• 4/28/2007
  • web-based article
  • staff
  • CancerConsultants.com

Researchers from France have reported that intensity-modulated radiotherapy (IMRT) was associated with improved quality-of-life (QOL) measurements compared to conventional radiotherapy (RT) for head and neck cancer. The details of this study appeared as an early online publication in the International Journal of Radiation Oncology* Biology* Physics on April 1, 2007.[1]

A recent study by researchers from MD Anderson has shown that head and neck RT causes oral mucositis in 100% of patients.[2] They reported that oral mucositis was more common in patients who received chemotherapy and those who received fractionated schedules. Oral mucositis was associated with severe pain in over half the patients and weight loss of over 5 pounds in 60%. They estimated that oral mucositis added $1700–$6000 to the medical costs, depending on severity.

There are few treatments for oral mucositis due to RT. Amifostine (ethyol) is approved by the FDA for prevention of xerostomia in patients receiving RT for head and neck cancer but has little, if any, impact on oral mucositis. Kepivance® (palifermin, keratinocyte growth factor) decreases mucositis associated with total body irradiation but has not been evaluated in head and neck cancer. However, an animal model has shown that Kepivance has a protective role in mice receiving chemoradiotherapy.[3]

Newer methods of radiotherapy delivery should decrease side effects. Intensity modulated radiation therapy (IMRT) is a relatively new way of delivering radiation that theoretically delivers more radiation to cancers while delivering less radiation to normal tissues than conventional three-dimensional conformal radiation (3D-CRT). IMRT developed through improvements and a decrease in the cost of server-type computers; the development of multi-leaf collimators with multiple tungsten shields, which allowed the delivery of radiation through multiple ports (often referred to as “beamlets”); and the development of software that combined computerized tomography (CT) or other imaging of the cancer with control of the radiation delivered. The equipment allows for intensity modulation of the radiation beam during treatment. This is accomplished by the computer telling the machine to shield or not shield various ports with the tungsten shields.

The current study compared the delivery of 45 Gy or more to patients with head and neck cancer. One group was treated with IMRT and the other with conventional RT. This was a matched-pair comparison involving 67 pairs of patients. Data was obtained by quality-of-life questionnaire. These authors reported that severe symptoms were more frequent following conventional RT than following IMRT. Patients in the conventional RT group were three times more likely to have dry mouth, sticky saliva, and pain than patients in the IMRT group. Patients in the conventional RT group also had more pain in the jaw, difficulty opening the mouth, and trouble swallowing and eating. These authors concluded that IMRT was associated with fewer side effects than conventional RT.

Comments: IMRT was adopted as standard of care before there was clear evidence that it would produce superior results. No randomized trials have been performed and physicians and patients have to rely on this type of study to document improvements over conventional RT. Even though IMRT may be better than conventional RT, more effective means of controlling oral mucositis need to be developed.

References:

[1]Graff P, Lapeyre M, Desandes E, et al. Impact of intensity-modulated radiotherapy on health-related quality of life for head and neck cancer patients: Matched-pair comparison with conventional radiotherapy. International Journal of Radiation Oncology* Biology* Physics 2007; published on-line on April 1, 2007.

[2] Elting LS, Cooksley CD, Chambers MS et al. Risk, outcomes and costs of radiation-induced oral mucositis among patients with head and neck cancer. International Journal of Radiation Oncology* Biology* Physics 2007; published on-line on March 28, 2007.

[3] Borges L, Rex KL, Chen JN, et al. A protective role for keratinocyte growth factor in a murine model of chemotherapy and radiotherapy-induced mucositis. International Journal of Radiation Oncology* Biology* Physics 2006;66:254-262.