• 12/28/2007
  • San Francisco, CA
  • staff
  • medGadget.com

Radiation-induced oral mucositis is the most common complication observed in patients with head and neck cancer who underwent radiation therapy. Thanks to a newly developed supersensitive infrared camera from Argonne National Laboratory, early diagnosis and possible prevention and/or treatment of oral mucositis could be possible:

While buccal and other head-and-neck cancers are treatable and frequently curable, patients who undergo the necessary treatment regimen — a combination of radiation and chemotherapy — frequently develop unpleasant side effects. One of the most common and painful of these, oral mucositis, involves the inflammation and ulceration of the mucous membranes of the mouth and soft palate. These sores can make speaking, eating or even opening the mouth extraordinarily painful. If patients experience especially severe toxicity, they may temporarily lose the ability to taste or may even need to be fed through a tube…

As part of the ongoing National Cancer Initiative, researchers at the U.S. Department of Energy’s Argonne National Laboratory have teamed up with oncologists at the University of Chicago to use infrared imaging of the head and neck to predict which patients have the highest risk for severe mucositis. Patients who show local increases in temperature around the tumor site in the immediate wake of the initial round of treatment may be more likely to suffer later side effects, said Ezra Cohen, a University of Chicago oncologist who will head up the clinical side of the project.

Cohen, in collaboration with Valentyn Novosad, a principal investigator in Argonne’s Materials Science Division (MSD), has already run a pilot study of six patient volunteers, which they parlayed into a successful grant proposal to the National Institutes of Health that will enable them to undertake a two-year study of 34 patients with head and neck cancers.

Oncologists use radiation therapy as an aggressive, but crude, method for fighting cancer. Although the radiation beam is typically focused on the area that contains the tumor, it cannot tell the difference between healthy and malignant cells. As a result, normal tissues suffer collateral damage as tumors are zapped. “At this point,” Cohen said, “we have no treatment that allows us to kill tumor cells without also damaging normal tissue. We accept the toxicity because it’s a necessary part of the intended cure, and we know that it eventually gets better…”

In order to detect possible toxicity, Novosad and Argonne physicist Volodymyr Yefremenko developed a prototype infrared camera that detects temperature gradations as small as one-twentieth of a degree Celsius. Typically, the tumor appears warmer than the surrounding tissue, but for some patients the infrared image taken after the first round of chemo- or radiation therapy shows a larger region of elevated temperature around the tumor site, indicating the beginning stages of inflammation. These patients, Cohen said, are the ones most likely to encounter problems with mucositis down the road, even if they are not yet symptomatic. Argonne scientists are developing a standardized approach to quantify changes in thermal signature of individual patients during the course of therapy…

Without this technology, doctors would have no way of telling which patients had the greatest risk for developing mucositis, Cohen said. “Right now, I can only say to a patient that there is a small chance of severe toxicity, a good chance of moderate toxicity, and a small chance of very little toxicity. The problem has been that we’ve had no way to predict upfront who will suffer the most.”

If doctors can use this technology to detect that a patient is likely to suffer a great deal of toxicity, it may enable them to tailor their treatment regimens more closely to patients’ individual needs, according to Cohen. “If I knew that a patient would encounter severe toxicity, I might want to reduce the doses of chemotherapy a little bit. Or I might want to put in a feeding tube early on knowing that they’re going to have trouble eating and drinking down the road. Or I might want to have very early consultations with physical therapists knowing that these are patients who are going to have trouble.”