A novel fast robust optimization algorithm for intensity-modulated proton therapy with minimum monitor unit...

Area of Science:

• Medical Physics
• Radiation Oncology
• Computational Biology

Background:

• Intensity-modulated proton therapy (IMPT) offers superior conformability but faces challenges from range and setup uncertainties.
• Robust optimization is crucial for addressing these uncertainties in IMPT.
• Developing efficient algorithms for robust IMPT is an active area of research.

Purpose of the Study:

• To develop a novel, fast algorithm for robust optimization of IMPT.
• The algorithm aims to incorporate a minimum monitor unit (MU) constraint.

Main Methods:

• A robust optimization problem was formulated and solved using a novel, fast algorithm based on the alternating direction method of multipliers (ADMM).
• The algorithm was evaluated on ten clinical cases, comparing it against nominal optimization (NMO-CTV, NMO-PTV) and conventional robust optimization (RBO-CONV).
• Plan quality was assessed using dosimetric metrics (D95, homogeneity index, Dmean), robustness via AUC and DVH bands, and computational efficiency by optimization time.

Main Results:

• Robust optimization (RBO) plans showed superior quality and robustness compared to nominal optimization (NMO) plans.
• The novel robust optimization method (RBO-NEW) demonstrated significantly improved computational efficiency and plan quality over RBO-CONV.
• RBO-NEW reduced computation time and mean organ-at-risk (OAR) dose compared to RBO-CONV.

Conclusions:

• A novel fast robust optimization algorithm for IMPT with a minimum MU constraint has been developed.
• The algorithm enhances plan robustness, computational efficiency, and overall treatment quality.
• This approach improves treatment plan reliability without compromising OAR sparing.