Radiation Therapy for Laryngeal and Hypopharyngeal Cancers

Radiation therapy uses high-energy x-rays, gamma rays, or particles to kill cancer cells. When treating laryngeal and hypopharyngeal cancers, Radiation therapy might be used in several ways:

• As the main (primary) treatment for some early stage laryngeal and hypopharyngeal cancers. If the cancer is small, it can often be destroyed by radiation and Surgery isn’t needed. This can help to preserve better voice quality.
• To treat patients who are too sick to have Surgery.
• After surgery, to try to kill any small areas of cancer that may remain and help lower the chance the cancer will come back. (This is called adjuvant treatment.)
• To treat cancer that comes back after treatment (cancer recurrence).
• To ease symptoms of advanced laryngeal and hypopharyngeal cancer such as pain, bleeding, trouble swallowing, and problems caused when cancer spreads to the bones. (This is called palliative or supportive care.)

Many times Chemotherapy is given along with the radiation. This combination, called chemoradiation, can work better than radiation alone, but it also has more side effects.

Radiation to this part of your body can affect your teeth and gums, so it’s important to see a dentist before starting treatment. A dentist can make sure your mouth is healthy before treatment. During and after treatment a dentist can help check for and treat any problems that may come up, such as infection or tooth/bone damage.

Smoking during radiation treatment is linked to worse outcomes, so you should stop smoking completely before starting treatment. Smoking also increases the risk of the cancer coming back after treatment as well as the risk of getting another cancer, so quitting smoking for good is the best way to improve your survival.

Types of radiation therapy

There are 2 main types of radiation therapy:

External beam radiation therapy

This is the most common type of Radiation therapy used to treat laryngeal and hypopharyngeal cancer. Radiation from a source outside the body is focused on the cancer.

Before your treatments start, the radiation team will use a CT scan to take careful measurements to determine the correct angles for aiming the radiation beams and the proper dose of radiation. A mesh head and body cast may be made to hold your head, neck, and shoulders in the exact same position for each treatment.

Radiation therapy is much like getting an x-ray, but the radiation is much stronger. The procedure itself is painless. Each treatment lasts only a few minutes, but the setup time – getting you into place for treatment – usually takes longer.

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 may be used to treat laryngeal cancer. For instance, in hyperfractionation radiation therapy, a slightly higher daily radiation dose is split into 2 smaller doses and the patient gets 2 doses per day instead of 1.

There are also newer techniques that help doctors focus the radiation more precisely:

• Three-dimensional conformal Radiation therapy (3D-CRT): 3D-CRT uses the results of imaging tests such as MRI and special computers to precisely map the location of the tumour. Several radiation beams are then shaped and aimed at the tumour from different directions. Each beam alone is fairly weak, which makes it less likely to damage normal tissues it passes through, but the beams meet at the tumour to give a higher dose of radiation there.
• Intensity modulated Radiation therapy (IMRT): IMRT is an advanced form of 3D therapy. It uses a computer-driven machine that actually moves around the patient as it delivers radiation. Along with shaping the beams and aiming them at the tumour from several angles, the intensity (strength) of the beams can be adjusted to limit the dose reaching the most sensitive nearby normal tissues. This may let the doctor deliver a higher dose to the tumour. This is the most common way radiation is given for laryngeal and hypopharyngeal cancer.

Brachytherapy

Internal radiation therapy, also known as brachytherapy, uses radioactive material put right into or near the cancer. Brachytherapy may be used alone or along with external beam Radiation therapy. It’s rarely used to treat laryngeal and hypopharyngeal cancer.

Side effects of radiation therapy

Many people treated with radiation to the neck and throat area have painful sores in the mouth and throat that can make it very hard to eat and drink. This can lead to weight loss and malnutrition. The sores heal with time after the radiation ends, but some people continue to have problems swallowing long after treatment ends. Ask about swallowing exercises you can do to help keep those muscles working and increase your chance of eating normally after treatment.

Other side effects of Radiation therapy may include:

• Skin problems in the area being treated, ranging from redness to blistering and peeling
• Dry mouth
• Worsening of hoarseness
• Trouble swallowing
• Loss of taste
• Possible breathing trouble from swelling
• Tiredness
• Hearing problems

Most of these side effects slowly go away when treatment is over. Side effects of radiation tend to be worse if Chemotherapy is given at the same time. Tell your doctor about any side effects you have because there are often ways to help.

Radiation aimed at the head and neck might damage the salivary glands, leading to Dry mouth that doesn’t get better with time. This can cause discomfort and problems swallowing, and can also lead to tooth decay. People treated with radiation to the neck and throat must pay close attention to their oral health.

Radiation may also damage your thyroid gland. Your doctor will do Blood Tests to see how well your thyroid is working. You may need treatment if it’s been damaged.

When radiation is used as the main treatment for cancer of the larynx, it could very rarely lead to breakdown of the cartilage in the throat. If this happens, you may need a tracheostomy or laryngectomy.