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Gamma Knife Question About How Small an Area can be Treated

06/08/2014 3:02 PM

Hello, can you help with this Gamma Knife question. Is it possible to destroy a group of neurons in a area smaller than 0.1mm.  The Gamma Knife uses 192 holes, and the focused beams go through to treat tumors in the brain. If you decreased the amount of holes the focused beams of gamma radiation go through to treat the tumour, instead of using 192, if their were only say 20 holes, or less, for the focused gamma beams to go through, and meet in the center, would using just 20 beams of gamma radiation create a smaller beam area where all the beams meet in the center to destroy neurons in a area a small as 0.1mm or less. I want to see if its possible to eliminate groups of neurons in a area in the brain smaller than 0.1mm , which is 1000 neurons, I want to see if  the nGamma knife can eliminate a group of 100 neurons, or smaller. If this cannot be done what has to be done to the Gamma Knife in terms of upgrading,modifying, and pushing the Gamma Knife to its full potential limits to be able to eliminate neurons on this 100 neurons small scale. Than you for your help with these questions.

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#1

Re: Gamma Knife question about how small a area can treat, can you help

06/08/2014 3:40 PM

I would not be willing to entrust an illiterate person with such a job.

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#2

Re: Gamma Knife question about how small a area can treat, can you help

06/08/2014 3:41 PM

I have no idea what you are talking about, but I have found that beer has done a very good job of destroying neurons in my brain.

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#5
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Re: Gamma Knife question about how small a area can treat, can you help

06/08/2014 8:06 PM

A hundred for every sip!

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#7
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Re: Gamma Knife question about how small a area can treat, can you help

06/08/2014 9:36 PM

Recent independent alcohol studies have now shown that the brain regenerates, so three steps back two steps forward.

;

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#9
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Re: Gamma Knife question about how small a area can treat, can you help

06/08/2014 11:56 PM

So how long do I have to drink to lose 100 cells now? Does continuous drinking help in the calculation?

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#11
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Re: Gamma Knife question about how small a area can treat, can you help

06/09/2014 12:06 AM

Beer makes me smarter. The surviving brain cells work harder.

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#12
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Re: Gamma Knife question about how small a area can treat, can you help

06/09/2014 12:32 AM

I cannot remember what the study said, something about short term (weeks or something), didn't really pay much attention after that.

;)

Everything in moderation, and know that each beer is NOT permanently reducing your IQ.

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#3

Re: Gamma Knife question about how small a area can treat, can you help

06/08/2014 4:05 PM

Not sure, but I don't see why not (assuming you can hit the now smaller target).

Have you tried? I am assuming you have access to the relevant parts of this rather complex and expensive piece of medical equipment so you can perform small scale lab experiments (at a university perhaps?).

There, that's a start and I didn't mention the Incredible Hulk once!

;)

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#4

Re: Gamma Knife question about how small a area can treat, can you help

06/08/2014 5:26 PM

No.

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#6

Re: Gamma Knife question about how small a area can treat, can you help

06/08/2014 8:07 PM

What did the manufacturer say about this?

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#8
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Re: Gamma Knife question about how small a area can treat, can you help

06/08/2014 9:40 PM

Given the equipment this is beyond what the manufacturer would know or would be comfortable discussing.

Like asking if you could modify a companies MRI machine to (say) project images into a human mind.

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#10
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Re: Gamma Knife question about how small a area can treat, can you help

06/08/2014 11:59 PM

Sure is! But asking does cost nothing and if the answer was negative it would still mean something. Maybe there is a Delta knive that can do what is asked for. The manufacturer knows!

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#13

Re: Gamma Knife Question About How Small an Area can be Treated

06/09/2014 1:22 AM

Well anything is possible....but things are usually done for a reason....These gamma ray machines are designed and built for purpose, to treat specific disorders of the brain...A gamma ray machine works by disrupting the DNA in a cell thus stopping the cell from reproducing......You might take a look at the rotating gamma system.... A lot depends on the control system used as well....

http://investor.integralife.com/releasedetail.cfm?ReleaseID=526598

http://www.ncbi.nlm.nih.gov/pubmed/11417508

https://www.brainlab.com/

http://www.researchgate.net/publication/13211622_Physics_of_rotating_gamma_systems_for_stereotactic_radiosurgery

https://www.youtube.com/channel/UCvj-_tBm_7kw2CZqX1BCmLw

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#24
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Re: Gamma Knife Question About How Small an Area can be Treated

06/11/2014 5:20 PM

great, thanks for your answer

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#14

Re: Gamma Knife Question About How Small an Area can be Treated

06/09/2014 1:28 AM

There is a very good reason why gamma knives use many holes (200+) rather than a score.

Why do they? Do you know?

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#21
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Re: Gamma Knife Question About How Small an Area can be Treated

06/09/2014 12:23 PM

I would assume the holes are used for collimation of the beam. I know this is how gamma radiation is collimated for diagnostic imaging.

The question is always dose: How many photons on target? How many photons do you need to "excise" a neuron? Smaller beam, fewer holes, longer dwell time on the target.

Don't forget that those photons are also interacting with any tissue between the gamma source and those neurons. That's one reason that collimation is important. You don't want any spread to expose tissue outside of the area of interest.

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#25
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Re: Gamma Knife Question About How Small an Area can be Treated

06/11/2014 5:22 PM

great, thank you for your answer.

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#15

Re: Gamma Knife Question About How Small an Area can be Treated

06/09/2014 8:33 AM

Why would you want to destroy a group of neurons in an area smaller than 0.1 mm???? The Gamma Knife is a machine designed for the treatment of certain conditions of the brain. The beams generated by this machine can be directed towards a very small target to perform a procedure called Stereotactic Surgery. Lets say the Gamma Knife can be pointed to such a small target as you propose, my question is: how will you identify the100 neurons you want to hit? How do you know these 100 neurons are those that have to be treated? Each neuron forms part of a neuronal network, function of most of these networks is still unknown, so: why trying to do something at such a small scale?

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#26
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Re: Gamma Knife Question About How Small an Area can be Treated

06/11/2014 5:28 PM

The yet to be built INUMAC MRI machine can see 0.1mm (1000 neurons) in the human brain, and if the gene therapy approach that is used on mice at Stanford University can work on a human, then hopefully that is how you see the groups of neurons that hold specific memories.

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#16

Re: Gamma Knife Question About How Small an Area can be Treated

06/09/2014 8:51 AM

I have a suspicion that your estimate of neuronal density is out by several orders of magnitude, but no matter: there is no point in having a knife that scrapes out a 0.1mm sphere if the positioning precision is only +/- 0.3 mm and the likelihood of picking up a tumour that small on conventional MRI is virtually zero.

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#20
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Re: Gamma Knife Question About How Small an Area can be Treated

06/09/2014 12:05 PM

I agree with you: so far, the whole theory in the OP is nonsense. About the number of neurones: just repeating the figures from mentioned in the OP, which are also wrong

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#22
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Re: Gamma Knife Question About How Small an Area can be Treated

06/09/2014 2:05 PM

I know a blonde who has exactly 100 neurons.

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#17

Re: Gamma Knife Question About How Small an Area can be Treated

06/09/2014 9:19 AM

stupid question, but cant the holes in the gamma knife be fitted with very small apetures to control the size of the area being irradiated?

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#18

Re: Gamma Knife Question About How Small an Area can be Treated

06/09/2014 11:37 AM

Not very likely. I suspect that even a well-collimated beam from a LINAC cannot accurately target something that small within the cranium. I am a recipicient of fractionated stereotactic radiosurgery at Johns Hopkins hospital for an acoustic neuroma back in 2000 (still no re-growth, knock on wood) for a tumor about 8 mm across in its largest dimension. Even back then, the Gamma Knife was considered a somewhat crude tool in it's ability to localize the treatment area. It probably still has clinical uses depending on what treatment is needed, but I wouldn't look to a Gamma Knife for precision.

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#19
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Re: Gamma Knife Question About How Small an Area can be Treated

06/09/2014 11:53 AM

if you want to talk about precision, proton beam therapy is pretty darn precise, but requires a cyclotron and really good beamline equipment. Hitachi makes the best ones on the market I am told. For those not in the know, proton beams are not like gamma or x-ray beams, being positively charged they don't interact much with matter until they break down and the distance they travel before they break down can be very precisely controlled by the energy imparted to the beam. So there is no damage to tissue in front of or behind the target, negating the need to do stereotactic therapy for the most part. But to control the target size that small might be a real trick even for that.

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#23
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Re: Gamma Knife Question About How Small an Area can be Treated

06/09/2014 2:49 PM

Proton therapy directs protons of highly specific energies at the target. Charged particles interact with matter through ionization. In the case of protons, as the particle passes an atom it strips away electrons, giving the atom a net positive charge. How well it does this depends on its energy, ie, its speed.

Faster protons interact less with surrounding matter than slower protons. As the proton traverses intervening matter on its way to its target it loses kinetic energy. The trick, then, is to give the proton just enough kinetic energy to reach the target and no more. When it reaches the target it has slowed to the point where it vigorously interacts with nearby atoms, altering their chemical behavior. If these atoms belong to a cell's DNA, the DNA is damaged. The objective is to damage it so much that it cannot be repaired. As the proton energy can be tightly controlled it is possible to conform the ionization region to the shape of the target. This cannot be done with conventional X-ray and gamma therapies.

When a cell's DNA is damaged, enzymes within the cell attempt to repair it. If the damage is too extensive the cell can no longer divide and eventually dies. Cancerous cells are particularly vulnerable as they divide much more frequently giving the enzymes very little time to work.

As an aside, proton decay has never been observed even though such decay is predicted by the Standard Model. If protons do decay their half life must surely exceed the age of the Universe by a considerable margin.

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#27

Re: Gamma Knife Question About How Small an Area can be Treated

06/12/2014 3:45 PM

This person is willing to use a device capable of destroying a small number of neurons which (according to him) hold specific memories, which (from the neurological point of view is a nonsense, as the events that constitute the "memory" pass trough different relay stations to be finally distributed over diverse areas (some are redundant) of the brain. Storage occurs by means of poorly understood chemical and electrical means.

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#28

Re: Gamma Knife Question About How Small an Area can be Treated

08/06/2014 1:31 PM

I have a Question on this Proton Therapy, I would like to know can the therapy be further targeted using antibodies and some sort of chemical/molecule attached to it that would help the proton destroy only those protein that the antibody is attached to? IE i have a protein i want to target and have made a antibody to that protein with this chemical/molecule attached which by itself is harmless but with the proton therapy becomes lethal/disruptive? I have been thinking about how certain cancer therapies are using this method of attaching gold atoms to cancer cells and then a ionizing radiation applied so it destroys the cells could we go further and target just certain proteins?

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