Select your language

Suggested languages for you:
Log In Start studying!
StudySmarter - The all-in-one study app.
4.8 • +11k Ratings
More than 3 Million Downloads
Free
|
|

All-in-one learning app

  • Flashcards
  • NotesNotes
  • ExplanationsExplanations
  • Study Planner
  • Textbook solutions
Start studying

Radioactive Implants

Save Save
Print Print
Edit Edit
Sign up to use all features for free. Sign up now
Radioactive Implants

The use of radiation in medicine is not limited to x-rays and radiotherapy using external sources. Another form of radiation therapy is brachytherapy, which is a type of internal radiation therapy.

Brachytherapy involves the implanting of small packets of radiation sources. The implants, which are placed near tumours, help to reduce radiation doses, allowing a more direct exposure of the tumours to the radiation sources.

Radioactive Implants. Implant seeds. Cancer. StudySmarterFigure 1. Radioactive seeds compared to a coin. Their size allows them to be implanted in organs affected by cancer. Source: Nuclear Regulatory Commission (CC BY 2.0).

What are radioactive implants?

The implants used in this radiation therapy, which contain radioactive material, can have several shapes, from needles to small capsules. Materials used in the implants include iridium, caesium, iodine, and palladium. Having been placed near the affected area, they might be left for a day or just a couple of minutes, depending on the treatment. Some treatments may require longer exposure.

This type of radiation therapy is used if the location of the tumour is well known and concentrated in a single mass of a limited size.

Radioactive implants are used in cancer treatments such as the following:

  • Prostate cancer.
  • Breast cancer.
  • Cervical cancer.
  • Uterine cancer.
  • Rectal cancer.
  • Skin cancer.
  • Bowel cancer.
  • Eye cancer.
  • Skin cancer.

Types of implants

The implants can be either interstitial or intracavitary.

  • Intracavitary implants are placed inside natural cavities where the tumour is developing. These implants tend to be temporal and are used in the treatment of colon and uterine cancer.
  • Interstitial implants are placed near the tumour inside the body tissue. They are advantageous in cases where tumours cannot be removed due to being close to critical organs. Interstitial implants can be permanent, with the radiation lasting until the isotope decays.

Radioactive Implants. Seeds. Interstitial Implant. StudySmarterFigure 2. Seeds used to treat prostate cancer. Source: James Heilman MD (CC BY SA 4.0).

Some other implant procedures include surface (placed over the tissue), intraluminal (inside hollow cavities in organs), and intravascular (inside arteries and veins) treatments.

The physics of radioactive implants

Radioactive implants use a radioactive isotope that emits radiation through decay. The emitted radiation is known as ionising radiation, which can modify the electrical bonds of molecules, breaking their DNA chains. The damage can also be induced by creating free radicals that react with the DNA, causing more damage to the cell.

The damage in the cell is caused by gamma, alpha, or beta radiation. In practice, alpha sources are not so widely used as their penetration is very short, which is why beta and gamma sources are preferred. The radiation issues from the decay of a radioactive isotope.

Damage to the cancer cells

Cells go through stages of growth. Those that are on active division, better known as mitosis, are affected more quickly by radiation. As cancer cells have an increased growth rate, this type of localised therapy kills cancer cells faster.

Damage mechanisms can be produced by apoptosis or cell arrest.

In the first case, the cell is damaged by the radiation, and the cell mechanics are activated to kill the damaged cell. Apoptosis happens to cells that have had a long life span and need to die to make space or new tissue.

Radioactive Implants. Cell apoptosis. StudySmarterFigure 3. The process of cell apoptosis, in which the cell self-destructs, leaving behind what is known as an apoptotic body (little sealed sacks). The process is self-triggered when the cell damage is extensive. The damage can also be produced by exposure to radiation from implants. Source: Manuel R. Camacho, StudySmarter.

Cell arrest happens when the cell is affected by its reproduction mechanism, also known as cycle arrest. During this process, the cell stops being involved in any division or multiplication to repair its damaged DNA. If the damage is as extensive as the damage produced by radiation, the cell goes into apoptosis.

Cells are also damaged by the action of free radicals, which are molecules that result from the impact of radiation on the water molecules that make up most of the human body. The free radicals are highly reactive, impacting the DNA and breaking some of its bonds.

Radioactive implant precautions

When radioactive implants are used, some precautions need to be taken to protect both the patients and the persons interacting with them. Usually, when a radioactive implant is given to a person, they become a source of radiation. People under this treatment can be put in isolation, and the medical personnel might need to take certain measures when they treat them.

If the implant is supposed to stay a long time, close contact with the area is not recommended for that time period.

Radioactive Implants - Key takeaways

  • Brachytherapy, one type of internal radiation therapy, uses radioactive implants.
  • Radioactive implants are devices used to treat cancer by exposing cancer tissue to localised sources of radiation.
  • Implants, which can be very small, can be inserted into the tissue.
  • The implants damage the cell’s DNA by emitting ionising radiation, which inhibits the cell division process by producing cell arrest and later apoptosis. The cell can also directly undergo apoptosis if the damage is extensive.
  • When implants are placed in patients, cautions need to be taken. Sometimes, the patients need to be isolated, and in the case of long-time implants, prolonged contact with the treated area is not advised. Even so, radiation is highly unlikely to cross all human tissue.

Frequently Asked Questions about Radioactive Implants

Cancer treatments, such as for prostate cancer, colon cancer, breast cancer, skin cancer, eye cancer, lung cancer, and many others can include radioactive implants as part of the therapy. The implants are used in circumstances where the cancer source is localised and small.

Radioactive implants are small implants filled with radioactive isotopes. The implants are used in the treatment of cancer by exposing the cancer cells to radiation.

The exposition to radiation damages the DNA of the cell by breaking its bonds or by creating free radicals. The damage induces cell arrest. During the arrest, the cell stops its processes of division or multiplication to repair its DNA.

If the damage is as extensive as the damage produced by a radiation source, the cell goes into apoptosis, which is the programmed death of cells.

Radioactive implants work by emitting radiation (gamma, beta, or alpha). The radiation comes from the decay of a radioactive isotope.

Radioactive implants damage a cell by the direct action of the radiation, which impacts the DNA, or by creating free radicals, which then damage the DNA of the cancer cells.

Final Radioactive Implants Quiz

Question

What is brachytherapy?

Show answer

Answer

A type of internal radiation therapy.

Show question

Question

Are radioactive implants used in cancer therapy?

Show answer

Answer

Yes, they are used in treatments that range from prostate to lung cancer.

Show question

Question

Which of the next materials is used in brachytherapy as a radiation source?

Show answer

Answer

Iodine.

Show question

Question

Does brachytherapy consist of implanting small radiation sources?

Show answer

Answer

Yes, they are known as seeds.

Show question

Question

The implants can be …?

Show answer

Answer

Interstitial and intracavitary.

Show question

Question

What is an intracavitary implant?

Show answer

Answer

One that is placed inside the tumour.

Show question

Question

Where are intravascular implants placed?

Show answer

Answer

In veins and arteries.

Show question

Question

The radiation used in brachytherapy is …?

Show answer

Answer

Ionising radiation.

Show question

Question

What is the name given to the process during which a cells divides?

Show answer

Answer

Mitosis.

Show question

Question

What is apoptosis?

Show answer

Answer

A mechanism by which a cell commits suicide.

Show question

Question

Name the two mechanisms by which a cell is affected during brachytherapy.

Show answer

Answer

Cell arrest and apoptosis.

Show question

Question

Does cell arrest induce a stop in the cellular activities?

Show answer

Answer

Yes, it does.

Show question

Question

Apart from direct damage to the DNA, which other mechanism also damages cells during radiation therapy?

Show answer

Answer

Free radicals.

Show question

Question

How does radiation induce direct damage to the cells?

Show answer

Answer

By breaking the DNA.

Show question

Question

Does a person emit radiation when an implant is inside them? Is this dangerous?

Show answer

Answer

Yes, they will emit radiation. Caution is advised but the radiation will not travel too far from the local tissue.

Show question

More about Radioactive Implants
60%

of the users don't pass the Radioactive Implants quiz! Will you pass the quiz?

Start Quiz

Discover the right content for your subjects

No need to cheat if you have everything you need to succeed! Packed into one app!

Study Plan

Be perfectly prepared on time with an individual plan.

Quizzes

Test your knowledge with gamified quizzes.

Flashcards

Create and find flashcards in record time.

Notes

Create beautiful notes faster than ever before.

Study Sets

Have all your study materials in one place.

Documents

Upload unlimited documents and save them online.

Study Analytics

Identify your study strength and weaknesses.

Weekly Goals

Set individual study goals and earn points reaching them.

Smart Reminders

Stop procrastinating with our study reminders.

Rewards

Earn points, unlock badges and level up while studying.

Magic Marker

Create flashcards in notes completely automatically.

Smart Formatting

Create the most beautiful study materials using our templates.

Just Signed up?

Yes
No, I'll do it now

Sign up to highlight and take notes. It’s 100% free.