What is a GFR test?
The glomerular (say: glom-er-yoo-lar) filtration rate (GFR) test measures how well your kidneys are working to filter and clean your blood.
Your kidneys filter your blood to keep it clean. The glomerulus is the part of your kidney that does this work. The waste that your kidneys remove leaves your body when you pee.
Why do I need a GFR test?
Some medicines to treat cancer may change the way your kidneys work. If you are taking these medicines, you will have a GFR test before and during treatment. This will show how the medicines may be affecting your kidneys.
How is a GFR test done?
The GFR is a combination of a blood test and a scan. First, a safe radioactive dye is injected into your vein through an IV or through a port-a-cath or central venous line if you have one.
Then you will have blood tests three different times: two, three, and four hours after the injection. The blood tests will show how much radioactive dye is left in your blood. This shows your health-care team how well your kidneys are cleaning your blood. A machine will also take pictures of the dye when it is in your kidneys. Your doctor will talk to you and your family about the results.
