The first part of the treatment, transarterial chemoembolization (TACE), is "a mixture of occlusion (closing off passages), reduction of the blood supply and chemotherapy to help decrease the size of the tumor," said study author Thomas J. Vogl, M.D., chairman of the Department of Diagnostic and Interventional Radiology at University Hospital Frankfurt, Germany.
Once the tumor is small enough, an interventional radiologist inserts laser fibers into the tumor and heats the tumor to 100 degrees in a procedure called laser-induced thermotherapy (LITT).
"This was initiated because we could not perform the laser therapy on tumors that were too large," Dr. Vogl said. "We see a lot of patients with liver tumors larger than 5 centimeters (about the size of a golf ball) and in the past we had to refuse them. We needed a way to reduce the tumor to a size where we could perform the laser treatment," he said.
Between March 1999 and December 2001, the researchers used TACE to treat 162 patients with liver tumors. Each patient underwent two to seven TACE treatments.
The largest tumor measured 80 millimeters (a little over 3 inches) in diameter before treatment. The size of each tumor was measured before and during treatment using magnetic resonance (MR) imaging. If the diameter of the tumor decreased to less than 50 millimeters (just under 2 inches), the patient was treated with MR imageguided LITT.
Eighty-two patients (51%) responded successfully to TACE, with a mean reduction in tumor size of 35 percent, and were treated with LITT. In 47 patients no reduction in tumor size was achieved, and in 33 patients disease progression was found, leading to further TACE treatments or change to systemic chemotherapy.