[ RadSafe ] MIT method reveals how radiation damages the body

[John Jacobus]

Roy,
Thanks for the information.  I wonder how they are
going to control for the 480 keV photons from the
decay of Li-7 to the ground state.  

"Individual boron atoms in the blood capture a 
neutron, become unstable, and immediately split in
half, giving off two short-range radiations . . .
These particles are too big to move from the blood
into normal tissues, so the short-range radiations
from the boron-neutron reactions in the blood only
reach the blood vessel walls and cannot damage the
normal tissues outside the blood vessels."

--- ROY HERREN <royherren2005 at yahoo.com> wrote:

>  Public release date: 28-Feb-2006
> 
> Contact: Elizabeth Thomson
> thomson at mit.edu
> 617-258-5402
> Massachusetts Institute of Technology 
>   MIT method reveals how radiation damages the body 
> Work could reduce side effects for cancer
> patientsCAMBRIDGE, Mass. -- Researchers at MIT have
> devised a new method for examining how radiation
> damages normal tissue in the body. The knowledge may
> make it possible to reduce side effects for cancer
> patients or to develop treatments for radiation
> exposure.   About 50 percent of all cancer patients
> are treated with radiation therapy, either alone or
> in combination with some other type of treatment.
> Radiation can be very effective in killing tumor
> cells, but it also kills normal tissues nearby. In
> the gastrointestinal (GI) tract, this killing of
> normal cells can cause such side effects as nausea
> or diarrhea within days or weeks of treatment, and
> serious GI tissue damage can occur months or years
> later.   "The long-term effects that occur six
> months to a year or more after exposure aren't
> reversible like the short-term ones, and they are a
> big unknown," said Associate Professor Jeffrey
>  A. Coderre of MIT's Department of Nuclear Science
> and Engineering. The damage is similar to scar
> tissue formation and can seriously affect tissue
> function in the GI tract.   "We've come up with a
> tool to selectively irradiate blood vessels to study
> how radiation damages normal tissue over both the
> short term and the long term," said Coderre, who is
> co-author of an article appearing online the week of
> Feb. 27 in the Proceedings of the National Academy
> of Sciences (PNAS). "This is the first time it has
> been possible to do this."   Conventional techniques
> using external radiation beams are not specific
> enough for this type of study. "We are selectively
> delivering a radiation dose to all of the cells that
> make up the microscopic blood vessels throughout the
> body," he said.   The method Coderre and his
> colleagues at MIT and UCLA came up with involves
> putting boron into a drug administered intravenously
> in mice, and then subjecting the animals to
> whole-body neutron radiation using the MIT
>  research reactor. Individual boron atoms in the
> blood capture a neutron, become unstable, and
> immediately split in half, giving off two
> short-range radiations (an alpha particle and a
> lithium ion) in the process.   The boron is kept in
> the blood by trapping it inside a type of
> nanoparticle known as a liposome, which is only
> billionths of a meter in size. These particles are
> too big to move from the blood into normal tissues,
> so the short-range radiations from the boron-neutron
> reactions in the blood only reach the blood vessel
> walls and cannot damage the normal tissues outside
> the blood vessels.   By selectively irradiating the
> blood vessels, it is possible to see where the
> breakdown of tissue structure and function starts
> following radiation exposure. And that information
> could lead to more effective and less damaging
> treatments, Coderre said.   Coderre said the method
> can be applied to other tissues. It also has
> implications for the development of radioprotectors
> or treatments for
>  radiation exposure. But perhaps the greatest
> potential is in understanding the sequence of steps
> that begin at the time of irradiation but take years
> to create damage.   For example, there will be
> approximately 240,000 new cases of prostate cancer
> diagnosed in the United States in 2006. Depending on
> the dose of radiation delivered to their tumor,
> anywhere from 20 percent to 40 percent of those
> patients could show some degree of late damage.  
> The lead author on the PNAS paper is Bradley W.
> Schuller, a graduate student in Coderre's lab. Peter
> J. Binns and Kent J. Riley, both research scientists
> in MIT's Nuclear Reactor Lab, also are authors on
> the paper, as are Ling Ma and Professor M. Frederick
> Hawthorne, both at UCLA.     ###
>   This research was funded by the U.S. Department of
> Energy, the National Institutes of Health and the
> MIT Center for Environmental Health Sciences. 
> 
> 
> Roy Herren
> 		
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+++++++++++++++++++
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-- John
John Jacobus, MS
Certified Health Physicist
e-mail:  crispy_bird at yahoo.com

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