Preventing potential treatment collisions on a TrueBeam system using a 3D video game engine
PD-0906
Abstract
Preventing potential treatment collisions on a TrueBeam system using a 3D video game engine
1Sahlgrenska University Hospital, Department of Medical Physics and Biomedical Engineering, Gothenburg, Sweden; 2University of Gothenburg, Department of Medical Radiation Sciences, Institute of Clinical Sciences, Sahlgrenska Academy, Gothenburg, Sweden
Show Affiliations
Hide Affiliations
Purpose or Objective
To discover potential collisions between the machine and the patient/treatment couch on a TrueBeam system (Varian Medical System, Palo Alto, USA) during the dose planning process.
Material and Methods
A 3D model of a TrueBeam treatment was obtained from Varian Medical Systems and modified to our needs. The model was then imported to the video game engine Unreal Engine 4 (Epic Games, Cary, USA) where a game level was modelled around the TrueBeam model and a graphical user interface, as well as intuitive controls, were implemented. To obtain all the parameters from the treatment plan that needs to be checked against potential collisions, a script was developed in Eclipse (Varian Medical Systems) using the Eclipse Scripting API. The script exports information such as isocenter position and fields data, as well as 3D volume information about the patient and the PTV structure. For this last part, the meshes making up the body and PTV structures in the treatment plan (point positions + triangles information) are exported in a text file.
Results
Upon starting the collision program, information about the treatment plan and the patient are automatically loaded. The patient and PTV meshes are reconstructed in the level and positioned right in relation to the isocenter. The treatment couch is also adjusted to be in the right position. The program then carries on checking if one of the following scenarios are detected for each field: no-collision, warning (two or more physical entities are less than 30 mm away from each other) or collision (less than 15 mm, to allow some margins). This is done quickly and independently if the fields are static beams or arcs. Within one second of starting the program, a report summary is displayed to the user. The user can then decide to exit the program or to enter the level to check each field manually (figure).
Conclusion
A fast and efficient solution to detect potential collisions during treatment delivery on a TrueBeam system using a video game engine was developed. This solution is currently in use at our department to detect risks of mechanical collisions between the gantry and the treatment couch or patient.