凑型便携式设备来确定：1）其在评估年轻健康女性与乳腺癌（BC）女性之间年龄相关差异方面的效用；2）BC女性上臂部位的差异；3）单次测量与三次测量平均值相比的效用和局限性。总共纳入了84名女性；42名是年轻（24.0±2.4岁）自称健康的女性（A组），42名是年龄较大（65.5±1.6岁）、最近诊断为BC且正在等待手术的女性（B组）。在两组中，均在前臂进行TDC值评估，在B组中还在手部、前臂和二头肌处进行评估，所有测量均为双侧且重复三次。结果如下：1）年轻组和老年组的前臂TDC值相似，组间、优势侧与非优势侧之间或双臂比率均无显著差异（NSD）。2）手部TDC值比前臂和二头肌的值大约高21%，但双臂比率（患侧/对侧）在各部位之间无显著差异，手部、前臂和二头肌的值分别为1.027±0.180、0.997±0.066和1.010±0.075。3）基于一致性界限分析，单次TDC测量对于大多数前臂和二头肌评估来说是足够的，但手部测量可能需要多次测量。4）使用双臂比率的3SD界限对单侧淋巴水肿的理论检测阈值，对于手部、前臂和二头肌分别为1.57、1.20和1.24。这些比率表明前臂和二头肌的阈值可能有用，但手部的比率不太有用，主要是因为患者手部TDC值的差异较大。
