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Here's What You Should Know About Radiation Therapy Side Effects

Here's What You Should Know About Radiation Therapy Side Effects

Radiation therapy is a common cancer treatment. It may be used as the sole treatment for the cancer patient, or together with other treatments like surgery, and targeted therapy. Radiation therapy side effects may differ for different patients. Side effects may also be resolved or prevented entirely. Some people may experience few side effects or none at all, whole others experience many effects.

What is radiation therapy?

Radiation therapy is a treatment that involves the use of powerful radioactive beams to kill cancer cells. Normally, cells break up and multiply. But with cancer cells, they break up and multiply at an alarming rate. In radiation therapy, x-rays are shot at affected cells to destroy their genetic material, or DNA, which are in charge of how the cells grow and multiply. Radiation therapy only targets affected cells. Therapy is planned to reduce chances that healthy cells are affected.

Another type of radiation therapy involves taking a radioactive pill or substance. The substance will gather at the point where cancer cells are. This type lessens the effect on non-cancer cells or otherwise healthy parts of the body.

However, this type of treatment is not very effective for cancer types that have spread to the rest of the body.

When is it used?

Radiation therapy is commonly used to:

  • Shrink cancer cells at an early stage
  • Prevent the return of cancer cells
  • Manage cancer cells that have returned
  • Help with symptoms caused by an advanced stage of cancer

Preparation for treatment and radiation therapy side effects

Before treatment, the healthcare provider will discuss possible radiation therapy side effects, risks, and the overall process. A planning stage will be scheduled to pinpoint the exact location of the treatment area. This would normally happen in two stages:

  • Radiation simulation – During this process, the patient will be asked to lie down so the medical team can pinpoint the treatment area with a marker or a small permanent tattoo.
  • Planning scans – The patient will undergo a computerized tomography or CT scan to determine the exact location where the treatment would be needed.

The healthcare team can then decide how the treatment will proceed depending on the patient’s overall well-being, cancer stage, and treatment objective.

Treatment Options Available For Lung Cancer

Treatment process

During the therapy, a machine is used to administer the beams to the patient’s treatment location. This machine is called a linear accelerator, and is used to deliver radioactive beams to the patient’s treatment area from different angles.

The treatment may continue in a series of sessions that last a few days each, with intervals of several weeks in between sessions to allow healthy cells to recuperate.

Radiation therapy side effects

Side effects occur depending on where the cancer is located, its type, the radiation dose and the patient’s overall health.

Radiation therapy side effects: Early side effects

At first, the patient may experience short-term and treatable radiation therapy side effects such as:

  • Tiredness
  • Sore skin
  • Sore mouth
  • Appetite loss
  • Hair loss

Patients may also be emotionally affected so contacting support groups may help. These symptoms usually disappear after treatment.

Radiation therapy side effects: Later side effects

These side effects take time to develop. Radiation treatment may have long-term effects on body tissues. To prevent these, the treatment planning should be done carefully. When undergoing this type of treatment, the patient should discuss with their doctor in-depth regarding the possible long-term radiation therapy side effects.

Among long-term radiation therapy side effects are the following:

  • In the case of radiation therapy to the brain, long-term affects may include loss of memory, stroke-like symptoms, poor brain function
  • Radiation therapy to the breast may result in less skin sensitivity, and larger pores. The size of the breast may change.
  • Radiation therapy to the chest may produce heart complications, such as damage to the arteries and heart valve.
  • Chest radiation therapy may also result in inflammation of the lungs.
  • Radiation to the pelvis may result in radiation cystitis, urinary incontinence, and fistulas.
  • In women, menstrual periods may stop permanently. In men, radiation therapy may reduce number and quality of sperm cells.

Key takeaway

In treating cancer, the radiation therapy procedures and side effects may be intimidating.

Early side effects include fatigue, sore skin and mouth, and hair loss. Long-term side effects may include damage to the tissues and other complications.

Planning and consultation with their medical team may help patients feel more confident in their treatment.

Learn more about Cancer here.

Hello Health Group does not provide medical advice, diagnosis or treatment.


How Radiation Therapy Is Used to Treat Cancer, https://www.cancer.org/treatment/treatments-and-side-effects/treatment-types/radiation/basics.html

Accessed April 19, 2021


Radiation Therapy Side Effects, https://www.cancer.org/treatment/treatments-and-side-effects/treatment-types/radiation/effects-on-different-parts-of-body.html

Accessed April 19, 2021


Side Effects of Radiotherapy, https://www.nhs.uk/conditions/radiotherapy/side-effects/

Accessed April 19, 2021


Radiation Therapy, https://www.mayoclinic.org/tests-procedures/radiation-therapy/about/pac-20385162

Accessed April 19, 2021


Cancer treatments – Radiotherapy, https://www.betterhealth.vic.gov.au/health/ConditionsAndTreatments/cancer-treatments-radiotherapy

Accessed April 19, 2021


Slide show: Radiation therapy treatment planning, https://www.mayoclinic.org/diseases-conditions/cancer/multimedia/radiation-therapy/sls-20076358?s=6

Accessed May 12, 2021


Planning your external radiotherapy, https://www.cancerresearchuk.org/about-cancer/cancer-in-general/treatment/radiotherapy/external/planning/about

Accessed May 12, 2021




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Written by Red Ricafort Updated May 20
Fact Checked by Hello Doctor Medical Panel