What is the difference between the types of radiation that cause cancer and the types of radiation used to treat cancer?
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Targeting and control of the dose. Dr’s control how much and where it’s delivered. Otherwise it’s pretty much the same thing
Nothing is different about the radiation itself. The radiation is the same, but things like the intensity, and how targeted it is are different.
Below a certain intensity, ionizing radiation will damage your cells. Above a certain intensity, it will kill them. Damaged cells can mutate and become cancerous, which is why low-level, long-term irradiation from (for example) tanning beds or radioactive material poses such a threat.
When radiation is used to treat cancer, it is actually being used to *kill* the cancerous cells in your body – they are living tissue, and can’t multiply if they’re dead. In this case, the radiation will be at a very high dose and directed to a very specific area so that it will cause as little damage to the surrounding healthy tissue as possible.
Radiation causes damage to DNA. There a genes that control the cell cycle and cell growth called oncogenes. If these genes get damaged, cells can keep dividing and dividing until you have a tumor. But most of the time radiation will just kill a cell or have no effect. If you get lots of radiation exposure over time, the chance of it damaging an oncogene goes up, so that’s how radiation causes cancer. However very intense focused radiation can be used to kill tumors because it is so damaging to cells.
Radiation therapy uses x-rays, which are ionizing radiation thus increase risk of developing cancer. However, the risk is relatively low:
1. Radiation therapy is relatively brief, so overall there is little radiation outside the focused area, thus risk is not too high.
2. In the focused area, radiation is brief but intense. It is intense enough to kill cells, including healthy cells caught in the treatment area. Killing the healthy cells is actually good since it leaves them too dead to develop cancer.
So, overall, we are talking about a low risk of cancer in the future, which is well worth not dying now to the cancer at hand.
There is not much of a difference – it’s the same type of energy being fed into your body. When they use it for medical treatment they tend to target specific parts of the body – if you have a tumor in your stomach somewhere then they’re not gonna want to expose your legs and feet to radiation unnecessarily, to try to limit the area of damage.
It is unfortunate but this also can cause damage to nearby parts of the body (skin and tissue damage, or even new cancer growths, but it’s a risk they try to control).
First of all, you need to understand the basics of radiation. There are three main types:
1. Alpha particles
2. Beta particles
3. Gamma rays
Alpha particles are just 2 protons and 2 neutrons. It is the same structure as the nucleus of a Helium atom (specifically Helium-4). This is the weakest of the radiation types and can be blocked by a sheet of paper, or even clothing and skin. It can really only harm you if it gets inside your body through inhalation or ingestion.
Beta particles are simply high-energy electrons (or their anti-matter counterpart, positrons). They have a bit more energy than alpha particles and require a thin layer of lead or concrete to stop them.
Gamma rays are high-energy photons… in other words, they are just light. Light starts to become ionizing once it gets into the ultraviolet range. Gamma rays are far more energetic. So much so that they would very likely pass through you as if you weren’t even there.
Very quickly, I will mention neutron radiation. Free neutrons are unstable and will decay in about 15 minutes. They are only produced by fission and fusion reactions. While they can be extremely harmful to us, the only way you would be exposed to them is by proximity to fission or fusion processes, in which case you’ve got much bigger problems than neutron radiation.
Ok, so here’s a fun little thought experiment–I will give you three cookies: one has a small quantity of alpha particles emitting substance baked inside, the second is made with beta particles, and the third is made with gamma rays. You have three options: eat the cookie, sit on the cookie, or throw the cookie out the window. BUT you can only use an option one time. So… what do you do?
The correct answer is that you eat the cookie with gamma rays, sit on the cookie with alpha particles, and throw the beta particle cookie out the window. You see, just like a bullet, damage is done if your body absorbs the energy. So, if you eat the alpha particle cookie, you body will absorb 100% of that energy. If you eat the beta particle cookie, you will absorb about 50% of that energy (the rest will pass right through you). And the vast majority of gamma rays will exit your body as if you’re not even there, so the energy absorption is very low. If you sit on the alpha particle cookie, you clothing and skin will block nearly 100% of the energy. With the beta particle cookie, however, your body will still absorb nearly 50% of the energy if you’re sitting on it, so you want that one as far away from you as possible.
As for radiation treatment, there are two general types: external and internet. External treatment uses high-energy photons in the form of x-rays (lower energy than gamma rays, so they will absorb a bit more into your body) which can be targeted to a specific tumor. However, as mention above, these high-energy photons will largely pass through the body without hitting anything, so you need a lot of them to get the job done. And, of course, they can and will damage any non-tumorous cells that are in the line of fire.
For internal treatment, they identify which substances (usually some type of hormone) will bind to the cancer cells. Then, it’s just a matter of mixing that substance with a small amount of a radioactive material that produces mostly alpha particles. Here again, other non-tumor cells will be destroyed in the process, but the goal is to destroy as many of the cancer cells while mitigating collateral damage to the the healthy cells.
This also give you some insight into why the “stage 4” or metastasis phase of cancer is so often terminal. At the this point, the cancer cells have “metastasized” or spread throughout the body. If you were to try radiation treatment (or pretty much any other treatment) at this point, it would do more damage to the person than they could recover from, and still not get all of the cancer cells.
I know this was pretty long, but hopefully it gives you a better understanding of radiation and how it works.
* Radiation is just a mechanism of transferring energy through a medium. Your heater radiates heat. Your TV radiates visible light. Uranium radiates alpha particles. That’s all radiation.
* Ionising radiation describes the types of radiation that can damage biological structures like cells or DNA.
* Cancer is a group of diseases caused by faulty DNA. Faulty in just the right way that it causes the cell to stop functioning properly and replicate uncontrollably. Ionising radiation is one possible cause for that, but there are other causes.
* Radiation therapy is the use of ionising radiation to kill cancer cells, with specific targeting and dosage to avoid damaging surrounding healthy cells.
* It’s possible that the same type of radiation that caused the cancer could be used to treat it, but that would purely be a coincidence. The fact that there are different causes of cancer, and different methods of treatment, make it fairly unlikely from a mathematical standpoint.
* Also it’s rarely as simple as getting cancer from one specific source or event. Usually it’s a combination of multiple risk factors over many years, and using statistical probability to infer the primary cause. eg. we know that statistically, smoking increases the chance of lung cancer, but it’s impossible to look at a specific case of lung cancer and definitively prove it was caused by smoking and nothing else. That’s how cigarette companies got away with it for so long.
as someone in his early 40’s going through chemo, i was told chemo was better for me than radio due to my age, as radiation, which good at killing cancer, comes itself with a cancer risk 15 years down the road. As I am still young (doctors words, not mine), long term it is better for me to do chemo as first attempt. If I was 85, it would be a different conversation.
Radiation treatment is also easier to take, thus easier for the more fragile to be treater.
As a number of other people have said, there’s nothing inherent to radiation that makes it cure or cause cancer, only where it is applied.
However, one type of radiation that generally is only used to treat cancer and almost never causes it is proton radiation. This isn’t because the radiation isn’t harmful in the wrong place, but humans are unlikely to encounter it outside of proton therapy.
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