Radiation Therapy

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What is Radiation Therapy?

Radiation therapy is a type of cancer treatment that uses high level radiation doses to either kill and eliminate the cancer cells or to shrink the malignant (cancerous) tumors in the body. In fact, every time you use an X-Ray to peep inside your body for a broken bone, you are using an ultra low-dose radiation therapy to obtain the images.

The primary goal of radiation therapy is to focus on the abnormal cell multiplication (in case of cancer) and destroy the growing cells without causing damage to the healthy cells around it. This is probably why radiation therapy is based on precision and expertise and is handled by professional Radiation oncologists only.

Quick Fact:

Radiation therapy is quite popular for cancer treatments, but did you know this form of treatment can also be used for thyroid disorders and certain blood-related diseases too?

How does Radiation Therapy work?

The whole point of radiation therapy is to prevent the growth of abnormal cells which are primarily responsible for cancer. Now, this is done using high, focused light or heat waves which according to science, breaks down the DNA of the cancer cells in such a way that repair or growth becomes impossible for them.

However, do note, radiation therapy does not affect the cancerous cells right away. It may take weeks for the effect to start and the radiation left in the body from the treatment can continue to kill cancerous cells for weeks to come. Often, multiple radiation therapy settings are recommended to impact the cancerous cells.

Radiation Therapy Types: External Beam Vs Internal Radiation

The type of radiation therapy depend on a lot of variables, which include-

  • The type of cancer or the part of the body affected
  • The growth rate or size of the tumor
  • Previous medical history / current medical conditions
  • Whether alternative treatment methods will be better or not
  • Age, severity of the tumor, patient’s immunity etc.

External Beam Radiation

External Beam Radiation uses a machine to aim the radiation waves at the cancer cells/ tumor. This is a beam-centric, local treatment method where the machine will not touch you, but it will move around the part of the body with the cancer cells.

Internal Radiation

Internal Radiation uses an invasive form of treatment method where the radiation is induced in your body in a solid/ liquid form.

  • Brachytherapy is a form of internal radiation therapy that uses a radioactive implant in the form of capsules or seeds (solid) to target the cancer cells.
  • Systemic radiation therapy is another form of internal radiation which uses swallowing, IV or injection (liquid) to target the cancer cells.

Are there any side effects to Radiation Therapy?

Radiation therapy is notoriously known for its side-effects which may vary from person to person. This depends on the amount of radiation exposure, the body part that has been exposed to radiation, the overall health and immunity/ core strength of the patient, etc.

Radiation therapy side effects can be divided into two parts, more precisely:

Short term side-effects

These show up during or immediately after the procedure and may stick around for a few days or weeks after that. These side effects include: 

  • Extreme fatigue
  • Constant feeling of nausea (may be accompanied by vomiting )
  • Diarrhea
  • Hair loss
  • Change in skin color/texture


These side-effects are often harmless (if experienced in moderation) and are most likely to go away on their own.

Long term Side-effects

These side-effects are a tough nut to crack and may often leave long, if not permanent damage. These include-

  • Lymphedema- a condition where lymph fluid build-up may cause extreme pain and discomfort in patients
  • Heart or lung damage (if the radiation therapy is directed to/ or nearby to the chest region)
  • Increased thyroid problems
  • Hormonal changes in women which may lead to menstrual irregularity or menopause.


The good news is, not everyone who undergoes radiation therapy experiences long-term side effects from this condition. However, radiation exposure to certain body parts can increase the risk of long-term effects.

What type of cancers can be treated using Radiation Therapy?

The radiation therapy is often determined by the position of the cancer. For example, Brachytherapy is often recommended for cancer in the eye, neck, breast, cervix or prostate whereas systemic radiation can be used for thyroid gland and hormone related cancers. Based on your diagnosis, your healthcare professional will be the best judge of which radiation therapy to use and for which part.

The Radiation Therapy Dream Team

Here’s a run down of the main team of healthcare professionals who will be appointed to treat you-

  • Radio Oncologist & respective nurse
  • Radiation therapist
  • Radiation physicist
  • Dosimetrist (to determine the accurate dosage required)
  • nutritionists/ additional help / physical therapists (will be appointed post-therapy as additional help)

What are the other treatments that are used along with Radiation Therapy?

Radiation therapy is not a stand-alone treatment. Often cancer treatments include a medley of procedures, amongst which radiation therapy is one of the crucial ones. However, procedures like chemo, targeted therapy or surgery still are the front-runners to cancer treatment. Radiation therapy is often combined with these or either one of these procedures for maximum effect, pain relief and steady cancer cure.

Radiation Therapy- pre-treatment preparation

Here’s a quick rundown of everything you should cover before your radiation therapy takes place. This includes-

  • Helping your medical professionals with a full-suite medical history, including your past or current medication prescription
  • Your doctor will prescribe some physical exams which has to be completed and submitted to your doctor on-time.
  • Ask your doctor for dietary requirements for 24 hrs leading up to the procedure

What to expect from/ during Radiation Therapy?

We know it must be nerve-wrecking heading for radiation therapy which is why we have listed down everything you should expect during the procedure.

  • Before starting the procedure, your radiation oncologist will determine the type of therapy and the required dosage for the procedure.
  • Initially an image-testing will be prescribed to locate the exact point where the radiation should be focused at.
  • You may be asked to wear a plaster cast to ensure the focus point remains steady and still throughout the radiation process. Don’t worry, this is temporary.
  • Often patients undergoing internal radiation are subjected to anesthesia to reduce pain and discomfort.
  • The external radiation therapy is painless and you will not feel any discomfort during the procedure. However, surrounding healthy tissues and cells, often exposed to radiation, may show signs of distress.
  • Radiation therapy usually continues for weeks- often on a consecutive 5-day stretch with a 2-day break to help the surrounding affected tissues heal themselves.

What will your post-Radiation Therapy care be like?

Radiation therapy may leave some short and long term side effects, most of which will affect your diet. We have summarized your diet requirements below, but it’s best if you can ask your appointed nutrition for details since dietary regulations vary from person to person.

Diet Check: Since nausea (and maybe vomiting) will be persistent during this time, your body may develop some mouth sores or throat problems along with it. However, a recovering body would need a lot of energy which is why high calorie and protein intake should be added to your everyday diet.

Lifestyle Check: While some patients are strong enough to continue everyday chores and work during radiation, some might need a little more time to get back to their usual life. Since fatigue will be a common side effect around this time, we encourage patients to mostly work from home or from a comfortable setting where they can get their rest as and when needed.


Is Radiation therapy only used to kill the cancer?

In the initial stages, yes, radiation therapy solely focuses on killing the cancer cells, but later in the recovery period, radiation can be used to treat pain and discomfort in patients too.

How long will the side-effects last?

Depending on a lot of factors, your radiation therapy side-effects can be in the form of nausea or extreme tiredness which are depicted as EARLY side effects. These last for a few weeks after the procedure. LATE side effects such as heart or lung problems will probably take years to recover.

Is medical leave necessary for radiation therapy?

This heavily depends on your body’s ability to heal and your level of fatigue. Since side effects like extreme tiredness and nausea may accompany you for a few days- it’s necessary to first access your situation before committing yourself to work.

My side effects are increasing- what should I do?

Notify your doctor immediately.

How should I take care of the radiation exposed area?

Your healthcare professional will help you out with the care guidelines. In most cases, the skin around the exposure area will be sensitive and should not be exposed to harsh chemicals (cosmetics) or direct sunlight.

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