[14] Radiotherapy Flashcards
What is radiotherapy?
The use of high-energy rays to treat disease
How does radiotherapy work?
By destroying cancer cells in the area that is being treated
Is radiotherapy given internally or externally?
Can be either
What is done in external radiotherapy?
High-energy x-rays are aimed at the affected area using a large machine
What is done in internal radiotherapy?
Radioactive material is placed inside the body
Can normal cells be damaged by radiotherapy?
Yes
What is the result of normal cells be damaged by radiotherapy?
Can cause side effects
How does the effect of radiotherapy differ in normal cells compared to cancer cells?
Cancer cells cannot repair themselves after radiotherapy, but normal cells can
What is it called when chemotherapy is given alongside radiotherapy?
Chemoradiation, or chemoradiotherapy
What effect might chemotherapy drugs have on radiotherapy?
May make cancer cells more sensitive to chemotherapy
What is the down side of giving chemotherapy and radiotherapy together?
Can make the side effects of treatment worse
What are the main types of radiotherapy?
- External beam radiotherapy
- Internal radiotherapy
What are the types of external beam radiotherapy?
- Conformal radiotherapy
- Intensity modulated radiotherapy (IMRT)
- Image-guided radiotherapy
- 4C radiotherapy
- Stereotactic radiotherapy
- Total body irradiation
- Intraoperative radiotherapy
What does conformal radiotherapy use?
A device inside the radiotherapy machine to shape the radiotherapy beams to fit the treatment area
What is conformal radiotherapy used to treat?
Many types of cancer
What does IMRT do?
Shapes the radiotherapy beams, and allows different doses of radiotherapy to be given to different parts of the treatment area
What is the advantage of IMRT?
It means lower doses of radiotherapy are given to healthy tissue surrounding the tumour
What is the importance of the reduction in radiotherapy to healthy tissue around in the tumour in IMRT?
- It reduces the risk of immediate and long-term side effects
- May allow higher doses of radiotherapy to be given to the tumour
What is the result of IMRT having a reduced risk of damage to healthy tissue and side effects on the tumours is used to treat?
It is often use to treat tumours that are close to important organs and structures
What kind of cancers is IMRT mainly used to treat?
- Breast cancer
- Head and neck cancer
- Anal cancer
- Prostate cancer
- Bladder cancer
- Gynaecological cancer
- Lung cancer
dunno why i wrote cancer after every single one lol obvs its treating cancer its in the cancer care deck
What is volumetric modulated arc radiotherapy (VMAT)?
A newer way of giving IMRT, where the radiotherapy moves around the person while treatment is being given
What is the advantage of VMAT?
- Shortens treatment time
- Uses lower dose of radiation
What is image-guided radiotherapy?
Where images are taken just before each treatment
What is the purpose of image-guided radiotherapy taking images just before each treatment?
It allows for comparison with images taken during the planning scan, and adjustment of to the treatment area
What is the advantage of adjusting the treatment area with image-guided radiotherapy?
It means it is very precide
Why is image guided radiotherapy helpful?
Because some tumours can shrink in size, or change in shape or position, during or between treatment
Give an example of a cancer that might change in shape or position during or between treatments
Prostate or cervical tumours can change depending on if the patient has a full bladder
What does 4D radiotherapy use?
A radiotherapy machine that takes images during the treatment
What is the purpose of 4D radiotherapy?
It shows any movement of the tumour, which is then used to adjust the radiotherapy treatment area during treatment
What is the purpose of 4D radiotherapy?
it means that if the tumour moves, it’s possible to make sure that it’s fully treated
When is 4D radiotherapy useful?
In tumours that move during treatment
Give an example of a tumour that moves during treatment
Lung cancer, which moves as you breathe
What does stereotactic radiotherapy use?
Many small beams of radiation to target the tumour
What is the advantage of stereotactic radiotherapy using many small beams of radiation?
It makes it very precise, and able to deliver high doses of radiotherapy to very small areas of the body, reducing the risk of side effects
What does total body irradiation involve?
Giving large single doses, or 6-8 smaller doses, of radiation to the whole body
What is the purpose of total body irradiation?
To destroy the cells of the bone marrow
When is total body irradiation used?
May be given to people who are having stem cell transplants as part of their treatment
What is intra-operative radiotherapy?
Giving a single dose of radiation in the operating theatre at the time a cancer is being removed
What are the types of internal radiotherapy?
- Bradytherapy
- Radioisotope therapy
What is brachytherapy?
The insertion of radioactive material directly into the affected area
What is the advantage of brachytherapy?
A high dose of radiation is given to the tumour, but healthy tissue only gets a small amount of radiation
What are the ways of giving brachytherapy for prostate cancer?
- Permanent seed brachytherapy
- High-dose rate brachytherapy
What is permanent seed brachytherapy also known as?
Low-dose rate (LDR) brachytherapy
What does permanent seed brachytherapy use?
Small radioactive ‘seeds’ that are inserted into the tumour
What is the purpose of the seeds in permanent seed brachytherapy?
They mean the radiation is released slowly
Are the seeds removed in permanent seed brachytherapy?
No obviously not otherwise why would it be called permanent seed
What happens to the radiation in permanent seed brachytherapy over time?
It fades away over about 6 months
What precaution should be taken when patients are receiving permanent seed brachytherapy?
Patient should avoid long periods of contact with children and pregnant women