Intravoxel incoherent motion imaging kinetics during chemoradiotherapy for human papillomavirus‐associated squamous cell carcinoma of the oropharynx: preliminary results from a prospective pilot study |
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| Authors: | Yao Ding John D Hazle Abdallah S R Mohamed Steven J Frank Brian P Hobbs Rivka R Colen G Brandon Gunn Jihong Wang Jayashree Kalpathy‐Cramer Adam S Garden Stephen Y Lai David I Rosenthal Clifton D Fuller |
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| Affiliation: | 1. Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA;2. Department of Imaging Physic, The University of Texas MD Anderson Cancer Center, Houston, TX, USA;3. Department of Clinical Oncology and Nuclear Medicine, Faculty of Medicine, University of Alexandria, Alexandria, Egypt;4. Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA;5. Department of Radiology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA;6. Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA;7. Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital/Division of Health Sciences & Technology, Massachusetts Institute of Technology, Charlestown, MA, USA;8. Department of Head and Neck Surgery, The University of Texas MD Anderson Cancer Center, Houston, TX, USA;9. The University of Texas Graduate School of Biomedical Sciences, Houston, TX, USA |
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| Abstract: | This study aims to identify the temporal kinetics of intravoxel incoherent motion (IVIM) MRI in patients with human papillomavirus‐associated (HPV+) oropharyngeal squamous cell carcinoma. Patients were enrolled under an Institutional Review Board (IRB)‐approved protocol as part of an ongoing prospective clinical trial. All patients underwent two MRI studies: a baseline scan before chemoradiotherapy and a mid‐treatment scan 3–4 weeks after treatment initiation. Parametric maps representing pure diffusion coefficient (D), pseudo‐diffusion coefficient (D*), perfusion fraction (f) and apparent diffusion coefficient (ADC) were generated. The Mann–Whitney U‐test was used to assess the temporal variation of IVIM metrics. Bayesian quadratic discriminant analysis (QDA) was used to evaluate the extent to which mid‐treatment changes in IVIM metrics could be combined to predict sites that would achieve complete response (CR) in multivariate analysis. Thirty‐one patients were included in the final analysis with 59 lesions. Pretreatment ADC and D values of the CR lesions (n = 19) were significantly lower than those of non‐CR lesions (n = 33). Mid‐treatment ADC, D and f values were significantly higher (p < 0.0001) than pretreatment values for all lesions. Each increase in normalized ΔADC of size 0.1 yielded a 1.45‐fold increase in the odds of CR (p < 0.0003), each increase in normalized ΔD of size 0.1 yielded a 1.53‐fold increase in the odds of CR (p < 0.0002), and each unit increase in Δf yielded a 2.29‐fold increase in the odds of CR (p < 0.02). Combined ΔD and ΔADC were integrated into a multivariate prediction model and attained an AUC of 0.87 (95% confidence interval: 0.79, 0.96), as well as a sensitivity of 0.63, specificity of 0.85 and accuracy of 0.78, under leave‐one‐out cross‐validation. In conclusion, IVIM is feasible and potentially useful in the prediction and assessment of the early response of HPV+ oropharyngeal squamous cell carcinoma to chemoradiotherapy. Copyright © 2015 John Wiley & Sons, Ltd. |
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| Keywords: | intravoxel incoherent motion imaging HPV‐associated oropharyngeal cancer chemoradiotherapy response assessment |
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