Glossary M to R

Cancer that has spread from one part of the body to another, such as from the breast to the lymph nodes or bones.

MR or MRI scan
A magnetic resonance imaging scan is a procedure that uses a magnetic field to create detailed pictures of the body.

Multileaf collimator or MLC
A part of a linear accelerator that is used to shape the radiation beam.

Neutron beam therapy
A specialized type of external beam radiation therapy similar to proton therapy.

Palliative care/palliation
Treatment that is intended to relieve symptoms, but not cure disease.

PET scan
A positron emission tomography scan uses a small dose of a chemical called a radionuclide combined with a sugar, which is injected into the patient. The radionuclide emits positrons. The PET scanner detects the positron emissions given off by the radionuclide.

Proton beam therapy
An external beam therapy that uses protons rather than X-rays to treat tumors.

Radiation oncologist
A doctor who specializes in treating cancer and other diseases with radiation therapy.

Radiation oncology
The medical specialty that deals with treating cancer and other diseases with radiation.

Radiation therapy
The careful use of various forms of radiation to treat cancer and other diseases.

The use of radiolabeled antibodies to deliver radiation directly to a tumor.radiolabeling.

A type of drug that protects normal tissues in the area being treated.

A term used to describe a tumor that does not respond well to radiation therapy.

A type of drug that can make a tumor respond better to radiation therapy.