Radioimmunotherapy
Treatment with a radioactive substance that is linked to an antibody that will attach
to the tumor when injected into the body.
Until the mid-1990s, the only way to treat cancer that has spread (metastasized) to
multiple locations throughout the body has been with traditional chemotherapy, which uses
drugs that kill cells that divide and reproduce quickly (proliferate) in a non-specific
way. Recently, cancer vaccines have been used to successfully extinguish metastatic
melanoma; this treatment is a form of immunotherapy and specifically kills melanoma cells
and not other cells, even though they may be proliferating.
Radioimmunotherapy is another form of immunotherapy
Radioimmunotherapy is another form of immunotherapy, which is still experimental.
Researchers envision that radioimmunotherapy will be able to kill metastatic cancer cells
almost anywhere. Antibodies are immune system molecules that specifically recognize and
bind to only one molecular structure, and they can be designed to bind specifically to a
certain type of cancer cell. To carry out radioimmunotherapy, antibodies with the ability
to bind specifically to a patient's cancer cells will be attached to an isotope that emits
gamma rays and injected into the patient's bloodstream. These special antibody molecules
will travel around the body until they encounter a cancer cell, and then they will bind to
it. Then the gamma rays will kill the cancer cell. It will be difficult to calculate the
correct dose of antibody and isotope to kill an unknown number of cancer cells and at the
same time use isotope levels that don't destroy the antibody molecules before they
encounter cancer cells. |