<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html><head><meta content="text/html;charset=UTF-8" http-equiv="Content-Type"></head><body ><div style='font-size:10pt;font-family:Verdana,Arial,Helvetica,sans-serif;color:#00000;'><div><br></div><div>Hi, <br></div><div>I am trying to determine the accumulated dose at the isocenter of a CT. I have been <br></div><div>adjusting the parameter setResolution and looking at the effect it has on the total dose. <br></div><div>My understanding is that setResolution will divide up my dose actor volume into <br></div><div>this many dosels to measure the dose. I expected that if I continued to increase <br></div><div>the setResolution values, the sum of the values in the dose output file would <br></div><div>approach some value, the total dose (in Gy). But I am seeing that as I increase <br></div><div>the setResolution values, the the sum of the values in myDoseActorOutput.txt <br></div><div>file keeps increasing. <br></div><div><br></div><div>If someone can please let me know what I am doing wrong, I would <br></div><div>appreciate it very much. <br></div><div><br></div><div>I am using vGate8.0. Here is the part of my simulation that deals with the <br></div><div>dose actor. <br></div><div><br></div><div>Thanks, <br></div><div><br></div><div>Terry<br></div><div><br></div><div><br></div><div>/gate/world/daughters/name airCyl<br></div><div>/gate/world/daughters/insert cylinder<br></div><div>/gate/airCyl/geometry/setRmin 0.0 mm<br></div><div>/gate/airCyl/geometry/setRmax 3.09 mm<br></div><div>/gate/airCyl/geometry/setHeight 100.0 mm<br></div><div>/gate/airCyl/placement/setRotationAxis 0 1 0<br></div><div>/gate/airCyl/placement/setRotationAngle 90.0 deg<br></div><div>/gate/airCyl/setMaterial Air<br></div><div>/gate/airCyl/vis/forceSolid<br></div><div>#/gate/airCyl/vis/forceWireframe<br></div><div>/gate/airCyl/vis/setColor magenta<br></div><div><br></div><div>/gate/actor/addActor DoseActor myDoseActor<br></div><div>/gate/actor/myDoseActor/save myDoseActorOutput.txt<br></div><div>/gate/actor/myDoseActor/attachTo airCyl<br></div><div>/gate/actor/myDoseActor/enableDose true<br></div><div>/gate/actor/myDoseActor/enableEdep false<br></div><div>/gate/actor/myDoseActor/enableUncertaintyDose false<br></div><div>/gate/actor/myDoseActor/enableUncertaintyEdep false<br></div><div>/gate/actor/myDoseActor/enableNumberOfHits true<br></div><div>/gate/actor/myDoseActor/stepHitType random<br></div><div>#/gate/actor/myDoseActor/setSize 100 100 100 mm<br></div><div>/gate/actor/myDoseActor/setResolution 100 100 50<br></div><div><br></div><div><br></div></div><br></body></html>