An orthogonal matching pursuit optimization method for proton IMPT, ARC and FLASH with large-minimum-MU constraints
Date:
In proton radiation therapy (RT), the intensity of each deliverable proton spot—measured in monitor units (MU)—must either be zero or meet a minimum-MU (MMU) threshold. This constraint creates a nonconvex optimization problem. Higher-dose-rate treatments, such as efficient intensity-modulated proton therapy (IMPT), ARC proton therapy, and FLASH therapy, require solving this MMU problem with even larger MMU thresholds. However, increasing the MMU threshold makes the problem even more challenging to solve. This work aims to develop a more effective optimization method based on orthogonal matching pursuit (OMP) to address the MMU problem with large MMU thresholds. The proposed method demonstrated superior performance compared to the state-of-the-art methods, including the alternating direction method of multipliers (ADMM), proximal gradient descent (PGD), and stochastic coordinate descent (SCD).
