What is Radiation Therapy?
Radiation therapy is the use of radiation to safely and effectively treatcancer and other diseases. It works by damaging cancer cell's ability to multiply. When these cells die, the body naturally eliminates them. Healthy cells near the tumour may be affected by radiation, but they are able to repair themselves in a way tumour cells cannot. New techniques also allow doctors to better target the radiation to avoid damaging healthy cells.
Radiation treatment may be used to completely destroy an entire tumor, control its growth, shrink its size and/or relieve symptoms such as pain and bleeding.
Radiation therapy may be used alone or in combination with other cancer treatments, such as chemotherapy or surgery.
EXTERNAL BEAM RADIATION THERAPY
During external beam radiation therapy, a beam of radiation is directed at the main tumour and any nearby cancer cells. To minimize side effects, the treatments are typically given five days a week, over several weeks. This allows the doctor to get enough radiation to destroy the cancer cells while allowing healthy cells time to recover.
The radiation beam consisting of high-energy X-ray or electronsis usually generated by a machine called a linear accelerator or LINAC. Nowadays, advanced treatment machines can control the shape and amount of the radiation beam to effectively treat the tumour while sparing the surrounding healthy tissue or organs.
There are several types of external beam radiation therapy and your doctor will recommend the most suitable treatment for you.
- Three-Dimensional Conformal Radiation Therapy (3D-CRT)
Tumours come in different shapes and sizes. The 3D-CRT uses 3D imaging techniques (eg. CT scan or MRI) to determine the size, shape and location of the tumour. This information will help your Radiation Oncologist to tailor the radiation beams to the actual tumour using multileaf collimators (MLC) or fabricated customized field shaping blocks.
- Intensity Modulated Radiation Therapy (IMRT)
IMRT is a specialized form of 3D-CRT whereby the radiation beams can split up into many "beamlets". The intensity of each beamlet can be adjusted to either further increase the amount of radiation to the tumour or to limit the amount of radiation to the healthy tissue near the tumour. It will result in a higher dose of radiation being delivered to the tumour, potentially increasing the chance of a cure.
- Stereotactic Radiosurgery (SRS) and Stereotactic Radiation Therapy (SRT)
Both SRS and SRT are techniques used to treat tumours in the head region. Radiation beam is precisely focussed to a smaller area compared to 3D-CRT and this additional precision is achieved by using a very secured immobilization head frame.
SRS is prescribed as a single dose treatment while SRT is delivered over several sessions.
- Image-guided Radiation Therapy (IGRT)
IGRT involves the delivery of radiation guided by imaging (such as CT, X-rays) taken in the treatment room just before the patient undergoes radiation treatment. Some tumours may move during treatments due to the differences in organ filling (eg. full or empty bladder) or breathing (eg. lung).
During IGRT, the Radiation Oncologist will compare images taken during CT simulation and before treatment to decide if the treatment position needs to be adjusted. This allows for the radiation beams to better target the tumour daily while avoiding nearby healthy tissues.
Your Radiation Therapy Team
A team of highly trained medical professionals will be involved in your care during radiation therapy.
- Radiation Oncologists are doctors who oversee your radiation treatment. They work together with the Radiation Therapy Team to develop your treatment plan. They will monitor your progress and treat any side effects that may occur due to radiation therapy.
- Radiation Physicists develop and direct quality control programs for the treatment machines and procedures. They also ensure thatthe treatment machinesfunction properly by taking precise measurements of the radiation beam and performing other safety tests regularly.
- Dosimetrists work with your Radiation Oncologistto develop your treatment plan. Using state-of-the-art treatment planning system, they design and carefully calculate the radiation dose that can most effectively destroy the tumour while sparing the healthy tissues.
- Radiation Therapists work closely with your Radiation Therapy Team to deliver your daily radiation treatment according to your Radiation Oncologist's prescription. They maintain daily records and regularly check the treatment machines to ensure that they are functioning properly.
- Radiation Oncology Nurses will coordinate your care, counsel you on the management of side effects and address your concerns about your treatment.
Your Radiation Treatment Process
The following information provides you with a step-by-step process of your treatment at the Radiotherapy Centre.
Before Therapy
Meeting Your Radiation Oncologist
During your first visit, your Radiation Oncologist and/or Resident (Radiation Oncologist in training) will evaluate your need for radiation therapy and the likely outcome. He / She will review your current medical problems, past medical and surgical history, family history, medications, allergies and lifestyle. He / She will assess the extent of your disease and your general physical condition.
After reviewing your medical test results and completing a thorough physical examination, he / she will discuss the potential benefits and risks of radiation therapy and answer any questions you may have.
A series of appointments will be arranged to prepare you for treatment. The duration from your first visit to the start of treatment may vary from a day to a few weeks depending on the radiation therapy plan prescribed by your Radiation Oncologist.
Computed Tomography (CT) Simulation
Before you commence your radiation treatment, it is necessary to perform a CT Simulation and identify the treatment area so that the radiation beams can be precisely targeted.
During CT Simulation, your Radiation Therapists will position you on the CT couch in the exact position thatyou will be in during the actual treatment. In some situations, immobilization devices and / or contrast medium may be used. Immobilization devices such as head masks or body casts can help you retain the same position during the entire treatment, while the use of contrast medium will highlight organs within the body during CT Simulation.
After the CT Simulation, your Radiation Therapists will mark your skin with a set of small permanent tattoos. These markings are to ensure the accurate reproduction of your treatment position.
Treatment Planning
Your Radiation Oncologist and Dosimetrist will use the acquired CT Simulation images along with your previous medical test results to develop an optimum treatment plan using state-of-the-art treatment planning system. This customised plan ensures that the tumour site receives the maximum amount of radiation while minimising radiation to nearby healthy tissues and organs.
During Therapy
Radiation Treatment
Treatments are usually scheduled 5 days a week, Mondays to Fridays, over a period of 1 to 7 weeks. The number of radiation treatments you need depends on the size, location and type of cancer you have, the intent of your treatment, your general health and other medical treatments you may be receiving.
In the treatment room, the Radiation Therapists will reproduce your treatment position as you were during the CT Simulation. If an immobilization device was made during CT Simulation, it will be used now to ensure that you are in the exact same position during every treatment.
Once you are positioned correctly, the Radiation Therapists will proceed to the control room just outside the treatment room. They will continue to monitor you through a closed circuit television while delivering the radiation. There is an intercom in the treatment room for communication with the Radiation Therapists if you need assistance. The Radiation Therapists can stop your treatment any time if you are not feeling well or uncomfortable.
During the treatment, the Radiation Therapists may move the treatment machine and treatment bed to target the radiation beam to the exact area of the tumour. The machine might make some noise as it moves.
Sometimes your treatment may be interrupted for a day or more when you develop side effects and require a break from treatment. The missed treatment session may be compensated depending on your health status.
Try to be punctual and not to miss any of your appointments. Time spent in the treatment room may vary according to the type of radiation therapy, but it generally ranges from 10 to 30 minutes. Most patients are treated as an outpatient, and many patients can continue with normal daily activities.
During your course of treatment, the Radiation Therapists will acquire X-ray images of your treatment site periodically with the treatment beam. These images represent important quality assurance checks but they do not provide an evaluation on the tumour status.
Weekly Status Review
Your Radiation Oncologist or Resident will monitor your progress weekly to evaluate how you are coping with the side effects and recommend medication to relieve any discomforts. He may order blood tests and other tests to review your response to the radiation therapy.
Some questions and answers on Side Effects
What are the side effects of radiation therapy?
Many of the side effects of radiation therapy are confined only to the area that is being treated. For example, a breast cancer patient may notice skin colour changes over the treated chestwall like a mild to moderate sunburn, while a patient with cancer in the mouth may have soreness and ulcers in t he mouth. Some patients who are having their abdomen treated may feel sick in their stomach. These side effects are usually temporary and can be treated by your Radiation Oncologist
Side effects usually begin by the second or third week of treatment, and they may last for several weeks after the final radiation treatment. Do talk to your Radiation Therapy Team about any side effects you are having. They can advise you on how to manage them and may prescribe medicines or suggest changes in your eating habits to help relieve your discomfort.
Radiation therapy is usually well tolerated and many patients are able to continue their daily routines
What should I do during the period of radiation therapy?
Get plenty of rest. Many patients experience fatigue during radiation therapy, so it is important to get plenty of rest. If possible, ask friends and family members to help run errands and prepare your meals. This will help you get the rest you need to focus on fighting your cancer.
Eat a balanced, nutritious diet. A nutritionist, nurse or doctor may work with you to make sure you are eating the right food and getting the vitamins and minerals you need. With certain types of radiation therapy, you may need to change your diet to minimise side effects and/or increase your calories intake.
Treat the skin that is exposed to radiation with extra care. The skin in the area receiving treatment may become red and sensitive, similar to getting a sunburn. Your Radiation Therapy Team will provide you with specific instructions for caring for your skin. Some guidelines include:
- Clean the skin daily with room temperature water and a mild soap recommended by your Nurse.
- Avoid using any lotion, perfume, deodorant or powder in the treatment area unless approved by your Radiation Oncologist or Nurse. Try not to use products containing alcohol and perfume.
- Avoid putting anything hot or cold on the treated skin. This includes heating pads and ice packs.
- Stay out of the sun. If you must spend time outdoor, wear a hat or carry an umbrella.
Support Groups. There are many emotional demands that you must cope with during your cancer diagnosis and treatment. It is common to feel anxious, depressed, frightened or hopeless. It helps to talk about your feelings with a close friend, family member, nurse, social worker or psychologist. To find a support group in your area, do ask your Radiation Therapy Team.
What is lymphoedema?
Lymphoedema is an excessive collection of fluid in the leg, trunk or body part, due to disruption of the normal lymph flow. The disruption is mainly due to the removal of the lymph nodes during surgery for cancer and/or radiotherapy for cancer treatment. If you have undergone surgical removal of lymph nodes or radiotherapy, you may be at risk of developing lymphoedema.
It may be helpful to find out from your doctor which lymph nodes have been removed during the surgery and which part of the body has been treated by radiotherapy.
You can reduce this risk with the following advice and precautions:
- Keep the skin clean, supple and moisturised. Dry any wet areas thoroughly. You may need a hair dryer for difficult areas like the skin folds and between toes.
Make sure that your underclothes are regularly washed.
- Avoid any injuries to the leg, for example, cuts, bruises, insect bites and knocks.
- Avoid sunburn by using protective clothing and a sunscreen (SPF 15 or more).
- The leg must not be used for injections, drips or having blood samples taken.
- Removal of hair from the leg should only be done using a well-maintained electric razor. Blade razors, creams and waxing increase the chance of cuts and redness of the skin.
- If travelling by air, a compression garment must be worm. This also applies to long bus, train and car journeys.
- Avoid tight clothing. No redness or indentation should be visible on removal of clothing.
- Avoid constrictive jewellery. No redness or indentation should be visible on removal of jewellery.
- Avoid prolonged standing and high heels. When you have to stand, walk in short bursts to increase lymph flow.
Consult your doctor immediately if:
- You notice redness or increased warmth of your leg at risk. They may be signs of infection or fungal infections.
- You notice a slight increase in the size of your leg at risk. You may want to measure your leg monthly to monitor for changes in size.
The treatment of lymphoedema of the leg is carried out by the physiotherapist and includes:
- Skin care
- Manual lymphatic drainage
- Compression bandaging
- Exercises
- Compression garments
After Treatment
Follow-Up Consultation
After your treatment is completed, your Radiation Oncologist will schedule follow-up appointments to monitor your recovery and health status.
As time goes by, the number of follow-up visits decrease. Nevertheless, your Radiation Therapy Team will always be available should you need someone to talk about your concerns.
All information is intended for educational purposes only and should not be used as a substitute for consultation with your doctor.
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