Introductory Vocabulary - Radiation Therapy Equipment and Terms

Vocabulary flashcards covering key terms from introductory notes on radiation therapy equipment and concepts.

Isocenter

Fixed reference point in space around which the gantry rotates.

Gantry

Mechanical C-shaped device that supports the collimator on one end and an image system on the other end.

Collimator

Arrangement of shielding material designed to define the dimensions of the radiation beam.

Treatment Couch

Table that supports the patient.

Record and Verify

Computer system that helps drive or run the treatment machine and serves as an electronic medical record.

Wedge

Beam modifying device used to tilt an isodose line.

Block

Used to shield an area in the treatment field.

MLC

Multi-leaf collimator.

Benign

Not malignant; self-limiting.

Malignant

Characterized by uncontrolled growth; invasive.

Tolerance dose

Amount of radiation that will cause damage to an organ or structure.

Treatment field

Area of treatment.

DRR

Digitally reconstructed radiograph.

Orthogonal

Two beams with angles 90 degrees apart.

BEV

Beams eye view.

Elapsed days

Number of days a patient has been undergoing treatment.

SSD

Source to skin distance; distance from the source of radiation to the patient's skin.

SAD

Source to axis distance; the distance from the source of radiation to the axis of rotation of the treatment unit.

Dmax

Depth of maximum absorbed dose and ionization for photons.

Neoadjuvant chemo

Before radiation, used to shrink tumors

Adjuvant chemo

After radiation, to kill remaining cancer cells

Two forms of chemo is called

Concurrent chemo-radiation, can make radiation work better

Radiation therapy

Common treatment for cancer that uses beams of high energy radiation most often x-rays to kill cancer cells or stop them from growing

Uses high doses of radiation to kill cancer cells and shrink tumors

When is radiation therapy used?

To cure cancer by destroying all cancer cells when the tumor is small and in one place

Two shrink tumors before surgery

To kill cancer cells left behind after surgery

To relieve symptoms, like pain in advanced cancers

Types of radiation

X-rays, gamma rays, charge particles like protons and electrons

X-rays?

Most common produced by linear accelerator and external treatments

Gamma rays?

Sourced from radioactive materials like cobalt-6o sometimes used in machines like the gamma knife for brain tumors

Charged particles like protons or electrons?

Used in specialized treatments, proton therapy electron therapy when precision is crucial for sparing, healthy tissue

Ways in which radiation is delivered (therapy types)

External beam, internal beam brachytherapy, systemic radiation therapy

External beam radiation therapy

Most common, the machine moves around the patient to target the tumor from different angles

internal radiation therapy, brachytherapy

Places, a small radioactive source inside or next to the tumor

Systemic radiation therapy

Radioactive medicine given by mouth or IV spreading through the body mostly used for specific cancers

Immunotherapy

Helps your immune system fight cancer

There are several types of immunotherapy, including monoclonal antibodies, nonspecific, immunotherapies, and cancer vaccines

What is radioimmunotherapy

Deliver radiation directly to cancer cells

How does immunotherapy work?

Immunotherapy makes it easier for amine cells to spot and destroy cancer by either removing the brakes to let him immune cells attack more strongly or by training them to better target cancer

Most immunotherapy treatments are systemic (work throughout the whole body), helping kill cancer cells that may have spread

What is targeted therapy?

Targets the changes in cancer cells that help them grow divide and spread

Targeted therapies act on specific molecular targets that are associated with cancer most standard chemotherapy act on all rapidly dividing normal cancerous cells

They were designed interact with their target

Targeted therapies are often?

Static which means they block tumor cell proliferation, whereas standard chemotherapy agents are cytotoxic meaning they kill two cells

What is hormone therapy?

Stops or slows the growth of cancer that uses hormones to grow

I it is often use as an juvenile therapy to help reduce the risk of cancer coming back after surgery

What is used in hormone therapy to block estrogen receptors in breast cancer cells?

tamoxifen

What box the hormones and prostate cancer?

Lupron

What is stem cell transplant?

Procedures that restore blood forming cells in people who have had their destroyed by high doses of cancer treatments, such as chemotherapy and radiation therapy

What are the ionizing radiation types

Photon radiation, particle radiation

What is photon radiation?

X-ray and gamma rays

The same type of radiation that is used in x-ray machines and comes from a radioactive source, such as cobalt CCM or a machine called a linear accelerator

Photo beams affect the cells along their path as they go through the body to get to the cancer pass through the cancer and then exit the body

What is the most common form of radiation used for cancer treatment?

Photon radiation

What is particle radiation?

Electrons, protons, neutrons, carbon ions, alpha particles, and beta particles

Electron beams are also produced by a linear accelerator, they are negatively charged parts of atoms. They have a low energy level and don’t penetrate deeply into the body so this is often used to treat skin cancer, as well as tumors and lymph nodes that are close to the surface of the body

Proton beams are positively charged and they release their energy only after traveling a certain distance and cause little damage to tissues they pass through this is effective at killing cells at the end of their path

What is superficial radiation therapy?

A low energy radiotherapy that penetrates only a short distance below the surface of the skin. It is highly effective painless and cosmetically, attractive alternative to surgery for selective cancers.

What is 3D conformal?

Delivers radiation beams from different directions designed to match the shape of the tumor

Static fields - gantry isn’t moving

Helps to reduce radiation damage to normal tissues and better kill the cancer by focusing the radiation dose on the tumor

IMRT

Intensity modulated radiation therapy

It is a conformal treatment

Similar to 3-D, but it also changes the strength of some beams in certain area

It can deliver high doses to a specific area areas while protecting normal tissues to reduce side effects

Gantry and MLC moving at the same time

SBRT

Stereotactic body radiotherapy

Delivers high doses in minimal fractions, usually less than five

Moving towards this

Need to be very precise

SRS

Not actually traditional surgery

Delivery of a large dose to a small tumor usually in one to two treatments (fractions)

For small brain tumors

Stereotatic radiosurgery

Biopsy can determine

The stage (spread)