Radiation Robot Destroys Lung Tumors

from the University of Pittsburgh Medical Center (PA, USA) will present his findings in early August 2006 at the 48th annual meeting of the American Association of Physicists in Medicine in Orlando (FL, USA). Although it is too early to determine the technique's long-term effectiveness, Dr. Ozhasoglu and his colleagues see potential in this new approach to treating lung cancer and other tumors that move during breathing.

At the University of Pittsburgh, Dr. Ozhasoglu and about 30 colleagues from one of the largest U.S. teams devoted to the CyberKnife, a radiation delivery system that uses an accurate, precise robotic arm to target highly focused x-ray beams at the site of a tumor. Currently there are 76 active CyberKnife sites worldwide (with 45 in the United States), and an additional 62 planned to be installed globally.

Recently, the Pittsburgh researchers upgraded their CyberKnife by adding a system called "Synchrony,” which precisely targets tumors that move as a result of breathing. Synchrony instructs the robotic arm to move the radiation source (a linear accelerator that produces x-rays) in sync with the tumor motion.

Treating lung tumors with the enhanced Cyberknife requires only one to three sessions lasting 60-90 minutes. In conventional radiotherapy, patients must endure dozens of radiation treatments, each lasting about 15 minutes but requiring 20-30 hospital visits.

In a single treatment, Cyberknife blasts a lung tumor from all sides by delivering typically 100-150 intense, focused x-ray beams, causing the tumor to absorb approximately 10 times more radiation than in a conventional radiotherapy session. Cyberknife can deliver a lot more radiation than other techniques because its robotic arm aims the x-rays precisely enough to avoid surrounding healthy tissue.

To follow the moving tumor, the CyberKnife takes real-time x-ray images of the patient while using external markers attached to the patient's abdomen or chest to track tumors in real time with a few millimeters of accuracy. The researchers also applied Synchrony to treating tumors in the thorax and abdomen, which can move as much as 4 cm during respiration.



Related Links:
University of Pittsburgh Medical Center