Department of Radiology, University of Washington Medical Center, Seattle, WA 98195, USA.
Nucl Med Biol. 2011 Oct;38(7):969-78. doi: 10.1016/j.nucmedbio.2011.03.002. Epub 2011 May 5.
(18)F-Fluoroestradiol (FES) PET imaging provides a non-invasive method to measure estrogen receptor (ER) expression in tumors. Assessment of factors that could affect the quantitative level of FES uptake is important as part of the validation of FES PET for evaluating regional ER expression in breast cancer.
This study examines FES uptake in tumors from 312 FES PET scans (239 patients) with documented ER+ primary breast cancer. FES uptake was compared to clinical and laboratory data, treatment prior to or at time of scan, and properties of FES and its metabolism and transport. Linear mixed models were used to explore univariate, threshold-based and multivariate associations.
Sex hormone-binding globulin (SHBG) was inversely associated with FES SUV. Average FES uptake did not differ by levels of plasma estradiol, age or rate of FES metabolism. FES tumor uptake was greater for patients with a higher body mass index (BMI), but this effect did not persist when SUV was corrected for lean body mass (LBM). In multivariate analysis, only plasma SHBG binding was an independent predictor of LBM-adjusted FES SUV.
Calculation of FES SUV, possibly adjusted for LBM, should be sufficient to assess FES uptake for the purpose of inferring ER expression. Pre-menopausal estradiol levels do not appear to interfere with FES uptake. The availability and binding properties of SHBG influence FES uptake and should be measured. Specific activity did not have a clear influence on FES uptake, except perhaps at higher injected mass per kilogram. These results suggest that FES imaging protocols may be simplified without sacrificing the validity of the results.
（18）F-氟雌二醇（FES）PET 成像提供了一种非侵入性的方法来测量肿瘤中的雌激素受体（ER）表达。评估可能影响 FES 摄取定量水平的因素对于验证 FES PET 评估乳腺癌中区域 ER 表达非常重要。
本研究检查了 312 例（239 例患者）有记录的 ER+原发性乳腺癌 FES PET 扫描的肿瘤中 FES 的摄取。将 FES 摄取与临床和实验室数据、扫描前或扫描时的治疗以及 FES 及其代谢和转运的特性进行比较。使用线性混合模型探索单变量、基于阈值和多变量关联。
性激素结合球蛋白（SHBG）与 FES SUV 呈负相关。平均 FES 摄取与血浆雌二醇水平、年龄或 FES 代谢率无关。对于 BMI 较高的患者，FES 肿瘤摄取更高，但当 SUV 校正为瘦体重（LBM）时，这种影响并不持久。在多变量分析中，只有血浆 SHBG 结合是 LBM 校正的 FES SUV 的独立预测因子。
为了推断 ER 表达，计算 FES SUV，可能需要校正 LBM，这足以评估 FES 摄取。绝经前雌二醇水平似乎不会干扰 FES 摄取。SHBG 的可用性和结合特性会影响 FES 摄取，应进行测量。特异性活性对 FES 摄取的影响似乎并不明确，除非每公斤注射质量更高。这些结果表明，在不牺牲结果有效性的情况下，简化 FES 成像方案是可行的。
