Varian Medical Systems receives FDA clearance for new radiosurgery device

Sep 18 2007

Varian Medical Systems, Inc. has received FDA 510(k) clearance for a new high-definition multileaf collimator (MLC), an ultra-fine beam shaping device for radiosurgery.

The new HD120 MLC multileaf collimator enables clinicians to deliver extremely precise radiosurgical treatments, including intensity-modulated radiosurgery (IMRS), and will be included with the new Novalis Tx(R) radiosurgery system that Varian is teaming up with BrainLab to offer (see related press release entitled Varian Medical Systems and BrainLAB Join Forces to Introduce Novalis Tx(R)).

The Novalis Tx offers a non-invasive alternative to conventional surgery for a wide spectrum of conditions, including benign and malignant tumors, metastatic cancer, and neurological conditions like arteriovenous malformations, trigeminal neuralgia, and acoustic schwannoma.

"Successful irradiation of these types of abnormalities depends on doctors' ability to deliver a high dose of radiation with the precision of a surgical strike, sparing the surrounding tissues," said Calvin Huntzinger, MS, marketing and engineering manager for Varian's Surgical Sciences product line. "Varian's new HD120 MLC multileaf collimator doubles the resolution of our best MLC, so it is ideal for carrying out delicate intensity-modulated radiosurgeries near critical structures like the optic chiasm, brain stem, or spinal cord."

A multileaf collimator is a device with many computer-controlled mechanical "leaves" or "slats" that continually shape the treatment beam as the radiation is delivered from different angles around the patient. Prior to the new HD120 MLC multileaf collimator, Varian's finest MLC had a central group of beam-shaping leaves that were each 5 millimeters wide. The HD120 MLC has reduced the width of the central leaves to just 2.5 millimeters, increasing the beam-shaping precision by 100 percent.

The new collimator also offers improved dose delivery characteristics, including a steeper dose fall-off gradient, so that the amount of dose delivered decreases rapidly outside the targeted area, protecting healthy tissues more effectively than is possible with earlier beam shaping devices. The HD120 MLC was also designed for durability, so that it can be relied upon during continual use in a busy clinic.

"This new high-definition multileaf collimator builds on Varian's widely recognized accomplishments in advancing MLC technology, and underscores our commitment to meeting the unique needs of clinicians offering stereotactic radiosurgery and stereotactic body radiotherapy," Huntzinger said. Varian already offers the broadest range of beam-shaping products, including 52-, 80- and 120-leaf collimators for radiation oncology. Multileaf collimators are now included with nearly every order for Varian's linear accelerators.

"The multi-leaf collimator has revolutionized radiotherapy and it is now poised to do the same with radiosurgery," Huntzinger said. "We are committed to extending this life-saving technology to help more patients in a broader range of cases."