Department of Nuclear Medicine, Centre Eugène Marquis, Rennes, France.
Department of Nuclear Medicine, Univ Rennes, CLCC Eugène Marquis, Inserm, LTSI - UMR 1099 research unit, Rennes, France.
PLoS One. 2020 Apr 22;15(4):e0232141. doi: 10.1371/journal.pone.0232141. eCollection 2020.
3,4-dihydroxy-6-[18F]fluoro-L-phenylalanine (FDOPA) uptake quantification in glioma assessment can be distorted using a non-optimal time frame binning of time-activity curves (TAC). Under-sampling or over-sampling dynamic PET images induces significant variations on kinetic parameters quantification. We aimed to optimize temporal time frame binning for dynamic FDOPA PET imaging.
Fourteen patients with 33 tumoral TAC with biopsy-proven gliomas were analysed. The mean SUVmax tumor-to-brain ratio (TBRmax) were compared at 20 min and 35 min post-injection (p.i). Five different time frame samplings within 20 min were compared: 11x10sec-6x15sec-5x20sec-3x300sec; 8x15sec- 2x30sec- 2x60sec- 3x300sec; 6x20sec- 8x60sec- 2x300sec; 10x30sec- 3x300sec and 4x45sec- 3x90sec- 5x150sec. The reversible single-tissue compartment model with blood volume parameter (VB) was selected using the Akaike information criterion. K1 values extracted from 1024 noisy simulated TAC using Monte Carlo method from the 5 different time samplings were compared to a target K1 value as the objective, which is the average of the K1 values extracted from the 33 lesions using an imaging-derived input function for each patient.
The mean TBRmax was significantly higher at 20 min p.i. than at 35 min p.i (respectively 1.4 +/- 0.8 and 1.2 +/- 0.6; p <0.001). The target K1 value was 0.161 mL/ccm/min. The 8x15sec- 2x30sec- 2x60sec- 3x300sec time sampling was the optimal time frame binning. K1 values extracted using this optimal time frame binning were significantly different with K1 values extracted from the other time frame samplings, except with K1 values obtained using the 11x10sec- 6x15sec -5x20sec-3x300sec time frame binning.
This optimal sampling schedule design (8x15sec- 2x30sec- 2x60sec- 3x300sec) could be used to minimize bias in quantification of FDOPA uptake in glioma using kinetic analysis.
在评估胶质瘤时，使用非最佳时间帧 binning 对 3,4-二羟基-6-[18F]氟-L-苯丙氨酸（FDOPA）摄取进行定量可能会产生偏差。动态 PET 图像的欠采样或过采样会导致动力学参数定量的显著变化。我们旨在优化动态 FDOPA PET 成像的时间框架 binning。
分析了 14 名经活检证实为胶质瘤的患者的 33 个肿瘤 TAC。比较了注射后 20 分钟和 35 分钟时的平均 SUVmax 肿瘤与脑比（TBRmax）。比较了 20 分钟内的 5 种不同时间框架采样：11x10sec-6x15sec-5x20sec-3x300sec；8x15sec-2x30sec-2x60sec-3x300sec；6x20sec-8x60sec-2x300sec；10x30sec-3x300sec 和 4x45sec-3x90sec-5x150sec。使用 Akaike 信息准则选择具有血容量参数（VB）的可逆单组织隔室模型。使用 Monte Carlo 方法从 5 种不同时间采样中从 1024 个噪声模拟 TAC 中提取的 K1 值与目标 K1 值进行比较，目标 K1 值是使用每个患者的成像衍生输入函数从 33 个病变中提取的 K1 值的平均值。
与 35 分钟 p.i.相比，20 分钟 p.i.时 TBRmax 明显更高（分别为 1.4 +/- 0.8 和 1.2 +/- 0.6；p <0.001）。目标 K1 值为 0.161 mL/ccm/min。8x15sec-2x30sec-2x60sec-3x300sec 时间采样是最佳的时间框架 binning。使用此最佳时间框架 binning 提取的 K1 值与使用其他时间框架采样提取的 K1 值显着不同，除了使用 11x10sec-6x15sec-5x20sec-3x300sec 时间框架 binning 提取的 K1 值外。
这种最佳采样方案设计（8x15sec-2x30sec-2x60sec-3x300sec）可用于最小化使用动力学分析定量 FDOPA 摄取在胶质瘤中的偏差。
