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Hello everyone,
I am trying to run a Monte Carlo simulation to estimate the delivered dose of alpha-particles from Ra-223 decay to cancer cells. My system is simple. Just cells and Ra-223 media. Do you have any recommendations?
Thank you.
Best regards,
Mehran
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Thank you so much dear Ashok. Good to know you.
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I have to check the radiotherapy plan and dosimetry distribution for a CT image that I have generated and need to compare it with other plan.
Is there any free software to compute the radiotherapy plan using a CT volume?
Please suggest one.
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Is it possible? =) What do you think about it?
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Thank you for your interest,
But I would like to tell you the thought in my mind in more detail.
If we simply consider TLDs or OSLDs; The electrons of the dosimeters exposed to the B particles are trapped in the traps and when they are excited with the help of heat or light, they gain energy and get rid of the traps, and we record a luminescence emission.
My opinion is to record the signals obtained from the transitions inside the trap energy levels using microwaves which will cause a movement in the energy levels within the traps because this stimulation energy will be lower energy than the activation energy of the traps.
I am aware that such a study has not been done before and this requires calculations. Just a thought right now.
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It would be appreciated if anyone could help obtain the voxels' dose from voxelized phantom dose output, which has been recorded as a binary format like *.bin (zubal.bin).
Regards,
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Hi Dr. Parach,
I really appreciate your help. It has a procedure as you mentioned. Fortunately, I could develope a MATLAB code to read the file.
The whole MATLAB code is here:
#For reading a dose file:
File=fopen('filepath', 'rb');
Data=fread(File, 'float');
A=reshape(Data, 128,128,243);
#For reading a phantom:
File2= fopen ( 'phanompath', 'rb');
Data2= fread(File2, 'int8');
A2= reshape (Data2, 128, 128, 243);
imlook3d( A2); #for phantom view
#For dose extraction: [cGy unit]
d= sum (Data(A2==2)); #num 2 is for example the ID of brain.
#For isodose
A3= 100* A2./max(A2(:));# normalization
a= A3(:,:,87); #cross section selection
contour (a); # isodose curve plotting
Also, I need to appreciate Dr. Asgaree.
Regards,
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Or anything related with shielding materials and dosimetry for medical application. I need topics that can be researched on and suitable for undergraduate research work.
Thank you.
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In my opinion, you could expand and search for "luminescence methods for radiation dosimetry applications". Or you may be interested in the topic "Armoring of rooms containing radionuclide in hospitals using shielding materials". Of course, you can enrich and restrict these titles by considering your major university and research opportunities.
Best wishes
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When measuring gamma spectra from the decay of a radioactive nucleus, I observe 3 peaks in the spectrum. The databases indicate that during the decay of this nucleus, there are only 2 lines that lie in a cascade. The third observed peak is cumulative and is approximately 10% of the first or second peak. What is the possibility of dividing the third peak into contributions from the first and second transitions?
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I guess you talking about something like Co-60 1.17+1.33 = 2.5 MeV.
That comes to probability of detecting both gammas. E.g if you bring the detector closer the fraction of the events in combined line will relatively grow . Note that there might be or is (at least in case of Co-60) angular correlation/anti-correlation of emitted gammas.
So in simple case if you detect first gamma (as photopeak not Compton partial event) with probability a1, the second one with a2 the fraction of of combined line over total photopeak events will be simply a1*a2 /(a1+a2+ a1*a2). Note that some 'pot' or 'well' type gamma detectors may have a1,a2 approaching one for some cases.
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I have created a geometry of a concrete hollow box, placed a point source inside it. I got the Edep plot, now I need to calculate the depth dose profile in it.
I see extended example TestEm2,4, and 11 but I got bogged down seeing the enormous jungle of code. My understanding so far is, I need to access longitudinal and radial depth of the detector. Then need to get dose= edep/mass in each profile. Then show it in a histogram.
I need instructions whether my way is right and how can I do it simply.
Please do help, I got stuck here for a long.
Regards,
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Thanks Ashok Tiwari , I have done it with scoring volume in geant4.
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Being IN charge of secondary standard dosimetry laboratory and trying to establish luminescent dosimetry laboratory for start of remote audit services to cancer hospitals of Pakistan. I am trying to purchase the RISO/TL-OSL reader DA-20. For calibration of our dosimeters, we have a huge range of irradiation facility (alpha, Beta and gamma standard radiation sources). I don't want to purchase the 90 Sr/Y beta source along with this system. Is it necessary to purchase this beta source ( 90 Sr/Y ) for start and operation of RISO reader system?
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I Think, Beta irradiator should be purchased as, without an irradiator, working efficiency will get disturbed. Furthermore, the granular size measurement will become difficult.
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Hello for all;
I'm going to write a literature review for PhD proposal, the research topic about fabricating a glass dosimetry doped with gadolinium. can you please provide me some papers relate to this topic?
In addition, usually, how many literature review I have to add in proposal?
Best Regards
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There are some suggestions which I have been using for years.
Have 10 papers from the current year, 10 from last five years and 10 from the remaining years.
Start with the definitions of the constructs and then move to relation between the constructs. The relations would not be found for your variables directly so look how the others have done it. More and more reading will give you confidence to do this work. The literature review will be your base for your whole work, give it more and more time.
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What is the logic or significance for using the inverse square factor for calibration of in vivo dosimeters (placed on surface) to the dose measured by ion chamber at dmax?
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Nazia Toor I do understand your point now, thanks for elucidating your thoughts.
While the addition of ISF in the dose calibration formulae may lack significance due to the cancellation during the calculation. However, I think the ISF further acts as a factor to correct for any (if at all) change during setup.
Also, I tried to find relevant articles that have evaluated the ISF effect in in-vivo dosimetry calibrations but to no avail. This may suggest again that both accuracy and precision are needed during calibration procedures.
I hope this helps!
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What are the most advanced and novel dosimetry techniques?
In particular in medical dosimetry both therapy and diagnostic fields.
small field dosimetry?
proton dosimetry?
Or?
I appreciate any response and new idea in advance.
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small field Dosimetry
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Hi all,
I’m running a modified version of Example B1 for my graduate thesis. Pretty simple setup, the geometry is all modded and brand new (Basically just a bunch of boxes) and I cleared all overlaps so that part is good to go. For my source, I’m trying to use a GPS that takes up 99.9999% of the world volume in the shape of the world volume (world volume is a square, so I have a ParaP with all angles set to 90’), which shoots off gamma’s. So the problem I’m having is that the GPS code is seg Faulting when a gamma leaves the world volume instead of killing the interaction. I’m wondering how to fix the issue? I’ve tried to modify it in the stepping action, but do I need to find the StackingAction.hh file and modify it there/include it in exampleB1.cc?
Here is the error:
Some /vis commands (optionally) take a string to specify colour. “/vis/list” to see available colours. Checking overlaps for volume FrontWall1 … OK! Checking overlaps for volume FrontWall2 … OK! Checking overlaps for volume RightWall … OK! Checking overlaps for volume LeftWall … OK! Checking overlaps for volume BackWall … OK! Checking overlaps for volume TopWall … OK! Checking overlaps for volume BottomWall … OK! Checking overlaps for volume PbFW … OK! Checking overlaps for volume PbBW … OK! Checking overlaps for volume PbRW … OK! Checking overlaps for volume PbLW … OK! Checking overlaps for volume PbTW … OK! Checking overlaps for volume PbBottom … OK! Checking overlaps for volume WATER … OK! Issue /vis/viewer/refresh or flush to see effect. /tracking/storeTrajectory 1 Attributes available for modeling and filtering with “/vis/modeling/trajectories/create/drawByAttribute” and “/vis/filtering/trajectories/create/attributeFilter” commands: G4TrajectoriesModel: Event ID (EventID): G4int Run ID (RunID): G4int G4Trajectory: Charge (Ch): unit: e+ (G4double) Track ID (ID): G4int Initial kinetic energy (IKE): G4BestUnit (G4double) Initial momentum magnitude (IMag): G4BestUnit (G4double) Initial momentum (IMom): G4BestUnit (G4ThreeVector) No. of points (NTP): G4int PDG Encoding (PDG): G4int Parent ID (PID): G4int Particle Name (PN): G4String G4TrajectoryPoint: Position (Pos): G4BestUnit (G4ThreeVector) WARNING: Trajectory storing has been requested. This action may be reversed with “/tracking/storeTrajectory 0”. G4VisManager: Using G4TrajectoryDrawByCharge as fallback trajectory model. See commands in /vis/modeling/trajectories/ for other options. HepRepFile writing to G4Data0.heprep /run/verbose 1 /event/verbose 1 /tracking/verbose 1 /gps/verbose 1 /gps/particle gamma /gps/pos/type Plane /gps/pos/shape Rectangle /gps/pos/centre 0 0 0 cm /gps/pos/halfx 816 cm /gps/pos/halfy 228 cm /gps/pos/halfz 230 cm /gps/ang/type iso /gps/energy 10 MeV /gps/ene/min 0.1 MeV /gps/ene/max 30 MeV /run/beamOn 100
========= Table of registered couples ==============================
Index : 0 used in the geometry : Yes Material : G4_AIR Range cuts : gamma 1 mm e- 1 mm e+ 1 mm proton 1 mm Energy thresholds : gamma 990 eV e- 990 eV e+ 990 eV proton 100 keV Region(s) which use this couple : DefaultRegionForTheWorld
Index : 1 used in the geometry : Yes Material : G4_STAINLESS-STEEL Range cuts : gamma 1 mm e- 1 mm e+ 1 mm proton 1 mm Energy thresholds : gamma 20.9232 keV e- 1.31345 MeV e+ 1.22809 MeV proton 100 keV Region(s) which use this couple : DefaultRegionForTheWorld
Index : 2 used in the geometry : Yes Material : G4_PLEXIGLASS Range cuts : gamma 1 mm e- 1 mm e+ 1 mm proton 1 mm Energy thresholds : gamma 2.78665 keV e- 389.196 keV e+ 376.336 keV proton 100 keV Region(s) which use this couple : DefaultRegionForTheWorld
Index : 3 used in the geometry : Yes Material : G4_Pb Range cuts : gamma 1 mm e- 1 mm e+ 1 mm proton 1 mm Energy thresholds : gamma 101.843 keV e- 1.36749 MeV e+ 1.27862 MeV proton 100 keV Region(s) which use this couple : DefaultRegionForTheWorld
Index : 4 used in the geometry : Yes Material : G4_WATER Range cuts : gamma 1 mm e- 1 mm e+ 1 mm proton 1 mm Energy thresholds : gamma 2.94056 keV e- 351.877 keV e+ 342.545 keV proton 100 keV Region(s) which use this couple : DefaultRegionForTheWorld
====================================================================
/vis/scene/notifyHandlers scene-0
Run 0 starts.
Rotated and Translated position (-2113.3,-799.247,0) Generating isotropic vector: (0.759379,0.522945,-0.387133)
G4EventManager::ProcessOneEvent()
G4PrimaryTransformer::PrimaryVertex (-2113.3(mm),-799.247(mm),0(mm),0(nsec)) 1 primaries are passed from G4EventTransformer. !!! Now start processing an event !!!
  • G4Track Information: Particle = gamma, Track ID = 1, Parent ID = 0
Step# X(mm) Y(mm) Z(mm) KinE(MeV) dE(MeV) StepLeng TrackLeng NextVolume ProcName 0 -2.11e+03 -799 0 10 0 0 0 World initStep 1 -1.47e+03 -357 -328 10 0 846 846 RightWall Transportation 2 -1.46e+03 -349 -333 10 0 14.6 861 World Transportation 3 -573 262 -785 10 0 1.17e+03 2.03e+03 BackWall Transportation 4 -551 277 -797 10 0 28.5 2.06e+03 World Transportation 5 5.69e+03 4.57e+03 -3.98e+03 10 0 8.21e+03 1.03e+04 OutOfWorld Transportation Segmentation fault (core dumped)
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Hi Konnor!
I had a similar issue (Segfault in my implementation of G4UserSteppingAction::UserSteppingAction). In order to ascertain if a particle is en route to leave the world volume I came up with the following solution:
Provided the step pointer s, i used retrieved the step's track (eg. track = s->GetTrack()) and then checked if track->GetNextVolume() returns a null pointer. This is the case if the particle is about to leave the world volume (link to docs eg: http://www.apc.univ-paris7.fr/~franco/g4doxy/html/classG4Track.html#0dabd467c3157ce11e54612bf24b1ffd)
Hope this still helps, cheers
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I am doing internal dosimetry by using OLINDA software and for this, I required injected activity and residence time. THE SPECT/CT planner system was installed in our hospital which gives counts rate now how I am getting activity and residence time from this counts rate. the below picture gets from SPECT/CT system so plz someone understood me that how I get injected activity and residence time from spect/cr planer images.
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Mam if you share me the data which you obtain yourself and all the process to obtain tha data then i will be vary vary vary thanks full to u.
If you not tels me the process to obtain R.time then just share your own experimental values with me.
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i use OLINDA/EXm software for internal dose culculation and this software wants No of disintegration( MBq-hr/Mbq) sp from where i get this valus
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Thanks sir butts i was little bit confuse.bC this software wants total no of disintegration in give amount if time in source region and i cant find a way to get this valu....from ICPR this valu cant be fine For example if we injected 100Mbq dose to kideny so after 15 mints what amounts of activity decay in kideny.
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I am searching about a software for analyzing of electronic and communication boards viewpoint of radiation tolerance. for example the output of this software is 40 krad. it means this boards can tolerate 40 krad in radiation environments.
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If what you are searching for is the capacity to simulate the damage in boards when irradiated, you could use TCAD for that (through the Sentaurus Workbench). Once the electronics is designed, it allows for a radiation damage model.
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I need images taken at several doses during radiotherapy. It would be a positive addition if the scan has been done under MRI guidance. Information on Web resources, databases and texts would be highly appreciated. Thank you in anticipation of your suggestions!
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Please have a look at:
There are a lot of databases containig CT data sets. Some also provide MRI data,
such as:
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Biophysical effects of muons have been studiend mostly in human samples, existing a lack of knowledge on how they act on other living beings.
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Muons are ultrarelativistic and loose an energy of 2 MeV /g cm-2 (i.e. 2 MeV in every layer of 1 cm water or , apprximately, tissue).
The conversion coefficent from fluence to effective dose for muons above 150 MeV is approximately 350 pSv cm2, about 2/3 of the corresponding coefficent for electrons.
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Hi, I am a student who is studying about dosimetry using plastic scintillators.
I have a question about simulation with MCNPX.
The density of BC 408(Saint-Gobain) is 1.032 g/cm3 found from the document but the one I have is 1.117 g/cm3.
Then if I want to simulate for dosimetry with BC 408, which density should I use?
Thank you.
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Dear Ki Hong Pak,
the difference in density is just about 8% and will affect x-ray attenuation.
So, if you will compare your simulation results with experiments to be done with your scintillator material, you should take the density of your present scintillator.
However you should investigate the density dependence of your results bearing in mind that there is some other material available.
Good luck
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Even for equal doses when effect of heating rate for given TL glow curve on different identical samples of same TL material, the results on the effect of heating rate on TL glow curves lead to misconception on 
1. Variation of glow peak height with changing heating rate
2. Area under glow curve
3. Thermal quenching phenomena.
4. Even TL glow curve generally known not to exhibit thermal quenching exhibits same when measurement is made on Risoe reader system.
Please note that in the original work of Gorbics, Nash and Attix on glow curves of 6 standard TL materials, results different from those recorded using RISOE reader were observed and predicted.
Please provide your experience as the feedback will be of great use and help for TL community.
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@Ritesh in the absence of thermal quenching , the peak height would have increased by a approximate factor with which heating rate increases, if heating rate doubles the height would have increased by 1.9 times or so ideally .
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Chromosomal aberrations related
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Two questions require two answers.
1. Officially, as stated in the IAEA Manual on cytogenetic biodosimetry, a minimum dose limit is about 50-100 mGy of acute X- or gamma-rays for dicentric assay and roughly about 300 mGy for translocation assay, however the latter value depends essentially on the age of examined person. It should be kept in mind that there is a difference between exposure detection and dose measurement. I'd recommend to read 3 papers on this issue, especially the first one:
D. Lloyd, A. Edwards and M. Szluinska, The minimum detectable dose by biodosimetry in a radiation overexposure. In: Radiation Risk Estimates in Normal and Emergency Situations (A. A. Cigna and and M. Durante, Eds.), pp. 253–258. Springer, Berlin, Heidelberg, New York, 2006.
M. Szłuin´ska, A. Edwards and D. Lloyd, Presenting statistical uncertainty on cytogenetic dose estimates. Radiat. Prot.Dosimetry 123, 443–449 (2007).
W. Zhang, C. Wang, M. Minamihisamatsu, L. Wei, T. Sugahara and I. Hayata, Dose limits below which the effect of radiation on health becomes undetectable due to background variation. Mutat. Res. 654, 96–99 (2008).
These data were briefly summarized in our review:
Vinnikov V.A., Ainsbury E.A., Maznyk N.A., Lloyd D.C., Rothkamm K. Limitations associated with analysis of cytogenetic data for biological dosimetry, a review. Radiat. Res. Vol. 174 (4). 403-414 (2010).
2. There is no a stand-alone method, which guarantees a clear discrimination between spontaneous and radiation-induced cancers of the same hystological type. There is at least 2 cancers, strongly associated with specific radionuclide action: small cell lung cancer is usually attributed to alpha particles of radon (e.g. in uranium miners), and thyroid cancer typically occurs after radioactive iodine accumulation (e.g. in children in areas polluted due to the Chernobyl NPP accident in 1986).
There were some promising data regarding molecular markers of radiation-induced leukemias - for that, please, look for papers published by Christophe Badie and Simon Bouffler of Public Health England, UK.
The most popular approach now is to look for difference in gene expression in tumors occuring in radiation-exposed versus unexposed organisms, including humans. My search performed 6 years ago gave 4 papers:
Imaoka T., Yamashita S., Nishimura M., et al. Gene expression profiling distinguishes between spontaneous and radiation-induced rat mammary carcinomas. J. Radiat. Res. (Tokyo). Vol. 49, No 4. 349-360 (2008).
Detours V., Delys L., Libert F., et al. Genome-wide gene expression profiling suggests distinct radiation susceptibilities in sporadic and post-Chernobyl papillary thyroid cancers. Brit. J. Cancer. Vol. 97. 818-825 (2007).
Port M., Boltze C., Wang Y., A radiation-induced gene signature distinguishes postchernobyl from sporadic papillary thyroid cancers. Radiat. Res. Vol. 168. 639-649 (2007).
Ory С., Ugolin N., Levalois C., et al. Gene expression signature discriminates sporadic from post-radiotherapy-induced thyroid tumors. Endocrine-Related Cancer. Vol. 18. 193-206 (2011).
I'm sure much more similar papers have been published in the last 5 years. Hope, these papers will be useful for your research.
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I'm planning to use Geant4 to calculate the effective dose for mammography examination but I faced two problems:
1. I was trying to use the human phantom in advance example but some of the organs eg liver, lung and thyroid etc are missing. People suggests I could use XCAT phantom but it is quite expensive and I'm not so sure whether this phantom is suitable for mammography dosimetry or not?
2. Unlike PET or SPECT in GATE there are no benchmark for mammography unit do I need to build it from scratch? Even I modeled the mammography unit I cannot verify my simulation results...
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The license policy shouldn't be unfriendly. We're always glad to help as far as I know.
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ICRP in the report 110 published the female model image which can have been used for internal dosimetry. But I can't find the ICRP report 110 and female model image
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Dear Ali:
Sorry again for giving you the link to the wrong report. Unfortunately as far as I can see ICRP Report 110 is not available through my sources. It's peculiar since most of the other reports are.
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I would like to know wich was the procedure employed to perform dose assessment in the times were montecarlo codes and methods were not employed.
I searched in internet but I found no clue. Maybe some of the most experience members of the comunity can help me a little.
Thank you in advance
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Monte Carlo codes perform dose assessments using the same equations and information used to perform dose assessments using pencil and paper. Computers allowed programing some of the tedious parts of the calculations. Commercial programs were developed. An example is MICROSHIELD, which used kernel type calculations.
A good Monte Carlo program will incorporate all the necessary physics to perform calculations of multiple simulations. Hand calculations use the same physics and calculations. Hand calculations require interpolation to estimate detail between calculations. Hand calculations are only as good as the amount of effort allows. Monte Carlo can provide much more detail to a sufficient accuracy. Nevertheless, Monte Carlo is limited by the effort in detailing the exposure situation.
If you cannot perform the hand calculations you should not perform Monte Carlo simulations.
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I'm doing some dosimetry research on the MIGB-I123, MIGB-I131 and 68 Ga-DOTANOC using Internal Dose Computer Program called IDAC but this software doesn't has the preadult phantoms therefore I can't estimate the organ and effective dose for children (1,5,10 and 15 year old patient) in ICRP Publication 103 . After an extensive literature search I noticed that there is a software called OLINDA/EXM® 2.0 which has the preadult phantoms but it is very expensive to buy it for this purpose...
I was wondering is there any free software similar to OLINDA/EXM® 2.0 which has preadult phantoms?
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I do not know relevant free software, but the following paper may help
FYI, the predecessor of the OLINDA/EXM (Organ Level INternal Dose Assessment/EXponential Modeling) version 1.0 code was the formerly freely available MIRDOSE 3.0 and 3.1 codes, and these codes were written and rewritten by the same investigator.
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EPIQA is commissioned at EPID position 0,0,0. Can it be commissioned at 50,0,0?
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Yes, it can
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Can Lead (Pb) sheet filter gamma and is it transparent to Fast and Epithermal Neutrons?
How thick should the filter be?
Does it produce secondary radiation during the filtration?
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I published a paper last year showing spectra from Am-Be sources (with/without lead) measured with a HPGe. Other sources (Cf, Am-Li, Am-B) are also included.
N.J. Roberts, Photon spectra in NPL standard radionuclide neutron fields, Radiation Protection Dosimetry, 10.1093/rpd/ncx172
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In ANSI N13.15-1985 (PERSONNEL DOSIMETRY), the criteria for Accuracy(Bias) and Precision(standard deviation) as follow:
for photon from .3 to 10 MeV: (Bias <1.5/sqrt(Absorbed Dose) and Standard Deviation <0.2)
Can you tell me these criteria for environmental dosimtery?
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Hello Majid,
The concepts of accuracy and precision are usually applied to systematic and random errors, respectively, associated with measurements. But while precision can be measured, accuracy cannot.
Precision is a way of quantifying repeatability of a measurement, i.e., if you
are using TLD's, for example, you can estimate the precision of the measurement by exposing N dosimeters of the same type (same model number and same lot number and stored under the same conditions including time), one at a time, to the same radiation field and calculating the sample standard deviation of the dosimeter responses, but there is a rub or two in doing this procedure.
First, you need to convert the estimated sample standard deviation to an estimated population standard deviation, i.e., the sample standard deviation must be multiplied by a coefficient which takes into account the size of the sample, N, and the underlying distribution of the population of all dosimeter responses, not just the N dosimeters you employed. Note, it is very unlikely that the population distribution is normal (Gaussian), although the the distribution of sample means may approach normality. The underlying distribution of the population of all dosimeter responses of the same type cannot be normal because the responses of the TLD's cannot be negative; a Gaussian distribution extends from negative infinity to positive infinity.
Second, the precision you determine depends on a number of factors: 1) the intrinsic precision of the TLD's itself, i.e., the amount of active material in the individual TLD due to how it is manufactured; 2) the repeatability of the fixturing used to hold the TLD in place in the radiation field; and 3) the
temporal variation in the radiation field itself.
Note, while precision quantifies repeatability, it does not necessarily
quantify reproducibility, i.e., if a different researcher measures the
precision of the same type of TLD's in a different laboratory, they will almost certainly find a different value of precision.
Accuracy, which is the sum of the bias plus the estimated population standard deviation, cannot be measured because the bias cannot be measured independently. Consider the following scenario. You place a TLD in a known radiation field and measure its response. The problem with the aforementioned procedure is the word 'known'. How was the radiation field known? You say it was known via a calibrated instrument, but how was the bias of that calibrated instrument independently determined? What happens is that you get into an infinite regress. Most people would say that you break the infinite regress by determining the radiation field in a national laboratory using a primary standard instrument such as a calorimeter, i.e., an instruments whose response can be determined by measuring the mass, length, time, etc. of the detector. A TLD is a not primary standard. But even the bias of a primary standard
instrument is only calculated. It should be noted, that national laboratories
only use a very limited number of radiation sources. The radiation source
(type and strength) you intend to measure with your TLD's may not correspond to the radiation sources used in the national laboratories.
I realize this answer is too terse, but I don't want to bore you anymore than I
probably already have.
Regards,
Tom Cuff
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Dear All,
I want to simulate Protontherapy machine by using Geant4 Monte Carlo code. I'm asking if there is any document in which I can find all data required to perform a Monte Carlo model of ProtonTherapy.
Thanks,
Best Regards,
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Every model has different components, materials and their compositions. Paganetti's document contain main idea - that you can use for "ideal" device. If you want real data you must ask manufactures of devices. It unlikely that such data present in open access.
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ICRP-118-2011) Published new version decreased dose limit for occupational workers from 150 mSv to 20 mSv but i did not find any publication concerning any change in eye lens dose limit for public. 
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Situations should be different among countries each with different national regulation and policy, but all people who enter radiation control area (regardless of whether routinely or occasionally) should wear dosimeter.
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I want to make a dosimetry evaluation of a dental CBCT scanner using a Monte Carlo simulation software. 
What software package includes a volumetric head phantom easy to be used (possibly with graphic UI) without big experience in Monte Carlo programming?
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I can recommend you to use MCNPX (version 2.4.0) but somehow there is another codes that most suitable for begginers since MCNPX need a bit manual definition of simulation tools inside the input file.
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The annual dose limit for skin dose in occupational exposure has been defined 500 mSv by ICRP. However this dose limit is averaged for 1 cm2 of the skin.  Assume that we use a filtered TLD pellet with “A” cm2 in area. Is it necessary to divide any of theTLD readout by “A” to compare it with the dose limit?
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Its not necessary to divide any of theTLD readout by “AREA” to compare it with the dose limit as the calibration has previous;y been performed using same discs having area A. Ideally TLD pellet should be covered by very thin layer of tissue equivalent material say polythene etc. so measure skin dose or Hp(0.07). Too thick filtration is not recommended. Filter must be ~.0.07 mm thick of low Z type materials. Worldwide LiF TLD being used are of smaller size say 4 mm size to OSLDs being 7 mm or CaSo4:Dy TLDs being upto 13.3 mm in some countries. So size square/circular varies from ~(4-14) mm.
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dear colleague.
I wish to use T2 images , and analyse them by using an automated detection of the ROI, to build a nomogram aiming to predict the risk of biochemical failure after EBRT.
The MRI done here are made before EBRT in a purpose for dosimetry...
if if you could help me in automatizing the analysis, we could draw a score, and then a nomogram as a tool to add hormonotherapy to the patients with MRI' high risk prostate cancer.
best regards.
françois Luyckx 
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Hi, Francois I am interested in this research study. Kindly let me know where a Medical Physicist can participate. Thank you.
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Which dosimetric term used when the source of radiation exposure is from radioactive material located within the body?
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If you are specifically asking internal exposure here, then the relevant radiation protection quantity is committed effective dose and committed equivalent dose. Committed dose quantities are necessary, because the intake of radionuclides leads to irradiation of the tissues over a period of time according to its physical half-life and biological half-time.
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Dear Researchers,
I need some real data of a patient treated with chemotherapy. This data includes the tumor reduction with time. For example, what is the tumor size (or the number of cancerous cells) just before the first dose, the second dose, the third dose,..,etc.? Any type of cancer is acceptable.
Any answer is appreciated.
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There are also free datasets in internet
Try this one
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I am planning to doing Gamma H2AX assay as a biodosimetry in my laboratory. If somebody can provide us the protocol how to doing Gamma H2AX foci assay on peripheral blood lymphocytes and also what reagent we must buy to do Gamma H2AX assay it will help us a lot.
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The Special Issue on the European European Network of Biodosimetry (RENEB) project guest edited by Drs Ulrike Kulka and Andrzej Wojcik has just become available online as the January 2017 issue of International Journal of Radiation Biology. All papers in this special issue are freely downloadable.
Of these papers, you may be especially interested in 
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Hi everyone!
I'm currently optimizing my [35S]GTPγS assay in whole rat brain homogenates and I'm only getting 50% stimulation over basal with 10uM DAMGO. Another thing is that the difference in efficacy between DAMGO and morphine is rather small (148 vs. 125%). Thus, DAMGO doesn't seem to act as a full agonist in my system. When I was running the assay (in a 1 ml format) in another lab Emax values were 190% for DAMGO and 140% for morphine and I could clearly see the difference between the efficacy of both drugs. 
My binding buffer composition is as follows: 50mM Tris-HCl (pH 7.4), 3 mM MgCl2, 100 mM NaCl, 1mM EGTA and 30uM GDP. The assay is run in a 250 ul format with 0.05 nM [35S]GTPγS and 15ug/ml of added protein for 1h on a shaker set to 30oC. The samples are filtered with the FilterMate Harvester onto GF/B Unifilter plates and dried for 2 h at 50oC. The scintillation fluid I'm using is Microscint-20 (45ul on each filter). I've already tried different protein, GDP and Mg2+ concentrations with no improvement in efficacy. I'll be running another experiment with different Na+ concentrations next week, but I doubt that'll bring a breakthrough though. Did anyone of you encounter such a problem with your assay? If you have some tips please share. 
Anna
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Hi Sandor!
Thank you so much for your reply. Hoping that you are well. As you probably have guessed already the lab I mentioned was your lab that I visited some time ago to learn the GTPgammaS assay :) In my last experiment, morphine produced slightly less stimulation, but in the one before, the Emax values were identical for both drugs. I was surprised because you mentioned morphine being a partial agonist and DAMGO giving much more stimulation than 50%. Another thing is that I also get 10-times lower EC50's than I got in your lab. I know that the EC50 values are not accurate when determined in GTPgammaS assays due to the presence of sodium, but this inconsistency still worries me a bit. I don't remember which membranes I used when I visited your lab, but I think I'll try the brain regions you mentioned and see how it goes. Do you also use spinal cord homogenates? Do you see a clear distinction between the efficacy of DAMGO and morphine? 
All the best,
Anna
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The source consists of eight encapsulated Cobalt-60 pencils arranged in a cylinder. Each source pencil is of 1.4 cm outer diameter and 45.2 cm length. I want to compare the observed dose with theoretical calculated data using "Line source" formula not "point source". Is there any software available of dose calculation for "Line source"?
Please see the attached file for more information.
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Re: comments of Nelson Omi: Nowadays, cable-connected precision ion chamber-electrometer systems with miniature ion chambers(for high range) are available. The electrometer reading system can be therefore located in a radiation-free area. As per the table, the dose at 1m distance for the source configuration is about 600 rads/min which can be accurately estimated. The cables used are double-screened antimicrophonic type with minimum noise and radiation-induced conductivity. If needed, the cable can be routed so the exposed parts may be kept away from the radiation sources. Both dose and dose rates can be measured here. The errors due to the addition of doses contributed by raising and lowering of sources and room/table scatter can be taken into account by measuring the TOTAL dose to the sample under actual conditions. This method will thereby provide a secondary check on the Fricke dosimetry which involves some assumptions for spectrophotometer dosimetry calculation. Besides, ion chamber dosimetric systems calibrated against primary standards in NIST/BIPM/NPL laboratories are available from several companies. Hope this helps. Thanks.
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I found very limited number and any help would be highly appreciated.
Thank you in advance.
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I scanned the cone phantom either using axial or helical CT scan, and im trying to calculate the dose conversion coefficients. 
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the traditional way to calculate the conversion coefficients is to get the ratio of personal dose to the air kerma taking to account the phantom(head, abdomen)
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Geology, Dosimetry & Dating, Paleo-climate reconstruction
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sorry,do not ask me .Refer to a geologist
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Hi,
I am using iterative reconstruction algorithm to reconstruct CT image, the image looks ok, but it has a meshgrid in the whole reconstructed field. That give strong influence on the image recognition. Has anybody meet this case before? Thanks.
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OK, if the reconstruction using FBP method looks good, you are probably right that the mesh grid comes from the algorithm. Maybe it has something to do with the starting point of the iteration process, if the mesh grid is less visible when increasing step lenght. So, you could have a look at interim reconstruction results. In addition, you could also try to change/increase your sinogram data/resolution (more angular steps) to check influence of your input data. But I don't know this reconstruction algorithm, so I'm only guessing...
Good luck!
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I performed the radiation dose calculations and radiological consequences of a hypothetical accident by HotSpot, How to calculate values of error bars shown in figures? How to calculate combined relative error?
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HotSpot is an excellent tool for preparing response to radiological accidents. In particular, its ability to predict instrument response is very useful for planning purposes. HotSpot is woefully inadequate for dose calculations as are all other air dispersion programs. Actual conditions for any accident are manifestly impossible to predict. Placing error bars or propagated relative error is not possible. Nevertheless, you can estimate reasonable upper and lower limits. Use your judgement, but do not pretend that you have some statistically justified error calculations.
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I have a ct  dicom image of a phantom and I want to dosimetry with dosxyznc code , for this purpose i gave the directory path  of my phantom in the prompt of ctcreate code  and i have  met this error
Working on file :
Error opening file .
Program received signal SIGSEGV: Segmentation fault - invalid memory reference.
backtrace for this error;
0#  0X7FA030FCD777
1#  0X7FA030FCDF7E
2# 0X7FA030FCD777
#3 0x7FA030C5D800
#4 0x410FDF in read_elem_vr
#4 0x410FDF in read_elem_vr
#5 0x41190E in readct_dicom_
Segmentation fault
my platform is a linux  mint 17.1
thanks in advance to your attention or maybe your answer.
 
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Segmentation fault occur when you try to access memory that is not available for you. It could be practically everything and in general case needs a lot of debugging. There are a few things you can start with though.
  1. Check array boundaries.
  2. Do not use direct memory allocation (use smart pointers instead).
  3. Never use direct pointer arithmetic unless you are experienced system programmer.
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I have been wondering if the shape of the thermoluminescence glow curve of any mineral can change (even subtly) under varying β-particle energies. Put differently, if a mineral is irradiated by packages of progressively higher β-particle energies will the relative peak intensity of the TL signal change?  Would such a change be observable?
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 I wonder if you mean the change in the dose of the Beta radiation or the energy of the Beta particles. If the TL peak is not of first order, it is expected to shift to lower temperature with higher doses and the shape of the peak may somewhat change. If you are talking about changing the energy of the Beta particles, this effect is not expected. However, when you use a number of Beta sources and compare the shape of the TL peak, you have to make sure that the dose is kept the same. 
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I have a ct  dicom image of a phantom and I want to dosimetry with dosxyznc code , for this purpose i gave the specification of my phantom and when enter it in the ct create code i have met this error
Working on file :
Error opening file .
Program received signal SIGSEGV: Segmentation fault - invalid memory reference.
backtrace for this error;
0#  0X7FA030FCD777
1#  0X7FA030FCDF7E
2# 0X7FA030FCD777
#3 0x7FA030C5D800
#4 0x410FDF in read_elem_vr
#4 0x410FDF in read_elem_vr
#5 0x41190E in readct_dicom_
Segmentation fault
thanks in advance to your attention or maybe your answer.
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Hello Milad,
Without your input file it is next to impossible to give exact answer to your question but I will try to give at least some help.
I myself encountered this problem several times and it did not have anything to do with program itself (except for not too good error reporting). Always it was problem with syntax of input file, with such things as empty line in middle of geometry definition, two empty lines as separator between cells and surfaces, or invalid number of parameters for some function I have been using for first time for example. 
I tried as first step to go slowly through input and double checked everything in it. As it usually did not help (I an only human, you know), the next step was to "cripple" my input file and deleted parts and/or simplified it. That mean for example delete 15 of 16 surfaces and cells. Yes, it totally destroyed the geometry and/or physics, but as soon as the error changed I stepped back (undoing that deletion) and examined those line carefully and usually finding something like wrong sign or cell defined with old surface number etc.
I know this is not an easy way, but I could not think of anything easier (except for rewriting from scratch, but I am not sure if it is easier through :-) ). If you found an simpler solution, I would not mind If you share it ;-).
Also check the name of your file for typos, and folder in which you are running it if it actually contains this file, as the first two lines ("Working on file : " and "Error opening file .") are somewhat free from any filenames/paths despite from what spaces suggest.
Hope this helps,
Michal
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Hi Dear friends
I want to work with CR39 films for neutron dosimetry for the first time. I need help for knowing about 1) the interaction between films and neutron or other particle (which is produced by high energy photons like 15Mev) which make track on films, etching procedure and reading the track.
Do they record the fast or thermal neutron or both of them?
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I want to carry out some dosimetric calculations for dosimetry of bone. I am able to find much of information online. Please provide some relevant references.
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Dear Deepak Kumar Akar: If I understand correctly, your question is on bone dosimetry and not on bone densitometry. I believe you require the techniques for bone dosimetry estimation following radiotherapy of patients or for radiation accident victims. Well, one important method is based on using Electron Paramagnetic Resonance (EPR) or Electron Spin Resonance (ESR)  spectroscopy techniques. There are a number of articles available in the website, Please do a Google search on "Bone dosimetry using EPR". You will see a number of scholarly articles here. The Wikipedia article elucidates the principles and application of EPR. EPR is similar to NMR. EPR involves spin of electrons whereas NMR involves spin of nucleii. For NMR, the exciting radiation is RF whereas for ESR, the exciting radiation is microwave. There are also other differences. There are IAEA  and NIST publications and article by K.Krefft (latest 2014) and many earlier ones by other important authors. You will also get from here the manufacturers and suppliers of EPR spectroscopy equipment.
Incidentally there is a group working on EPR dosimetry in Radiation Safety Systems division (RSSD) of BARC.
I have not worked on EPR but,nevertheless, am able to provide you the requested information.
I hope the above will be helpful.
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I'm considering doing a study to measure thyroid dose during neurointerventional procedures, using a biplane unit with an undercouch x-ray tube. Would the measurements done with a dosimeter on the neck over the thyroid be accurate? 
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There is a NaI-based scintillation dose rate meter (Model  SCINTO Thyroid) available from SEA, Germany. The detector is of spherical shape, suitable for the neck region covering the thyroid area very well. The technical pamphlet of the manufacturer gives a table showing estimation of expected thyroid dose for various measured doses (uSv/hr) for adults and children. Reference is provided for dose calculation.
For theoretical estimation of thyroid dose, a text book on Nuclear Medicing may be consulted.
Is this helpful? 
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In MCNP if i want to enter air in data cards, by which accurate percents can it be done (density , composition)?
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the standard composition and density of about 300 most used material for MCNP could be found in the  following link::
all the best,
yaser
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One idea to improve a TLD response sensitivity and other its characteristics is to add co-dopants to the phosphors. Is there any rule for co-dopant selection in a specific phosphor which already has a dopant? Is there any way to predict the effects of adding a co-dopant to a TLD phosphor?
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In the case of lanthanide doping, look for the papers by Pieter Dorenbos, e.g.
Dorenbos, P. and Bos, A.J.J., 2008. Lanthanide level location and related thermoluminescence phenomena. Radiat. Meas. 43, 139-145.
Other co-dopants can also increase the TL intensity by introducing new defects or acting as charge compensators, increasing the incorporation of the dopants. In the materials we synthesized, Li co-doping often increases the TL intensity by many orders of magnitude:
Oliveira, L.C., Milliken, E.D. and Yukihara, E.G., 2013. Development and characterization of MgO:Nd,Li synthesized by Solution Combustion Synthesis for 2D Optically Stimulated Luminescence dosimetry. J. Lumin. 133, 211-216.
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In most of the literature reported that the activation energy is in the range of 0.5 - 2.0 eV at the T max temperature range  is around 373 - 673 K. But 673 K temperature is equivalent to 0.058 eV only (by calculation using http://www.colby.edu/chemistry/PChem/Hartree.html). However the heat energy (T max) sufficient to over come the activation energy i.e. that energy is sufficient to eject an electron from trap to CB ? Hence please explain me what other parameters and how that parameters effect on activation energies to precise the reported activation energy range.
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T max is not sufficient to eject all traped electrons to the conduction band. The evidence of this is if you remeasure the sample you may find some residual and you have to anneal the sample after reading and before next irradiation.
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Can anyone know the Primaquine dose on Plasmodium berghei infected Balb/c mice?
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Sorry, I don't know...
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EPID in vivo dosimetry
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Can you send me a procedure to calibrate it
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In developing a new TLD dosimeter a key issue is the type of dopants which are used in an especial phosphor. Is there any role for selecting dopants?
Can someone introduce me a good reference for this topic?
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I am interested in compiling a list of all the REVIEW papers for luminescence dating and dosimetry, going back to at least 1980. I realize there are literally over a 100 such papers (possibly 200 such papers), but I would like to know of any articles in journals I may not read routinely (i.e. anything starting with the word Quaternary). I have already checked the bibliography lists in Ancient TL but I think that there are probably more than a couple I am missing because they might have been published in medical or space journals. If you read this message and want me to know about your favorite review paper please send me a message . Thank you.
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Far too many!!!!
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I want to use Fricke dosimetry (liquid and gel) system for alpha radiation, but the issue is G-value of the system. I want to know how to increase the G-value?
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 1. Chemical Dosimetry during Alpha Irradiation: A Specific System for UV-Vis in Situ Measurement /Cedric Costa, Johan Vandenborre, Francis Crumière, Guillaume Blain, Rachid Essehli, Massoud Fattahi
2. 
Radiolysis of 0.4 M sulfuric acid solutions with fission fragments from dissolved californium-252. Estimated yields of radical and molecular products that escape reactions in fission fragment tracks / Ned E. Bibler J. Phys. Chem., 1975, 79 (19), pp 1991–1995
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Hello I'm Jungjin Kim.
I plan to determine G(H2O2) of electron and gamma radiation.
So I will follow a recommended recipe of fricke dosimetry as shown below.
The Fricke solution has the following composition : 1 mM FeSO4 or Fe(NH4)2(SO4)2 + 0.8 N H2SO4air saturated +1 mM NaCl.
Dose anyone know whether fricke solution is air saturated?
Thanks
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You can use of high pressure O2 gas for better response. 
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If I calculate the collected effective dose of all the CT studies performed in one month (DLP x k x #studies) and compare that to the collected dose in another month; what would be the best way to describe the difference in the total radiation per patient.
Ex. lets say the first month total was 20 Sv total with 1,000 patients scanned and in the second month the total dose was 25 Sv also with 1,000 patients scanned. Are the following statements appropriate:
  • there is 25% increase in radiation dose from month 1 to month 2
  • the average dose for the scanned population (total monthly dose/ scan population) was 20 mSv in month 1 and 25mSv in month 2
  • the dose in month 1 (20 mSv) to the study population is comparable to 7 years of background radiation
  • the dose in month 2 (25 mSv) to the study population is comparable to 8 years of background radiation 
  • the study population in month 2 was exposed to an increase of 1 year of background radiation compared to month 1.
Thank you in advance for any help in clarifying this!
REVISION:
The issue behind this question is looking at the total number of CTs performed in one month at baseline, and then the number of CTs performed after instruction of appropriateness. In the second month there was a decrease in the number of CTs ordered (yes, opposite of what I described above).
Given the decrease in # of CTs (which is known) and the effective dose (from the sum  individual DLPs multiplied by appropriate k-values), I am challenged to describe the effect of the decreased number of studies and subsequent amount of radiation saved to the study population. I'm also trying to compare this decrease in radiation with a metric that more people will be familiar with (background radiation or even # of chest Xrays).
Is there a more appropriate way to describe? Thank you again!
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I would highly recommend staying away from risk estimates for this type of calculation.  There is some controversy surrounding this issue and it does not help with what you are trying to illustrate.  Effective dose is an appropriate metric to use for your purposes if it is calculated properly.  If you want to remove the bias of having a range of patient sizes, you could calculate the size-specific dose estimate using the procedures in AAPM Report 204.  This will require a bit more effort than simply using the machine reported DLP values.  If the patient size and study type distributions are constant, then you can still show the relative decrease in radiation delivered if you ignore the patient size effects.  If they are not constant from month to month, you could theoretically have a reduced or constant total DLP yet an increased effective dose.  You should also break down the DLP into specific body region values and use the specific k factor for that region.
I don't think you need to compare to background, a chest x-ray, or anything else.  The collective effective dose is what it is, and if you are showing e.g. a decrease of 25% on average, then that's what's important.  If you want a reference value for people who have no idea what a Sievert represents, then give a typical annual background value.
Other than that, your suggestions for comparison are ok but I would want a lot more than two months data as suggested by Hanno.
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How do we measure the dose rate of Sr-90 Beta Applicator?
Which Dosimetry equipment is required for the dose rate measurement?
In case of non availablity of such dosimetry unit, how is this measurement done?
Is there any formulai for the calculation of dose rate from activity of Sr-90 Beta Applicator?
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you will find the equation in MIRD Pamphlet No 21 
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I am researching on the use of alanine/EPR dosimetry to measure absorbed dose for radiotherapy. I have been able to obtain my EPR spectrum with a Bruker Elexsys E500 Spectrometer. I am intending to use peak to peak analysis but would like to improve my readings by reducing background distortion. Any suggestions would be helpful. Thanks!
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If you have a SHQE resonator that is more sensitive but be sure that the sample is properly fixed in the cavity. Good luck
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Dear RG community,
I need to obtain information of the prostate volume changes during the brachytherapy for my project. The software used in the collaborating clinic is Variseed for brachytherapy dosimetry. In the brochure of the software I see is possible to obtain a so-called "User-defined report for contiguous volume analysis" has anyone experience with the software and this feature?
Thank you very much in advance,
Konstantinos.
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Of course there is. And the last calibration comes up as the default. You just need to click through the wizard to confirm nothing has changed.
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I am working on electromagnetic field effects on pregnant rats, so I want to now how can I measure SAR for rat's bodies.
Thanks for your help.
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Thank you so much Maciej M Kmiec and Somayeh Asadi for your help. I  will wait you Dr. Somayeh Asadi. 
best regards
Ali
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Dear Colleagues!
I am looking for some apparatus that allows me to drip a solution in quick succession from a vessel (e.g. a syringe). I tried a syringe pump but I was not successful in reliably controlling the speed of the drops (which is somewhat critical in my application).
Any help is greatly appreciated!
Yours,
Chris 
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dear colleague!
what about a single nozzle inkjet printhead - controlled by a piezo?
regards,
sebastian
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To simulate a lot of spheres (10 ^ 12) with the nanoscale in a particular cubic volume (1cm ^ 3) in fluka code (flair), What do you recommend? It seems that using the lattice card due to the increased number of regions is not appropriate!
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As far as i understand, geometry at this level is not important. This assumes, that your spheres are "small" in the sense that fluctuations in beam direction randomly another sphere.
So just create a new material and add the elements H, O, and Au (assuming you have gold spheres) in the correct weight fractions.
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I am trying to compute the heat generated in anatomical human body tissues, particularly in the head, due to the induced SAR. The human body is inside a low-pass birdcage MRI. I am using a FDTD-based software. I tried to define some boundary conditions for the tissues of a 1-mm anatomical human body but the results were not accurate. Any paper/document give extensive details about the definition of the thermal boundary conditions? Anybody tried such a research can give a help?
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I like this discussion though, since temperature will increasingly be the base for limits, as e.g. suggested in the attached paper
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if you know an article addressing this question with quantitative results will be great
treatment site , GYN, skin ,etc  
thank you in advance
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Many articles are available on this issue.
Two articles are attached for your perusal.
1. DeWard et al., A dosimetric uncertainty analysis for photon-emitting brachytherapy sources: Report of AAPM Task Group No. 138 and GEC-ESTRO (published 14 Jan 2011)
This report addresses uncertainties pertaining to brachytherapy single-source dosimetry preceding clinical use. The International Organization for Standardization (ISO) Guide to the Expression of Uncertainty in Measurement (GUM) and the National Institute of Standards and Technology (NIST) Technical Note 1297 are taken as reference standards for uncertainty formalism. Uncertainties in using detectors to measure or utilizing Monte Carlo methods to estimate brachytherapy dose distributions are provided with discussion of the components intrinsic to the overall dosimetric assessment. Uncertainties provided are based on published observations and cited when available.
2. Antony Palmer et al., Physics-aspects of dose accuracy in high dose rate (HDR) brachytherapy: source dosimetry, treatment planning, equipment performance and in vivo verification techniques.
Journal of Contemporary Brachytherapy (2012/volume 4/number 2) 81-91
This study provides a review of recent publications on the physics-aspects of dosimetric accuracy in high dose rate (HDR) brachytherapy. The discussion of accuracy is primarily concerned with uncertainties, but methods to improve dose conformation to the prescribed intended dose distribution are also noted. The main aim of the paper is to review current practical techniques and methods employed for HDR brachytherapy dosimetry.
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Energy deposited per unit mass (absorbed dose) in a medium is proportional to its mass to some extent. But if the medium changes its density also plays a role. I wonder whether there is a direct relationship in absorbed dose and mass attenuation coefficient?
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There isn't quite a direct relationship between mass-attenuation coefficient and dose, since not every attenuated photon deposits all it's energy in the medium (e.g. for Compton or Rayleigh scattering). There is a related quantity called the mass energy-absorption coefficient that can be multiplied by the photon fluence to calculate the dosimetric quantity kerma (see the link below). Kerma is closely related to dose, but not exactly the same either. So the short answer to your question is "no".
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Is there any reference data available for reliability  and availability of GM based radiation survey meters which are used for routine survey purpose in industrial or medical institutions. 
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Thanks Lung-Kwang Pan for your views, but the facilities which really use only GM for practical applications, it may not be appropriate to use data of other monitors/detectors.
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If you are a clinical medical physicist, what are the major challenges in your department in order to perform invivo dosimetry for each individual patient when he/she is receiving radiotherapy or undergoing for a diagnostic radiological procedure?
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Hi Shakardokht,
I don't have any experience with dosimetry in diagnostic radiology but I have been doing radiotherapy in vivo dosimetry (TLDs and GaF film) for a while now.  Narayan's work is really intra cavitory dosimetry, which, these days is not performed regularly as modern planning systems can predict/estimate the doses to OARs quite accurately. I have found eye lens dosimetry to be the most challenging one. In vivo dosimetry in this case uses surrogates on the skin to estimate dose to lens at depth. The other issue the uncertainty in dose estimation using TLDs due to the angular dependence of TLDs. Not sure if a phantom exists where one could place TLDs in place of lens and then performs dosimetry by putting TLDs on the skin and comparing the doses from on the skin TLDs to the TLDs placed inside the phantom where the lens is located. The other anatomical areas where in vivo can be challenging are the nose and ear, especially when MV electron are used to treat skin tumours in these areas. The issues to consider here are the electron backscatter, uneven surface and the lack of tissue. There probably are other areas/issues such as dosimeter preparation readout etc. which can also be challenging.
Cheers
Vinod 
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I am working with dose issues in CT. In my former institute we used TLD measurements inside the Rando phantom for accurate dose estimations. Besides the fact that these measurements are very time consuming, the phantom + equipment cost a lot of money. Do you have suggestion about any alternatives? May be simulations?
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We started a PhD on this subject. We will employ MCNP and try also EGSnrcMP. That gives our aspect on the theme.
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Treatment time (for teleterapy unit) is similar with monitor unit (for LINAC).
Manual calculation for MU or time depends on dose delivery technique, there are SSD tech. and isocentric tech.
To calculate MU in LINAC,
If we calculate in SSD tech., we used data of PDD.
if we calculate in isocentric tech, we used data of TMR.
How does to calculate treatment time Cobalt-60 teletherapy unit for in SAD/isocentric techique?
we use TAR or TMR ?
if we have data of TAR and PSF Cobalt-60 from BJR Supplement 25, to calculate time in isocentric tech, we use TAR data? or must convert TAR to TMR ?
Thanks a lot for your discussion.
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To calculate treatment time Cobalt-60 teletherapy unit for in SAD/isocentric technique
we can use
1) TAR if dosimetry system is calibrated interms of dose to air (NDair) which is then be converted to NDwater (IAEA TRS 277)
2) TMR if dosimetry system is calibrated interms of dose water (NDwater) using IAEA TRS 398 
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AAPM Report Task Group 71 described recommendation for manual calculation of Monitor Unit calculation for photon and electron beams. In this report, d0 =10 cm (depth of normalization) used as reference depth. It not use dmax (depth of maximum dose) as reference depth.
How does if we do manual calculation of treatment time cobalt?
Is AAPM Report TG 71 applicable for calculation of treatment time cobalt-60 ?
can we use this recommendation?
if yes, how many reference depth that we must choose?
dmax
d0=10cm
or d0=5cm
thanks a lot for your discussion.
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For proper measurement of the beams, some reference depth other than depth of maximum dose is recommended. Although for Co-60, 4MV-9MV 5cm is sufficient and for energy more than 9MV, 10cm is recommended by IAEA and other protocols but we can use 10cm or more and the at Dmax for any beam, the calculated dose will be same.
dose at Dmax of Co-60= Measured dose at any depth x 100 / PDD at that depth
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I apply EBT2 Film for dosimetry. to measure collimator scatter factor (Sc), I want to use Matlab for reading the optical density of the films . How can I write a program for MATLAB to average the optical density for some points in a circle with radius of 0.5 cm?
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Leon's answer above is correct in that it will give you a numerical value that you can use as a starting point. However, it will not directly give you optical density. There are a few other things you need to do (including scanning each film prior to irradiation, calibrating your scanner etc.).
You might find some useful information in this MSc thesis from the University of Wollongong:
You may also find this article on ResearchGate useful:
(it is for EBT3 but shouldn't be radically different I think).
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Most of time, we used five or several point dose vs OD values to produce the fitting equation, then we use this equation to translate the optical density to dose.
Question : For the calibration film,
Supposing we chose five dose levels (50cGy,100cGy,150cGy,200cGy,300cGy) and background film, the lowest dose level was around 50cGy. If we wanted to perform low dose measurements for TOMO MVCT dosimetry, because of  low dose, the measurements were repeated several times. This method was used to improve the signal to noise ratio of 30cGy doses. Does it overestimate or underestimate the low dose for EBT3 film ?
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In general, it is not a good practice to measure doses outside the calibration dose range. However, you need to know the dose response of the film at lower doses than .5 Gy (it can be non-linear).
There are some (open-acces) papers on this:
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I am working on SIB technique planning. I have done dosimetry on Phantom but I am curious about acute and late effects.
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yes
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Radon and its daughters
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Thank you very much Dr. Dimitrios for your answer. 
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