What is Radiotherapy?
Radiotherapy, also known as radiation therapy is the use of ionizing radiation, a high-energy form of radiation, to treat cancer, and less commonly certain blood disorders and non-malignant tumours.
Radiation therapy delivers huge waves of energy which disrupts the ability of cancer cells to divide and grow, consequently killing cancer cells, inhibiting their growth, and shrinking tumour size to make surgery easier.
How does Radiotherapy work?
Although the mechanism by which radiation treats cancer is quite complex and still been researched, it is clearly known that ionizing radiation breaks up the DNA of cancer cells, disrupting the ability of each cancer cell to divide and reproduce. The radiation could also kill the cancer cells.
What are the forms of Radiotherapy?
In describing how radiotherapy works, the forms of radiotherapy would be explained.
There are two forms of radiotherapy including external beam radiation therapy and internal radiation therapy. External beam radiotherapy is the more commonly used form.
In external beam radiation therapy, a machine called linear accelerator is used to emit radiation within a targeted energy range focused onto the area to be treated while internal radiotherapy involves using a radioactive material that has a short range to generate low energy radiation to kill off the cancer cells.
In internal radiation therapy, highly radioactive material may be placed in or close to the organ needing treatment and removed after satisfactory result. In other cases, less radioactive materials may be used and kept in place permanently in the tissue till they lose their radioactivity.
Examples of radioactive materials employed in internal radiation therapy are radioactive iodine, which is used in treatment of thyroid cancer, radioactive phosphorus, strontium, and radium. In internal radiotherapy, the radioactive material may also be in liquid form which is either drunk or injected into your body.
Internal radiation therapy presents a low threat to those around the patient because they are not directly exposed to the radioactive material. However, precautions are advised because of multiple exposures to the patients.
When is Radiotherapy done?
Radiotherapy is used either as a curative therapy or a palliative measure. As a palliative measure, radiotherapy shrinks the size of a tumour and relieves symptoms associated with the tumour.
Cancers that are suitable for radiotherapy are those that are confined and well-defined. However, total body irradiation may be necessary for certain types of cancers such as leukaemia.
Radiotherapy may be employed alone or used to shrink a tumour before surgery, or used in conjunction with chemotherapy. Some tumours such as sarcomas and breast cancers may be treated with a combination of radiotherapy, chemotherapy, and surgery.
What health risks does Radiotherapy pose?
The problem with radiation is its inability to distinguish cancer cells from healthy ones. However, cancer cells are more vulnerable to radiation because of how fast they divide and their poor self-repair ability.
The side effects of radiotherapy depends on the dose and duration of radiation used, and the part of the body exposed. Long term risks of radiotherapy include sterility, development of a second cancer, and recurrence of the same cancer under treatment.