Radium-228 in targeted Alpha Therapy for cancer treatment

Radium-228: A daughter of the Thorium Decay Chain

Radium-228 is a radioactive isotope that forms as part of the decay process of thorium-232. It decays through a series of intermediate isotopes, eventually leading to the stable element lead-208.

Radium-228 itself has a relatively short half-life of approximately 5.75 years and decays by emitting alpha particles, which are high-energy, helium nuclei. These alpha particles have a very short range in biological tissues—on the order of a few micro meters; making them highly effective at delivering localized, concentrated radiation to targeted cells through Targeted Alpha Therapy.

Targeted Alpha Therapy

Targeted alpha therapy is an innovative form of cancer treatment that utilizes alpha-emitting isotopes to selectively target and destroy cancer cells. Unlike traditional radiation therapy, which can damage both cancerous and healthy tissues, TAT aims to deliver a highly localized dose of radiation directly to cancer cells. This approach is particularly beneficial for treating solid tumours, hematologic malignancies, and micrometastases that may not be easily reached by conventional therapies.

entX-Diagram

Advantages of Radium-228 in cancer treatment

  • Localized Radiation Delivery: The short range of alpha particles emitted by 228Ra ensures that radiation is concentrated within the tumour.
  • High Potency Against Resistant Tumours: Alpha radiation is highly effective at destroying tumour cells.
  • Potential for Treating Micrometastases: Alpha-emitting isotopes like 228Ra can effectively target microscopic cancerous.
  • Short Half-Life: The relatively short half-life of 228Ra (5.75 years) may be advantageous in clinical settings.

Targeted Alpha Therapy in Cancer Treatment

Radium-228 is the parent isotope for Thorium-228 which in turn is the parent isotope for injectable Lead-212 used in anti-cancer drugs. As the call for Lead-212 oncology doses climbs, so does demand for Thorium-228, and in turn for Radium-228.

Fast growing novel market for cancer treatment.

The radiotherapeutics market is expected to grow significantly in the coming years and reach close to USD 20bn by 2030. Radionuclide therapy based on alpha emitters is a promising technology for cancer treatment. However, alpha emitters are in short supply and the current production processes are dependent on irradiation, which is expensive and complex.

Investigations are underway to potentially produce Radium-228 from Thorium which would be generated from phase 2 of the planned processing strategy at Steenkampskraal, where Thorium will be cracked from the Monazite concentrate.