Pitch, yaw and roll.

 

Generally, those terms are used to describe the movements measured in angles of an airplane or spacecraft in flight. Pitch is up and down like a box lid; yaw is left and right like a door on hinges; and roll is rotation.

 

Yet those terms are also common today at Vanderbilt University Medical Center, which completed installation in May of a Novalis Tx™ system, a powerful image-guided radiosurgery program with a patient couch that pitches, yaws and rolls. The system – a linear accelerator and then some – offers noninvasive treatment for a wide range of malignancies and other conditions, offering precision that helps spare healthy tissue from radiation exposure.

 

Until the Novalis Tx, manufactured by California-based Varian Medical Systems and BrainLAB, couch movements were limited – up and down, left and right, forward and back and a 360-degree spin. "The robotic couch associated with this new machine has six degrees of freedom. With the patient secured, of course, the table can actually move at an angle and also angle left and right, like it's pitching the patient off the table. Then you can get even more precise with your beam and get angles you could not get before," explained Arnold Malcolm, MD, interim chair of the Vanderbilt Department of Radiation Oncology.

 

Vanderbilt was scheduled to complete installation of the system by the end of May. "It takes an entire room because it has so many cameras associated with the machine operation for imaging the patients at the same time we're treating them. It's a fantastic unit," Malcolm said. Infrared readers in the ceiling and infrared sensors on the patient enable the system's "ExacTrac" ability for continual imaging during the treatment. The system detects patient movements – even those associated with breathing – and minutely modifies the patient's position accordingly. When it comes to imaging, the system is equipped with fluoroscopy and cone-beam computed tomography for 3D imaging of soft tissue.

 

Novalis Tx performs stereotactic body radiotherapy (SBRT), a form of non-invasive radiosurgery that uses precisely shaped and targeted radiation beams, which can actually be bent around irregularly shaped tumors. These tighter margins allow for a higher dose of radiation to be delivered to the site.

 

Precision also means speed, Malcolm noted. Treatments take two-to-20 minutes, as compared to some other existing technologies that take an hour or more. That means more patients treated per day.

 

Malcolm added that the software allows a physician to remotely plan and monitor a patient's treatment. "I can be in New York, but if I have access to a computer, I know what's going on," he said.