Lutetium-177, Prostate Specific Membrane Antigen, PSMA, Cancer Treatment, What to Expect, Theranostics, Theranostics Singapore, Dr Andrew Tan

What Is Lutetium-177 Prostate-Specific Membrane Antigen (PSMA) Therapy? 

Prostate-Specific Membrane Antigen (PSMA) is a type of receptor found on cell membranes throughout the body and is particularly increased on the cell surfaces of prostate cancer. 

Lutetium-177 PSMA Therapy uses two components. One of them is a PSMA molecule that binds to the PSMA receptor in cancer cells. The other is a radioactive drug known as Lutetium-177 (Lu 177), which, when transported to the cancer cell by the PSMA molecule, is able to kill the cancer through radioactivity. 

The purpose of the treatment with Lu-177 is to destroy cancer cells, preserving healthy tissue – and – although it is not a cure – it can minimise the cancer’s symptoms, slow tumour growth, and prolong the patient’s quality of life.

What Is Prostate Cancer?

Prostate cancer is one of the most common cancers among men. Approximately 1 in 9 men will be diagnosed with prostate cancer in their lifetime, and it is the second leading cause of cancer-related death in men in the United States. While the majority of prostate cancers are early stage at diagnosis, a significant portion will have regional or distant metastases. 

As men get older, the prostate increases in size. This abnormal growth often does not produce any symptoms, so prevention is key. However, this abnormal growth of the prostate gland usually oppresses the bladder and urethra, which can thus manifest the first symptoms. 

In turn, a man may present difficulties with his erection. Sterility is also a possibility.

If you suspect that you are suffering from some of the symptoms of prostate cancer, make an appointment with your doctor.

What to Expect Before Treatment With Lutetium-177 Prostate-Specific Membrane Antigen (PSMA) Therapy? 

Our doctor will conduct a series of tests – from blood tests to more specialised studies to evaluate the state of the kidney and salivary glands – that will determine if you are the right candidate for treatment with Lutetium-177 PSMA.

This will typically include a PET scan (Positron Emission Tomography) using PSMA as the ligand. This will allow us to stage the disease. Our doctor will explain the possible side effects of the treatment and clarify any concerns you may have. 

What to Expect During Treatment With Lutetium-177 Prostate-Specific Membrane Antigen (PSMA) Therapy? 

This type of therapy is typically used for men with castrate-resistant metastatic prostate cancer who have undergone previous hormonal treatments and chemotherapy and are now progressing.

Typically, this type of treatment is done in a nuclear medicine department. Treatment with Lutetium-177 PSMA Therapy minimises the effects of prostate cancer and prevents its spread to neighbouring tissues and organs. 

How Long Does Lutetium-177 Prostate-Specific Membrane Antigen (PSMA) Therapy Take?

Once you are in the treatment area, our doctor will briefly explain the procedure: a peripheral catheter will be placed in your arm to start treatment.

Generally, each treatment will take approximately 30 minutes. It consists of 2 – 4 doses with 4 – 8 weeks apart between each dose.

What to Expect After Treatment With Lutetium-177 Prostate-Specific Membrane Antigen (PSMA) Therapy? 

Our doctor may recommend the additional use of an antiemetic (for nausea) and a diuretic to help clear the lutetium from your body. 

After the administration, you must wait a few hours in the hospital while the effects of the radiation diminish. Approximately 1- 2 days after treatment, our doctor will request an imaging study, specifically a Single-Photon Emission Computed Tomography (SPECT) scan.

How Long Do I Have to Wait to Be Discharged After Lutetium-177 Prostate-Specific Membrane Antigen (PSMA) Therapy? 

Once the first treatment session is over, the patient must stay in the nuclear medicine centre for roughly two hours. Patients must wait for the radioactivity to diminish in intensity before being allowed to go home.

How Am I Going to Feel After Treatment With Lutetium-177 Prostate-Specific Membrane Antigen (PSMA) Therapy? 

In general, the infusion of the Lutetium 177 PSMA is usually fast and painless, with no complications encountered. 

As expected, any treatment brings with it potential side effects, which may or may not occur. Some of the more common side effects include

  • Tiredness or fatigue
  • Xerostomia (dry mouth). In some cases, this may be fairly severe, usually in patients undergoing multiple rounds of treatment. 
  • Nausea, not always accompanied by vomiting.
  • Effects on the bone marrow, resulting in reduced blood counts (platelets, red blood cells). This is usually transient and mild, but blood transfusion may be needed in some patients. 
  • Dry eyes

There may be radiation exposure to other organs such as the kidneys and small intestine, but reported side effects are rare. 

However, you should feel free to speak to our doctor if you have any concerns about how you feel post-treatment. 

What Questions Should I Ask My Doctor?

If you are feeling overwhelmed by your diagnosis, here are some questions that you can ask your doctor. 

  • How do I know if I am qualified to receive PSMA treatment with Lutetium-177?
  • Is Positron Emission Tomography (PET Scan) necessary?
  • How long does Lutetium-177 Prostate-Specific Membrane Antigen (PSMA) Therapy last?
  • Should I stay long after the first therapy session is completed?
  • Will I have all the side effects, and for how long?
  • Will I have sexual dysfunction-related issues?
  • Will the therapy cure my cancer?

After treatment, it is normal for the body to experience different symptoms. The type and severity of symptoms vary between patients, and the more common side effects have been outlined. 

If you have any symptoms, consult your doctor immediately, especially if prolonged or increasing in severity. Our doctors are available to clarify any doubts or concerns you have and help you minimise the side effects.

Finally, it can be concluded that therapy with Lutetium 177 Prostate-Specific Membrane Antigen (PSMA) is often a satisfactory therapy option to reduce pain and other symptoms associated with mCRPC (castration-resistant metastatic cancer) – notably if other treatments have failed. Remember to consult with your doctor for any questions you may have.