Combining segment generation with direct step-and-shoot optimization in intensity-modulated radiation therapy
2008 (English)In: Medical physics (Lancaster), ISSN 0094-2405, Vol. 35, no 9, 3828-3838 p.Article in journal (Refereed) Published
A method for generating a sequence of intensity-modulated radiation therapy step-and-shoot plans with increasing number of segments is presented. The objectives are to generate high-quality plans with few, large and regular segments, and to make the planning process more intuitive. The proposed method combines segment generation with direct step-and-shoot optimization, where leaf positions and segment weights are optimized simultaneously. The segment generation is based on a column generation approach. The method is evaluated on a test suite consisting of five head-and-neck cases and five prostate cases, planned for delivery with an Elekta SLi accelerator. The adjustment of segment shapes by direct step-and-shoot optimization improves the plan quality compared to using fixed segment shapes. The improvement in plan quality when adding segments is larger for plans with few segments. Eventually, adding more segments contributes very little to the plan quality, but increases the plan complexity. Thus, the method provides a tool for controlling the number of segments and, indirectly, the delivery time. This can support the planner in finding a sound trade-off between plan quality and treatment complexity.
Place, publisher, year, edition, pages
2008. Vol. 35, no 9, 3828-3838 p.
intensity-modulated radiation therapy; step-and-shoot delivery; optimization; column generation; DIRECT-APERTURE OPTIMIZATION; COLUMN GENERATION; IMRT; RADIOTHERAPY; NUMBER; TIME
Computational Mathematics Radiology, Nuclear Medicine and Medical Imaging
IdentifiersURN: urn:nbn:se:kth:diva-8185DOI: 10.1118/1.2964096ISI: 000258773000002ScopusID: 2-s2.0-50449095767OAI: oai:DiVA.org:kth-8185DiVA: diva2:13439
QC 20100709. Uppdaterad från in press till published (20100709).2008-04-032008-04-032010-07-09Bibliographically approved