What do you obtain in combining the Incredible Hulk and Cerebro?
Gamma knife was invented by Lars Leksell in 1967 in Stockholm. It consists in a helmet delivering gamma rays from ionized Cobalt 60 in 201 rays coming together to the brain tumor we want to destroy.
About Cobalt 60
Cobalt 60 is derived from Cobalt 59, a stable isotope of Cobalt. It decays in Nickel 60 by a beta minus reaction. It has a half-life of 5,27 years. One of the inconvenient of Cobalt 60 is the requirement to clear out every 5 years from a very radioactive source (in fact, even after those five years, the cobalt stays radioactive, even if half of the atoms had decay), able to cause accidents and it can fall out in dusts. Cobalt 59 can be used in a nuclear bomb to give Cobalt 60, which would infect the place, becoming uninhabitable for decades.
Cobalt 60 was widely used in radiotherapy, but now we tend to use linear accelerators (also called linacs) to have a best control and not the disadvantages of cobalt. Those accelerators emit X-rays by accelerating charged particles to give them an important amount of energy. This kind of accelerators uses linear successive accelerations to induce energy. But those linacs are no longer used in radiotherapy today.
The fact is that, in a simple point of view, gamma rays have 1000 times more energy than x-rays. Both are electromagnetic rays but they have different frequencies (gamma ray’s is higher: more than 1020 Hz against 3x106 Hz for X-rays) . But in a more technical explanation, if we take the electromagnetic Spectrum (EM spectrum), we can reach a point where gamma rays and X-rays are identical in EM properties, including in the energy. At this point, the only difference is the origin of the ray. The x ray comes from the electron shell of an atom, and the gamma ray comes from its nucleus. The first one originates from an over-excited electron, moving up in the layers. But it wants to come back down, so it emits energy in x ray. The second one comes from a nuclear reaction on an atom, something which excites the nucleus, as an alpha reaction, a beta reaction, a fusion or a fission.
During the treatment, the patient wears the helmet and it delivers a higher and higher dose of gamma rays. Using the coordinates, the nature of the rays, their energy and the thickness of tissues to go through, we can see with a computer where the highest dose should be delivered. In fact, we have a total control of the operation and the precision is allowed by today’s level of technology. Moreover, to avoid a dangerous irradiation, the entry points are multiplied to send less radiation on a larger zone of healthy cells with short times of exposure.
The great advantage of the gamma knife is the limitation of the risks of hemorrhage and infections. Moreover, it just takes a 10 minutes session to destroy a tumor, there are neither cranium opening nor anesthesia, and the visualization is simplified, even though the patient could suffer from headaches after the intervention and the healthy zones are irradiated (in small quantity, but it stays kind of harmful).
Now, there are about 300 gamma knife units in the world, including 6 centers in the UK (they got their first gamma knife in the 1970s), AND more than 100 in the USA. The San Diego center has treated 3700 patients in the last 18 years. The finest unit in the world is located in Marseille.
According to the Leksell Society, over 676,000 patients were treated with the Leksell Gamma knife through 2011, against 7,000 in 1991.
The main concentrations of patients treated by Gamma Knife are in Japan, the USA, Korea and China, and Europe.
Today, the original Leksell Gamma Knife is in UCLA Medical Center in Los Ageles, CA. It was donated in 1982, served for animal research and was used to cure some human patients.
Explanation of the problematic
Bruce Banner was originally a scientist specialized in gamma rays and he became The Hulk by being irradiated with gigantic doses. Cerebro is a tool created by Magneto and Professor X from Marvel’s X-men to expand Xavier’s telepathy. But the patients cured by the Gamma knife apparently don’t become a super violent green monster after being treated!
To go further...
- Here is a simple explanation in the differences between gamma rays and X-rays : http://wiki.answers.com/Q/What_is_t...
- A long explanation, more complex : http://wiki.answers.com/Q/What_is_t...
- Learn more about nuclear decay : http://edtech2.boisestate.edu/linda...
- About the difference between nuclear fusion and nuclear fission : http://wiki.answers.com/Q/Differenc...