The Impact of Optimal Respiratory Gating and Image Noise on Evaluation of Intratumor Heterogeneity on 18F-FDG PET Imaging of Lung Cancer.

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Date
2016-11ICR Author
Author
Grootjans, W
Tixier, F
van der Vos, CS
Vriens, D
Le Rest, CC
Bussink, J
Oyen, WJG
de Geus-Oei, L-F
Visvikis, D
Visser, EP
Type
Journal Article
Metadata
Show full item recordAbstract
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.<h4>Methods</h4>We used an optimal-respiratory-gating algorithm on the list-mode data of 60 lung cancer patients who underwent <sup>18</sup>F-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.<h4>Results</h4>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.<h4>Conclusion</h4>The tested textural parameters are robust in the presence of respiratory motion artifacts and varying levels of image noise.
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Subject
Humans
Lung Neoplasms
Fluorodeoxyglucose F18
Radiopharmaceuticals
Radiographic Image Interpretation, Computer-Assisted
Positron-Emission Tomography
Radiographic Image Enhancement
Artifacts
Sensitivity and Specificity
Reproducibility of Results
Respiratory Mechanics
Algorithms
Aged
Aged, 80 and over
Middle Aged
Female
Male
Respiratory-Gated Imaging Techniques
Signal-To-Noise Ratio
Research team
Translational Molecular Imaging
Language
eng
Date accepted
2016-05-10
License start date
2016-11
Citation
Journal of nuclear medicine : official publication, Society of Nuclear Medicine, 2016, 57 (11), pp. 1692 - 1698