Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY, United States of America.
Division of Radiation Oncology and Cancer Imaging, The Peter MacCallum Cancer Centre, Melbourne, Australia.
PLoS One. 2022 Apr 21;17(4):e0266704. doi: 10.1371/journal.pone.0266704. eCollection 2022.
To devise a new body-habitus normalizer to be used in the calculation of an SUV that is specific to the PET tracer 18F-FDG.
A cohort of 481-patients was selected for analysis of 18F-FDG uptake into tissues unaffected by their disease. Among these, 65-patients had only brain concentrations measured and the remaining 416 were randomly divided into an 86-patient test set and a 330-patient training set. Within the test set, normal liver, spleen and blood measures were made. In the training set, only normal liver concentrations were measured. Using data from the training set, a simple polynomial function of height and weight was selected and optimized in a fitting procedure to predict each patient's mean liver %ID/ml. This function, when used as a normalizer, defines a new SUV metric (SUVfdg) which we compared to SUV metrics normalized by body weight (SUVbw), lean-body mass (SUVlbm) and body surface-area (SUVbsa) in a five-fold cross-validation. SUVfdg was also evaluated in the independent brain-only and whole-body test sets.
For patients of all sizes including pediatric patients, the normal range of liver 18F-FDG uptake at 60 minutes post injection in units of SUVfdg is 1.0 ± 0.16. Liver, blood, and spleen SUVfdg in all comparisons had lower coefficients of variation compared to SUVbw SUVlbm and SUVbsa. Blood had a mean SUVfdg of 0.8 ± 0.11 and showed no correlation with age, height, or weight. Brain SUVfdg measures were significantly higher (P<0.01) in pediatric patients (4.7 ± 0.9) compared to adults (3.1 ± 0.6).
A new SUV metric, SUVfdg, is proposed. It is hoped that SUVfdg will prove to be better at classifying tumor lesions compared to SUV metrics in current use. Other tracers may benefit from similarly tracer-specific body habitus normalizers.
设计一种新的体廓归一化因子，用于计算特定于 PET 示踪剂 18F-FDG 的 SUV。
选择了 481 名患者的队列来分析组织中未受疾病影响的 18F-FDG 摄取情况。其中，65 名患者仅测量了大脑浓度，其余 416 名患者随机分为 86 名患者测试集和 330 名患者训练集。在测试集中，测量了正常的肝脏、脾脏和血液浓度。在训练集中，仅测量了正常的肝脏浓度。使用训练集的数据，选择了一个简单的身高和体重多项式函数，并在拟合过程中进行了优化，以预测每位患者的平均肝脏 %ID/ml。该函数用作归一化因子，定义了一种新的 SUV 度量（SUVfdg），我们将其与通过体重（SUVbw）、瘦体重（SUVlbm）和体表面积（SUVbsa）归一化的 SUV 度量在五次交叉验证中进行了比较。还在独立的脑仅和全身测试集中评估了 SUVfdg。
对于所有体型的患者，包括儿科患者，注射后 60 分钟肝脏 18F-FDG 摄取的正常范围以 SUVfdg 为单位为 1.0 ± 0.16。与 SUVbw、SUVlbm 和 SUVbsa 相比，肝脏、血液和脾脏 SUVfdg 的变异系数均较低。血液的 SUVfdg 平均值为 0.8 ± 0.11，与年龄、身高或体重无相关性。与成人（3.1 ± 0.6）相比，儿科患者（4.7 ± 0.9）的大脑 SUVfdg 测量值显著更高（P<0.01）。
提出了一种新的 SUV 度量 SUVfdg。希望与当前使用的 SUV 度量相比，SUVfdg 能够更好地对肿瘤病变进行分类。其他示踪剂可能会受益于类似的示踪剂特异性体廓归一化因子。
