Image-Guided Radiosurgery for Cancer and Neurologic Disorders Provides More Effective Treatment

Kresl, M.D., Ph.D., and colleagues at Banner Good Samaritan Medical Center (Phoenix, AZ, USA) have treated a wide variety of cancers and neurologic disorders with highly-accurate, noninvasive, image-guided radiosurgery using the Novalis Tx radiosurgery platform, developed by Varian Medical Systems, Inc. (Palo Alto, CA, USA) and BrainLAB (Munich, Germany), has now been used to treat numerous conditions quickly and accurately, including lung cancer, head and neck cancer, liver cancer, brain tumors, spine tumors, and trigeminal neuralgia, a debilitating nerve disorder that triggers intense facial pain.

Novalis Tx is optimized to deliver stereotactic radiosurgery for tumors of the brain or spine, and stereotactic body radiotherapy (SBRT) for tumors elsewhere in the body. Both types of treatment involve attacking a tumor or abnormality with high doses of radiation while minimizing exposure of surrounding normal cells and tissues. The Novalis Tx platform at Banner Good Samaritan is also outfitted with RapidArc radiotherapy technology, which additionally speeds up treatment in some cases to just a few minutes. In most cases treatment is given on an outpatient basis, requires no anesthesia or head-frame screwed to the patient's skull, and is completed in one week or less.

A 76-year-old woman with early stage lung cancer was among the first patients to benefit from SBRT on the Novalis Tx platform, delivered using RapidArc. "Her treatments took less than 30 minutes to deliver; comparable treatments using older radiosurgery technology had been taking anywhere from 45 to 60 minutes a day, sometimes more,” said Dr. Kresl, medical director for the department of radiation oncology. "In addition to being faster to deliver, and so more comfortable for this patient, the RapidArc treatment plan was superior in terms of both the amount of dose we could direct at the tumor, and the degree to which we could minimize exposure of the patient's healthy tissues--particularly the lung and spinal cord. This patient was adamantly opposed to conventional surgery and the associated risks. Fortunately, we had a noninvasive option for her that is superior to standard forms of radiation therapy.”

Another recent radiosurgery patient was treated for a tumor at the top of his nasal cavity, which was invading his skull, destroying bone, causing significant pain, and affecting his optic nerve, making his left eye useless. This patient was treated in five 20-30 minute sessions, delivered on an outpatient basis over five consecutive days, without the need for anesthesia. "Four weeks later, the tumor had shrunk considerably, the patient was off his pain medications, and had regained the use of his left eye,” Dr. Kresl said. "He was very excited, and we fully expect to see further regression of the tumor in future follow-up visits.”

The Novalis Tx radiosurgery platform can also be used to treat an array of neurologic disorders, including trigeminal neuralgia. "To treat trigeminal neuralgia with radiosurgery, you need enormous precision,” Dr. Kresl said. "We treat just a short segment of the nerve, right where it exits the brain stem. That requires hitting a target that's only two to four millimeters long and less than a millimeter in diameter.” Within one week of launching a radiosurgery program for treatment of trigeminal neuralgia, Dr. Kresl treated three patients. "The treatments are completed in a single 30-minute session,” he said. "At this point, two of the most recently treated patients report feeling much less facial pain within the first two weeks after treatment.”

The Novalis Tx platform incorporates a selection of imaging technologies that are used to guide treatments and ensure precise targeting. A three-dimensional (3D) computed tomography (CT) imager or in-room 2D stereoscopic X-ray imager can be used to position patients for treatment with submillimeter accuracy. Furthermore, the stereoscopic X-ray imager with Snap Verification generates images during a treatment to ensure accurate targeting throughout.

"This is an important feature of the platform--the ability to generate images during the treatment delivery or ‘beam on' process, in order to monitor and ensure the position of the radiation beam relative to the targeted area,” Dr. Kresl said. "This level of precision is what makes it possible for us to treat something as small as a trigeminal nerve. It also makes it possible for us to treat cancers anywhere in the body without using invasive head frames to immobilize patients.”

Varian Medical Systems is a world-leading manufacturer of medical devices and software for treating cancer and other medical conditions with radiotherapy, radiosurgery, proton therapy, and brachytherapy. The company supplies informatics software for managing comprehensive cancer clinics, radiotherapy centers, and medical oncology practices. Varian is a major supplier of tubes and digital detectors for X-ray imaging in medical, scientific, and industrial applications and also supplies X-ray imaging products for cargo screening and industrial inspection.

BrainLAB develops, manufactures, and markets software-driven medical technology that enables procedures that are more precise, less invasive, and also less expensive than traditional treatments. Among the core products are image-guided systems that provide highly accurate real-time information used for navigation during surgical procedures.

Related Links:
Varian Medical Systems
BrainLAB