Download TrueBeam Developer Mode - Radiotherapy Research Tools

Reminder: Developer Mode is intended for non-clinical use only and is NOT cleared for use on humans
A Dynamic Beam
Below is a dynamic beam example. This beam is similar to a RapidArc®-type Beam except that it also
rotates the collimator during irradiation. The gantry makes a full clockwise revolution from 360 to 0
degrees while MU is being delivered. As seen in the control points parameters, gantry rotation is not
proportional to MU, therefore the MU is not uniformly distributed along the arc (i.e. variable MU per
degree). However, within a segment (i.e. between any two successive control points) the behavior is
linear, i.e. MU delivered, gantry motion, and change in MLC shape are all proportional. As previously
mentioned, this intra-segment linearity is actively enforced by the control system.
<VarianResearchBeam SchemaVersion="1.0">
<!--****************************************************************************-->
<!--RapidArc with collimator rotation. Gantry rotates 360, MLC changes shape and also
collimator rotates.
-->
<!--****************************************************************************-->
<SetBeam>
<Id>1</Id>
<MLCModel>NDS120</MLCModel>
<Accs></Accs>
<ControlPoints>
<Cp>
<!--first control point: Set up to initial positions-->
<SubBeam><Seq>0</Seq><Name>Beam ON</Name></SubBeam>
<Energy>6x</Energy>
<Mu>0</Mu>
<DRate>400</DRate>
<GantryRtn>360.00</GantryRtn><CollRtn>177.05</CollRtn>
<CouchVrt>90.0</CouchVrt><CouchLat>100.00</CouchLat>
<CouchLng>100.00</CouchLng><CouchRtn>180.0</CouchRtn>
<Y1>5.31</Y1><Y2>4.81</Y2><X1>7.18</X1><X2>7.18</X2>
<Mlc><ID>1</ID>
<B>0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 -0.550 -0.875 -1.465 1.125
1.835 2.125 2.555 3.625 3.775 1.225 4.325 2.925 1.325 1.725 1.525 -0.175
-0.275 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0</B>
<A>0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.726 0.926 1.626 -0.175
–0.575 -0.495 -0.175 0.725 0.825 0.465 1.025 1.825 2.025 1.625 1.025
0.525 0.326 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0</A>
</Mlc>
</Cp>
<Cp>
<!--In this next control point, MU is being delivered uniformly as the
Gantry and Collimator rotate, while MLC changes shape. -->
<Mu>2.13</Mu>
<!--Deliver 2.13 MU -->
<GantryRtn>357.03</GantryRtn> <!--Rotate gantry from 360 to 357.03 deg. -->
<CollRtn>177.54</CollRtn> <!--Rotate collimator from 177.05 to 177.54 deg-->
<Mlc>
<!--and linearly change to following MLC shape -->
Varian Medical Systems – TrueBeam™ Developer Mode User’s Manual – Draft – Not for Further
Distribution – April 2011
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