Radiation therapy uses high-energy x-rays (generated by a linear accelerator) or gamma rays (produced by radioactive cobalt isotope) and particles (such as electrons) to kill cancer cells.

Types of radiation therapy

External beam radiation therapy: Radiation delivered from outside the body is focused on the cancer. This type of radiation therapy is most often used to treat laryngeal and hypopharyngeal cancer. External beam radiation therapy for laryngeal and hypopharyngeal cancer is usually given in daily fractions (doses), 5 days per week, for about 7 weeks. Other schedules for radiation doses have been studied in clinical trials.

Hyperfractionation refers to dividing the total radiation dose over a larger number of doses (2 treatments per day instead of 1, for example). Accelerated fractionation indicates that the radiation treatment is completed faster (6 weeks instead of 7 weeks, for instance).

Several studies have found that hyperfractionation and accelerated fractionation schedules reduce the risk of local recurrence of laryngeal and hypopharyngeal cancer. A recent study found that these types of radiation improve survival rates. But these schedules also increase the severity of temporary side effects.

Brachytherapy: Internal radiation therapy, also known as brachytherapy, uses radioactive material placed directly into or near the cancer. Brachytherapy may be used alone or in combination with external beam radiation therapy. It is rarely used to treat laryngeal and hypopharyngeal cancer.

The role of radiation therapy in treatment

Radiation may be used as the main (primary) treatment of laryngeal and hypopharyngeal cancer. If the cancer is small, it can often be destroyed by radiation without surgery. Radiation therapy can be an option to partial laryngectomy for treating small cancers. This treatment can help to preserve better voice quality. It is also used to treat patients whose general health is too poor to undergo surgery. Often, chemotherapy is given with the radiation. This can be more effective than radiation alone, but it also has more side effects. (See the "Chemotherapy" section for more details.)

After the cancer is removed with surgery, radiation therapy may be used to kill very small deposits of cancer that cannot be seen and removed during surgery. This is called adjuvant treatment.

Radiation therapy is also used to ease symptoms of laryngeal and hypopharyngeal cancer such as pain, bleeding, difficulty swallowing, and problems caused by bone metastases.

Side effects

Many people treated with radiation to the neck and throat area have problems with painful sores in the mouth and throat. These sores can make eating and drinking very difficult, and can lead to weight loss and malnutrition. The sores heal with time after the radiation has stopped.

Some less severe side effects of radiation therapy may include mild skin problems, dry mouth, sore throat, initial worsening of hoarseness, difficulty swallowing, decreased taste, possible breathing difficulty from swelling of the larynx, and tiredness. Most of these side effects go away after a short while. Side effects of radiation tend to be worse if chemotherapy is given at the same time. Talk with your doctor about these because there are ways to help.

Radiation can worsen any tooth problems that already exist. Depending on the expected radiation plan and the condition of your teeth, it may be necessary to remove some or all of your teeth.

Radiation aimed at areas near the salivary glands may permanent damage, leading to dry mouth that does not improve with time. In addition to discomfort, a dry mouth can promote tooth decay. People with dry mouth after radiation must pay close attention to their oral health.

Last Medical Review: 05/07/2009
Last Revised: 05/07/2009