The Consumer’s Guide to Radiopharmaceuticals for Metastatic Prostate Cancer

Both are effective but work in slightly different ways:

• The newer of the two, lutetium-177, can treat cancer that has metastasized anywhere in the body — bones, internal organs, and lymph nodes.
• Only cancer in the bones is targeted by radium-223. In addition to destroying cancer cells, the drug may also make bones less hospitable to the cells, says Dr. Tagawa.

They replace two older radiopharmaceuticals, strontium-89 and samarium-153, that were originally used to treat bone pain but are rarely prescribed anymore, says Thomas Hope, MD, vice chair of clinical operations and strategy in the department of radiology and director of molecular therapy at the University of California in San Francisco.

Research shows lutetium-177 can extend a person’s life expectancy with metastatic prostate cancer by an average of 38 percent. Similarly, a study that looked at the effectiveness of radium-223 found the medication extended life expectancy by an average of 30 percent.

In practical terms, for someone with metastatic prostate cancer whose life expectancy is one year, treatment with lutetium-177 could increase that time by about four and a half months, while treatment with radium-223 could increase it by about three and a half months.

Some people may live even longer, though, says Dr. Hope, especially if prostate cancer is at an early stage or growing slowly. He estimates that about 25 percent of people who receive lutetium-177 and 5 percent who receive radium-223 may live for years after treatment.

Radium-223 and lutetium-177 also tend to provide significant relief from bone pain, which can improve quality of life. This alone can make the treatment worth it, says Tagawa.

The first type is a bone scan, which can confirm whether the cancer has metastasized to the bones.

The second is a PSMA positron emission tomography (PET) scan or computed tomography (CT) scan, which can show if the cancer cells contain a protein called PSMA. More than 80 percent of people with metastatic prostate cancer have the protein, research shows.

Nausea and vomiting are common side effects of lutetium-177 and radium-223. But, Tagawa says, “I tell my patients that the side effects of the treatments are less [significant] than the side effects of uncontrolled cancer.”

Lutetium-177 can also cause fatigue, dry mouth, decreased appetite, constipation, and anemia. Radium-223 can cause diarrhea and edema (swelling) in the arms or legs.

For people who receive lutetium-177, the radiation could be harmful to others for certain periods of time. For this reason, after receiving treatment, it’s advised to:

• Stay at least three feet away from other people (including those living in your home) for two days.
• Stay at least three feet away from children and pregnant women for seven days.
• Sleep in a separate bedroom from household members for three days, children for seven days, and pregnant women for 15 days.
• Abstain from sex for seven days.
• Use contraception for 14 weeks after the final dose of lutetium-177

There are no restrictions on contact with others after receiving radium-223, but because the drug can affect sperm, it’s important to wear a condom during sex.