Prostate-specific membrane antigen (PSMA) is a protein found in small amounts in your prostate gland. When you have prostate cancer, you have many times more PSMA than normal. This makes PSMA a good target for treating advanced prostate cancer. You might hear this new treatment called lutetium PSMA therapy, Lu-PSMA, or just PSMA therapy.
What It Is
PSMA therapy uses two drugs joined together. One is a molecule called PSMA-617. It finds and attaches to PSMA on cancer cells. The other is a radioactive medicine named lutetium 177 (Lu 177). It binds to PSMA-617, which carries it into the tumor.
This helps destroy cancer with less harm to healthy tissue. PSMA therapy won’t cure prostate cancer, but it may ease symptoms, slow its growth, and help you live longer.
Who Gets It
PSMA therapy is for men with metastasized prostate cancer who've tried hormone treatments and chemotherapy. When they don’t slow cancer spread, PSMA therapy may be an option.
Before Treatment
Your doctor will talk with you about possible side effects and answer any questions you have. You'll have tests to make sure PSMA therapy is right for you. These include blood tests and tests to check your kidneys and salivary glands. You’ll also have a PSMA PET scan that can spot cancer outside your prostate. This will help target your treatment.
How You Get It
PSMA therapy usually takes place in a hospital’s nuclear medicine department. A health care professional injects the medicine into a vein in your arm.
It takes about 30 minutes for the drug to infuse into your bloodstream.
You get anti-nausea meds and a diuretic to help flush the Lu 177 from your system. After that, you may need to wait in the hospital for a few hours or longer to make sure your radiation levels start to come down.
A day or two after your treatment, you'll have an imaging test called a single-photon emission computerized tomography (SPECT) scan. This checks to make sure your therapy hit the right targets.
Side Effects
PSMA therapy can cause:
- Dry mouth
- Dry eyes
- Nausea
- Vomiting
- Fatigue
Most of these symptoms go away in a few days. There’s a small chance dry eyes and mouth can be permanent. A few people have lower blood counts because Lu 177 can affect your bone marrow.
Lu 177 can also target healthy organs that have very small amounts of PSMA, like your salivary glands, small intestine, and kidneys.
Talk with your doctor to see if PSMA treatment is right for you.
