Robotic radiosurgery expanded to breast cancer
The University of Texas Southwestern Medical Center has completed the first of 45 planned post-lumpectomy high-beam radiation treatments as part of a clinical trial to assess the effectiveness of the focused, shorter-course treatment.

The Dallas-based University of Texas (UT) Southwestern Medical Center trial will investigate Accuray’s CyberKnife System, already in use for head and neck radiation oncology procedures, for use in women with localized early-stage breast cancer following successful lumpectomies.

The system delivers multiple, millimeter-specific radiation beams via a robotic arm. The image-guided arm tracks the targeted sites by identifying gold seed markers, fiducials, implanted in the patient’s affected breast tissue prior to the therapy.

Led by Robert Timmerman, MD, professor of radiation oncology at UT Southwestern, the researchers will evaluate patients over the next 10 years for tumor recurrences as well as cosmetic changes, for which the system is purported to deliver improved results. According to UT Southwestern, CyberKnife delivers less radiation to surrounding tissue over a course of two weeks, as compared with six weeks under alternative procedures, such as brachytherapy.

The first treatment consisted of five 90-minute sessions, and was pain free, according to Kristin Wiginton, PhD, professor of health studies at Texas Women’s University in Dallas and the first breast cancer patient to be treated with the therapy.

"The impetus for this protocol is to avoid that invasiveness [of brachytherapy] while still achieving excellent cosmetic results," explained Timmerman. "This [treatment] gives the same amount of radiation, but in a noninvasive way. Each beam is very weak, so it causes very little entry damage,” while irradiating the tumors from over 200 positions, according to Timmerman.