RE: " new reactor will make certain Australia remains at the forefrontof cancer treatments "

["Jaro" <jaro-10kbq@sympatico.ca>]

Yes, I agree.

I would only point out that the Italian example is rather unique, as are one

or two others -- usually due to the limitations of the reactor facility

available, specifically the intensity of the neutron flux, as well as its

energy distribution (as I recall, the Tapiro reactor used in the Italian

BNCT project is a very small fast neutron reactor.... probably the last

thing you would think useful in BNCT work).

One other such example is a Japanese project, several years ago, which

required scull cap removal to achieve adequate neutron flux to the brain

tumor. Of course this is far from ideal.



More recently, the trend has been to design each lab's system for close to

ideal BNCT neutron flux (high intensity, with epithermal neutron energy and

minimal gamma contamination).

In some cases this involves merely installing the right kind of neutron

filter & gamma shield, while in others (for example MIT) a "fission

converter" (subcritical amplifier) needs to be installed upstream of the

filter, some distance away from the reactor core.

This kind of setup is intended to realize the original idea you describe,

and has in fact been implemented in places like MIT (US), Studsvik (Sweden)

and the VTT Technical Research Center of Finland.

It avoids the need for organ explantation or scull cap removal, or what have

you....

As I see it, the Italians (and others) are simply doing the best they can

with what they've got. IMO, its pretty impressive, original work.



 Jaro



^^^^^^^^^^^^^^^^^^^^^







-----Original Message-----

From: John Jacobus [mailto:crispy_bird@yahoo.com]

Sent: Tuesday, February 17, 2004 9:37 PM

To: Jaro; Radsafe (E-mail)

Subject: RE: " new reactor will make certain Australia remains at the

forefront of cancer treatments "



Jaro,

I think that taking organs out of patients, treating

them and then reimplanting presents significant risks

to the patient.  When you are dealing with patients in

the end-stages of disease, it may seem apropriate but

is it ethically sound?  The original idea, dating to

the 1950s I believe, was to inject into the patient a

boron-labeled which would be taken up by the tumor.

Neutron bombardment would then destroy the

boron-labeled cells.  Until this can be achieved, BNCT

will have limited application.  Particularly for brain cancers.



I do understand your point about the new facility in

Australian.  There are certainly a number of promising

therapies involving alpha-emitting radionuclides that

could be made in a reactor.  I am not sure that they

are excluding medical research as much as avoiding the

BNCT.  I do not think that the Trevatron was built for

neutron therapy applications.  It may be possible to

channel off thermal neutrons to a treatment room for

BNCT in the future.





************************************************************************

You are currently subscribed to the Radsafe mailing list. To

unsubscribe, send an e-mail to Majordomo@list.vanderbilt.edu  Put the

text "unsubscribe radsafe" (no quote marks) in the body of the e-mail,

with no subject line. You can view the Radsafe archives at

http://www.vanderbilt.edu/radsafe/