Analysis and evaluation of periodic physiological organ motion in radiotherapy treatments.

Background and purpose: A system for the detection, measurement and analysis of the periodic physiological organ motion during radiotherapy treatment is proposed and clinically tested in this paper. Material and methods: The procedure is based on the acquisition of fluoroscopic sequences, followed by an automatic detection of the movement using cross-correlations with matched filters. Results: The system generates a probability density function (PDF) of finding a mobile organ in a position at a certain time. The maximum path of the mobile structures can be determined to define the planning target volume (PTV) without ambiguities. Conclusions: Physiological movements can be accurately includ…