Treatment with Lutetium-177 PSMA

Treatment goals

Prostate cancer cells have a specific structure on the cell's surface. This structure is known as 'prostate-specific membrane antigen' (PSMA). PSMA is present in various tissues, but the concentration of PSMA is especially high in prostate cancer cells.

This high concentration of PSMA makes it possible to treat prostate cancer with a radioactive substance, which will bind to this structure. This radioactive substance (Lutetium-177, a radioactive substance abbreviated as ^177Lu, linked to PSMA) can start to irradiate the prostate cancer cells locally. To do this, the radioactive substance must be injected into a blood vessel in the arm every six weeks.

Advantages of treatment

This treatment is prescribed for patients with metastatic prostate cancer that does not respond to classic hormone inhibitors and in whom the disease is in an evolving phase. Lu177-PSMA injections will stabilise or reduce disease activity in about two out of three patients. In the majority of patients, characteristic symptoms, such as bone pain, will also be dealt with, improving overall quality of life.

The treatment

Preliminary examinations

Blood test:

We look at the risks of anaemia, too few white blood cells or platelets, problems in liver or kidney function and PSA levels before and after treatment.

PET/CT scan with PSMA and FDG:

The PSMA PET/CT scan shows the metastases and shows how much PSMA is absorbed into the lesions. This will help to determine whether you are eligible for treatment. Depending on the results, a PET/CT scan with FDG should also be performed. This uses light radioactive sugar and tells us something about the aggressiveness of tumour cells. This scan is performed on a different day than the PSMA PET scan.

MAG3 scan:

To evaluate the flow of urine from the kidneys to the bladder. As the elimination of Lu177-PSMA occurs via the kidneys and urinary tract, damage may occur if there is a delayed flow. With this examination, this can be anticipated and preventive stent placement can be chosen if necessary.

Treatment procedure

You should only drink water four hours before the treatment until one hour after, but not eat anything.

An infusion with physiological water is inserted. About 30 minutes before the administration of ^177Lu-PSMA, you will receive medication through this drip to prevent nausea. Afterwards, the radioactive substance is also administered through this infusion.

For the sake of radiation protection, you are required to stay in hospital for 24 hours. You cannot have any visitors because of the radiation that is emitted. You will be measured the day after the treatment to determine how much radiation is emitted by your body. If this value is low enough, you may go home.

Three or four days after treatment, you should come to the hospital for a post-therapy scan at the nuclear medicine department. This imaging is needed to measure the radiation dose to your kidneys and to verify that all lesions are treated properly.

Complete therapy usually consists of four administrations of ¹⁷⁷Lu-PSMA with an interval of six - eight weeks between each administration.

Risks and possible side effects

The potential risks and side effects are minimised by careful preparation.

The treatment cannot be given in the case of:

Kidney or liver failure
Blood cells too low

Possible side effects:

Red and white blood cell counts may decrease, leading to anaemia. To check this, your blood count should be checked every three weeks after each administration.
Your kidney function may decline. Therefore, we check this with blood sampling beforehand and every three weeks. If you develop renal failure, you may need to stop treatment early or prescribe lower doses.
The radioactive substance is also absorbed into the salivary and tear glands, which can cause slight damage to them. This can cause dry mouth and dry eyes.
Shortly after administration, you may feel nauseous.
Radiation can cause fatigue.

Inform your physician if you have any of these side effects, or if you develop fever or bruising in the weeks following treatment.

Rules of life at home

You should take extra care for 2 weeks after each administration of ¹⁷⁷Lu-PSMA:

Drink plenty of liquid (water, fruit juice,...) before and after the injection.
Urinate as often as possible and urinate sitting down. Flush the toilet twice with the lid closed. Wash your hands carefully with soap and water every time you use the toilet. If other people use the same toilet, they should also wash their hands thoroughly with soap and water after each toilet visit.
If you use nappies or incontinence pads or stoma material, keep them separate in sealed bag for an extra week before putting them in the household waste.
Use disposable gloves to touch body fluids or dirty laundry. These disposable gloves are also best stored separately for an extra week before putting them in the household waste.
The underwear and bedding (and any clothing soiled by blood, vomit, urine or stool) you use during the first two weeks after each administration of ¹⁷⁷Lu-PSMA should be washed separately. Do not use a water-saving function and programme an extra rinse if possible.
Because a small amount of radiation is still emitted by your body when you return home, this results in a radiation exposure for your family members. Please be sure to keep a distance of at least one metre where possible for the first two weeks after the administration of ¹⁷⁷Lu-PSMA.
As children are more sensitive to radiation, avoid visits from children (<6 years) and pregnant women. For 21 days, all prolonged or close (<1m) contact with them should be avoided.
It is recommended that you and your partner sleep in separate beds (min. 2 metres away) or in separate rooms (the beds should not be against the same wall of adjacent rooms) for the first two weeks after ¹⁷⁷Lu-PSMA administration.
You should use a condom during sexual intercourse for the first two weeks after each injection of ¹⁷⁷Lu-PSMA. You should also not conceive children during treatment and for six months after the last administration of ¹⁷⁷Lu-PSMA. So you should use reliable contraceptives during this period.

Other practical aspects

Please inform Your care providers (physicians, nurses, physiotherapists, dentist...) of your treatment with ¹⁷⁷Lu-PSMA. To this end, you have a treatment card that you have to keep with you for 28 days after each treatment and that you should show when you receive care or if you are hospitalised.
Stick to the treatment calendar. If you are unable to attend, it is very important to notify the nuclear medicine department (min. 10 days before the scheduled date). If you are unable to attend due to illness, it is best to call our department as soon as possible so that we can cancel the creation of the Lu177-PSMA on time and avoid charges.
If you die prematurely (within 28 days of ¹⁷⁷Lu-PSMAadministration), burial is absolutely preferred for radiation protection reasons. If you do wish to be cremated, special measures should be taken to ensure the radiation protection of all involved. You will be given a treatment card after each treatment: you must keep it with your identity card for 28 days.

Centres and specialist areas

Nuclear Medicine

Isotope, radioisotope department

Latest publication date: 16/05/2024
Supervising author: Dr Van Den Bossche Bieke