A Closer Look at Drugs

Bill Snyder
Published: February, 2006

Just as imaging technologies are guiding and, in some cases, replacing the scalpel, they are revolutionizing the evaluation of new cancer drugs.

Traditionally, a drug’s effectiveness has been determined by its impact on patient survival, or by measuring the diameter of a tumor on a series of X-rays or CT scans taken over the course of several weeks.

That’s too slow for oncologists like Craig Lockhart, M.D., assistant professor of Medicine in the Vanderbilt-Ingram Cancer Center. If there was a way of telling, within 48 hours, that a patient’s tumor was not shrinking or otherwise responding to the drug, “we’d be able to save that patient a lot of time and potential toxicity,” he says.

John Gore, Ph.D., director of the Vanderbilt University Institute of Imaging Science, is equally impatient. “We want to have more quantitative, more sensitive and more specific measures” of drug response, he says. “Imaging is the only way to do that.”

Gore envisions radiologists and imaging scientists from the institute sitting down with oncologists at the cancer center to plan “what imaging should be done for every clinical trial.”

That’s also the goal of the National Cancer Institute (NCI), which is funding the establishment of Image Response Assessment Teams, composed of radiologists and imaging scientists, who would contribute to the design of clinical studies at cancer centers across the country.

“We’re trying to get oncologists and imagers to work on the same team… to prove the value of therapeutic maneuvers,” explains C. Carl Jaffe, M.D., chief of the NCI’s Diagnostic Imaging Branch.

“We don’t mean to imply the imaging community doesn’t care about oncologic trials,” Jaffe adds. “They’re leading the development of new methods… (But) cancer trials are a special situation. You have to have greater uniformity, greater communication and greater discipline in order to produce quality data that can be trusted.”

Advances in imaging technology will continue to refine—and challenge—the testing of new drugs. “For now, we have pretty darn good technology, but it’s relatively undisciplined,” Jaffe says. “… It just needs to be stabilized. That’s where we’re headed.”

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