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Trial Will Test Radioactive Implants, Restricted Surgery For Lung Cancer

Gwen Ericson

April 11, 2006 – A newly opened clinical trial will evaluate the use of radioactive implants combined with surgical removal of small sections of lung to treat stage I lung cancer. The first patients are now being enrolled at Washington University School of Medicine in St. Louis, and the trial will soon be opened at centers nationwide.

For lung cancer patients who can tolerate it, lobectomy or removal of an entire lobe of lung containing a cancerous tumor is the preferred treatment. But some patients – those with poor lung function, heart disease or other conditions that raise the potential for surgical complications – can be at a high risk from a lobectomy.

Stage I lung cancer patients whose doctors have declared they are not good candidates for a lobectomy may be candidates for the new clinical trial. Patients in the trial will receive a more limited surgery in which only a section or wedge of lung surrounding the tumor is removed to reduce the amount of postsurgical complications.

"In this trial, we'll remove half of a lobe or less," says Bryan Meyers, MD, associate professor of surgery who treats patients at Barnes-Jewish Hospital and the Siteman Cancer Center. "The less lung we take, the more lung function we leave behind, so patients will be better able to handle the surgery. Without this option, we would be able to treat the high-risk patients only with radiation and chemotherapy, and these treatments aren't as successful as actually removing the cancer."

Some investigations have suggested that limiting the amount of lung tissue removed to a small section can increase the possibility of cancer recurring near its original site. To overcome this potential drawback, a few recent studies have examined the use of either external beam or implanted radiation therapy to reduce local recurrence and have seen some success.

"There are encouraging studies that have analyzed retrospective data and shown an advantage to including radiation therapy after removal of part of a lobe, but it's difficult to avoid statistical bias with a retrospective approach," Meyers says. "Our study is designed to eliminate bias in the selection of patients to see if a randomized approach can confirm earlier results."

The trial will use radioactive implants, or brachytherapy, instead of external beam radiation to irradiate the area surrounding the tumor site in randomly selected patients to determine whether brachytherapy decreases the rate of cancer recurrence.

"The implants are tiny seeds of radioactive iodine embedded in surgical thread, which we place along the cut and stapled edges of the lung," Meyers says. "By placing this radioactive source at the site of the resection, we are able to effectively increase the radiation dose in the area where the tumor is most likely to recur."

Brachytherapy also has the advantage of avoiding the "innocent bystander" effect associated with external beam radiation, which can cause damage to surrounding tissue potentially leading to lung dysfunction. In addition, external beam radiation must be given in 20 to 30 small daily doses, and it can be difficult for patients to maintain this schedule. Brachytherapy placed in the lung at the time of surgery eliminates these problems.

Most patients in this clinical study will be enrolled by their physicians, but more information about the trial can be obtained by calling 314-362-8598.

Funding from the National Institutes of Health and the American College of Surgeons will support this research.