Daniel C. McCarthy
A new non-invasive technique combining interactive magnetic resonance imaging (MRI) and fiber optic laser delivery has shown promise in locating and ablating cancerous breast tumors. Researchers at the University of Arkansas for Medical Sciences developed the procedure, which could offer a percutaneous alternative to surgical lumpectomy and thus reduce the likelihood of scars or disfigurement in patients with confirmed cancer.
"Treating breast cancer has always been a struggle between obtaining local control of the tumor and providing the best possible cosmetic result," said Dr. Steven Harms, director of the research. "This will allow us to provide the ultimate in breast conservation with almost no sign of the treatment."
He added that the technique offers a favorable cost advantage over mastectomy procedures, a benefit that is not realized by current lumpectomy methods, which usually entail subsequent radiation treatment.
Harms' procedure uses interactive magnetic resonance to find the tumor and guide a needle into the cancerous tissue. The doctor feeds a fiber optic wire down the needle and uses an 805-nm laser from Diomed Ltd. of Cambridge, UK, to char the tumor at 25 W for three seconds. The laser energy is reduced to 3 W for more than eight minutes to ablate the tumor. Harms said it is possible to split the optical fiber into four fibers and thus bypass the charring step.
The enabling technology behind Harms' method is a computer software adaptation of standard magnetic resonance imaging technology called Rodeo MR (Rotating Delivery of Excitation Off-resonance). This interactive MRI technique, which is still in clinical trials, allows doctors to accentuate the contrast of breast tissue to distinguish exactly where the tumor ends.
Harms' study examined 15 patients who were scheduled to receive surgical cancer treatments following the laser lumpectomy. Tissue analysis from these subsequent surgeries confirmed that in each case the laser technique had successfully eliminated the targeted tumors.
Harms next plans to treat patients using only his laser technique, without surgical treatments. He estimates that this phase of research will take five years to determine whether the cancer recurs.