Abstract
Purpose: To determine whether radiomics texture features can be reproducibly obtained from megavoltage computed tomographic (MVCT) images acquired by Helical TomoTherapy (HT) with different imaging conditions.Methods: For each of the 195 textures enrolled, the mean intrapatient difference, which is considered to be the benchmark for reproducibility, was calculated from the MVCT images of 22 patients with early-stage non-small-cell lung cancer. Test–retest MVCT images of an in-house designed phantom were acquired to determine the concordance correlation coefficient (CCC) for these 195 texture features. Features with high reproducibility (CCC > 0.9) in the phantom test–retest set were investigated for sensitivities to different imaging protocols, scatter levels, and motion frequencies using a wood phantom and in-vitro animal tissues.Results: Of the 195 features, 165 (85%) features had CCC > 0.9. For the wood phantom, 124 features were reproducible in two kinds of scatter materials, and further investigations were performed on these features. For animal tissues, 108 features passed the criteria for reproducibility when one layer of scatter was covered, while 106 and 108 features of in-vitro liver and bone passed with two layers of scatter, respectively. Considering the effect of differing acquisition pitch (AcP), 97 features extracted from wood passed, while 103 and 59 features extracted from in-vitro liver and bone passed, respectively. Different reconstruction intervals (RI) had a small effect on the stability of the feature value. When AcP and RI were held consistent without motion, all 124 features calculated from wood passed, and a majority (122 of 124) of the features passed when imaging with a “fine” AcP with different RIs. However, only 55 and 40 features passed with motion frequencies of 20 and 25 beats per minute, respectively.Conclusion: Motion frequency has a significant impact on MVCT texture features, and features from MVCT were more reproducibility in different scatter conditions than those from CBCT. Considering the effects of AcP and RI, the scanning protocols should be kept consistent when MVCT images are used for feature analysis. Some radiomics features from HT MVCT images are reproducible and could be used for creating clinical prediction models in the future.
Highlights
Helical Tomotherapy (HT) has been widely used for intensitymodulated radiation therapy (IMRT) [1, 2]
We examined whether the addition of scattering material will introduce changes to the texture features that were larger than the mean intrapatient difference (MID)
For wood, our results found that 75.15% of features with correlation coefficient (CCC) > 0.9 changed less than the MID, which indicated that megavoltage computed tomotherapy (MVCT) features are more reproducible in various scatter conditions than CBCT features
Summary
Helical Tomotherapy (HT) has been widely used for intensitymodulated radiation therapy (IMRT) [1, 2]. Daily MVCT scans have been widely used for setup verification [4] These daily MVCT images contain setup information and variations of the tumor and organs at risk. Studies have demonstrated that extracting texture features from computer tomography (CT) [5,6,7], contrast-enhanced CT [8, 9], or positron emission tomography (PET) [10,11,12] images using radiomics techniques may be used to predict cancer diagnosis [13], tumor hypoxia status [14], metastases [15], and irradiation-induced complications [16]. Texture features extracted from MVCT images may have the potential to predict clinical outcomes
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
