Jensen Mads R, Simonsen Lene, Karlsmark Tonny, Bülow Jens
Department of Clinical Physiology and Nuclear Medicine, Bispebjerg Hospital, University Hospital of Copenhagen, Copenhagen, Denmark.
Clin Physiol Funct Imaging. 2012 Mar;32(2):126-32. doi: 10.1111/j.1475-097X.2011.01066.x. Epub 2011 Nov 10.
Lymphoscintigraphy is currently the leading diagnostic modality of lower extremity lymphoedema but has been criticized for being unreliable. Washout rate constants have been investigated and proven to be of diagnostic value in several studies of breast-cancer-related lymphoedema; however, the applicability in lower extremity lymphoedema needs further evaluation. The aim of the study was to verify if washout of (99m) Tc-human serum albumin ((99m) Tc-HSA) is a reliable diagnostic tool in lower extremity lymphoedema.
Twenty healthy volunteers and eight patients (11 legs) with lymphoscintigraphy verified lower extremity lymphoedema participated in the study. A depot consisting of 0.1 ml 10 MBq/ml (99m) Tc-HSA was injected subcutaneously into the dorsum of each foot. The depot washout rate was measured using a portable scintillation detector system and time-activity curves were generated. After 30 min of supine rest and 10 min of standardized ergometric exercise, measurements were recorded for 20 min. Following correction for physical decay of (99m) Tc, the depot washout rate constant was calculated using linear regression analysis. Finally depot half-life was calculated from the washout rate constant.
Median half-life for healthy volunteers was 9.4 h (range 2.5-28.3 h). Median half-life for lymphoedema patients was 10.7 h (range 1.5-35.1 h). No statistical significant difference could be detected between healthy volunteers and lymphoedema patients (P = 0.78).
The washout rate of a subcutaneous (99m) Tc-HSA depot is not a reliable diagnostic tool in examination of lower extremity lymphoedema. Additional examinations revealed in vivo instability of the utilized (99m) Tc-HSA as the likely reason.
淋巴闪烁造影术目前是下肢淋巴水肿的主要诊断方法，但因其不可靠而受到批评。洗脱率常数已在多项与乳腺癌相关的淋巴水肿研究中进行了调查，并被证明具有诊断价值；然而，其在下肢淋巴水肿中的适用性需要进一步评估。本研究的目的是验证（99m）锝-人血清白蛋白（（99m）Tc-HSA）的洗脱是否是下肢淋巴水肿的可靠诊断工具。
20名健康志愿者和8例经淋巴闪烁造影术证实患有下肢淋巴水肿的患者（11条腿）参与了本研究。将由0.1 ml 10 MBq/ml（99m）Tc-HSA组成的储存库皮下注射到每只脚的背部。使用便携式闪烁探测器系统测量储存库的洗脱率，并生成时间-活性曲线。在仰卧休息30分钟和进行10分钟标准化测力计运动后，记录20分钟的测量值。在对（99m）Tc的物理衰变进行校正后，使用线性回归分析计算储存库洗脱率常数。最后根据洗脱率常数计算储存库半衰期。
健康志愿者的中位半衰期为9.4小时（范围为2.5-28.3小时）。淋巴水肿患者的中位半衰期为10.7小时（范围为1.5-35.1小时）。健康志愿者和淋巴水肿患者之间未检测到统计学显著差异（P = 0.78）。
皮下（99m）Tc-HSA储存库的洗脱率不是检查下肢淋巴水肿的可靠诊断工具。进一步检查发现，所用（99m）Tc-HSA在体内不稳定可能是原因。
