Abstract：
:In external beam radiotherapy, electronic portal imaging becomes more and more an indispensable tool for the verification of the patient setup. For the safe clinical introduction of high dose conformal radiotherapy like intensity modulated radiation therapy, on-line patient setup verification is a prerequisite to ensure that the planned dosimetric coverage of the tumor volume is actually realized in the patient. Since the direction of setup fields often deviates from the direction of the treatment beams, extra dose is delivered to the patient during the acquisition of these portal images which may reach clinical relevance. The aim of this work was to develop a new acquisition mode for the PortalVision aS500 electronic portal imaging device from Varian Medical Systems that allows one to take portal images with reduced dose while keeping good image quality. The new acquisition mode, called RadMode, selectively enables and disables beam pulses during image acquisition allowing one to stop wasting valuable dose during the initial acquisition of "reset frames." Images of excellent quality can be taken with 1 MU only. This low dose per image facilitates daily setup verification with considerably reduced extra dose.
journal_name
Med Physjournal_title
Medical physicsauthors
Vetterli D,Riem H,Aebersold DM,Greiner RH,Manser P,Cossmann P,Kemmerling L,Born EJ,Mini Rdoi
10.1118/1.1668391subject
Has Abstractpub_date
2004-04-01 00:00:00pages
828-31issue
4eissn
0094-2405issn
2473-4209journal_volume
31pub_type
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