INTRA-FRACTION MOTION MANAGEMENT SYSTEM

摘要

The present invention relates to the field of radiation therapy. In particular, the invention concerns systems and methods for monitoring intra- fraction motions of patients in connection with treatment cancer in radiation therapy system. Ultrasound waves are generated in a direction of a bone or a part of a bone of the patient being in a fixed relation to a cancer tumor to be treated by radiation therapy such that the generated ultrasound waves are reflected by the bone or part of bone using an ultrasonic transducer and sensing the reflected ultrasound waves at least one ultrasonic transducer. Time intervals between generated ultrasound waves and corresponding sensed reflected ultrasound signals are determined for the at least one ultrasonic transducer. Based on the time intervals, motions of the bone or part of bone are monitored using changes of the time intervals, wherein the motions indicate that the patient or a part of the patient has moved.