The Impact of Optimal Respiratory Gating and Image Noise on Evaluation of Intratumor Heterogeneity on 18F-FDG PET Imaging of Lung Cancer
The Impact of Optimal Respiratory Gating and Image Noise on Evaluation of Intratumor Heterogeneity on 18F-FDG PET Imaging of Lung Cancer
复制标题
DOI：
10.2967/jnumed.116.173112
复制
发表时间：
2016-11-01
影响因子：
9.3
通讯作者：
Visser, Eric P.
中科院分区：
文献类型：
--
作者：
Grootjans, Willem;Tixier, Florent;Visser, Eric P.
使用PET图像上的纹理参数精确测量肿瘤内异质性对于精确表征癌症病变是必不可少的。在这项研究中，我们研究了呼吸运动和不同的噪声水平对肺癌患者纹理参数量化的影响。方法：我们使用最优呼吸门控算法对60例肺癌患者进行F-18-FDG PET检查的列表模式数据进行分析。使用35%的占空比（总采集PET数据的百分比）重建图像。此外，还重建了不同统计质量的非电离图像（使用35%和100%的PET数据），以研究图像噪声的影响。计算了与患者结局相关的几个全局图像衍生指数和纹理参数（熵、高强度强调、区域百分比和相异性）。采用考克斯回归模型评价最佳呼吸门控和图像噪声对肿瘤内异质性评估的临床影响，以总生存率作为结局指标。使用Bonferroni校正调整统计学显著性阈值以进行多重比较。结果如下：在下肺叶中，呼吸运动显著影响了除熵（P > 0.007）外的所有纹理参数（P <0.007）的瘤内异质性定量。熵、相异性、区域百分比和高强度强调的平均增加分别为1.3% +/- 1.5%（P = 0.02）、11.6% +/- 11.8%（P = 0.006）、2.3% +/- 2.2%（P = 0.002）和16.8% +/- 17.2%（P = 0.006）。肺上叶病变组间差异无统计学意义（P > 0.007）。PET图像的统计质量差异对纹理参数的影响小于呼吸运动，未观察到显著差异。中位随访时间为35个月（范围，7-39个月）。在总生存率的多变量分析中，总病变糖酵解和高强度强调是两个最相关的图像衍生指数，被认为是模型的独立显著协变量，无论考虑的图像类型如何。结论：所测试的纹理参数在存在呼吸运动伪影和不同水平的图像噪声的情况下是稳健的。
Accurate measurement of intratumor heterogeneity using parameters of texture on PET images is essential for precise characterization of cancer lesions. In this study, we investigated the influence of respiratory motion and varying noise levels on quantification of textural parameters in patients with lung cancer. Methods: We used an optimal-respiratory-gating algorithm on the list-mode data of 60 lung cancer patients who underwent F-18-FDG PET. The images were reconstructed using a duty cycle of 35% (percentage of the total acquired PET data). In addition, nongated images of varying statistical quality (using 35% and 100% of the PET data) were reconstructed to investigate the effects of image noise. Several global image-derived indices and textural parameters (entropy, high-intensity emphasis, zone percentage, and dissimilarity) that have been associated with patient outcome were calculated. The clinical impact of optimal respiratory gating and image noise on assessment of intratumor heterogeneity was evaluated using Cox regression models, with overall survival as the outcome measure. The threshold for statistical significance was adjusted for multiple comparisons using Bonferroni correction. Results: In the lower lung lobes, respiratory motion significantly affected quantification of intratumor heterogeneity for all textural parameters (P < 0.007) except entropy (P > 0.007). The mean increase in entropy, dissimilarity, zone percentage, and high-intensity emphasis was 1.3% +/- 1.5% (P = 0.02) 11.6% +/- 11.8% (P = 0.006), 2.3% +/- 2.2% (P = 0.002), and 16.8% +/- 17.2% (P = 0.006), respectively. No significant differences were observed for lesions in the upper lung lobes (P > 0.007). Differences in the statistical quality of the PET images affected the textural parameters less than respiratory motion, with no significant difference observed. The median follow-up time was 35 mo (range, 7-39 mo). In multivariate analysis for overall survival, total lesion glycolysis and high-intensity emphasis were the two most relevant image-derived indices and were considered to be independent significant covariates for the model regardless of the image type considered. Conclusion: The tested textural parameters are robust in the presence of respiratory motion artifacts and varying levels of image noise.