1. A new sparse optimization scheme for simultaneous beam angle and fluence map optimization in radiotherapy planning
- Author
-
P. Dong, Lei Xing, and Hongcheng Liu
- Subjects
Male ,Mathematical optimization ,Radiological and Ultrasound Technology ,Computer science ,Radiotherapy Planning, Computer-Assisted ,Computation ,Liver Neoplasms ,Regular polygon ,Prostatic Neoplasms ,Radiotherapy Dosage ,Feature selection ,Beam angle ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,0302 clinical medicine ,Head and Neck Neoplasms ,030220 oncology & carcinogenesis ,Norm (mathematics) ,Humans ,Radiology, Nuclear Medicine and imaging ,Radiotherapy, Intensity-Modulated ,Gradient method ,Algorithms - Abstract
[Formula: see text]-minimization-based sparse optimization was employed to solve the beam angle optimization (BAO) in intensity-modulated radiation therapy (IMRT) planning. The technique approximates the exact BAO formulation with efficiently computable convex surrogates, leading to plans that are inferior to those attainable with recently proposed gradient-based greedy schemes. In this paper, we alleviate/reduce the nontrivial inconsistencies between the [Formula: see text]-based formulations and the exact BAO model by proposing a new sparse optimization framework based on the most recent developments in group variable selection. We propose the incorporation of the group-folded concave penalty (gFCP) as a substitution to the [Formula: see text]-minimization framework. The new formulation is then solved by a variation of an existing gradient method. The performance of the proposed scheme is evaluated by both plan quality and the computational efficiency using three IMRT cases: a coplanar prostate case, a coplanar head-and-neck case, and a noncoplanar liver case. Involved in the evaluation are two alternative schemes: the [Formula: see text]-minimization approach and the gradient norm method (GNM). The gFCP-based scheme outperforms both counterpart approaches. In particular, gFCP generates better plans than those obtained using the [Formula: see text]-minimization for all three cases with a comparable computation time. As compared to the GNM, the gFCP improves both the plan quality and computational efficiency. The proposed gFCP-based scheme provides a promising framework for BAO and promises to improve both planning time and plan quality.
- Published
- 2017