Radiation is frequently used as part of the treatment of cance...

Question

Radiation is frequently used as part of the treatment of cancer. The radiation works by damaging DNA and components of the cell. How can radiation treatment control or cure cancer?

Accepted Answer

Welcome back, everyone. Here's our next question. Radiation therapy is a kind of cancer treatment that uses high energy beams to kill cancer cells. Which of the following types of radiation therapy is the most commonly used to treat breast cancer. Choice. A volumetric modulated arc therapy, V MA T choice B. External beam radiation therapy, EB RT. Choice C, image guided radiation therapy, IG RT or Choice D, none of these. Well, the important thing to note when looking at these answer choices is that choices A and C are actually both forms of EB RT because external beam radiation therapy just refers to radiation being delivered from an external source. So beams of high energy radiation being projected at the tumor, there's also internal radiation therapy which involves actually injecting something that will release radiation to this tumor site from inside the body. So in this case, all three A B and C are forms of external beam radiation therapy because all involved externally delivered uh radiation. So choice B, external beam radiation therapy is the more generic term and A NC are more specific forms. In the case of breast cancer. Choice B is our correct choice here, most breast cancers are treated by this more generic form. Um where beams are shot at the tumor area and usually more areas of the breast where there's concern, the cancer might have spread or there might be cancer cells that hadn't been detected when you look at these more specialized forms. Um they're usually limited in the sense of cost and availability. So they limit the usage of choices A and C two occasions when they're particularly necessary. So let's look at what those are to understand why they're not usually called upon in uh treating of breast cancer. So choice, a volumetric modulated arc therapy has sort of two characteristics. This term modulated refers to the fact that the it uses multiple radiation beams of different intensities. So you're not delivering the same intensity of radiation to the entire area. And this is useful when you have say a tumor with very irregular outlines. Um It's also useful when you have um tumors in located next to sensitive organs or tissues that you want to be extra careful, you're not damaging. So you can deliver more intense radiation to areas away from that. Um It's also the arc therapy, you have um the radiation is delivered from different directions. So it rotates around and that's where the, the arc comes in. Word arc here because you have literally radiation being delivered in a 3d arc around the body. So you can deliver these radiation beams from all different directions. So the prime benefit of V MA T is that it involves a shorter treatment time. And of course, the minimization of side effects is really important when it comes to radiation therapy. And if you have a form of cancer that needs particularly intense radiation, limiting the length of time of the treatment helps reduce side effects. So then you might turn to a V MA T with irregular borders or a need for particularly intense radiation because being able to deliver more radiation in a short amount of time would reduce the significant side effects you'd expect. But in general, that's not necessary when it comes to the treatment of breast cancer. So that's why choice a isn't our correct answer. And then should I see image guided radiation therapy, what we have right there, an image guided where you have particularly detailed imaging or scanning combined with the delivery of radiation. And this would be used when you have uh tumors that are very, very close to particularly delicate structures or tissues in the body. Um particularly if you imagine in the brain where um damage to areas, everything is very close together and a little being a little bit off could have very deleterious effects. So having very detailed imagery can help with very precise delivery of the radiation and limiting the damage to sensitive surrounding areas. Uh In addition, it's useful for a cases when the the tumor might move between treatments So you need to make sure each time that you're delivering it to the correct area. But again, this is a more expensive, harder to deliver, it needs more specialized equipment. So it would be reserved for those situations when specifically it would be warranted. So that's why source C isn't correct. And since we have that correct answer and B we can obviously eliminate choice D. So again, the most commonly used radiation therapy to treat breast cancer is choice B external beam radiation therapy. See you in the next video.

Radiation is frequently used as part of the treatment of cancer. The radiation works by damaging DNA and components of the cell. How can radiation treatment control or cure cancer?

Key Concepts

DNA Damage and Repair Mechanisms

Cancer Cell Proliferation

Selective Targeting of Cancer Cells

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