National Diploma in Radiography Therapy
National Diploma in Radiography Therapy
National Diploma in Radiography Therapy
Before considering any form of treatment it is important to understand what it entails. It is our responsibility to provide you with more information regarding radiation therapy. Radiation therapy is the type of cancer treatment that uses beams of intense energy to kill cancer cells. Radiation therapy damages cells by destroying the genetic material that controls how the cells grow and divide. While both healthy and cancerous cells are damaged by radiation therapy, normal cells can often repair much of the damage caused by radiation. Radiation therapy can also be used to treat some noncancerous tumors. During your radiation treatment you may experience some side effect such as dry mouth, difficulty swallowing, shortness of breath ,vomiting, sexual dysfunction etc…. depending on the part of the body is been treated. Most side effects are temporary and can be controlled, they also generally disappear over time once you treatment has ended. Be sure to understand your doctor about the potential side effects that may occur after your treatment.
In simple terms, radiotherapy means treatment with ionizing rays; obtained from different sources. External radiation is delivered mainly by Linear accelerators (high energy X-rays). Brachytherapy (internal radiation) is obtained from radioactive substances placed inside or against the tumor area. To understand how ionizing rays work, you must understand how cancer cells affect your body.
The goal of radiation therapy is to damage and eventually destroy the cancer cells, but the rays cannot distinguish between normal and malignant cells.
The success of irradiation lies in the fact that malignant cells are more sensitive to irradiation than normal cells. The goal of irradiation is therefore to irradiate until the malignant cells have been killed or sterilized. The surrounding normal tissue is, however, still capable of complete recovery.
In certain phases of division cells are more sensitive than in other, dormant phases.
To irradiate as many of the cells as possible in the sensitive phase, the treatments are fractionated; in other words, they are spread over a period of time.
Another reason for fractionation is to give the normal cells, which recover faster than malignant cells, a chance to recuperate. This is why the total required dose is not given in one treatment. The sensitivity of the various types of tissues and the various organs differ, thus the number of treatments for different diagnoses will inevitably also differ. The number of treatments prescribed bears no relation to the degree to which the cancer has advanced, therefore, if you are to receive thirty-five treatments and another person receives only five, you cannot assume that your prognosis is worse than theirs. The dose administered, the number of treatments and the specific diagnosis are very closely linked. It is important to understand that because irradiation is used differently for the different conditions, it is not wise to compare treatments, symptoms or side effects.
Irradiation is only done during the week, and sometimes it is interrupted for a day when the machine is being serviced or work is being done on the machine.
Because the radiation passes through normal tissue to reach the effected area the side effects must be limited. To ensure this a CT scan is done which is then transferred to a dedicated Treatment Planning System (TPS). On the TPS a 3D image of the treatment area is created using the CT slices. The oncologist delineates the area of interest (tumor) on this 3D image. MRI images where soft tissue tumours are better shown can also be used in conjunction with CT images. The 3D image is used to plan the treatment with multiple field combinations with different angles and energies, to ensure that the dose to the normal tissue and sensitive organs is limited while an optimal dose to the tumor is achieved. The combined dose of the fields where they intersect give the optimal dose required. The different tissue densities, the beam is traveling through, is also taken into account since they have different absorption properties.
To limit the dose to critical organs and normal tissue in the beam path, shielding is used to shape the radiation beam. Modern technology allows for this to be done easily with multi leaf collimators (MLC) instead of lead shielding blocks which are time consuming and labour intensive. To achieve optimum treatment planning, highly skilled and experienced planning radiographers, physicists and a specialized TPS is essential.
To ensure that the treatment is being given correctly, recording and verification systems are essential. This will prevent treatment being given unless all parameters are set-up correctly. The system also records treatment data for future reference. Anatomical verification is also required to ensure that the correct treatment position is used. This is done with a portal imager or the use of verification films.
The area to be irradiated is determined by means of a localising scan or X-rays, and then marked. This is called a simulation.
PLEASE BRING ALONG ANY PREVIOUS X-RAYS OR SCANS that may be of use. Sometimes the treatment area is decreased during the course of the treatments. This is called a booster.
It is very important that the marks that have been made on your body remain there.
YOU MAY BATH OR SHOWER, but you must make sure that these marks are not washed off. A quick bath or shower is preferable. If you do take a bath, do not soak in the water. Use a gentle soap for example Dove soap.
Irradiation is not painful and patients are not radioactive after irradiation, therefore you pose no threat to other people.
During irradiation you will be alone in the treatment room, but you will be monitored on a television screen. There is also an intercom system.
It is extremely important that you keep very still, but you may breathe normally.
It is only human to be concerned about the side effects of irradiation, especially as there are so many misconceptions about irradiation.
However, if you understand what may or may not happen, you can avoid unnecessary anxiety and fear.
The aim of the following information is to give you peace of mind.
Only patients who receive irradiation over their abdominal organs sometimes experience nausea and vomiting. If you find that this is a problem, please ask your oncologist for a prescription for medication.
If the symptoms continue in spite of the medication, inform your oncologist immediately so that other medication may be prescribed.
It is extremely important that you take your medication as prescribed to prevent nausea, and not only when you feel nauseous.
It is also important that you continue to eat enough. If you start losing weight or find that you are no longer eating regularly, consult the dietician immediately.
Patients who receive irradiation over the lower abdominal area may suffer from diarrhoea, constipation, a burning sensation when urinating and / or piles.
Please ask for medication immediately if you suffer from any of the above.
It is also important to ask the radiotherapists whether your bladder should be full or empty during irradiation.
Patients receiving irradiation over the throat area will start suffering from a sore throat after about ten treatments. Gargling with a solution of half a teaspoon of bicarbonate of soda mixed with half a teaspoon of salt in a glass of lukewarm water will help. There will also be dryness of the mouth due to the irradiation affecting the salivary glands. This condition may be permanent. You may experience a temporary loss of speech, but speech will be regained in the course of time. You might also find that you develop a double chin after irradiation.
Men who are receiving irradiation over the face must not shave the treatment area, as it would cause skin irritation.
It is important that you drink a lot of fluids.
If you experience problems with your diet due to a sore throat or mouth, please consult the dietician.
If you have three or four loose stools a day, you should drink clear fluids (soup, soft drinks, tea and ± two litres of water per day). Also consult your general practitioner or oncologist immediately.
You must prevent your body from dehydrating.
Eat a lot of bananas, carrots (cooked) and grated apple (without the skin).
The dietician can compile a special diet for you to help combat the diarrhoea. It may also be advisable to take one or more nutritional supplements. These supplements can be prescribed by the dietician. You may also take medication for the diarrhoea. Please ask the nursing staff to assist you with this.
CAUTION: Please do not use any ointment, powder or deodorant spray on the irradiation area. These will make any skin irritations worse. You may use a roll-on deodorant (like Dove). If the skin feels tender, you could use Aqueous water-soluble cream. If necessary your doctor will prescribe a special cream.
Do not expose the treatment area to direct sunlight. Wear a hat and suitable clothes in the sun. If a skin reaction is to be expected, the oncologist or radiotherapist will tell you. A reddening of the skin will become visible after about fifteen treatments.
Your hair will only fall out if you receive irradiation over the scalp. Irradiation of other parts of the body will not cause hair loss on the head.
The hair will only start falling out after about fifteen treatments, and in most cases will start growing again after about three months.
White blood cells are the body's protective mechanism against infections.
The white blood cell count of patients receiving irradiation over large areas of bone may decrease, therefore regular blood counts will be taken if you are such a patient.
When smaller areas of the body are irradiated, the loss of white blood cells is so small that regular blood counts are not necessary.