10th March 2025

The relationship between Nuclear Medicine, Theranostics, Radiopharmaceuticals (RPT), Radioligand Therapy (RLT) and Lutetium-177 PSMA Therapy explained

Mater Private Network is now offering an advanced cancer treatment called Lutetium-177 PSMA Therapy, a highly targeted approach for treating prostate cancer. This therapy is part of a broader medical field known as nuclear medicine. To help you understand how Lutetium-177 PSMA Therapy fits into this evolving field, this guide explains key concepts such as theranostics, radiopharmaceutical therapy, and radioligand therapy. By understanding these terms, you can see how this innovative treatment works and why it represents a major step forward in personalised cancer care.

An older man sitting at a desk speaking to a doctor

What is Nuclear Medicine?

Nuclear medicine is a specialised area of medicine that uses tiny amounts of radioactive materials known as radiopharmaceuticals to diagnose, treat, and monitor diseases. These radiopharmaceuticals, are designed to target specific organs, tissues, or disease activity in the body. Common diagnostic applications include PET scans and bone scans, which many patients may already be familiar with. In Ireland, nuclear medicine physicians are usually also radiologists and it is normal for the nuclear medicine department to be based in the radiology department.

What is Theranostics?

Theranostics is a combination of two words: therapeutics (treatment) and diagnostics (diagnosis). In nuclear medicine, theranostics means using the same or similar radiopharmaceuticals to both diagnose a condition and to treat it.

For example, in cancer, a radiopharmaceutical can first be used to locate and evaluate a tumour or tumours (diagnosis). Then, a similar radiopharmaceutical can be used to deliver radiation directly to the tumour(s), killing the cancer cells while avoiding damage to healthy tissues (therapy). Theranostics is a highly personalised approach to treatment, ensuring the therapy is specifically tailored to each patient’s cancer.

What is Radiopharmaceutical Therapy?

Radiopharmaceutical therapy (RPT) refers to the treatment aspect of nuclear medicine. Here, radiopharmaceuticals are used to deliver targeted radiation to destroy diseased or cancerous cells. These therapies are designed to specifically target cancer cells or other affected tissues, reducing side effects compared to traditional treatments like chemotherapy or external radiation therapy.

Nuclear medicine

Nuclear medicine imaging involves using minimal amounts of radioactive materials that may be injected into the bloodstream, inhaled or swallowed. At Mater Private Network, we offer a wide variety of different nuclear medicine scans.

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What is Radioligand Therapy?

Radioligand therapy (RLT) is a type of radiopharmaceutical therapy that uses a specific type of radiopharmaceutical called a radioligand. A ligand is a molecule that binds to a specific target in the body, such as a protein on cancer cells. In radioligand therapy, a radioactive element is attached to the ligand which brings the radiation directly to the target (e.g., cancer cells). This precision minimises damage to healthy tissue and enhances treatment effectiveness.

What is Lutetium-177 PSMA Therapy?

Lutetium-177 PSMA Therapy is a specific type of radioligand therapy used to treat prostate cancer. It uses a radioactive isotope called Lutetium-177, which emits radiation to destroy cancer cells. In this therapy, Lutetium-177 is paired with a ligand that specifically targets the Prostate-Specific Membrane Antigen (PSMA)—a protein found in high levels on prostate cancer cells. This targeted approach allows the radiation to focus directly on cancerous tissue while sparing healthy cells, leading to fewer side effects and improved outcomes.

How they all relate to each other?

Nuclear medicine is an area of medicine that uses radioactive substances in medical care. Theranostics combines the diagnostic and treatment capacity of nuclear medicine into a personalised approach. Radiopharmaceutical therapy (RPT) is one of the main therapeutic applications, and radioligand therapy (RLT) is a specialised type of RPT that uses ligands to target specific disease markers. 177Lutetium PSMA therapy is an example of RLT and is highly effective in treating cancers like prostate cancer.

Cancer Care

At Mater Private Dublin’s Cancer Centre, you will be cared for by a group of highly experienced consultants, each specialising in a particular area of cancer diagnosis and treatment.