• 11/2/2006
  • Memphis, TN
  • staff
  • CancerConsultants.com

According to the results of two studies published in the International Journal of Radiation Oncology, Biology, Physics, treatment of head and neck cancer with intensity-modulated radiation therapy is less likely to result in dry mouth (xerostomia) than treatment with conventional radiation therapy.

Head and neck cancers originate in the throat, larynx (voice box), pharynx, salivary glands, or oral cavity (lip, mouth, tongue). Most head and neck cancers involve squamous cells, which are cells that line the mouth, throat, or other structures.

Standard treatment for head and neck cancer is largely determined by the stage (extent to which the cancer has spread) and by the specific locations within the head or neck area where the cancer has spread.

For head and neck cancer patients treated with radiation therapy, xerostomia is a potential side effect of treatment. Xerostomia refers to a condition of an abnormally dry mouth. Patients with severe xerostomia have very limited or virtually no saliva production. This results in difficulty eating, speaking, and swallowing. These symptoms make xerostomia extremely uncomfortable, and patients who suffer from the condition have a drastically reduced quality of life. Xerostomia can last long after treatment is completed.

Intensity modulated radiation therapy (IMRT) is a newer approach to radiation therapy that allows for the more precise delivery of radiation to cancer cells, while sparing healthy surrounding tissue.

Two studies recently evaluated parotid gland function among head and neck cancer patients treated with IMRT or conventional radiation therapy. The parotid glands are the largest of the salivary glands.

The first study was conducted in the Netherlands and enrolled 56 patients with oropharyngeal cancer.[1] Roughly half the patients were treated with IMRT and half were treated with conventional radiation therapy.

– Parotid gland flow decreased to a greater extent among patients treated with conventional radiation therapy than among patients treated with IMRT.

– Parotid flow complications at six weeks or six months after treatment were more common among patients treated with conventional radiation therapy than among patients treated with IMRT.

The second study was conducted in Hong Kong and enrolled 51 patients with early-stage nasopharyngeal cancer.[2]

– One year after treatment, saliva production was lower among patients treated with conventional radiation therapy than among patients treated with IMRT. Patients treated with IMRT reported better quality of life and fewer problems with dry mouth.

Together, these studies suggest that IMRT causes less damage to the parotid and other salivary glands than conventional radiation therapy in patients with head and neck cancer.

References:

[1] Braam PM, Terhaard CHJ, Roesink JM, et al. Intensity-modulated radiotherapy significantly reduces xerostomia compared with conventional radiotherapy. International Journal of Radiation Oncology*Biology*Physics. 2006;66:975-980.

[2] Pow EHN, Kwong DLW, Mc Millan AS, et al. Xerostomia and quality of life after intensity-modulated radiotherapy vs. conventional radiotherapy for early-stage nasopharyngeal carcinoma: initial report on a randomized controlled clinical trial. International Journal of Radiation Oncology*Biology*Physics. 2006;66:981-991.