<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=us-ascii">
<meta name="Generator" content="Microsoft Word 15 (filtered medium)">
<!--[if !mso]><style>v\:* {behavior:url(#default#VML);}
o\:* {behavior:url(#default#VML);}
w\:* {behavior:url(#default#VML);}
.shape {behavior:url(#default#VML);}
</style><![endif]--><style><!--
/* Font Definitions */
@font-face
{font-family:"Cambria Math";
panose-1:2 4 5 3 5 4 6 3 2 4;}
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0cm;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:"Calibri",sans-serif;
mso-fareast-language:EN-US;}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:#0563C1;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:#954F72;
text-decoration:underline;}
span.EmailStyle17
{mso-style-type:personal-compose;
font-family:"Calibri",sans-serif;
color:windowtext;}
.MsoChpDefault
{mso-style-type:export-only;
font-family:"Calibri",sans-serif;
mso-fareast-language:EN-US;}
@page WordSection1
{size:612.0pt 792.0pt;
margin:72.0pt 72.0pt 72.0pt 72.0pt;}
div.WordSection1
{page:WordSection1;}
--></style><!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]-->
</head>
<body lang="EN-GB" link="#0563C1" vlink="#954F72">
<div class="WordSection1">
<p class="MsoNormal">Hi all<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">This question isn’t specifically about GATE, but it is a task I need to do in order to continue using my GATE macros – the dreaded validation. I’m sure other people might have ran into the same issues at some point, or might have a better
solution. My code is intending to work out dosimetry in a voxelised PET-CT scan, and I was originally going to validate my code by sticking some LiF TLDs on the outside of a phantom containing F18. The phantom would then be PET-CT scanned to generate the
CT and PET data for the simulation, then left for a period of time to allow the TLDs to accumulate dose. I’m aware that there is then a component of CT dose to the TLDs, but with a low enough CT exposure and large enough activity, I am hoping that this dose
just washes out in the overall errors.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I don’t know the calibration of the TLDs (they are RT TLDs so are used more for MV than PET) so I put a bunch of them at various distances from a known activity of F18 in a vial for a known time period, and measured the dose rate and accumulated
the total dose. By plotting the light output against the known dose, I could then measure the light output of my validation TLDs to determine their dose and compare it to the dose modelled by GATE.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">The problem I am having is that obviously the TLDs have a component of positron dose alongside the 511 keV annihilation photons. My dose rate was calculated using a Fluke Raysafe 452 which has a filter to convert to a dose rate, which I
suspect blocks the majority of the positrons, underestimating the dose rate.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Has anyone else validated their positron/photon dose combined or have any suggests on ways I could make this better?<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Thank you<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><b><span style="color:#006871;mso-fareast-language:EN-GB">Mark Baker<o:p></o:p></span></b></p>
<p class="MsoNormal"><span style="color:#006871;mso-fareast-language:EN-GB">Principal Clinical Scientist<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#006871;mso-fareast-language:EN-GB">Imaging Physics (Ionising)<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#006871;mso-fareast-language:EN-GB">The Clatterbridge Cancer Centre NHS Foundation Trust<o:p></o:p></span></p>
<p class="MsoNormal"><i><span style="color:#006871;mso-fareast-language:EN-GB">(he, him)<o:p></o:p></span></i></p>
<p class="MsoNormal"><b><span style="color:#006871;mso-fareast-language:EN-GB"><o:p> </o:p></span></b></p>
<p class="MsoNormal"><span style="color:#006871;mso-fareast-language:EN-GB">CCCW Tel: 0151 556 5030
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#006871;mso-fareast-language:EN-GB">CCCL Tel: 0151 318 8438<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#006871;mso-fareast-language:EN-GB">Email:
</span><span style="color:#4472C4;mso-fareast-language:EN-GB"><a href="mailto:mark.baker23@nhs.net"><span style="color:#4472C4">mark.baker23@nhs.net</span></a></span><span style="color:#006871;mso-fareast-language:EN-GB">
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#4472C4;mso-fareast-language:EN-GB"><a href="https://teams.microsoft.com/l/chat/0/0?users=mark.baker23@nhs.net"><span style="color:#4472C4">Microsoft Teams (click here)</span></a><o:p></o:p></span></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-GB"> <span style="color:#006871"><o:p></o:p></span></span></p>
<p class="MsoNormal"><i><span style="color:#006871;mso-fareast-language:EN-GB">Honorary Lecturer, Dept. of Physics<o:p></o:p></span></i></p>
<p class="MsoNormal"><i><span style="color:#006871;mso-fareast-language:EN-GB">University of Liverpool<o:p></o:p></span></i></p>
<p class="MsoNormal"><span style="color:#006871;mso-fareast-language:EN-GB"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-GB"><img border="0" width="624" height="163" style="width:6.5in;height:1.6979in" id="Picture_x0020_3" src="cid:image002.jpg@01D86E90.BCC14B80" alt="CCC email footer April 2021"><o:p></o:p></span></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-GB"><o:p> </o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
<br>
<font face="Courier New" color="Black" size="2"><br>
************************************************************************************** ******************************<br>
<br>
This message may contain confidential information. If you are not the intended recipient please:<br>
i) inform the sender that you have received the message in error before deleting it; and
<br>
ii) do not disclose, copy or distribute information in this e-mail or take any action in relation to its content (to do so is strictly prohibited and may be unlawful).
<br>
Thank you for your co-operation.<br>
<br>
NHSmail is the secure email, collaboration and directory service available for all NHS staff in England. NHSmail is approved for exchanging patient data and other sensitive information with NHSmail and other accredited email services.<br>
<br>
For more information and to find out how you can switch visit <a href="https://support.nhs.net/article-categories/joining-nhsmail/">
Joining NHSmail – NHSmail Support</a><br>
<br>
</font>
</body>
</html>