<div dir="ltr"> Hi, It is true that general_trpd is a shape a bit complex to describe. <div style="margin:0cm 0cm 0pt">I would advise you first to have a look in the help (<a href="http://wiki.opengatecollaboration.org/index.php/Users_Guide_V6.2:Defining_a_geometry">http://wiki.opengatecollaboration.org/index.php/Users_Guide_V6.2:Defining_a_geometry</a>), where the different inputs (X1, X2, Y1, Y2, etc.) are described.</div><div style="margin:0cm 0cm 0pt"> </div>I did not work with it for a long time, but I guess that all lengths: X1, X2, etc. are described relatively to what you call the center point coordinate. I can also suggest you to use the graphical display and make simple tests, in order to check that the displacement is as expected: for instance, create a single trpd, define X1=4cm, X2=5cm and make a translations of +/-4 cm then +/-5cm etc. to check. Hope this help. Loïc From: <a href="mailto:david.sarrut@gmail.com">david.sarrut@gmail.com</a> [<a href="mailto:david.sarrut@gmail.com">mailto:david.sarrut@gmail.com</a>] On Behalf Of David Sarrut Sent: Donnerstag, 16. Mai 2013 08:59 To: Grevillot Loic Subject: Fwd: [Gate-users] how to set MU prescription dose lines tu peux éventuellement lui répondre STP (faut mettre la gate-user mailing list en copie pour garder une trace) ... merci ! David ---------- Forwarded message ---------- From: 刘斌信件 <<a href="mailto:golder_time@163.com">golder_time@163.com</a>> Date: Wed, May 15, 2013 at 11:43 AM Subject: Re: [Gate-users] how to set MU prescription dose lines To: <a href="mailto:David.Sarrut@creatis.insa-lyon.fr">David.Sarrut@creatis.insa-lyon.fr</a> hi David, Thank you very much ,you always kindly and warmly offer me help ,I am so grateful to you . I'm sorry to that there another problem I want to get adive from you. In the multileaf collimator simulation macro file , the shape of leaf is described as general_trpd, I can't sure relation between the center point coordinate postion which is important to translation of leaf and the whole general_trpd position. The related macro sentences are as below: /gate/mylinac_MLC_Leaf2_Right/daughters/name mylinac_MLC_Leaf2_Right_trp_sup /gate/mylinac_MLC_Leaf2_Right/daughters/insert general_trpd /gate/mylinac_MLC_Leaf2_Right_trp_sup/setMaterial AcceleratorCollimatorLeafMaterial /gate/mylinac_MLC_Leaf2_Right_trp_sup/geometry/setX1Length 16 mm /gate/mylinac_MLC_Leaf2_Right_trp_sup/geometry/setX2Length 16 mm /gate/mylinac_MLC_Leaf2_Right_trp_sup/geometry/setX3Length 162.60 mm /gate/mylinac_MLC_Leaf2_Right_trp_sup/geometry/setX4Length 162.60 mm /gate/mylinac_MLC_Leaf2_Right_trp_sup/geometry/setY1Length 3 mm /gate/mylinac_MLC_Leaf2_Right_trp_sup/geometry/setY2Length 3 mm /gate/mylinac_MLC_Leaf2_Right_trp_sup/geometry/setZLength <a href="tel:31.77" target="_blank">31.77</a> mm /gate/mylinac_MLC_Leaf2_Right_trp_sup/geometry/setTheta 66.567 deg /gate/mylinac_MLC_Leaf2_Right_trp_sup/geometry/setPhi 0 deg /gate/mylinac_MLC_Leaf2_Right_trp_sup/geometry/setAlp1 0 deg /gate/mylinac_MLC_Leaf2_Right_trp_sup/geometry/setAlp2 0 deg /gate/mylinac_MLC_Leaf2_Right_trp_sup/placement/setTranslation -<a href="tel:38.38" target="_blank">38.38</a> 0.0 21.615 mm I know the center postion of mylinac_MLC_Leaf2_Right_trp_sup is same to mylinac_MLC_Leaf2_Right's central position before translating, however , I am not clear about connections between center point of general_trpd and Xlength 、Ylength、Zlength，Only know the relation I will properly set the placement of leaf in MLC geometry. sincerely Bin. ----- Original Message ----- From: <a title="David.Sarrut@creatis.insa-lyon.fr" href="mailto:David.Sarrut@creatis.insa-lyon.fr" target="_blank">David Sarrut</a> To: <a title="golder_time@163.com" href="mailto:golder_time@163.com" target="_blank">刘斌信件</a> Cc: <a title="gate-users@lists.opengatecollaboration.org" href="mailto:gate-users@lists.opengatecollaboration.org" target="_blank">gate-users</a> Sent: Wednesday, May 15, 2013 4:41 PM Subject: Re: [Gate-users] how to set MU prescription dose lines yes, but only 4 values [10;5], [5;0], [0;-5] and [-5;-10]. The SetPosition could be used to move the actor inside the attached volume (waterbox in your case), in the coordinate system of the waterbox. So if you set position to "0 0 5" for example, you will still have 4 dosels (dose in volume) : [15;10] [10;5], [5;0], and [0;-5]. But the first one is thus outside the volume so no dose deposition will be stored in the first dosel. Note that if you are saving the dose actor in mhd image file format, the "origin" of the image is updated according this position. David On Wed, May 15, 2013 at 4:30 AM, 刘斌信件 <<a href="mailto:golder_time@163.com" target="_blank">golder_time@163.com</a>> wrote: Hi david , What is the relationship between Doseactor and setPostion ,do the "setPostion " set the origin of the scored dose voxel ? As the following is an example, /gate/world/daughters/name WaterBox /gate/world/daughters/insert box /gate/WaterBox/setMaterial Water /gate/WaterBox/geometry/setXLength 20 mm /gate/WaterBox/geometry/setYLength 20 mm /gate/WaterBox/geometry/setZLength 20 mm /gate/WaterBox/placement/setTranslation 0.0 0.0 0.0 mm /gate/actor/addActor DoseActor dose /gate/actor/dose/attachTo WaterBox /gate/actor/dose/setPosition 0 0 0 mm /gate/actor/dose/setSize 5 5 20 mm /gate/actor/dose/setVoxelSize 5 5 5 mm as above , in my view , the actor will gets five dose points , their z-axis coordinates are 10 ,5, 0, -5,-10, is that right? The "setpostion " is used to set the symmetrical center of the volume of detected by doseactor . Thank you so much Yours sincerely Bin. ----- Original Message ----- From: <a title="David.Sarrut@creatis.insa-lyon.fr" href="mailto:David.Sarrut@creatis.insa-lyon.fr" target="_blank">David Sarrut</a> To: <a title="golder_time@163.com" href="mailto:golder_time@163.com" target="_blank">刘斌信件</a> Sent: Friday, May 10, 2013 6:58 PM Subject: Re: [Gate-users] how to set MU prescription dose lines this is classical "variance reduction technique" that consists in producing n photons (instead of a single one), each of them with a relative weight of 1/n. It means that such photons behave like 1/n part of photon. Look for articles/chapter on "variance reduction technique" Sincerely, David On Fri, May 10, 2013 at 10:42 AM, 刘斌信件 <<a href="mailto:golder_time@163.com" target="_blank">golder_time@163.com</a>> wrote: Hi, I'm sorry that I yet can't understand clearly the "weight" and "the splitting factor n ", the following are the part of the text in the paper : When a primary electron hit the target and produce a bremsstrahlung photon, the SBS tool sampled n photons at once, with a weight of 1/n each, all having the same energy and starting from the electron hit point in the target, only the photon direction was sampled, according to the direction criterion. User can define the splitting factor n, as well as the direction criterion. What is meaning of the setence "the SBS tool sampled n photons at once, with a weight of 1/n each"? Thank you very much . yours sincerely, Bin ----- Original Message ----- From: <a title="David.Sarrut@creatis.insa-lyon.fr" href="mailto:David.Sarrut@creatis.insa-lyon.fr" target="_blank">David Sarrut</a> To: <a title="golder_time@163.com" href="mailto:golder_time@163.com" target="_blank">刘斌信件</a> Cc: <a title="gate-users@lists.opengatecollaboration.org" href="mailto:gate-users@lists.opengatecollaboration.org" target="_blank">gate-users</a> Sent: Friday, May 10, 2013 3:20 PM Subject: Re: [Gate-users] how to set MU prescription dose lines Hello, there is no direct relationship between MU and number of primaries. You need to somehow calibrate your system such as a given number of particles gives you a given dose (ie 1 Gy at 10 cm in water), and make the link with the MU. Yes the weight (1/N) of the particle is taken into account in the doseactor. This is a weight associated with a particle (the E is not divided, only the deposited E). Sincerely, David On Thu, May 2, 2013 at 4:11 PM, 刘斌信件 <<a href="mailto:golder_time@163.com" target="_blank">golder_time@163.com</a>> wrote: hi, I do not know the relation between "setTotalNumberOfPrimaries" of simulation and MU prescription dose in the external radiotherapy . How should I set the number of the photon or events in simulation that the absorbed depth dose in phantom will arrive at a expected value. In addition , in Selective bremsstrahlung splitting (SBS) technology, the final state of the process is generated N times and the weight of each secondary is 1/N. Does it divide the energy of photon ( original produced by the bremsstrahlung) into N pieces of energy ,and then get single photon with original energy of 1/N in the same direction ? Thank you for attention? yours sincerely, Bin _______________________________________________ Gate-users mailing list <a href="mailto:Gate-users@lists.opengatecollaboration.org" target="_blank">Gate-users@lists.opengatecollaboration.org</a> <a href="http://lists.opengatecollaboration.org/mailman/listinfo/gate-users" target="_blank">http://lists.opengatecollaboration.org/mailman/listinfo/gate-users</a> -- David Sarrut, Phd Chargé de recherche CNRS CREATIS, UMR CNRS 5220, Inserm U 1044 Centre de lutte contre le cancer Léon Bérard 28 rue Laënnec, 69373 Lyon cedex 08 Tel : 04 78 78 51 51 / 06 74 72 05 42 <a href="http://www.creatis.insa-lyon.fr/~dsarrut" target="_blank">http://www.creatis.insa-lyon.fr/~dsarrut</a> _________________________________ "2 + 2 = 5, for extremely large values of 2" _________________________________ -- David Sarrut, Phd Chargé de recherche CNRS CREATIS, UMR CNRS 5220, Inserm U 1044 Centre de lutte contre le cancer Léon Bérard 28 rue Laënnec, 69373 Lyon cedex 08 Tel : 04 78 78 51 51 / 06 74 72 05 42 <a href="http://www.creatis.insa-lyon.fr/~dsarrut" target="_blank">http://www.creatis.insa-lyon.fr/~dsarrut</a> _________________________________ "2 + 2 = 5, for extremely large values of 2" _________________________________ -- David Sarrut, Phd Chargé de recherche CNRS CREATIS, UMR CNRS 5220, Inserm U 1044 Centre de lutte contre le cancer Léon Bérard 28 rue Laënnec, 69373 Lyon cedex 08 Tel : 04 78 78 51 51 / 06 74 72 05 42 <a href="http://www.creatis.insa-lyon.fr/~dsarrut" target="_blank">http://www.creatis.insa-lyon.fr/~dsarrut</a> _________________________________ "2 + 2 = 5, for extremely large values of 2" _________________________________ -- David Sarrut, Phd Chargé de recherche CNRS CREATIS, UMR CNRS 5220, Inserm U 1044 Centre de lutte contre le cancer Léon Bérard 28 rue Laënnec, 69373 Lyon cedex 08 Tel : 04 78 78 51 51 / 06 74 72 05 42 <a href="http://www.creatis.insa-lyon.fr/~dsarrut" target="_blank">http://www.creatis.insa-lyon.fr/~dsarrut</a> _________________________________ "2 + 2 = 5, for extremely large values of 2" _________________________________ </div>