Radiation Treatment Types

Types of Radiation Therapy

External-Beam Radiation Therapy (EBRT)

External-beam radiation therapy (EBRT) is a treatment where radiation beams come from a source outside the body. Usually, it comes from a machine called a linear accelerator (also called a LINAC).

These beams are carefully pointed exactly at your tumor. For example, if you have cancer in your lung, you will only have radiation aimed at your chest, not your entire body. This is the most common type of radiation therapy that people get to treat cancer.

EBRT includes the following types of treatments, which are all offered at Fred Hutch:

Electron Therapy

Electron therapy is also called electron beam therapy (EBT). It is most often used to treat tumors on or near the surface of the body, like skin cancers. This is because electrons do not go as deeply into the body as other types of radiation, like X-rays or photons.

Three-dimensional Conformal Radiation Therapy (3D-CRT)

Three-dimensional conformal radiation therapy (3D-CRT) allows radiation to be customized to the patient’s body. First, the radiation therapist does a computed tomography (CT) scan of the part of the body being treated. These images are loaded into a special computer and used to create the radiation treatment plan.

The plan is designed to send a beam of radiation that closely matches the size and 3D shape of the tumor.

Intensity-modulated Radiation Therapy (IMRT)

With IMRT, the radiation beam closely matches the patient’s tumor and can be split into smaller beams of different strengths. This helps the radiation oncology team send a higher dose of radiation to the tumor while sending as little as possible to nearby healthy tissue. IMRT is a type of three-dimensional conformal radiation therapy (3D-CRT), which is a computer-based procedure that creates a 3D image of the tumor

Intraoperative Radiation Therapy (IORT)

When tumors cannot be removed completely from the pelvis or abdomen because they are attached to organs or nerves, IORT might be used. Also, if there are any cancer cells left over after surgery to remove a tumor, IORT might be used.

To prepare for IORT, a surgeon moves healthy body tissues and organs out of the way before surgery, so the tumor can be exposed to high doses of radiation. Next, a machine called a Mobetron is set up for the patient. It has a special cone that aims the radiation beam at a target, with as little radiation as possible for nearby healthy tissues and organs. Finally, a carefully measured dose of radiation is sent to the tumor. The amount of radiation is a small fraction compared to the total radiation given over a traditional multi-week course of EBRT.

IORT is used to treat:

• Locally advanced rectal cancers that cannot be removed because they are attached to healthy nerves, blood vessels or the pelvic side wall
• Abdominal and pelvic sarcomas that are attached to the back wall of the abdomen
• Locally advanced gynecologic tumors, such as uterine or cervical cancers
• Some pancreatic cancers
• Recurrent tumors (tumors that have come back)
• Some early-stage breast cancers
  

Neutron Therapy

Neutron therapy is a specialized and very powerful form of external beam radiation therapy (EBRT). It is often used to treat tumors that are difficult to destroy using regular X-ray radiation therapy. Neutron therapy targets cancer cells using neutrons (tiny particles that are smaller than an atom). It puts about 20 to 100 times as much energy into the cancerous tissue as radiation therapy does (like electrons, X-rays or protons).

Proton Therapy

Proton therapy targets tiny, charged particles called protons at cancer cells. It can send high doses of radiation that are carefully targeted, so as little radiation as possible goes to nearby healthy tissue. Doctors can pinpoint the treatment so most of the radiation goes exactly to the tumor site, no matter whether the tumor is near the surface of the skin or deep inside the body.

Stereotactic Body Radiation Therapy (SBRT)

Stereotactic body radiation therapy (SBRT) aims many beams of high-dose radiation from different angles at tumors. These tumors can be in areas such as the liver, lungs, adrenal glands and spine. To target the radiation beams exactly, special cushions that fit the shape of your body are used. These help you hold still and are used to position you before each treatment.

Stereotactic Radiosurgery

Stereotactic radiosurgery sends a high dose of radiation to an exact area from many angles, usually in one treatment session.
Gamma Knife is one type of radiosurgery. It is not an actual knife or scalpel — instead, it uses carefully focused beams of radiation. It is usually used on brain tumors or tumors inside the head. The patient wears a mask during treatment to keep their head still, which allows the radiation to be aimed as precisely as possible.

Total Body Irradiation (TBI)

Total body irradiation (TBI) is radiation therapy given to the whole body to get ready for a blood and marrow transplant (BMT).