Use of the Laser Beam for Markerless Tracking of the Patient Breathing Motion for Respiratory Gated Radiotherapy

Abstract

Respiratory gating is broadly used method in modern radiotherapy to lessen uncertainties related to patient respiratory motion. Most of the currently available commercial respiratory gating systems involve use of mechanical markers attached to the patient chest for caption of motion during CT scanning as well as radiotherapy treatment. The present paper explores the possibility to use infrared laser light reflected from the moving surface as optical markers instead of mechanical marker box for commercially available gating systems. Performed tests demonstrated, that reflected laser spot movement can be used to obtain breathing patterns, and acquired signals are suitable for respiratory gating