Abstract:
:Multileaf collimators (MLCs) have been in clinical use for many years and meanwhile are commonly used to deliver intensity-modulated radiotherapy (IMRT) beams. For this purpose it is important to know their dosimetric properties precisely, one of them being inter- and intraleaf leakage. The Siemens 160 MLC features a single focus design with flat-sided and tilted leaves instead of tongue-and-groove. The leakage performance of the 160 MLC was investigated on a dual energy linear accelerator Siemens ARTISTE with 6 MV and 18 MV photon energies. While the intraleaf leakage amounted to nearly the same dose for 6 and for 18 MV, a much higher interleaf leakage for 6 MV was measured. It could be reduced by simply rotating the collimator, and also by changing the voltage applied to the beam steering coils. The leakage of the 160 MLC is shown to be sensitive to beam alignment. This is of special interest for dual energy accelerators, as the two focal spots of both energies, neither in position nor in shape, do not necessarily always coincide. As a consequence of that, a higher leakage can be expected for one out of two energies for the 160 MLC.
journal_name
Phys Med Bioljournal_title
Physics in medicine and biologyauthors
Klüter S,Sroka-Perez G,Schubert K,Debus Jdoi
10.1088/0031-9155/56/2/N02subject
Has Abstractpub_date
2011-01-21 00:00:00pages
N29-37issue
2eissn
0031-9155issn
1361-6560pii
S0031-9155(11)62755-8journal_volume
56pub_type
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