Motion modelling and motion compensated reconstruction of tumours in cone-beam computed tomography

A method is presented which fits a surrogate-driven motion model to a standard clinically-acquired cone-beam computed tomography scan, taken prior to a fraction of stereotactic body radiotherapy treatment. The motion model can account for motion hysteresis, and is intended to drive gated or tracked radiotherapy treatments. The method can be applied in cases with or without implanted markers. Results with simulated and phantom marker data, and simulated markerless data (based on real patient data) are given.