Understanding Radiation Therapy

Radiation therapy is one of the major treatments for any type of cancer. It is a procedure that uses high energy particles such as gamma rays, protons, electrons, x-rays, and electron beams to destroy cancer cells. Other names for radiation therapy include x-ray therapy, radiotherapy, or irradiation.

Radiotherapy can be used alone or used together with other cancer treatments such as chemotherapy or surgery. Chemotherapy drugs are used as radiosensitizers, which means they can induce cancer cells and make them more sensitive to radiation. This helps radiation destroy cancer cell in a better way.

Why Do You Need Radiotherapy?

Specialists who perform radiation therapy are known as radiation oncologists. Radiation therapy used to treat cancer will require a specific number of treatments before the main procedure. The major goal of radiation therapy in treatment of cancer is to kill cancer cells, and slow the growth of tumors without bringing harm to the nearby cells and healthy tissues.

Radiation therapy is mainly used in the treatment of cancer. After radiation therapy is complete, another cancer treatment, known as adjuvant therapy, is usually started to help destroy any remaining cancer cells.

Radiation therapy can also be used to shrink tumors and reduce pain and pressure among other symptoms of cancer. This type of radiotherapy treatment is known as palliative radiation therapy. This treatment is mainly used when there is no possibility of curing cancer completely. Palliative radiation is meant only to improve one’s quality of life and also increase life expectancy.

More than half of patients with cancer all over the world will receive radiation therapy. Radiation therapy is very effective for some types of cancer. However, other cancer types, such as liver cancer, may respond well when radiotherapy is combined with other cancer treatment methods such as surgery, immunotherapy, and chemotherapy.

Types of Radiation Therapy

The following are the different types of radiation treatment that may be used for the treatment of cancer:

1. External Beam

External beam radiation therapy is the most common type of radiation therapy. It is a procedure that delivers radiations from a device outside of the body. This type of treatment can treat cancers that have invaded larger parts of the body.

A device known as a linear accelerator (LINAC) creates a radiation beam for either photon or x-ray radiation therapy. Special computers are then used to adjust the shape and size of the beam before the procedure. Adjusting the shape and size of the beam will help the oncologist target the tumor without damaging healthy cells and tissues. External beam radiation therapy may be delivered daily for several weeks to help treat cancer completely.

Types of External-Beam Radiation Therapy

• 3-D conformal radiation therapy (3-D-CRT) – This type of radiotherapy uses magnetic resonance imaging (MRI) or computed tomography (CT) scan to create detailed 3-D, or 3-deminsional, pictures of the cancer cells before the radiations are delivered. Imaging ensures that the radiation team is able to aim at the cancerous cells only. This means that a higher dosage of radiation can be delivered without damaging normal or healthy cells. Radiation administered with imaging pictures will help reduce side effects associated with this treatment. For example, drying of the mouth is common after head or neck radiation therapy. However, 3D-CRT can help limit salivary glands that cause it.
• Intensity modulated radiation therapy (IMRT) – It is a more complex form of 3D-CRT. In this method, the intensity of radiation is controlled by IMRT unlike in 3D-CRT. This method is used to target cancer cells while avoiding healthy cells and tissues.
• Proton beam therapy – This is a procedure that uses protons rather than conventional x-ray. A proton is a positively charged ion that at high energy can be used to destroy cancer cells. Protons are delivered to the targeted cancer cells, where they deliver the doses of radiation therapy needed. Unlike other radiations such as x-ray and photons, protons do not go beyond the tumors. This helps limit the damage that radiation can cause to healthy cells and tissues. This type of radiation therapy is used to treat certain types of cancer. However, proton beam therapy is not used to treat all types of cancer. It is a new method which requires special equipment that may not be available in every medical center.
• Stereotactic radiation therapy – It is a treatment that delivers a large, but precise, radiation dose to a relatively smaller tumor area. The patient should remain still throughout the procedure. Head frames and body molds will help the patient limit movement. This type of therapy may be given as a single treatment or a few treatments depending on the stage of the cancer.
• Image-guided radiation therapy – This is a radiation therapy treatment where the doctor takes pictures of the tumor area throughout the treatment process. The images can then be compared to the pictures used to plan the treatment and help target the tumor. This method is aimed to help reduce damage to healthy cells and tissues.

2. Internal Radiation Therapy

In internal radiation therapy, also known as brachytherapy, radioactive materials are placed on the cancerous area or the surrounding tissue. The implants placed may be either permanent or temporary, meaning that it requires a hospital stay.

Types of internal radiation therapy include:

• Permanent implants – These are small steel seeds that contain radioactive material. The implants resemble a grain of rice in size. They are used to deliver most of their radiation on the cancer cells. However, this type of radiation can escape out of the patient’s body.
• Temporary internal radiation therapy – This is a type of radiation therapy where radiations are given through needles, special applicators, and tubes called ‘catheters’. Radiations in this type of therapy stay in the body for several minutes to a few days.

 3. Other Types of Radiotherapy

• Systemic radiation therapy
• Radioimmunotherapy
• Intraoperative radiation therapy
• Radiosensitizers radiotherapy
• Radioprotectors radiotherapy

Safety Measures After Radiation Therapy

A patient undergoing radiation therapy should take the following precautions the first few days after treatment:

• Avoid sexual intercourse.
• Minimize your contact with pregnant mothers, children, or infants.
• Drink a lot of fluids to help remove any remaining radiations out of the body.
• Wash your hands after using the bathroom.
• Use separate towels and utensils with others.

Bottom Line

Radiation therapy is a treatment option that is mostly used in the treatment of cancer. This procedure may be more helpful in some cases than others. For example, some cancer types are more sensitive to radiations than others. Also, some cancers may be easier to treat using radiotherapy.

If your doctor recommends a radiation therapy, it means that he or she believes that the benefits of the therapy outweigh the possible risks and side effects.