Purpose: To develop a clinical workflow allowing to acquire image, create a treatment plan, and deliver the plan in one single setup (image-plan-treat) on a highly integrated kVCT and Linac platform (CT-Linac).
Methods: The image-plan-treat workflow was developed based on a newly-available CT-Linac platform with highly integration of kVCT, MVCT, treatment planning, record and verify, and helical and 3D-conformal delivery systems in the following steps: (1) comparing image quality (image uniformity, spatial resolution, contrast, and dimensions) of the kVCT with that of a regular CT simulator (RCT) based on phantom measurements; (2) measuring image doses for a variety of kVCT image protocols on CT-Linac using an ion chamber; (3) establishing CT number-to-density calibration based on measurements using a cheese phantom with various plugs of different materials and densities; (4) verifying kV-MV alignment for image-guided repositioning; (5) testing auto-segmentation and plan creation on the newly acquired kVCT and comparing the obtained dose distribution with the reconstructed dose on RCT; (6) testing planning and delivery data transferring through direct link; and (7) testing plan delivery. The workflow was tested with sample 3D-confromal plans and the time needed in each step was recorded.
Results: The image quality and dose calculation of the kVCT were found to be comparable to those of RCT, with differences in CT numbers by 30HU and in doses by 3%. The kVCT acquired with field-of-view smaller than the body size could result in large CT number difference. Average execution time of the image-plan-treat workflow was <30 minutes: setup (5’), kVCT acquisition (1’), delineation (2-5’), plan generation (8-10’), QA and data transfer (2’), patient position verification (2’), and plan delivery (2-5’).
Conclusion: The newly developed image-plan-treat workflow was efficient and may be used for emergency radiation treatment.