Relationship of segment area and monitor unit efficiency in aperture‐based IMRT optimization

• DOI: 10.1120/jacmp.v14i3.4056
• Publication Date: 2017-02-27T23:05:58Z
• Authors: Peng Qi; Ping Xia
• Keywords: Monitor unit; Aperture (computer memory); Pinnacle

In step‐and‐shoot IMRT plans, aperture‐based optimization (or one‐step optimization) has been considered as a means of improving monitor unit (MU) efficiency compared to fluence‐based two‐step optimization). However, the extent improvement on MU varies, depending implementation and design optimization. this paper, we attempted investigate issue in two methods implemented commercial treatment planning systems (TPSs). Five patients with nasopharyngeal cancer five advanced prostate were selected for study. For these patients, clinically used plans generated using Direct Machine Parameter Optimization (DMPO) Pinnacle TPS. New created Aperture (DAO) method Panther purpose study, similar dose objectives beam configurations total number segments each pair DMPO DAO plans. With plan quality, required more MUs than The average (expressed mean SD) was nasopharynx cases, respectively. segment areas smaller those plans: vs. conclusion, algorithms, DAO, resulted much different parameters. This difference is largely attributed fact that large area are often PACS number: 87.55.de