Assessing the short-term effects of radiotherapy on the shear modulus of the common carotid artery as a new biomarker of radiation-induced atherosclerosis

Figures

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  Fig. 1.. A typical description of a three-dimensional (3D) clinical plan with contouring of the common carotid artery. A. The common carotid artery was countered. B. The arterial volume under irradiation with three fields was reconstructed in 3D dimensions. C. A 3D view of the position of the common carotid artery by the radiation therapy volume was illustrated. D. A dose-volume histogram for the contoured common carotid artery versus the planning target volume (PTV) for one patient shows that the delivered mean dose to the common carotid artery is as high as that of the PTV.

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  Fig. 2.. Methodology of processing ultrasound images to estimate the arterial wall thickness movements. A. The arterial wall was measured using the maximum gradient algorithm at the circumferential direction. B. The arterial movement was measured using the block matching algorithm at the axial direction.

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  Fig. 3.. Time-dependent changes in the common carotid artery of a patient throughout three cardiac cycles. Internal diameter (A), intima-media thickness (IMT) (B), and longitudinal displacement (C), before (left side) and after (right side) radiotherapy are plotted.

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  Fig. 4.. Blood flow velocities in the common carotid artery extracted using Doppler ultrasonography, before (A) and after (B) external radiotherapy

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  Fig. 5.. Schematic diagram showing the steps to measure the shear modulus behavior of the common carotid arteries in response to external radiotherapy. CT, computed tomography; 3D CRT, three-dimensional conformal radiotherapy; DVH, dose volume histogram.