Radiation therapy is a cancer treatment that targets fast-dividing cancer cells to slow their growth or damage them beyond repair. More than half of all cancer patients will undergo radiotherapy, either as their primary treatment or in conjunction with other treatments, like chemotherapy or surgery.
How Radiation Therapy Works
There are two main types of radiation therapy: external beam and internal.
External Beam Radiation Therapy
This type of radiotherapy involves using a machine to send radiation directly to cancerous cells from multiple directions. This allows radiation oncologists to focus the treatment on the cancer itself and spare healthy tissue. Doctors use external beam radiation therapy to treat many types of cancer.
Internal Radiation Therapy
Internal radiation therapy involves placing a source of radiation — either solid or liquid — inside your body.
There are two types of internal radiotherapy:
- Brachytherapy, in which an oncologist uses a solid source like capsules or wires, often to treat cancers of the head and neck, prostate, cervix, and breast
- Systemic therapy, in which they use a liquid source administered through ingestion, IV, or injection, often to treat cancers of the thyroid, prostate, and bone