Last Modified: September 17, 2012
Dry mouth is most commonly caused by radiation therapy given to the head and neck region of the body. During radiation therapy, saliva production is actually increased due to irritation caused by the radiation or the chemotherapy (if administered). Patients receiving radiation to the head and neck may experience a change in the production and quality of saliva in the major and minor salivary glands. During treatment the saliva tends to be thicker, often described by patients as "ropey" and difficult to mobilize. After treatment, the excessive saliva dissipates and the mouth becomes dry. This can be a temporary side effect, resolving completely or partially over the year after treatment, or result in a permanent loss of saliva production.
Dry mouth may affect speech, taste sensation, ability to swallow, and the use of dentures. Patients may complain of a sore or burning sensation, cracked lips, and fissures in the corners of the lips. There is also an increased risk of cavities, periodontal disease and ultimately, tooth loss due to less saliva. Normal saliva contains enzymes that protect the teeth and gums from bacteria, keeping them healthy.
There are medications and techniques aimed at preventing or reducing xerostomia.
IMRT (intensity modulated radiation therapy)may reduce the extent and permanence of xerostomia. With IMRT, the salivary gland on the side opposite of the cancer receives a lower dose of radiation; therefore salivary function may recover after 6 to 12 months following the completion of treatment. This is dependent upon the dose as well as the percentage of the salivary gland that receives radiation therapy.
Amifostine, a radiation protector of normal tissues, has been shown to protect the salivary glands when given daily with radiation therapy, although logistics and side effects have limited its use in practice. Furthermore, it is not clear what benefit Amifostine adds when modern radiation techniques such as IMRT are utilized since treatment with Intensity Modulated Radiation Therapy (IMRT) or Proton therapy may allow the radiation oncologist to spare the salivary glands from getting significant radiation dose. This may prevent dry mouth in the future. There is also some concern that Amofostine may be a radioprotectant. Meaning it may protect the tissues in the treatment area from the radiation, meaning the cancer cells would not receive the treatment.
If you are getting radiation therapy to the head and neck region, you should discuss these options with your radiation oncologist.
If you have developed xerostomia, there are management strategies that can effectively deal with your dry mouth and prevent cavities and periodontal disease. Try to follow these simple guidelines: