Optimization Approaches for Intensity Modulated Proton Therapy Treatment Planning

Date
2023-07
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Abstract
Radiation therapy is a critical modality in the field of oncology. The primary goal of radiation therapy is to destroy or control the growth of cancerous cells while minimizing damage to healthy tissues. Intensity Modulated Proton Therapy (IMPT) is a type of radiation therapy that utilizes protons to irradiate the tumor. The unique physical properties of protons enable precise control over the radiation dose distribution within the tumor and more effective sparing of healthy tissues. Typically, radiation therapy treatment planning is posed as a multi-criteria optimization problem, whereby the challenge is finding the best possible treatment plan. In this study, we formulate and compare two optimization approaches for IMPT treatment planning. We first explore a linear programming (LP) approach, followed by a moment-based approach where we incorporate the dose-volume requirements into the fluence map optimization (FMO) problem. The evaluation of these models is conducted using anonymized patient data corresponding to a lung cancer case, with a focus on generating a good-quality initial plan that is amenable to further refinement. The moment-based approach has a drawback in terms of its high memory usage. To mitigate this limitation, we explore several sparsification strategies aimed at reducing memory requirements. Employing an aggressive sparsification method, we demonstrate that the moment-based approach outperforms the LP model in dosimetric outcomes and computational run-time. We highlight a trade-off between the quality of the treatment plan and computational run-time when utilizing different sparcification strategies for the moment-based approach. By adopting a less strict sparsification method, we anticipate achieving higher-quality treatment plans at the expense of increased computational run-time.
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Keywords
Optimization, Intensity Modulated Proton Therapy, Treatment Planning, Cancer, Linear Programming, Moment
Citation
Mousazadeh, B. (2023). Optimization approaches for Intensity Modulated Proton Therapy treatment planning (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.