On June 9, 2015 Varian Medical Systems reported RapidArc Radiosurgery, a term for volumetric modulated arc radiosurgery delivered using a medical linear accelerator (linac) from Varian Medical Systems (NYSE: VAR), enables the precise and simultaneous treatment of multiple metastases in the brain, spine, head & neck, or lung, according to four notable clinical experts who spoke yesterday at a Varian-sponsored symposium at the 12th International Stereotactic Radiosurgery Society (ISRS) Congress taking place here this week (Press release, InfiMed, JUN 9, 2015, View Source [SID:1234505381]).

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Clark C. Chen, MD, PhD, co-director of neurological oncology and chief of stereotactic radiosurgery at the University of California, San Diego, offered a neurosurgeon’s perspective on the clinical use of surface imaging to guide RapidArc Radiosurgery for the treatment of brain metastases. He favors this more targeted approach over whole-brain radiotherapy for patients with a limited number of brain metastases to avoid the neurocognitive decline that is associated with the latter.

"The Varian TrueBeam is a powerful linear accelerator that allows precise and efficient delivery of high dose radiation to multiple brain metastases in a remarkably efficient manner," Chen said. His team also uses an optical surface image tracking device during treatment to help ensure accurate radiation delivery. "The combination of surface image tracking and RapidArc Radiosurgery allows us to treat patients with a level of efficiency that we could not achieve previously," he said.

Evan Thomas, MD, PhD, postdoctoral research fellow in the Department of Radiation Oncology at the University of Alabama at Birmingham (UAB), talked about the UAB approach to RapidArc Radiosurgery planning, which makes use of key features of Varian’s Edge and TrueBeam STx platforms for image-guided stereotactic radiosurgery (SRS), including Varian’s HD120 high-definition multileaf collimator for fine beam shaping and the High Intensity Mode for delivering high doses quickly.1 "Multiple refinements and iterations in the UAB technique have enabled us to reliably duplicate Gamma Knife plan quality on TrueBeam STx," Thomas said.2

At the Henry Ford Health System (HFHS) in Detroit, SRS treatments are delivered using Varian’s Edge radiosurgery system. Ian Lee, MD, neurosurgeon with the Hermelin Brain Tumor Center at HFHS, raised the question of how to determine whether surgery, radiosurgery, or both are indicated in cases of metastatic brain cancer. The HFHS uses a multidisciplinary tumor board to make those determinations as a team. He presented a broad range of metastatic brain cancer cases that were treated with stereotactic radiosurgery. "SRS is usually the treatment of choice for oligometastatic disease," he said, referring to patients with multiple brain metastases.

Farzan Siddiqui MD, PhD, director of head and neck radiation oncology at HFHS, described soon-to-be-published data on the precision and accuracy of the Edge system for radiosurgery, showing his institution’s findings of sub-millimeter accuracy for each of the system’s component parts.3 In addition to several metastatic brain tumor cases, Siddiqui presented about cases where the Edge system was used to deliver RapidArc stereotactic body radiotherapy (SBRT) –a medical term for radiosurgery of non-cranial targets—to simultaneously treat multiple metastatic lesions in the spine, lung or head & neck. "The Edge radiosurgery system has been shown to possess high accuracy localization and meets requirements for precisely treating patients with tumors in the various sites using SRS/SBRT-based techniques," he reported.