PALO ALTO, Calif., July 17, 2003 Varian Medical Systems, Inc. (NYSE:VAR) has released a new version of its Eclipse™ 3D radiotherapy treatment planning software for image-guided radiotherapy using combinations of PET, CT, and MRI. The company has also received 510(k) clearance from the U.S. Food and Drug Administration (FDA) to market an Electron Monte Carlo (eMC) dose calculation option for electron radiotherapy. The Eclipse release and the eMC option will be exhibited at the American Association of Physicists in Medicine (AAPM) meeting in San Diego, CA, August 10-14, 2003. The New Eclipse Release The latest Eclipse release harnesses the power of multimodality imaging to improve radiotherapy treatment targeting. It can combine images from PET, CT, and MRI systems to create conformal treatment plans that target tumors while minimizing the exposure of surrounding tissues and organs. The Eclipse system is part of Varian Medical Systems’ broad initiative to develop and offer, to radiation oncology departments, tools for integrating powerful imaging capabilities into treatment planning and treatment delivery. "While CT images have long been used for treatment planning, radiation oncologists are now seeking to blend them with imaging modalities like PET and MRI," said Corey Zankowski, PhD, Varian's treatment planning product manager. "CT and MR scans provide good anatomical data, while PET highlights the most metabolically active parts of a tumor. Blending the different kinds of images helps doctors to see the extent of the tumor more clearly and thus develop more precise treatment plans." Varian's Eclipse software incorporates advanced treatment planning, graphics, simulation, and dose visualization tools. In this release, Varian has enhanced the user interface, and has automated such functions as image registrationsomething that was previously a manual process. Data from different imaging modalities are easily superimposed and can be displayed several ways. The graphical display has been enhanced to make it easier to see anatomical structures and the 3D dose distributions. Varian also added several data processing features, including the ability to export data and statistics to the Radiation Therapy Oncology Group (RTOG), a research organization sponsored by the National Cancer Institute (NCI), so that institutions using Eclipse software can participate in national studies of dosimetry and radiotherapy outcomes. The Electron Monte Carlo Dose Calculation Option The new eMC dose calculation option provides enhanced planning capability for electron radiotherapy, an approach that is often appropriate for superficial cancers. The eMC algorithm has been integrated to work seamlessly with the Eclipse™ treatment planning system, functioning alongside other calculation algorithms for different forms of radiotherapy. Radiation oncologists treat cancer primarily with either photon (X-ray) or electron radiation, depending on the location of the tumor and other medical considerations. Photon (X-ray) radiation is generated by accelerating electrons to a very high speed and colliding them with a tungsten target. Varian Medical Systems' Clinac® medical linear accelerators can deliver photon and/or electron radiation, the latter by causing the electrons to bypass the tungsten target for direct delivery to the patient. According to Jeff Amacker, manager of Varian's treatment planning business, there are clinical advantages to treating some superficial cancers with electrons instead of photons. "Electrons are ideal for treating superficial tumors because their dose deposition falls off rapidly. They don’t penetrate the body as deeply as photons do, so they enable radiation oncologists to protect the healthy tissues located behind the tumor." "Varian is committed to the continuous improvement of our treatment planning system," said Zankowski. "By adding the new Electron Monte Carlo dose calculation algorithm, we have taken another step toward more precise treatment planning for electron radiotherapy."