Dosimetry - Science topic

Is there any one that worked with MCNPy or MontePy?

Can you Guide me please?

Hey everyone!

I'm a PhD candidate in materials science, working on a novel ionizing radiation detector (mainly for dosimetry). Long story short, the technology has many possible development routes. As such, I am taking it to the end users and asking what are your biggest difficulties when it comes to equipment calibration. What do you wish the dosimetry equipment would be capable of doing?

Also, on a different note, what do you wish your personal dosimeter could do?

This is just preliminary research, would love to chat more with anyone interested!

Many thanks and truly appreciate your kind feedback!

I 131 therapy of the thyroid is mostly followed by a planar or SPECT scan with a gamma camera and High Energy collimator.

The thought is that a better quality scan with I 123 would be feasible and could be used for Dosimetry thus omitting the need for a I 131 scan after therapy.

Can this be done and/or is there any experience with this already? Please your input

Hello I am a nuclear master student, so my main focus is physics. I want to pursue a career in research, my main domain will be dosimetry and radioprotection. I want to study the irradiation of cells but this also implies a lot of biology.

How a physicist can approach this interdisciplinary subject for a PhD?

Dosimetry

I would appreciate if you help me to find interesting topic in the area of dosimetry, since my master degree was in the field of Radiation biology and my current supervisor is working on solid dosimetry and prospective dosimetry (EPR techniques,...).I want to choose some topic that combined both bio dosimetry and physical dosimetry. For example, I found that working on DNA dosimeter is good issue, but I can not connect it with physical dosimetry, please help me.

Thank you

dosimetry simulation

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

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.

Is it possible? =) What do you think about it?

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,

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.

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?

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,

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?

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

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?

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.

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 !!!

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)

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.

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

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.

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!

Biophysical effects of muons have been studiend mostly in human samples, existing a lack of knowledge on how they act on other living beings.

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.

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.

Chromosomal aberrations related

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...

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

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

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?

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?

EPIQA is commissioned at EPID position 0,0,0. Can it be commissioned at 50,0,0?

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?

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,

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. 

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?

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?

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 

Which dosimetric term used when the source of radiation exposure is from radioactive material located within the body?

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.

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.

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.

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

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.

I found very limited number and any help would be highly appreciated.

Thank you in advance.

I scanned the cone phantom either using axial or helical CT scan, and im trying to calculate the dose conversion coefficients. 

Geology, Dosimetry & Dating, Paleo-climate reconstruction

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.

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.

 

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?

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.

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?

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.

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? 

In MCNP if i want to enter air in data cards, by which accurate percents can it be done (density , composition)?

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?

Can anyone know the Primaquine dose on Plasmodium berghei infected Balb/c mice?

EPID in vivo dosimetry

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?

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.

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?

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

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:

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!

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?

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!

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.

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.

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 

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!

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?

if you know an article addressing this question with quantitative results will be great

treatment site , GYN, skin ,etc  

thank you in advance

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?

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. 

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?

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?

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.