External Beam Radiation Therapy

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What is the meaning of External Beam Radiation Therapy?

External beam radiation therapy is the most common type of radiation therapy that is used for the treatment of cancer. A machine is used for aiming high-energy rays or particles from outside the body into the tumor. External beam radiation therapy is mostly provided in the form of photon or x-ray beams, and less often in the form of particles like protons and neutrons, or electron beams. External beam radiation therapy involves focusing the radiation beam on the exact location to maximize the radiation that reaches cancer and limit the effect of radiation on the surrounding healthy tissues.

In this article, we will be discussing in detail about external beam radiation therapy.

• What is the purpose of External Beam Radiation Therapy?
• What are the types of beams used for External Beam Radiation Therapy?
• What are the different types of External Beam Radiation Therapies?
• What is the diagnostic procedure before External Beam Radiation Therapy?
• How to prepare for External Beam Radiation Therapy?
• What is the procedure for External Beam Radiation Therapy?
• How to care after External Beam Radiation Therapy?
• What are the risks of External Beam Radiation Therapy?
• What is the cost of External Beam Radiation Therapy in India?

What is the purpose of External Beam Radiation Therapy?

External beam radiation therapy is performed in the following cases:

• Treatment of cancer
• Elimination of a tumor or prevention of a tumor from returning
• Before surgery to reduce the size of the tumor
• After surgery to remove any cancer cells that may still be remaining
• Reduce the symptoms of the patient in case of advanced types of cancer or cancer that has spread to the other parts of the body (metastasized)

The following types of cancers can be treated using external beam radiation therapy:

• Breast cancer
• Bowel cancer
• Esophageal cancer
• Head and neck cancer
• Lung cancer ( Know more about- What is Lung Cancer ? )
• Prostate cancer
• Colorectal cancer
• Melanoma
• Uterine cancer
• Brain tumor ( Know more about- What is Brain Cancer Treatment ? )

What are the types of beams used for External Beam Radiation Therapy?

The different types of beams used for external beam radiation therapy are usually invisible and cause no pain when passing through the skin of the patient. They may include:

Photon beam radiation therapy: 

• It is the same type of radiation used during an x-ray but at a much higher quantity.
• This radiation is released from the machine as an energy wave.
• The photon beams can travel deep into the body to the tumor, and can also damage the healthy tissue behind and in front of the tumor.
• The photons are emitted by a machine known as a linear accelerator.

Particle beam radiation therapy:

• Particle beams are separate energy units, like a proton or neutrons.
• The radiation is released from the machine in the form of a stream of high-energy particles.
• This type of radiation is given by a special type of machine, known as a particle accelerator, like a synchrotron or cyclotron.

Electron beam radiation therapy:

• Electron beams are separate units of energy and may act as particle beams or may be converted into photon beam radiation.
• Electrons usually do not travel too far and are mostly used to treat cancers on the skin or near the surface of the body.
• Electron beams can be emitted from a linear accelerator or a particle accelerator.

What are the different types of External Beam Radiation Therapies?

The different types of external beam radiation therapies are:

• 3D conformal radiation therapy: Computed tomography or CT scans and special computer software help to create a three-dimensional computer model of the treatment area. Treatment is targeted to the tumor region perfectly, not affecting the surrounding normal tissue.
• Intensity-modulated radiation therapy (IMRT) or volumetric modulated arc therapy (VMAT): IMRT helps in providing precise radiation therapy. The multi-beam system varies in the intensity of the radiation dose and narrows in on the diseased cells. VMAT involves performing this procedure over an arc, which is quicker.
• Image guided radiotherapy (IGRT): Three-dimensional imaging is done before treatment to help in better precision of the target. This can be performed by using imaging tests like CT scans, x-rays, and ultrasounds.
• Stereotactic radiosurgery or gamma knife radiosurgery: This type of treatment focuses on giving high doses of intense radiation to the targets outside the head region.
• Intraoperative radiation therapy (IORT): This therapy helps in radiation delivery at the time of the surgery, avoiding the need for external radiation after surgery. It provides radiation that is more focused on areas that have some tumors left behind.

What is the diagnostic procedure before External Beam Radiation Therapy?

The following diagnostic tests may be done before external beam radiation therapy:

• Physical examination: The doctor evaluates the physical health of the patient, along with the patient’s symptoms and medical history of the patient.
• Imaging tests: CT scans and MRI scans are performed to obtain clear images of an organ.
• Endoscopy: A tube with a camera on one end, known as an endoscope, is used to check an organ internally. ( Know more about- What is Endoscopy ? )
• Blood tests: These tests help to check for any medical disorders that may be present.
• Biopsy: The doctor surgically excised the suspected tissue growth and sent it to the laboratory to check it under the microscope. It helps in checking if cancer cells are present and what type of cancer cells are present.

How to prepare for External Beam Radiation Therapy?

• The doctor needs to be informed about any medical conditions that you may be having.
• The doctor needs to be told if you are currently taking any medications, herbs, or supplements.
• If you have any known allergies, tell the doctor about the same.
• The doctor reviews your medical history and test results and pinpoints the exact area that needs to be treated. This planning procedure is known as simulation.
• Simulation helps in delivering the radiation as precisely as possible to the tumor while causing minimal possible damage to the surrounding tissues.
• You are asked to lie still on a table, while imaging scans like CT scans or MRI scans may be performed to define the treatment field or treatment port. These are the exact places where the radiation beams are aimed.
• A special mask, mold, or cast of a body part is made to make sure that you are in the same position for each therapy session.
• The doctor may mark the field of treatment with freckle-sized dots using semi-permanent ink. You should avoid using soap or scrub on these marks till your treatment is completed.
• Sometimes, the doctor may mark the treatment area with permanent dots, such as a tattoo, which can later be removed using a laser.

What is the procedure for External Beam Radiation Therapy?

• You will be asked to change into a hospital gown or robe before treatment.
• You will then be positioned using the dots on your skin and body mild or face mask to help you stay in the right position.
• Colored lights may be seen pointed at your skin marks. These are harmless lights that help the doctor position you for treatment.
• The doctor’s team leaves the room just before radiation is given. They will most likely be in an adjacent room where they can see and hear you, and they can also control the radiation machine.
• You need to stay still so that the radiation reaches the exact same place every time.
• You will hear a buzzing sound of the radiation machine moving around, but you will not be able to hear, see, feel, or smell the radiation.
• You will receive radiation for about one to five minutes.
• A single external beam radiation therapy session lasts for approximately half an hour to one hour, with most of the time being spent on placing you in the appropriate position.
• Most patients get external beam radiation therapy daily, five times a week, for five to eight weeks.
• The number of treatment sessions and the total radiation dose depends on the type of cancer present, the location and size of cancer, the reason for treatment, the general health of the patient, and any other cancer treatments that you may be getting.

How to care after External Beam Radiation Therapy?

• Since there is no radiation source placed inside the body, the patient is not radioactive during or after the treatment.
• The patient usually goes home on the same day after a radiation therapy session.
• Side effects like skin irritation and fatigue may usually be noticed only after a couple of treatment sessions.
• The patient is asked to come for regular follow-ups with the doctor after the treatment.
• During these follow-up sessions, the patient will undergo evaluation, including blood tests or imaging tests, to check if cancer has been eliminated or if additional treatment is needed.
• Even if cancer has been cured, the patient needs to come for regular follow-ups to check for recurrence of cancer. ( Know more about- What is Skin Cancer Treatment? )

What are the risks of External Beam Radiation Therapy?

External beam radiation therapy may have the following side effects:

• Loss of hair at the treatment site
• Skin changes at the site of treatment ( Know more about- What are Skin Disorders ? )
• Nausea
• Fatigue
• Difficulty in swallowing
• Tenderness at the treatment site
• Inflammation at the treatment site 

What is the cost of External Beam Radiation Therapy in India?

The total cost of external beam radiation therapy in India can range from around INR 3,00,000 to INR 20,00,000. However, many prominent hospital doctors in India specialize in external beam radiation therapy. But the cost varies across different hospitals. 

If you are coming from abroad, apart from the cost of external beam radiation therapy, there will be an additional cost of living in a hotel and the cost of local travel. So, all the expenses come to a total of INR 3,90,000 to INR 26,00,000. 

We hope that we could answer all your questions regarding external beam radiation therapy through this article.

If you need more information about external beam radiation therapy, you can contact a Radiation Oncologist.

We only aim to provide you with information through this article. We do not recommend any medication or treatment to anyone. Only a qualified doctor can give you good advice and the correct treatment plan.