Role of Radiotherapy In Cancer Treatment
Posted On: April 12, 2018
Of the various treatments available for treating cancer - radiation therapy is one of the commonly used techniques.
It makes use of high-energy radiation for shrinking tumors and killing the cancer cells. Some of the commonly used radiation types include the X-rays, charged particles and gamma rays.
The radiation is delivered through a machine, either from outside the body or internally. The radiation that’s given from outside is known as the external-beam radiation therapy while the one given internally is called the internal radiation therapy - known as brachytherapy.
Most of the cancer patients happen to receive radiation therapy at some point of their treatment course.
How radiation therapy works on the cancer cells?
A cell turns cancerous when the DNA gets damaged and the cell deviates from its path as a result of which it starts multiplying uncontrollably.
Radiation therapy works by destroying the DNA of the cancer cells either directly or by creating charged particles in the cell that work to destroy the DNA. When the DNA of cancer cells gets destroyed, they either stop multiplying or die. When the cells die, they are further broken and discarded off the body through its natural process.
However, during this process, radiation therapy even harms the normal cells round, which further leads to side effects.
When a patient is to be given radiation therapy, the doctor will take note of the probable damage the normal cells may have to undergo and the therapy is planned accordingly.
Why radiation therapy?
Radiation therapy is administered with two objectives - curative and palliative. When the objective of radiation therapy is to cure the cancer then it will work by removing the tumor or preventing its recurrence. For curative purpose, radiation therapy is given as a stand-alone treatment or is combined with radiation therapy.
For palliative purpose, radiation therapy works with the objective of relieving the cancer symptoms and cut down the discomfort the patient is experiencing.
Planning a radiation therapy treatment
It all starts with your treatment planning, known as stimulation. During this process, your doctor will identify the location of your tumor through imaging scans; computed tomography (CT) and magnetic resonance imaging (MRI).
Once stimulation is done, the next thing is determining the precise area that has to be treated. Based on the location, the dose required will also be decided.
The area determined for the treatment will not only include the tumor but also some healthy tissues surrounding it. Healthy tissues are selected for:
- Taking into account the movement of the body, right from breathing and usual movement of the organs in the body, which can alter the tumor location between treatments.
- For reducing the possibility of tumor repetition from the cancer cells that spread to the healthy tissues next to the tumor.
Types of Radiation Therapy
External-beam radiation therapy: This radiation type is mostly delivered as photon beams, x-rays or the gamma rays. Photon is the unit of light and is known to be the bundle of energy. The energy amount present within the photon tends to vary.
Photons that are found in gamma rays contain more energy as compared to the x-rays. This radiation type is administered with the help of a machine known as the linear accelerator (LINAC). This machine makes use of electricity for forming a current of swiftly-moving subatomic particles which in turn creates high-energy radiation used in treating cancer.
If you are being given the external-beam radiation therapy, then you will have everyday treatment sessions for several weeks. The exact number of radiotherapy sessions will depend on various factors such as the dose as given.
External-beam radiation therapy is also classified into different groups as the 3D-CRT which stands for 3-dimensional conformal radiation therapy. It makes use of highly refined computer software with progressive machines for delivering the radiation very precisely to the target areas.
There are some other methods as well, like:
- Intensity-modulated therapy (IMRT): This makes use of multiple small radiation beam-shaping instruments, known as the collimators, for delivering a single radiation dose. These collimators can either be stationary or on the move at the time of treatment. This allows the vigor of the beams to alter throughout the treatment process. It even allows treating various areas of the cancer tumor or the healthy tissues around.
- Image-guided radiation therapy (IGRT): In this type, recurrent imaging scans like MRI or CT are done. The scans are then processed by different computers for identifying the changes in tumor’s size as well as location because of the treatment. It even allows positioning of the patient or adjusting the planned dose of radiation. This process increases the certainty of radiation treatment and can grant cutbacks in the projected size of the tissue that has to be treated by cutting down on the dose of radiation as given to the healthy tissues.
- Tomotherapy: It is an image-guided type of IMRT as the machine happens to be a hybrid amid the CT imaging scanner as well as the external-beam radiation therapy machine. The part of this machine which delivers radiation for imaging as well as treatment is able to swivel completely around you, quite like the usual CT scanner.
- Proton beam therapy: This radiation therapy type makes use of protons instead of x-rays. A positively charged particle, a proton is capable of destroying the cancer cells at high energy. During proton beam therapy, the protons are made to travel to the targeted tumor where they deposit the needed dose of radiation therapy. Contrary to x-ray beams, in proton beam, the radiation never goes beyond the tumor which apparently limits the damage as caused to healthy tissues around the tumor.
Internal radiation therapy: Also known as brachytherapy, in this process the radiation is delivered through the radiation sources; radioactive materials which are placed within or on your body. There are various brachytherapy techniques used in treating cancer. The interstitial brachytherapy makes use of a radiation source that is placed in the tumor tissue. The intracavitary brachytherapy will use the source which is placed in a surgical cavity or your body cavity, near the tumor. Then there is episcleral brachytherapy, used for treating melanoma in the eye, and the source is attached to your eye.
Depending upon the nature of the cancer and the location, the internal radiation therapy also has types. The two common types of internal radiation therapy happen to be:
- Permanent implants: These happen to be tiny steel seeds containing the radioactive material. Most of the radiation is usually delivered around the implant area but some radiation tends to exit the patient’s body. This is why it becomes important to take precautionary measures to safeguard others from the radiation exposure. With due course of time, the implants lose their radioactivity and remain in the body inactively.
- Temporary internal radiation therapy: In this type, the radiation is given using needles or tubes known as catheters.
Other radiation therapy options
Apart from the radiation therapy types as mentioned above, there are other options too, which include:
Intraoperative radiation therapy (IORT): This type of radiation therapy is given to the cancerous tumor at the time of surgery. It is given either as external-beam or internal radiation therapy. This type allows the surgeon to keep away from healthy tissues in advance. And is highly helpful in cases where the tumor happens to be in closer proximity to the essential organs.
Systemic radiation therapy: In this type, the cancer patient is made to swallow or take an injection of the radioactive materials which targets the cancer cells. The radioactive material then leaves the body via sweat, saliva, and urine. These discarded fluids are also radioactive in nature and people taking care of the patient must take proper safety measures.
Radioimmunotherapy: It is a kind of systemic therapy that makes use of the monoclonal antibodies for delivering the radiation dose directly to cancer cells. It works by delivering very low doses of radiation and causes no effect to the healthy cells.
Side effects of radiation therapy
Similar to various other treatments for curing cancer, the radiation therapy also comes with its share of side effects. The common side effects of this treatment module include fatigue, nausea, skin irritation, and others.
These side effects depend on the cancer type, the location, extent of cancer, radiation dose and hence differ from person to person.
In certain cases of radiation therapy, no side effect is seen while in some, more than one side effect tends to surface.
Radiation therapy is known to cause late or early side effects. As the name suggests, early side effects occur in a very short span after the treatment process or in some cases, the side effects can surface during the treatment process only.
The early side effects are mild, short-term and treatable. The most commonly occurring early side effects include fatigue and skin changes.
Late side effects usually surface over months and years of the treatment process. These side effects can occur in any of the body’s normal tissue that has received radiation. Chances of late side effects depend on the area where radiation was given as well as the dose. Late side effects can be avoided if the treatment is planned and designed carefully. It is advisable to consult the radiation oncologist at the best cancer hospital in India and Ahmedabad to understand and minimize the risk of the long-term side effects.
Common Side Effects of Radiation Therapy
The fatigue one experiences after radiation treatment is nothing like the usual tiredness or fatigue. It makes you feel tired not just physically but also mentally and emotionally. It’s a very common side effect of radiation therapy. Most people start feeling some amount of tiredness right after a few weeks of the therapy process. Fatigue occurs at the first place because during radiation therapy, the energy beam ends up destroying some healthy cells also, along with the cancer cells. With the progression of treatment process, the intensity of fatigue also starts increasing.
The skin part which has been exposed to radiation is likely to appear swollen, red, blistered, sunburned or tanned. The skin can become dry, itchy, and flaky and may start to peel after a few weeks of the process. This condition is known as dermatitis and if you come across any skin change, it should be brought to the notice of your radiation oncologist without any delay. To cope up or manage the skin changes, you should take care of a few things. Very importantly, you should avoid wearing body hugging clothes. Opt for loose clothes made of soft fabric. Take thorough care of the skin and don’t indulge in rubbing, scratching or scrubbing your skin. If you have to go out in the sun, never forget to apply a good quality sunscreen. All your skincare products like creams, moisturizers and lotions must be approved by your radiation oncologist.
Radiation therapy can make you lose your hair in the area where radiation is given. If the radiation dose is given on the head, you may notice thinning of your hair with unusual hair fall. Sometimes, it can even cause the hair in your eyebrows and lashes to fall. Radiation that’s given around the armpit can make the hair in your armpit to fall. The hair though will grow back, the density would differ.
If the radiation is given in the mouth or throat, or in stomach or intestine, you may have to bear eating and digestion troubles. The side effects include sores in mouth, vomiting, nausea and loss of appetite. Radiation oncologists advise that even if there exists an eating problem, you should make it a point to eat nutritional foods so that you don’t suffer from any nutritional deficiency.
Tips to deal with side effects
You may experience any of the above-mentioned side effects during or after the radiation therapy. However, you should make it a point to take care of certain things that will help you cope with the side effects in a better way.
Some of the things to take care of are:
Try and get plenty of rest. This will help you overcome fatigue and feel good. It is advised that you sleep properly so that your body gets to retain energy.
Your diet is very important for the effectiveness of the treatment and your health. Make sure that you eat a balanced diet and take care of the nutritional substances that form part of your everyday meal. Speak to your radiation oncologist and nutritionist to get the right information about diet during and after the treatment process.
Monitor your health and recovery during the process. If at all you notice any unusual change, do notify it to your medical team without any delay.
Seeking proper medical help can aid in managing the side effects in an effective manner. The radiation oncologist will help you with proper management of side effects while giving you the most effective cancer treatment. If the side effects are causing much of trouble, then you may be recommended certain medications that can help in relieving the symptoms or side effects.
Radiation therapy and chemotherapy
In most of the cancer treatments, the two treatment types commonly heard are radiation therapy and chemotherapy. And often people get confused between the two treatment types.
The Chemotherapy process, also known as chemo, makes use of a combination of drugs for treating cancer. Chemotherapy is more of a “systemic” treatment which works through the entire body for preventing the spread of cancer cells. The drugs as used in the process will depend on the cancer type and the cancer stage. It will even be affected by your overall health and age. The main objective of chemotherapy is to prevent the cancer from spreading to the other parts of your body.
You will be given the chemotherapy drug by an experienced medical oncology professional, usually a nurse or a doctor. Chemotherapy can be given as an outpatient process which normally happens in a hospital, at the doctor’s office, or sometimes, it can even be given at home. The chemo drugs can be given through any of the following ways:
- Injection in your muscles, vein, or the artery
- Injection in the body like abdomen
- Direct skin application
Like radiation, chemotherapy also has certain side effects and they differ based on the type and dosage of chemotherapy drug as used and the way your body reacts to it. As the chemotherapy drugs transit through your body, they also tend to impact the healthy cells in your body, which leads to various side effects.
Chemo is designed for killing the fast-growing cancer cells, however; this often leads to side effect that involves your body’s healthy and fast-growing cells.
Some healthy cells that can get affected because of chemotherapy treatment include:
- Blood making cells that are present in your bone marrow that can lead to anemia, higher risk of infection or bruising
- Hair follicles, which leads to temporary hair loss
- Cells in your mouth, reproductive and digestive tract that can make you experience nausea, constipation, loss of appetite and diarrhea
Some of the chemo drugs can even cause damage to the cells present in your heart, bladder, lungs, kidneys, and the nervous system. As you continue with the chemotherapy sessions, your doctor will continue monitoring your condition closely and can even prescribe certain medicines for protecting the normal cells in your body. If need be, you may even be recommended medicines that can help in relieving the side effects.
Contrary to chemotherapy, where drugs are used for treating cancer, the radiation therapy makes use of the high-energy particles or radiation waves for destroying or damaging the cancer cells.
The major difference between chemotherapy and radiotherapy is that radiotherapy is only used to treat the tumor which is why it will affect on the concerned part of your body. In chemo, the side effect can be associated with any cells in your body.
In most of the cases, a radiation therapy can be administered as a stand-alone treatment but in some cases, it will be combined with chemotherapy or for that matter any other cancer treatment type like surgery.
Radiation therapy is one of the effective treatments that can aid in managing cancer, its symptoms and the side effects it causes. While a radiation therapy can be used for treating any cancer type, your oncologist will be the best person to decide as to which treatment will work best in your case.
At Shalby Hospitals, we make use of the latest instruments and machines for radiation therapy. Our teams of highly proficient and expert radiation oncologists carefully examine your condition, overall health and medical history before prescribing the precise dose of radiation, that too with great care.
Our experts make it a point to consider the below factors before deciding on the duration of your radiation therapy. These factors include:
- Your age and disease history
- Size and area of the tumor
- Cancer type and spread in body
- Other treatment modes to be used in combination
- Tumor distance from the radiation sensitive tissues
With the expertise of well-trained radiation oncologists, skilled nurses and paramedical staff; our team ensures that you get highly effective and safe medical care during the entire process.
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