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How do cobalt-60 and cesium-137 help treat cancer?
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radioactivity
Figure 1: Radioactive decay of beryllium-7 to lithium-7 by electron capture (EC; see text).
Cobalt-60 and cesium-137 are radioactive isotopes used in radiotherapy to treat cancer by delivering ionizing radiation to malignant tumors.12
These isotopes function through the following mechanisms:
- Cellular Damage: The radiation emitted by these isotopes bombards targeted tissue, disrupting the atomic and molecular structure of cells. Specifically, this process introduces breaks in the double-stranded DNA within the cell nucleus.134
- Inhibition of Growth: By damaging the DNA, the radiation causes cancer cells to die and prevents them from replicating, which helps slow the progression of the disease or prompts the regression of malignant tumors.14
- Selective Administration: These isotopes can be administered selectively to malignant tumors, which helps minimize damage to adjacent healthy tissue.2
Cobalt-60 is commonly used in external beam teletherapy machines. While both isotopes are effective tools in medicine, it is important to note that ionizing radiation is inherently hazardous, and its use in therapy requires precise control to balance the destruction of diseased cells with the protection of the patient's overall health.516