MINNEAPOLIS, May 8, 2014 /PRNewswire/ -- Radiation oncologists and a neurosurgeon from noted institutions in the U.S. and Europe report that they are able to use non-invasive radiosurgery to treat a widening variety of cancers due to technology advances that are making it possible to deliver these treatments more quickly and with greater precision.
Clinical experts speaking at the "Sharpen Your Edge Against Cancer" educational symposium sponsored here yesterday by Varian Medical Systems (NYSE: VAR) detailed how Varian technologies like the Edge™ radiosurgery suite and RapidArc® radiosurgery are helping to make radiosurgery in the body—sometimes referred to as stereotactic ablative body radiotherapy (SABR) or stereotactic body radiotherapy (SBRT)—a feasible option for more cancer patients.
Early Adopters of the Edge Radiosurgery Suite
Among the presenters were clinicians from the first sites to deploy Varian's new Edge™ radiosurgery suite. Carlo Greco, MD, professor at the Champalimaud Center for the Unknown in Lisbon, Portugal, gave an overview of the first 100 patients treated on the Edge platform and discussed treatments for lung and prostate cancer. Greco outlined a high-precision approach to treating prostate cancer, using a treatment plan that reduces the margin of normal tissues irradiated to minimize the impact of treatment on the urethra, rectal wall, and bladder, as well as the nearby nerves and blood vessels.1
Salim Siddiqui, MD, PhD, director of the Stereotactic Radiation Program at the Henry Ford Health System in Detroit, Michigan, described cases that have been treated on the Edge radiosurgery suite since it was deployed in March, including pancreatic, liver, and lung cancer. According to Siddiqui, the Edge system's targeting and patient positioning capabilities, which include tools for adapting to tumor motion during treatment, make it possible to more confidently deliver precise treatments for patients with inoperable lung cancer.
Treating Brain Tumors with RapidArc® Radiosurgery
John Fiveash, MD, and Evan Thomas, PhD (pending) from the University of Alabama at Birmingham presented on RapidArc® radiosurgery in the treatment of brain cancer. Thomas demonstrated how RapidArc radiosurgery can enable clinicians to treat multiple brain metastases in a single treatment session.2
"These are accurate, high quality treatments that accommodate a neurosurgeon's busy schedule," said Fiveash. "RapidArc radiosurgery treatments are more comfortable for the patients because they're fast.3 Most are done in about half an hour; a similar Gamma Knife® treatment can take over two hours. At our institution, we've seen the number of Gamma Knife radiosurgery procedures decline steadily since 2007, while the number of RapidArc radiosurgery treatments has grown." Thomas noted that RapidArc radiosurgery treatment plans, when properly optimized, can be clinically equivalent to similar Gamma Knife plans in terms of tumor coverage and the amount of background dose falling outside the targeted area.4
Treating Lung Cancer
Billy W. Loo, Jr., MD, PhD, assistant professor of radiation oncology at Stanford University, focused on methods for using RapidArc radiosurgery, real-time image guidance, and respiratory gating to compensate for tumor motion during SABR treatments for lung cancer. Loo described his pioneering work with "triggered imaging," a capability of Varian's TrueBeam™ system that makes it possible to use imaging throughout a treatment session at specific points in the patient's respiratory cycle to verify that the treatment remains on target.5,6
Andrea McKee, MD, chairman of the Department of Radiation Oncology at Lahey Hospital & Medical Center in Massachusetts, outlined a lung cancer screening program that she helped to establish in early 2012.7 "Since then, over 2,000 people at high risk for developing lung cancer have received lung screening as a community benefit," she said. "It's important to catch lung cancer early, because early-stage patients who are medically inoperable have a better prognosis with radiosurgery than people whose cancer is first detected after it has spread."
Treating Prostate Cancer
Constantine Mantz, M.D., radiation oncologist with 21st Century Oncology in Fort Myers, Florida, discussed his use of the Calypso® real-time tumor tracking system during radiosurgery treatment for localized prostate cancer. He reported outcomes, in terms of reductions in patients' prostate-specific antigen (PSA) levels, comparable to men treated with brachytherapy.8
Daniel Hamstra, MD, PhD, associate professor of radiation oncology at the University of Michigan in Ann Arbor, reviewed data from several studies looking at quality of life after Calypso® guided radiation for prostate cancer using conventional or stereotactic body radiotherapy SBRT, as compared to conventional intensity-modulated radiation therapy (IMRT). He concludes that the published data suggest that the use of smaller margins with Calypso guidance for real-time tumor tracking can result in lower rates of bowel and sexual dysfunction side effects even when using SBRT.9
"A fast-growing body of published literature suggests that stereotactic radiosurgery is a feasible, noninvasive, well-tolerated therapeutic option for some patients with brain, spine, prostate, lung, liver, and other types of cancer," said Kolleen Kennedy, president of Varian's Oncology Systems business. "We were pleased to bring together some of the world's foremost clinical leaders to share their insights about implementing these sophisticated treatments."
Important Safety Information
Radiation treatments may cause side effects that can vary depending on the part of the body being treated. The most frequent ones are typically temporary and may include, but are not limited to, irritation to the respiratory, digestive, urinary or reproductive systems, fatigue, nausea, skin irritation, and hair loss. In some patients, they can be severe. Treatment sessions may vary in complexity and time. Radiation treatment is not appropriate for all cancers.
Varian as a medical device manufacturer cannot and does not recommend specific treatment approaches.
Except for historical information, this news release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Statements concerning industry outlook, including growth drivers; the company's future orders, revenues or other financial performance; the ability of the company's technology and products to treat cancer; and any statements using the terms "will," "can," "plan," "project," "estimated," or similar statements are forward-looking statements that involve risks and uncertainties that could cause the company's actual results to differ materially from those anticipated. Such risks and uncertainties include the effect of global economic conditions; demand for the company's products; the company's ability to develop, commercialize, and deploy new products; the company's ability to meet legal and regulatory requirements; changes in the legal or regulatory environment; and the other risks listed from time to time in the company's filings with the Securities and Exchange Commission, which by this reference are incorporated herein. The company assumes no obligation to update or revise the forward-looking statements in this release because of new information, future events, or otherwise.
About Varian Medical Systems
Varian Medical Systems, Inc., of Palo Alto, California, is the world's leading manufacturer of medical devices and software for treating cancer and other medical conditions with radiotherapy, radiosurgery, and brachytherapy. The company supplies informatics software for managing comprehensive cancer clinics, radiotherapy centers and medical oncology practices. Varian is a premier supplier of tubes, digital detectors, and image processing software and workstations for X-ray imaging in medical, scientific, and industrial applications and also supplies high-energy X-ray devices for cargo screening and non-destructive testing applications. Varian Medical Systems employs approximately 6,500 people who are located at manufacturing sites in North America, Europe, and China and approximately 70 sales and support offices around the world. For more information, visit http://www.varian.com or follow us on Twitter.
1Greco C. Extreme Hypofractionated Image-Guided Radiotherapy For Prostate Cancer. EMJ Oncol. 2013;1:48-55.
2Clark GM, et al. Plan quality and treatment planning for single isocenter cranial radiosurgery with volumetric modulated arc therapy. Practical Radiation Oncology, 2012 Oct; 2(4):306-313.
3Thomas EM et al. Effects of flattening filter-free and volumetric-modulated arc therapy delivery on treatment efficiency. Journal Of Applied Clinical Medical Physics, 2013 May 6;14(3):4126.
4Thomas ET, et al. Comparison of Plan Quality and Delivery Time Between Volumetric Arc Therapy(RapidArc) and Gamma Knife Radiosurgery for Multiple Cranial Metastases. Neurosurgery, 2014 in press.
5Li R et al. Clinical implementation of intrafraction cone beam computed tomography imaging during lung tumor stereotactic ablative radiation therapy. Int J Radiat Oncol Biol Phys. 2013 Dec 1;87(5):917-23.
6Li R et al. Intrafraction verification of gated RapidArc by using beam-level kilovoltage X-ray images. Int J Radiat Oncol Biol Phys. 2012 Aug 1;83(5):e709-15.
7McKee BJ, et al. Initial experience with a free, high-volume, low-dose CT lung cancer screening program. J Am Coll Radiol. 2013;10(8):586-592.
8Sandler HM et al. Reduction in Patient-reported Acute Morbidity in Prostate Cancer Patients Treated With 81-Gy Intensity-modulated Radiotherapy Using Reduced Planning Target Volume Margins and Electromagnetic Tracking: Assessing the Impact of Margin Reduction Study. Urology May 2010;75(5):1004-1008.
9Hamstra DA et al. Multi-institutional Prospective Evaluation of Bowel Quality of Life After Prostate External Beam Radiation Therapy Identifies Patient and Treatment Factors Associated With Patient-Reported Outcomes: The PROSTQA Experience. Int J Radiation Oncol Biol Phys, 2013 July 1;86(3):546-553.
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SOURCE Varian Medical Systems