Breathing motion can affect the ability to accurately target lung tumors during imaging and delivery of radiotherapy. Having the patient hold their breath is a simple and effective strategy for limiting tumor motion. However, some patients cannot hold their breath reproducibly, hence the development of active breathing control to assist the patient in achieving a reproducible, stable breath hold.
At the same time as the development of active breathing control, image-guided radiotherapy became available to help directly target the tumor during treatment. Our lab developed a new concept by combining these two existing strategies: cone beam CT-based image guidance for target localization with active breathing control (machine-induced breath hold) for reducing the impact of respiration.
We developed technology to enable integration of the active breathing control system with imaging and delivery systems on a linear accelerator, and then explored the ability of this system to improve the accuracy of delivery in a clinical imaging study. This study resulted in a process and equipment that is now in routine clinical practice at VCU and elsewhere.
This project was funded by the National Institutes of Health, Award No. R01CA116249.