title: Optimal field-splitting algorithm in intensity-modulated radiotherapy: evaluations using head-and-neck and female pelvic IMRT cases.
abstract: To develop an optimal field-splitting algorithm of minimal complexity and verify the algorithm using head-and-neck (H&N) and female pelvic intensity-modulated radiotherapy (IMRT) cases. An optimal field-splitting algorithm was developed in which a large intensity map (IM) was split into multiple sub-IMs (≥2). The algorithm reduced the total complexity by minimizing the monitor units (MU) delivered and segment number of each sub-IM. The algorithm was verified through comparison studies with the algorithm as used in a commercial treatment planning system. Seven IMRT, H&N, and female pelvic cancer cases (54 IMs) were analyzed by MU, segment numbers, and dose distributions. The optimal field-splitting algorithm was found to reduce both total MU and the total number of segments. We found on average a 7.9 ± 11.8% and 9.6 ± 18.2% reduction in MU and segment numbers for H&N IMRT cases with an 11.9 ± 17.4% and 11.1 ± 13.7% reduction for female pelvic cases. The overall percent (absolute) reduction in the numbers of MU and segments were found to be on average -9.7 ± 14.6% (-15 ± 25 MU) and -10.3 ± 16.3% (-3 ± 5), respectively. In addition, all dose distributions from the optimal field-splitting method showed improved dose distributions. The optimal field-splitting algorithm shows considerable improvements in both total MU and total segment number. The algorithm is expected to be beneficial for the radiotherapy treatment of large-field IMRT.
authors: Department of Electrical and Computer Engineering, University of Iowa, Iowa City, IA, USA.
authors: Xin
authors: X
authors: Dou
authors: Yusung
authors: Y
authors: Kim
authors: John E
authors: JE
authors: Bayouth
authors: John M
authors: JM
authors: Buatti
authors: Xiaodong
authors: X
authors: Wu
mesh_terms: D000465:Algorithms; D005260:Female; D006258:Head and Neck Neoplasms / Q000532:radiotherapy*; D006801:Humans; D008297:Male; D010386:Pelvic Neoplasms / Q000532:radiotherapy*; D011874:Radiometry / Q000379:methods*; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D011881:Radiotherapy, Computer-Assisted / Q000379:methods*; D020266:Radiotherapy, Conformal / Q000379:methods*; D012189:Retrospective Studies; D016896:Treatment Outcome