A Brief History
The concept behind theranostics is older than the name suggests. In the 1940s, doctors began using radioactive iodine to treat thyroid cancer. Thyroid cells naturally absorb iodine, so radioactive iodine could both reveal thyroid tissue on a scan and destroy cancerous thyroid cells with a treatment dose. This was theranostics before the word existed.
For decades, radioactive iodine therapy remained one of the few examples of this approach. The broader expansion of theranostics began in the 2000s and 2010s with the development of new molecular targets and improved radioactive tracers. Today, theranostics is one of the fastest-growing areas in oncology.
The Core Principle
Theranostics rests on a simple idea: if you can see it, you can treat it. A diagnostic scan identifies whether cancer cells carry a specific molecular target. If they do, a treatment molecule that homes in on the same target delivers radiation directly to those cells. The diagnostic and therapeutic molecules are two versions of the same targeting system.
This approach inherently personalises treatment. Rather than assuming all cancers of a given type will respond to the same therapy, theranostics confirms the target is present before treatment begins. Patients whose cancers do not express the target are spared an ineffective treatment and can explore alternatives.
Current Applications
The two most established theranostic applications beyond thyroid cancer are:
Prostate cancer: PSMA PET CT identifies prostate cancer cells expressing the PSMA protein. Lu-177 PSMA therapy then delivers targeted radiation to those cells. This has become an important option for patients with advanced prostate cancer.
Neuroendocrine tumours: Ga-68 DOTANOC PET CT identifies NET cells expressing somatostatin receptors. Lu-177 DOTATATE therapy targets those same receptors for treatment.
Emerging theranostic targets include FAPI (fibroblast activation protein), which could apply to a range of solid tumours, and CAIX, which is being explored for kidney cancer. Clinical research is actively investigating additional targets that could bring theranostics to more cancer types.
Learn more about the theranostic treatments currently available.
Why It Is Changing Cancer Care
Theranostics is changing cancer care for several reasons. It introduces a layer of personalisation based on the molecular biology of each patient’s tumour. It provides a built-in selection mechanism that links diagnosis to treatment eligibility. It offers a different mechanism of action compared to chemotherapy and immunotherapy, expanding the toolkit available to oncologists. And post-treatment imaging can verify that the therapy reached its targets, providing feedback that other treatments cannot easily offer.
As research progresses and new targets are validated, the range of cancers treatable through theranostics is expected to grow. For patients with cancers that express the right molecular targets, this approach represents a meaningful addition to available treatment options.
Is Theranostics Right for You?
Whether theranostics is relevant to your case depends on your cancer type, its molecular profile, and your treatment history. Discuss with your oncologist whether a diagnostic scan to evaluate a theranostic target could be useful in your situation.