Real-time breathing guidance system for external beam radiotherapy

Radiotherapy uses high energy radiation beam to disable the tumor cells. When the process is proceeded, the radiation illumination should be focused on the malignant tissues only. However, the cancerous sites may move with the respiration activity, and reduce the efficacy of radiotherapy or even cause damage of normal tissues unpredictably. In this work we introduce a real-time image alignment application to such problem, and build a breath-guidance system to help patients to control the timing and depth of their inhalation and exhalation. Then the radiotherapy can be given under a more controlled situation to reduce the side effect.