Understanding Radiation Therapy – Panacea Oncology

Understanding Radiation Therapy

Radiation therapy is the use of high-energy x-rays or other particles to destroy cancer cells. A doctor who specializes in giving radiation therapy to treat cancer is called a radiation oncologist. A radiation therapy regimen, or schedule, usually consists of a specific number of treatments given over a set period of time.

Goals of radiation therapy

Radiation oncologists use this type of treatment to destroy cancer cells and slow tumor growth without harming nearby healthy tissue.

Sometimes, doctors recommend radiation therapy as the first cancer treatment. Other times, people receive radiation therapy after surgery or chemotherapy. This is called adjuvant therapy. It targets cancer cells remaining after the initial treatment.

When it is not possible to destroy all of the cancer, doctors may use radiation therapy to shrink tumors and relieve symptoms. This is called palliative radiation therapy. Palliative radiation therapy may reduce pressure, pain, and other symptoms. The goal is to improve a person’s quality of life. More than half of people with cancer receive some type of radiation therapy. For some cancers, radiation therapy alone is an effective treatment. Other types of cancer respond best to combination treatments. This may include radiation therapy plus surgery, chemotherapy, or immunotherapy.

External-beam radiation therapy

This is the most common type of radiation therapy. It delivers radiation from a machine outside the body. It can treat large areas of the body, if needed.

A machine called a linear accelerator, or linac, creates the radiation beam for x-ray or photon radiation therapy. Special computer software adjusts the beam’s size and shape. This helps target the tumor while avoiding healthy tissue near the cancer cells.

Most treatments are given every weekday for several weeks. Form-fitting supports or plastic mesh masks are used for radiation therapy to the head, neck, or brain to help people stay still during treatment.

The types of external-beam radiation therapy are:

Types of internal radiation therapy include:

The radiation stays in the body for anywhere from a few minutes to a few days. Most people receive radiation therapy for just a few minutes. Sometimes, people receive internal radiation therapy for more time. If so, they stay in a private room to limit other people’s exposure to the radiation.

Other radiation therapy options

Intraoperative radiation therapy (IORT). This treatment delivers radiation therapy to the tumor during surgery using either external-beam or internal radiation therapy. IORT allows surgeons to move away healthy tissue in advance. This treatment is useful when vital organs are close to the tumor.

Systemic radiation therapy. Patients swallow or receive an injection of radioactive material that targets cancer cells. The radioactive material leaves the body through saliva, sweat, and urine. These fluids are radioactive. Therefore, people in close contact with the patient should take the safety measures recommended by the health care team.

Radioimmunotherapy. This is a type of systemic therapy. It uses monoclonal antibodies to deliver radiation directly to cancer cells. This therapy delivers low doses of radiation directly to the tumor. It does not affect noncancerous cells. Examples include ibritumomab (Zevalin) and tositumomab (Bexxar).

Radiosensitizers and radioprotectors. Researchers are studying radiosensitizers. They are substances that help radiation therapy better destroy tumors. Radioprotectors are substances that protect healthy tissues near the treatment area. Examples of radiosensitizers include fluorouracil (5-FU, Adrucil) and cisplatin (Platinol). Amifostine (Ethyol) is a radioprotector.

Safety for the patient and family

Doctors have safely and effectively used radiation therapy to treat cancer for more than 100 years.

Having radiation therapy slightly increases the risk of developing a second cancer. But for many people, radiation therapy eliminates the existing cancer. This benefit is greater than the small risk that the treatment could cause a new cancer.

During external-beam radiation therapy, the patient does not become radioactive. And the radiation remains in the treatment room.

However, internal radiation therapy causes the patient to give off radiation. As a result, visitors should follow these safety measures:

Permanent implants remain radioactive after the patient leaves the hospital. Because of this, the patient should not have close or more than 5 minutes of contact with children or pregnant women for 2 months.

Similarly, people who have had systemic radiation therapy should use safety precautions. For the first few days after treatment, take these precautions:

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