Radiopharmaceuticals

What are radiopharmaceuticals?

Radiopharmaceuticals are radioactive drugs that healthcare providers use in nuclear medicine imaging and procedures. They can help treat certain conditions as well, like tumors.

Nuclear pharmacists prepare and distribute these special drugs. Radiologists and radiologic technologists (RTs) use them in diagnostic imaging procedures. Radiation oncologists give radiopharmaceuticals as a treatment.

What are radiopharmaceuticals used for?

Healthcare providers mainly use radiopharmaceuticals for nuclear medicine imaging tests. These are called diagnostic radiopharmaceuticals. Providers perform millions of nuclear medicine procedures each year in the U.S.

Providers also sometimes use radiopharmaceuticals to help treat certain conditions. These are called therapeutic radiopharmaceuticals. This field of medicine is relatively new — researchers are actively studying new uses for therapeutic radiopharmaceuticals. They believe therapeutic radiopharmaceuticals will be a significant part of cancer treatment in the future.

Diagnostic radiopharmaceuticals

Radiopharmaceuticals are essential components of nuclear medicine imaging.

Diagnostic nuclear medicine imaging can show how your organs and tissues are functioning. To do this, you swallow, inhale or have an injection of a tiny amount of a radioactive drug. Providers may call these radiotracers. The radioactive drug doesn’t harm you. It simply builds up in specific parts of your body where there’s an issue. Then, a very sensitive camera (gamma camera) detects the radiation in your body and makes images for your provider to review.

Just a few examples of how providers use radiopharmaceuticals in imaging tests include:

• Fluorine-18 is often a radiotracer for PET scans (positron emission tomography scans).
• Technetium 99m is the most widely used radionuclide in nuclear medicine for the evaluation of bones, liver function and renal function.
• Xenon-133 is a radiopharmaceutical you inhale for pulmonary (lung) function testing.
• Rubidium-82 is a radiopharmaceutical you receive in an IV (through a vein in your arm) for myocardial (heart muscle) imaging.

Therapeutic radiopharmaceuticals

Therapeutic radiopharmaceuticals use very strong and damaging radiation to kill unhealthy cells. They seek out cancer cells — like bounty hunters — and deliver radiation therapy directly and specifically to them. This is different from external beam radiation therapy, in which a machine delivers beams of radiation outside of your body.

What radiopharmaceuticals are used in cancer treatment?

Examples of radiopharmaceuticals that providers use in cancer treatment include:

• PLUVICTO^® (lutetium Lu 177 vipivotide tetraxetan) is FDA-approved for the treatment of prostate-specific membrane antigen­-­positive metastatic castration-resistant prostate cancer (PSMA-positive mCRPC).
• Lutathera™ (Lutetium Lu 177 dotatate) is FDA-approved for the treatment of somatostatin receptor-positive gastroenteropancreatic neuroendocrine tumors.
• Iodine-131 is the main radiopharmaceutical providers use in radioactive iodine therapy. It can treat certain thyroid cancers and some cases of Graves’ disease (hyperthyroidism).
• Radium-223 is effective at treating bone tumors when prostate cancer spreads (metastasizes) to your bones. The U.S. Food and Drug Administration (FDA) has approved radium-223 dichloride (Xofigo™) for this use.

Several types of radiopharmaceutical therapies are currently undergoing clinical trial investigation for other types of cancer.

What are the most common radiopharmaceuticals?

Technetium-99m is one of the most common radiopharmaceuticals that healthcare providers use — mainly in diagnostic imaging. It can help with “seeing” the following body parts and processes:

• Blood flow in your lungs (pulmonary perfusion).
• Blood flow in your vascular system (vascular perfusion).
• Bones.
• Heart muscle (myocardial) tissue.
• Lacrimal (tear duct) glands.
• Thyroid.

Other common radiopharmaceuticals include:

• ¹⁸F Fluorodeoxyglucose (FDG).
• Gallium-68 DOTATATE​.
• Gallium-68 PSMA.
• ¹⁸F PSMA.
• Iodine 123.

Are radiopharmaceuticals safe?

When providers handle and use them properly, radiopharmaceuticals are safe. Know that your radiologist and/or radiation oncologist will work closely with a nuclear pharmacist to ensure that the amount of the radioactive drug you get is correct and safe.

Like all medications, therapeutic radiopharmaceuticals have certain side effects. But, in general, the benefit of the medication outweighs its potential risks. Your healthcare provider will go over the possible side effects with you before you start taking it.

A note from Cleveland Clinic

While healthcare providers have used radiopharmaceuticals for nuclear medicine imaging for decades, their use for treating cancer is newer. Researchers are actively studying how these radioactive drugs can target and kill cancer cells. If you’re interested in learning about radiopharmaceutical clinical trials for cancer treatment, talk with your provider. They’re available to help.