R through T


Radioactive isotope: an atom that emits radiation that can be seen by the radiological equipment.

Radiation therapy: (also called radiotherapy) the use of high-energy rays to kill cancer cells.

Radionuclide scanning: a procedure to find areas in the body where cells, such as tumor cells, are dividing rapidly. A small amount of radioactive material is injected into a vein or swallowed, and travels through the bloodstream. A scanner measures the radioactivity and produces pictures of internal parts of the body. The pictures can show abnormal changes in the area of the body containing the radioactive material. Examples of gamma scans include PET scans, gallium scans, and bone scans. Also called gamma scanning.

Rectum: the last several inches of the large intestine before the anus

Red blood cell (RBC): A cell that carries oxygen to all parts of the body. Also called red blood cell and erythrocyte.

Renal cell cancer: the most common type of kidney cancer. It begins in the lining of the renal tubules in the kidney. The renal tubules filter the blood and produce urine. Also called hypernephroma.

Renal cell carcinoma: cancer that forms in the lining of very small tubes in the kidney that filter the blood and remove waste products

Renal pelvis carcinoma: cancer that forms in the center of the kidney where urine collects

Reticulocyte: young, immature red blood cells that eventually turn into mature red blood cells.



Spirometer: an instrument that measures the amount and rate of air that is breathed in and out over a set amount of times. Used in a pulmonary function test.

Squamous cell: flat cell that looks like a fish scale under a microscope. These cells cover inside and outside surfaces of the body. They are found in the tissues that form the surface of the skin, the lining of the hollow organs of the body (such as the bladder, kidney, and uterus), and the passages of the respiratory and digestive tracts.



Thoracentesis: a procedure to remove fluid from the space between the lining of the outside of the lungs (pleura) and the wall of the chest.

Thorascope: a camera on the end of flexible tubing that allows your doctor to look into your chest.

Thrombin inhibitors: thrombin inhibitors are medicines that interfere with the clotting process. They are used to treat some types of clots and for patients who can’t take heparin.

Thrombocytopenia: a decrease in the number of platelets in the blood that may result in easy bruising and excessive bleeding from wounds or bleeding in mucous membranes and other tissues.

Thrombolytics: drugs that dissolve blood clots. Because thrombolytics can cause sudden bleeding, they are used only in life-threatening situations.

Thyroid: a gland located beneath the voice box (larynx) that makes thyroid hormone and calcitonin. The thyroid helps regulate growth and metabolism.

Thyroidectomy: surgery to remove part or the entire thyroid.

Tumor: a group of cells that stick together. Can be benign or malignant.