THE RADAR SITE:

RADAR INFORMATION:
Overview
News and Events

RADAR MEMBERS

RADAR Home Page



RADAR RESOURCES:

RADAR ON-LINE DATA:
On-Line Decay Data
On-Line Kinetic Data
On-Line Model Dose Factors

INTERNAL SOURCES:
Occupational Dose Factors
Nuclear Medicine:
Diagnosis
Therapy

EXTERNAL SOURCES:
Monte Carlo Applications
External Point Source
Beta Dose to Skin
Immersion in Air
Ground Contamination
Medical Sources
VARSKIN code

RADAR SOFTWARE

DOSE-RELATED LITERATURE

MEDICAL PROCEDURE DOSE CALCULATOR AND RISK LANGUAGE GENERATOR




RADAR DOCUMENTS:
System Overview
Internal Dose System
External Dose System
Decay Data
Kinetic Data
Phantoms
Risk Models


RADAR - Available Phantoms


You want phantoms, we got phantoms. Currently, an entire new generation of human body models is being developed. We are moving from our older models that looked like this.....:

to cool new ones that look like this.....:

Fetus don't fail me now.....

           

Dr. George Xu of Rensselaer Polytechnic Institute has organized a site which compiles and distributes information about the many new phantoms that are being developed by a number of groups, called the Consortium of Computational Human Phantoms (CCHP)

History of Phantom Development

For those of you who may have skipped over the initial overview of the system, and donít know, a phantom in the context of internal and external dose assessment is a mathematical representation of the human body used to calculate the Dose Factors (DFs) that we need to convert disintegrations in some source region to absorbed dose in a target region. To model anything - the human body, a cell, a city, etc. - one always starts with a sphere, because itís so simple mathematically. A great book on the subject of modeling was actually called "Consider a Spherical Cow" by John Harte (see web page). In the late 1950ís we did have a spherical human, with lots of little spherical organs. Easy to calculate numbers with, but not too realistic. Then, in about 1975, a phantom was developed that was supposed to represent an average adult worker of the Western Hemisphere, based on the so-called (and completely politically incorrect) Reference Man, so dubbed by the International Commission on Radiological Protection (ICRP). The ICRP didnít design the phantom, they just collected the data on the typical sizes of peopleís bodies and their organs, and two guys at Oak Ridge National Laboratory named Fisher and Snyder (the latter being Walt Snyder, who basically founded and ran the MIRD Committee for many years) designed a phantom based on Reference Man and ran a Monte Carlo code whose results were used to calculate DFs for all the organs in this phantom irradiating all the others (which, interestingly, contained both male and female organs - a mind bender, ainít it?).

OK, this did well for some time in calculating doses to adults, but in nuclear medicine as well as other applications we quickly found the need for phantoms representing other people. In 1987, Cristy and Eckerman published a very important work in which they described six phantoms representing children and adults. These six phantoms were designated as a Newborn, One-Year-Old, Five-Year-Old, Ten-Year-Old, Fifteen-Year-Old and an Adult. The adult was very similar to the Fisher-Snyder phantom, but had some minor modifications, and included some organs that the Fisher-Snyder phantom did not. All of the phantoms had both male and female organs. The age designations were meant to be approximate - Cristy and Eckerman researched the changes of organ size, position, and composition with age and, like the Reference Man document, catalogued what they felt were the appropriate values to use as averages for that age. Of course some children grow faster or slower than others - one can envision a 5-yr-old who is as big as the 10-yr-old phantom; in this case, the 10-yr-old phantom should probably be used, as what we are after is energy absorbed per unit mass (dose), and the important issue is probably mass. In any case, the idea was to give a set of phantoms that would span the size of people from infancy to adultery, I mean adulthood, and which could be used to calculate dose estimates for a range of people of different sizes.

By this point in our presentation about half of you are probably upset, because we are not giving enough consideration to the stronger sex. Women were somewhat slighted in all of this, as they were slighted in the workplace for so long. Although the Fisher-Snyder and Cristy-Eckerman phantoms had female organs, they were pretty much built around the average male for that age. The Cristy-Eckerman 15-year-old phantom was used for many years as a surrogate for an adult female, but who wants to have a surrogate representative? In 1995, Stabin and colleagues put out a document similar to the Cristy-Eckerman document, but with a series of 4 phantoms representing the adult female - the first was just a standard adult female (with several notable differences from the Cristy-Eckerman 15-year-old phantom) and the other three represented the woman at various stages of gestation, as dose to the fetus is such an important issue in both nuclear medicine and other areas.

So as of this date, one could argue, we have a more or less complete Ďfamilyí of phantoms - just like a real household - kids running around screaming, dad sitting there doing nothing, several pregnant women (all right, a strange household perhaps, but is yours, like, perfectly normal?). If you want to see the SAFs for any phantom, you can check them out them here:

Adult Male

15-yr-old

10-yr-old

5-yr-old

1-yr-old

Newborn

Adult Female

3 month Pregnant Woman

6 month Pregnant Woman

9 month Pregnant Woman



Staring at all those data can make you bug-eyed. If you'd prefer, you can download all the SAFs from these phantoms in one tidy zip file here:

Hit me with that SAF zip file


If you want tables of the organ masses from the Cristy/Eckerman pediatric and adult and Stabin et al. pregnant female phantom series, it is your inalienable right to click here. Thanks to Dan Strom for the suggestion and the supplied spreadsheet! The new phantoms will be based on the masses suggested in ICRP Publication 89. NOW how much would you pay...oh...I mean right here we have a link to tables with those data. Just kidding, it's ALL free, and no tipping, please.

Whereís the Beef?

The beef of the issue is in the DFs - the phantoms may be cute, but they donít walk and talk and they donít tell you how much dose their organs are getting without the DFs. The first more-or-less complete set of DFs was published in MIRD Pamphlet No. 11; this was referred to above. These were DFs (they called them "S values", don't ask me why) for the Fisher-Snyder phantom, calculated out for 117 radionuclides of importance to nuclear medicine. What if you donít care about nuclear medicine? Well, there was a document put out by ORNL, called ORNL-5000, which had DFs for lots more nuclides. It was hard to find, however. What about the other phantom series? Well, these were never officially endorsed by anybody, and no DFs were calculated by anybody, at least officially. The MIRDOSE 3 software, put out in 1995, included all 10 of these phantoms, and calculated DFs for users with the best available decay data of the time. So they were out there, just not officially. On this site, we will keep updated DFs for all 10 of these phantoms until the new generation of phantoms is ready to go (see material below). If that ain't official enough for you, we're also working on publishing all of these data with a reputable journal, in which the technical aspects will be described in the article, and the data will be available for electronic download. As soon as that's done, we'll let you know. Do you also want the DF's for these phantoms? Gee, you're pretty demanding. Well, we didn't set up the site to NOT give you information, here you go:

[Note - Be sure to have your web browser Java enabled to use this form. These data can take some time, even up to a few minutes to load, so be patient. Hey, it's faster than you can get them anywhere else!]




[Warning!! Will Robinson! No, I mean - be careful with these DFīs. Buyer beware, and remember this is a free service. Some alert RADAR users have noted that there were errors in the lookup indices in this applet for some of the metastable nuclides. The dose factors themselves were correct and matched with the right half-life, but the lookup index may have been wrong, so that you got a metastable when you asked for a non-metastable, or vice-versa. This has now been corrected, thanks to those who wrote in. Please inform us of any other irregularities you may find in the site. We are pleased to note that these data have been peer reviewed and are now accepted for publication in the Health Physics Journal (85(3):294-310, 2003)]

Weren't There Some Other Organ Phantoms, Too?

You want organs, we got organs. Yes, there were a number of other single organ phantoms developed, because of situations not covered well in the exisiting phantoms. Some of them are (alphabetically, because if we try to put them in order of importance or something, someone will surely get mad):

MIRD Head and Brain
Prostate Gland
Peritoneal Cavity
Unit Density Spheres (good for use as tumor or small organ models)

All of these models are well defined in the literature and have values calculated that permit the development of DFs for them. If you want DCFs for them, you can get them from this site. Just start clicking away (I've already noticed that you're good at that).



[Note - Yeah, you gotta have your web browser Java enabled to use this form, too. And yeah, yeah - be careful with these DFīs, too same **Warning** as above applies. As noted above, the data have been peer reviewed and are now accepted for publication in the Health Physics Journal. (85(3):294-310, 2003)]

(Hey, did we forget a cool phantom that you did? It wasn't personal, I swear. Just write us and tell us. If you want your data on RADAR, you'll have to supply them to us, or else just give us a pointer to your site and we'll mention it here.) Again check the Consortium of Computational Human Phantoms (CCHP) page all the time for updates.



Overview of the External Dose Assessment System