PREVENTION OF SETUP ERRORS IN RADIOTHERAPY

摘要

A patient safety system (PSS) (100) uses optical tracking in a linear accelerator treatment room to prevent gross setup errors. A patient (150) undergoes a computed tomography (CT) treatment-simulation scan while a CT ball bearing (BB) is on patient's surface. The CT BB is replaced with an infrared reflective marker (IRRM) (160) before radiotherapy treatment starts. Coordinates of the CT BB relative to an isocenter of the treatment room are used as reference for tracking. The coordinate system of an optical tracking system is converted to a coordinate system of the treatment room. The PSS evaluates setup accuracy for a radiotherapy session by comparing real-time position of the single IRRM determined by the optical tracking technology with a predicted reference position, and displays results on a graphical user interface. The PSS stops radiation when a deviation between real-time coordinates and predicted coordinates of the IRRM (160) exceeds a predefined threshold.

主权项

1. A method, with a computer, of tracking changes in position of a patient while the patient is undergoing radiotherapy, comprising:
placing a computed tomography ball bearing (CT BB) at a location on a surface of one of a face mask and an immobilization device for a patient; performing a treatment-simulation computed tomography scan of the patient; calculating, with a computer (110), coordinates of the CT BB, based on the treatment-simulation computed tomography scan of the patient; removing the CT BB from the surface of the one of a face mask and an immobilization device; placing an infra-red reflecting marker (IRRM) (160) at the location of the one of a face mask and an immobilization device; storing, in a database (212) communicatively coupled to the computer, the coordinates of the CT BB as predicted coordinates of a predicted location of the IRRM; and while the patient is receiving radiotherapy with a linear accelerator:
determining a real-time location of the IRRM,comparing, with the computer, the real-time location of the IRRM with the predicted location of the IRRM, anddisplaying results of the comparing in a graphical user interface (500) of a display (174) communicatively coupled to the computer.