Tracking Lung tumor and chest motion in the breathing process by digital volume correlation method / 医用生物力学

ABSTRACT

Objective To study the feasibility of using digital volume correlation (DVC) method to track displacement and deformation of lung tumor and chest during the period of respiration. Methods A DVC algorithm suitable for tracking 3D movement of tissues in chest was proposed. The 4D CT imaging technique was adopted to acquire images of a patient with lung cancer during one complete respiration stage. The inhalation was set as the initial stage for reference, to determine the locations of lung cancer and chest. Four specified regions of both the tumor and chest at the initiation of inhalation stage were selected. The corresponding 3D displacement of lung in the following 5 inhalation phase stages, i.e. 20%, 40% 60%, 80% and 100% as well as 3D displacement of chest in 100% inhalation phase stage were analyzed by DVC software. Results The displacement and deformation error of tumor was within 1 mm, while that of chest was within 0.5 mm. The maximum displacement of tumor presented itself along the vertical direction of human body during respiration, while that of chest at the end of inhalation stage appeared along the front and back direction of human body. Conclusions DVC methods can be potentially used to detect displacement and deformation of body tissues such as lung tumor and chest during the respiratory cycle. This study provides references for noninvasive, non X-ray, real-time image-guided radiation therapy for lung cancer based on DVC method.