While IMRT significantly reduces the risk of dry mouth (xerostomia) in head and neck cancer patients undergoing radiation therapy, in many patients, for example patients with large (bulky) lymph nodes adjacent to the salivary glands, it is not always possible to avoid high doses to the salivary glands. In these patients, dry mouth is unfortunately still a common concern.
At UCSD, such patients are treated with a combination of IMRT and a drug known as amifostine (ethyol). Amifostine belongs to a group of drugs called cytoprotectants, which protect normal tissues from some of the side effects caused by some treatments for cancer, including radiation.
Amifostine provides these protective effects after being broken down (metabolized) in the body. Through various chemical reactions, the metabolites of amifostine deactivate molecules that result in tissue damage from radiation.
Healthy cells are preferentially protected since amifostine and its metabolites are taken up significantly better by healthy than tumor cells. This preferential uptake is why amifostine is unlikely to protect the tumor itself from radiation.
The absence of tumor protection was recently illustrated in a study by Dr. Mundt and his colleagues. In this study, known as a meta-analysis since it pooled data from multiple clinical trials, lung cancer patients receiving amifostine had similar tumor control rates that those treated without amifostine. However, all the trials noted a significant reduction in toxicity using amifostine.
Amifostine is typically administered intravenously (into a vein). Amifostine is given approximately 15-30 minutes priot to radiation. Because low blood pressure may result, patients receive the drug lying down, have their blood pressure frequently monitored and may receive intravenous fluids.
To learn more about Ethyol (Amifostine), patients can consult the MedImmune website and/or the Package Insert.
Amifostine Publications by UCSD Radiation Oncology Faculty
Mell LK, Malik R, Komaki R, Movsas B, Swann RS, Langer C, Antonadou D, Koukourakis M, Mundt AJ. Effect of amifostine on response rates in locally advanced non-small-cell lung cancer patients treated on randomized controlled trials: a meta-analysis. Int J Radiat Oncol Biol Phys 2007;68:111-8