Radioimmunotherapy

Radioimmunotherapy (RIT) is a form of targeted cancer therapy that combines radiation therapy with the specificity of immunotherapy. This therapy uses an antibody labeled with a radionuclide to deliver cytotoxic radiation directly to a targeted cell.

History

The concept of RIT was first proposed in the 1970s, but it was not until the 1990s that the first RIT drugs were approved by the FDA. These were Zevalin and Bexxar, both used for the treatment of non-Hodgkin's lymphoma.

Mechanism of Action

In RIT, a monoclonal antibody is combined with a radioactive isotope, creating a radioimmunoconjugate. This conjugate is then administered to the patient, where it binds to a specific antigen on the surface of cancer cells. The radiation emitted by the isotope damages the DNA of the cancer cells, causing them to die.

Applications

RIT has been used to treat a variety of cancers, including non-Hodgkin's lymphoma, colorectal cancer, and prostate cancer. It is also being investigated for use in other types of cancer, such as breast cancer and ovarian cancer.

Advantages and Disadvantages

One of the main advantages of RIT is its specificity. Because the radioimmunoconjugate specifically targets cancer cells, it can deliver a high dose of radiation to the cancer while sparing healthy tissue. However, RIT also has some disadvantages. These include the risk of radiation exposure to healthcare workers and the patient's family, and the potential for side effects such as bone marrow suppression.

Future Directions

Research is ongoing to improve the effectiveness of RIT and to expand its use to other types of cancer. This includes the development of new radioimmunoconjugates, as well as strategies to overcome resistance to RIT.

Radioimmunotherapy

• Radioimmunotherapy schematic
  Radioimmunotherapy schematic