Promising Indiana University Lung Cancer Trial Enters New Phase

The procedure, extracranial stereotactic radioablation, uses three-dimensional imaging and high doses of radiation to more precisely target and kill cancer cells in the lung. It uses treatment concepts similar to those used in Gamma Knife radiosurgery, a non-invasive technique shown to be effective in treating brain tumors.

The procedure uses a 3-D computer generated grid system to more precisely map the location where therapy is directed. The patient is positioned in a specially fitted, lightweight body frame that limits mobility to ensure the precision of photon beams aimed at the tumor. "One advantage of the combined technology is that the risk of damaging healthy tissue despite such potent doses of radiation is reduced in comparison to conventional radiation."

"The results of the first phase were very encouraging and somewhat surprising," says Robert D. Timmerman, M.D., assistant professor of radiation oncology and the trial's principal investigator at the Indiana University Cancer Center. "We thought patients only would be able to tolerate lower doses since frail patients typically can't tolerate such rigorous treatment. To our surprise, we were able to increase dose levels without prohibitive toxicity."

This latest phase seeks to enroll 35 patients with early stage, non-small cell lung cancer whose tumors have not spread to lymph nodes or beyond and who have health conditions such as emphysema, severe heart disease, diabetes or a history of strokes, therefore making them poor candidates for surgery.

"Using a potent dose with assurance of reasonable safety to patients, we now want to measure the rate of controlling lung cancer and measure the patient's overall disease-free survival," Dr. Timmerman says.

Early stage lung cancer traditionally is treated with surgery, conventional radiation, or both. There is a 60 percent to 70 percent cure rate for early stage lung cancer in patients undergoing surgery, and a 20 percent to 30 percent cure rate for those treated with conventional radiation, which usually involves up to six weeks of daily radiation treatments.

In contrast, Phase 2 of this IU lung cancer trial delivers the entire treatment in three visits.

"We're optimistic this new therapy will bridge this large disparity giving patients a better chance of survival and a cure," notes Dr. Timmerman.