[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
What does high-dose rate brachytherapy involve?
Placing thin plastic or metal tubes into the prostate gland, and then inserting radioactive material into the tubes by a machine
What happens after insertion of the radioactive maternal in high-dose rate brachytherapy?
The radioactive material is left in the tubes for a set period of time (few minutes), then withdrawn
What happens after the treatment in high-dose rate brachytherapy?
The tubes are removed and no radioactive material is left in the prostate
How is brachytherapy for cervical and womb cancer given?
Through special hollow tubes called applicators that are inserted into the womb or vagina
What are the different types of brachytherapy used in cervical and womb cancer?
- High-dose rate
- Low-dose rate
How does the dose differ in high-dose rate and low-dose rate brachytherapy in cervical and womb cancer?
The same dose of radiotherapy is given, but over different times
Over what period of time is high-dose rate brachytherapy given in cervical and womb cancer?
10-15 minutes, given as one short burst, or several short bursts over a few days
Over what period of time is low-dose rate brachytherapy given in cervical and womb cancer?
Longer period of time, usually 12-24 hours
What happens in brachytherapy using caesium or iridium wires?
Very thin radioactive needles, wires, or tubes are inserted while under general anaesthesia
What can brachytherapy using caesium or iridium wires be used to treat?
A number of different cancers, including cancers of;
- Mouth
- Lip
- Cervix
- Breast
What does radioisotope therapy do?
Delivers radiation directly into cancer cells
How is radioisotope therapy given?
- Capsule
- Drink
- Injection into vein
How does radioisotope therapy work?
Cancer cells absorb the radioactive substance more than normal cells, so they receive a higher dose of radiation, causing the cells to die
What are the different types of radioisotope therapy?
- Iodine-131
- Strontium-89 and Samarium-153
- Radium-223
What is the most common type of radioisotope treatment?
Iodine-131
What is iodine-131 used to treat?
- Specific types of thyroid cancer
- Can also be used to treat some rarer types of cancer, such as neuroblastoma
What does a patient on iodine-131 treatment need to be made aware of?
They will be slightly radioactive for a short time after their treatment
How does the radioactivity leave the body after iodine-131 treatment?
Slowly leaves body in urine, stools, period blood, saliva, and sweat
What is the result of the patient being slightly radioactive after treatment with iodine-131?
They will need to follow safety measures after treatment, and for a short time after going home
What can strontium-89 and samarium-153 be used to treat?
Certain types of secondary bone cancer
What is the purpose of strontium-89 and samarium-153 in the treatment of secondary bone cancer?
- Reduce bone pain
- Improve quality of life
What is radium-223 used to treat?
Secondary cancer in the bone from prostate cancer that is no longer responding to hormonal therapy
How often is curative (radical) radiotherapy given?
Usually involves having a course of treatment given once a day, often with a rest at weekends
How long does curative radiotherapy treatment last?
1-7 weeks
What is each treatment called in radical radiotherapy?
A fraction
What is the purpose of giving radiotherapy treatment in fractions?
Ensures that less damage is done to normal cells than cancer cells
When might radiotherapy be given, with respect to other treatments?
- Given on its own
- Before or after surgery or chemotherapy
- Same time as chemotherapy
What is the purpose of palliative radiotherapy?
Symptom control
Give 3 examples of situations where palliative radiotherapy may be used
- To one or more of the bones, to help control pain caused by bone metastases
- To the lungs, to reduce coughing caused by cancer in the lungs
- To help control bleeding caused by lung, bladder, or skin tumours
How many sessions is palliative radiotherapy given over?
May involve only one or two sessions of treatment, but sometimes can involve 10 sessions or more
What is the disadvantage of palliative radiotherapy that is only given in 1 or 2 sessions?
It is more likely to cause short-term side effects, e.g. flu-like symptoms
What needs to be done before starting radiotherapy?
Treatment needs to be planned
What is the purpose of treatment planning in radiotherapy?
To make sure that the radiotherapy is aimed precisely at the cancer, and causes the least possible damage to surrounding tissue
What might done people need before treatment planning?
A mask or mould to be made
How long does a radiotherapy planning visit take?
30-60 minutes, although can take longer
What imaging is required in radiotherapy treatment planning?
Usually need a CT scan of the area to be treated, and sometimes an MRI or PET is also required
What is the purpose of moulds and masks in radiotherapy?
They are made to help the patient stay still and in the correct position during radiotherapy
What are moulds and masks for radiotherapy made out of?
Plastic mesh
How are moulds and masks for radiotherapy made?
They are warmed and put on the patient’s body part, so it moulds to fit the area being treated
What is done once the treatment area for radiotherapy has been decided?
Markings are made on the skin to help accurate positioning for treatment
How are skin markings made for radiotherapy treatment markings?
Via tattoos
What is true of side effects for most people having radiotherapy?
They will have few side effects, and they will often be mild
What do the side effects of radiotherapy depend on?
- Type of treatment
- Area of the body being treated
What are the most common side effects of radiotherapy?
- Fatigue
- Nausea
- Problems with eating and drinking
- Skin reaction
- Flu-like symptoms
- Hair loss
- Changes in blood count
How long do most side effects of radiotherapy last?
10-15 days after treatment finishes, and then gradually get better
Which side effect of radiotherapy may last for longer?
General tiredness
What is it called when side effects of radiotherapy persist after the patient has finished treatment?
Long-term or late effects
How do internal and external radiotherapy compare in terms of side effects?
External radiotherapy usually causes more general side effects than internal radiotherapy
Who might develop a skin reaction from radiotherapy?
People having external radiotherapy
How long after radiotherapy does a skin reaction begin if its going to happen?
Usually after about 10 days
What will how the skin reacts to radiotherapy depend on?
The amount of radiotherapy a patient has
What are the possible skin reactions that may result from radiotherapy?
- Red, sore, itchy skin
- Darker skin with black/blue tinge
- Breakages and leakage from skin
What might be required if the skin reaction to radiotherapy is severe?
The treatment may have to be delayed for a short time to allow the area to recover
How long do skin reactions from radiotherapy take to settle down?
Usually settle down 2-4 weeks after treatment has finished, however the area may stay slightly darker than the surrounding skin
What symptoms might patients experience if they are given palliative radiotherapy in one or two treatment sessions?
Flu-like symptoms, including;
- Headaches
- Aching joints or muscles
- Lethargy
What are the more serious long-term side effects of radiotherapy?
- Changes in blood count
- Second cancers
What kind of radiotherapy can cause a change in blood count?
Radioisotope therapy, such as strontium or samarium, and sometimes external radiotherapy
What effect might radiotherapy have on the blood count?
Can temporarily reduce the number of normal red and white blood cells produced by the bone marrow
What is the result of the change in blood count that can occur with radiotherapy?
It can cause an increased susceptibility to infection and anaemia
What do patients need to be made aware of as a result of the potential for radiotherapy to cause a change in blood count?
They need to be advised to seek medical advice if they feel unwell, have a fever, or start feeling cold and shaky
Why is radiotherapy given despite it’s potential to cause cancer?
Only a small number of people will develop a second cancer because of the radiotherapy, and the chance is so small that the risks of radiotherapy are far outweighed by the benefits
What do patients need to be advised of when having radiotherapy if they are of childbearing age?
That it is important that they don’t become pregnant during their treatment
Why is it important not to become pregnant during radiotherapy treatment?
As radiotherapy given during pregnancy could harm a developing fetus
What do you need to do when gaining consent for radiotherapy, regarding pregnancy?
Ensure the patient is not pregnant, and that they understand that they should not become pregnant during treatment, and therefore need to use a reliable form of birth control
What should male patients having radiotherapy be advised of, regarding fathering children?
They should be advised not to father a child during treatment, and for a few months father it’s finished
What will follow up after radiotherapy depend on?
- Type of cancer
- Type of radiotherapy
- Response of patient to treatment
Will everyone having radiotherapy need follow up appointments?
No
What should be done if a patient does not need follow up after radiotherapy?
They should be given advice on potential problems to look out for, and the details of someone to contact if necessary
When do follow up appointments for radiotherapy usually happen?
About 4-6 weeks after treatment has finished
Where can radiotherapy follow up appointments take place?
- Radiotherapy department
- Hospital
- On phone
What does a radiotherapy follow up appointment include?
- Assessment of how patient is doing
- Opportunity for patients to discuss any problems or worries they have
What should patients be advised of in radiotherapy follow up?
If they have any problems or notice any new symptoms at any time, or between appointments, they should contact their oncologist, rather than waiting for their next scheduled appointment
What is prophylactic cranial radiotherapy?
A treatment used to prevent or delay the spread of cancer to the brain
Who is prophylactic cranial radiotherapy given to?
Usually people with SCLC, but may occasionally be given to people with acute lymphoblastic leukaemia
