Abstract：
:Intensity-modulated radiation therapy (IMRT) can be delivered by the 'sliding-leaves' dynamic multileaf collimator (DMLC) technique. Intrafraction organ motion can be accommodated by arranging an identical tracking motion for 'breathing leaves'. However, this is only possible for very specific circumstances such as regular, mathematically parameterizable, rigid-body, density-conserving, one-dimensional translations. In this paper, we investigate what happens when planes of tissue in the line of sight of the MLC have differential motion with respect to the moving leaves. In this situation, there is no solution to the problem and a perfect tracking motion cannot be arranged. However, an iterative minimization-of-errors 'solution' (or strategy) can be found and the technique is presented for this. From this, under certain mathematically simple differential motions it is possible to obtain some elegant algebraic solutions which are presented. In general, however, a lengthy computational minimization is required and results of examples of these are presented.
journal_name
Phys Med Bioljournal_title
Physics in medicine and biologyauthors
Webb S,Binnie DMdoi
10.1088/0031-9155/51/18/005subject
Has Abstractpub_date
2006-09-21 00:00:00pages
4517-31issue
18eissn
0031-9155issn
1361-6560pii
S0031-9155(06)25864-0journal_volume
51pub_type
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