Understand Radiation Therapy & Its Use in Cancer Treatment

If you have been diagnosed with cancer, your care team will likely use some combination of surgery, chemotherapy, hormonal therapy, immunotherapy and radiation therapy to treat you. However, not everyone receives all those treatments.

“We use radiation therapy in more than half of patients who have cancer,” said Patrice McGowan, MD, a radiation oncologist with the Samaritan Cancer Program. “However, treatment looks different for everyone — there is no ‘one size fits all’ with radiation.”

What Is Radiation Therapy?

Radiation works by targeting rapidly dividing cells to prevent them from growing. After repeated treatments, the cells eventually die. During radiation therapy, a precise dose of high-energy particles is delivered to the cancer tumor to damage and kill the cells.

“The goal with radiation therapy is always to target the cancer while limiting the damage to healthy tissue,” said Dr. McGowan. “Cancer cells don’t recover from damage as quickly as healthy cells. We do several treatments over time to give healthy tissue a chance to heal between treatments which limits the side effects people experience.”

Types of Radiation Therapy

External Beam Radiation

This is the most common type of radiation therapy and can be used for many types of cancer. During external beam radiation, a machine called a linear accelerator located outside of the body delivers radiation to the tumor. The procedure is like having an X-ray taken. The machine does not touch the patient or the tumor, and the treatment is painless.

  • Conventional radiation therapy that uses this technique includes treatment given five days a week for up to 8 weeks.
  • Stereotactic body radiation therapy (SBRT) is a high dose of targeted radiation therapy and may be an option for some patients. This is typically delivered in five sessions over the course of 2 weeks.

Systemic Radiation Therapy

This treatment uses radioactive isotopes that may be swallowed as pills, given through an IV or injected into the body. This therapy is usually used for thyroid cancer or to treat pain due to cancer that has spread to the bone.

While there are different ways to deliver radiation, Dr. McGowan notes that no one method is “better” than another.

“The treatment that will be most effective is the one that is customized for the patient and the type and stage of cancer being treated,” she said. 

When Radiation Is Used

Sometimes radiation therapy is the only treatment needed for cancer, but more often, it is used in combination with other treatments like chemotherapy or surgery. 

Radiation therapy can be used at many different stages in the cancer treatment processes

  • Before surgery to shrink a tumor
  • After surgery to destroy any remaining cancer cells
  • To ease cancer symptoms or pain but without curing the cancer (palliative care)

“Radiation therapy isn’t without risks, but it is one of the most powerful tools we have to treat cancer,” said Dr. McGowan.

Patrice McGowan, MD, and Norman Yeh, MD, are radiation oncologists with the Samaritan Cancer Program.

 Learn more about cancer care centered around you at Samaritan Cancer Program.

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