<html><body><div style="color:#000; background-color:#fff; font-family:times new roman, new york, times, serif;font-size:12pt"><div></div><div> <div class="MsoNormal">Hi GATE users,</div><div class="MsoNormal"><br></div> <div class="MsoNormal">I am trying to figure out if it would be possible to obtain a 3D dose distribution map in a GATE simulation, in which a point source (geometric source: <span style="mso-spacerun:yes"> </span>1mm-diameter sphere) moves along a human gastro-intestinal tract. <br></div><div style="color: rgb(0, 0, 0); font-size: 16px; font-family: times new roman,new york,times,serif; background-color: transparent; font-style: normal;" class="MsoNormal"><br></div> <div class="MsoNormal">I have read the GATE user guide carefully, especially the section about voxelized phantom and dose collection. However, since I am quite new to the field of medical physics, there were many parts I could not understand clearly.</div><div class="MsoNormal"><br></div> <div class="MsoNormal">As far as I know, I would need to use a voxelized phantom, such as the “Extended 4D NCAT Phantom” in which the gastro-intestinal tract is also included. Then, a 1mm-diameter sphere source needs to be defined and it should be able to move along the intestine. <span style="mso-spacerun:yes"><br></span></div><div style="color: rgb(0, 0, 0); font-size: 16px; font-family: times new roman,new york,times,serif; background-color: transparent; font-style: normal;" class="MsoNormal"><span style="mso-spacerun:yes"><br></span></div> <div class="MsoNormal">I have successfully run several GATE simulations in which a geometric source moves in a basic trajectory inside a geometric phantom, but I have never worked with a voxelized phantom and a complex movement of the source before. <br></div><div class="MsoNormal"><br></div> <div class="MsoNormal">My questions are:</div> <div class="MsoNormal"><span style="font-style: italic;">1) Would it be possible to produce such a 3D dose distribution map in GATE when a 1mm-diameter spherical source moves along the intestinal tract (assuming the source has a constant speed, approximately 8 hours to complete its journey, similar to food excretion)?</span></div><div style="color: rgb(0, 0, 0); font-size: 16px; font-family: times new roman,new york,times,serif; background-color: transparent; font-style: italic;" class="MsoNormal"><span style="font-style: italic;"><br></span></div><span style="font-style: italic;"> </span><div class="MsoNormal"><span style="font-style: italic;">2) Assume that I already got the Extended 4D NCAT Phantom, how can I define the source movement so that the source can move along the intestine of the phantom?</span></div><span style="font-style: italic;"> </span><div class="MsoNormal"><span style="font-style: italic;"><br></span></div><div style="color: rgb(0, 0, 0); font-size: 16px; font-family: times new roman,new york,times,serif; background-color: transparent; font-style: italic;" class="MsoNormal"><span style="font-style: italic;">3) Does the 3D dose distribution map show the <span style="text-decoration: underline;">total absorbed dose</span> deposited in every voxel of the NCAT phantom throughout 8 hour moving of the source?</span></div> <div class="MsoNormal"><br></div><div style="color: rgb(0, 0, 0); font-size: 16px; font-family: times new roman,new york,times,serif; background-color: transparent; font-style: normal;" class="MsoNormal">Your help would be greatly appreciated. </div> <div class="MsoNormal">Thank you,</div> </div></div></body></html>