What is Lu PSMA (Lutetium-Prostate Specific Membrane Antigen) Therapy?

Lu177 PSMA Therapy is a treatment for patients with prostate cancer, especially those who have become refractory to conventional therapy. Lutetium PSMA therapy helps to slow down the growth of the cancer cells, reduce the size of the tumours and most importantly improve the quality of life of the patients by reducing the pain caused by the cancer.

Many prostate cancers, in particular those that have spread or become resistant to hormonal therapies, express a unique receptor on their cell surface called Prostate Specific Membrane Antigen (PSMA). When Prostate Cancer metastasizes i.e. spreads to other parts of the body, the PSMA receptor is expressed over the sites of metastases as well.

How does Lu PSMA Therapy Work?

Lutetium-177 is a radioactive substance that emits beta radiation, a destructive kind of radiation. Lutetium-177 is bound to a small peptide which attaches to the PSMA receptor expressed on the cancer cell surface. The Lutetium 177 – PSMA complex, thus attached to the prostate cancer cell, then emits killing radiation causing cell death of the cancer cell. Since the penetration of the emitted beta particle is very small, the surrounding normal cells are spared.

How is the Therapy Done?

Lu177 PSMA is administered intravenously. The patient is admitted to the hospital for 24 hours. A kidney function scan called a MAG3/EC scan is done prior to the administration of the Lu177 PSMA.

What are the Side Effects of Lu PSMA Therapy?

Lu177 PSMA is well tolerated. The most common side effects are a slightly dry mouth, fatigue and nausea. There may also be a slight fall in the white blood cells and platelets about 2 – 3 weeks after the Lu177 PSMA administration.

What is the Response Rate With Lu PSMA Therapy?

The response rates of Lu177 PSMA depend on the tumour biology of prostate cancer, the initial Gleason Score, the extent of disease and the responses to prior therapies. Typically, more than 70% of patients demonstrate a reduction in S. PSA and a shrinkage of tumours following Lu177 PSMA therapy.

What are the Treatment Schedules with Lu PSMA Therapy?

Most patients undergo three-four treatment cycles at intervals of 8-12 weeks. The number of cycles and the interim duration may vary between individuals depending on the response and interim assessments.

Why should I choose the nuclear medicine therapy center at Fortis Memorial & Research Institute (FMRI), Gurugram (Haryana, India)?

The Nuclear Medicine Therapy Centre at FMRI was one of the first institutes to offer Radio-ligand Therapy with Lu PSMA, and today, the center receives patients from the country and from across the world.

Find PRRT Therapy for Neuroendocrine Tumours in India

Q: When would the doctor consider using this Therapy?

Lu PSMA Therapy is a very specific therapy and is used for managing metastatic Prostate Cancer or when Prostate Cancer is no longer responsive to other types of treatment.

Summary (10 sec read)

Peptide Receptor Radionuclide Therapy (PRRT) is a molecular treatment for Neuroendocrine Tumors (NETs) like carcinoids and small cell lung carcinoma. It uses a cell-targeting peptide combined with a radionuclide, such as Yttrium-90 or Lutetium-177, which binds to tumor cells and delivers high-dose radiation. PRRT treats advanced, inoperable NETs and aims to relieve symptoms, slow tumor progression, and improve survival. Administered in multiple sessions, it involves amino acid infusions to protect kidneys. PRRT offers personalized, targeted treatment with fewer side effects than chemotherapy. Though not curative, it effectively controls disease progression and is generally well-tolerated.

WHAT IS PRRT AND HOW DOES IT WORK?

PRRT - Peptide Receptor Radionuclide Therapy, also known as Radioisotope Therapy, is a molecular therapy that is used to treat a specific type of cancer called Neuroendocrine Carcinoma or NETs (Neuroendocrine Tumours).

In PRRT, a cell-targeting protein (or peptide) is combined with a small amount of radioactive material, or radionuclide, creating a special type of radiopharmaceutical called a Radiopeptide. When this radiopeptide is injected into the patient’s bloodstream, it travels to and binds itself to the neuroendocrine tumour cells and delivers a high dose of radiation to cancer.

In PRRT, Yttrium 90 (Y-90) and Lutetium 177 (Lu-177) are the most commonly used radionuclides.

WHAT CONDITIONS ARE TREATED WITH PRRT?

PRRT or Peptide Receptor Radionuclide Therapy may be used to treat patients with Neuroendocrine Tumours (NETs) including:

Carcinoids
Islet Cell Carcinoma of the Pancreas
Small Cell Carcinoma of the Lung
Pheochromocytoma (a rare tumour that forms in the adrenal glands)
Gastro-enteropancreatic (stomach, intestines, and pancreas) Neuroendocrine Tumours, and
Rare Thyroid Cancers that are unresponsive to treatment with radioiodine.

WHEN WOULD THE DOCTOR CONSIDER USING THIS THERAPY?

Doctors might consider this therapy as an option for patients who

have advanced and/ or progressive Neuroendocrine Tumours.
are not candidates for surgery.
have symptoms that do not respond to other medical therapies.

WHAT IS THE MAIN GOAL OF PRRT?

The main goals of PRRT are:

To provide symptom relief,
To stop or slow down the tumour progression, and
To improve overall survival

WHAT ARE THE ADVERSE EFFECTS OF THE THERAPY?

While the administration of PRRT is well tolerated, some patients might experience nausea and vomiting during the amino acid infusion that is managed with anti-nausea medication.

HOW IS PRRT PERFORMED?

Depending on the type of cancer being treated and the medical facility performing the procedure, patients may need to undergo up to 10 PRRT sessions (usually there would be around four-six sessions) spaced two to three months apart.

The procedure may be done as an outpatient procedure or may require a few days of hospital stay depending upon the type of radionuclide being used.

Each PRRT session begins with an Amino Acid Solution delivered intravenously. This is done to protect the patient’s kidneys from the effects of radiation. The radiopeptide is then injected into the patient and that is followed by an additional Amino Acid Solution. The session lasts for approximately four hours.

In some cases, Molecular Imaging Scans may be taken during and following the treatment process to see where the injected radiopeptide has traveled in the body.

WHAT ARE THE ADVANTAGES OF PRRT?

PRRT and other such molecular therapies offer a more personalised cancer treatment as the radiopharmaceuticals can be tailored to the unique biological characteristics of the patient and the molecular properties of the tumour.
PRRT is also considered a targeted therapy as the radiopeptides are highly selective in their ability to damage the neuroendocrine tumour cells while limiting radiation exposure to the healthy tissues.
Also, since PRRT can target the neuroendocrine tumour cells while not affecting the healthy tissues, it has milder adverse effects as compared to chemotherapy.

While PRRT is a treatment option that is extremely effective in controlling Advanced Progressive Neuroendocrine Tumours, it is not a curative procedure. However, it has shown to help relieve symptoms and slow the progression of the disease.

HOW SAFE IS PRRT?

PRRT, like any other therapy, has some adverse effects and risks. It is advised that patients discuss the risks and benefits of PRRT with the Specialist Doctors at the centre. The doctors at the centre will determine whether the therapy is right for the patient given the patient’s medical history. It is also advised that the patients should inform the team of any prior therapies as it can play a role in determining the correct therapy and dosage.