Development and Clinical Implementation of Applications for Guiding Linac-Based Stereotactic Radiosurgery Planning
Date
2023-08
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Abstract
Stereotactic Radiosurgery (SRS) is a well-established treatment technique for brain lesions that uses a high dose of radiation delivered in a single fraction. Studies have shown improved cognitive outcomes with SRS for the treatment of brain metastases compared to whole brain radiation therapy. While effective, SRS planning is a complex and time-consuming process due to non-coplanar beam angles, multiple metastases, and proximity to organs-at-risk within the brain. Scripting can be used to automate complex planning processes and analyze patient data through a treatment planning system application programming interface. Applications developed using scripting can help inform planner decision-making and improve clinical efficiency. This thesis investigates the design and clinical implementation of two scripting applications developed to assist SRS planning at the Tom Baker Cancer Centre. The use of non-coplanar beam angles in SRS increases the risk of collision between the linac gantry and the patient or treatment table. We developed the Clearance Check application to predict possible collisions in radiation treatment plans using patient CT body contours and accurate models of the gantry and immobilization. The collision prediction algorithm uses oriented bounding boxes and binary tree hierarchies to improve algorithm efficiency. Algorithm accuracy was assessed using a calibration phantom and several simulated treatment positions. Initial results from clinical implementation are reported and a follow-up summary after five years of use is also included. Collision prediction, beam angle optimization and automated plan creation were combined to create the Stereotactic Optimized Automated Radiotherapy (SOAR) application. SOAR planning was compared to manual SRS planning and found to achieve similar plan quality with a significant increase in plan creation efficiency. SOAR was then benchmarked against the commercial SRS planning solution HyperArc. SOAR showed improved target conformity, better organ-at-risk sparing, and lower plan complexity. The SOAR application provides greater versatility in SRS planning, straightforward integration with the treatment planning system, and is not restricted to a specific immobilization device. Initial improvements in SRS planning efficiency using SOAR are reported. Overall, this thesis presents novel applications of scripting to improve the SRS planning process, enhancing clinical efficiency while maintaining plan quality.
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Keywords
Collision Prediction, Beam Angle Optimization, Stereotactic Radiosurgery, Eclipse Scripting API, Treatment Planning, Radiation Therapy
Citation
Mann, T. D. (2023). Development and clinical implementation of applications for guiding linac-based Stereotactic Radiosurgery planning (Doctoral thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.