Elekta has introduced an advanced solution for treating lung tumors that enables doctors to visually confirm the tumor's position during the breathing cycle. This new technology treats the lesion with a continuous radiation beam, increasing therapy accuracy while using less imaging radiation during treatment delivery.

Lung tumors have been among the most challenging radiation therapy targets because the patient's breathing causes tumors to move. New research has shown that the lung tumor shifts position from day to day during the course of treatment (baseline shift).1 Doctors often have had to use external skin surface markers or implanted markers to estimate lung tumor position during the breathing cycle and then apply the beam only during certain points in the patient's respiration. These strategies require complex, time-consuming planning and delivery, and prolong treatment with an inefficient stop-start (i.e., gated) beam delivery.

"Elekta's XVI Symmetry ™ and XVI Intuity™ completely change the approach when it comes to the treatment of lung tumors," says Dee Mathieson, Senior Vice President, Oncology Business Line Management. "Symmetry provides tools to manage shifts in the relative positions of the tumor and organs-at-risk during the respiratory cycle, and Intuity ensures that not only is the tumor's position accounted for, but also the position of nearby healthy critical structures. This contributes to a more patient-friendly and safe treatment."

Intuity and Symmetry were developed in collaboration with Elekta's clinical partner, The Netherlands Cancer Institute - Antoni van Leeuwenhoek Hospital (NKI-AvL), in Amsterdam. Both XVI tools are designed to significantly enhance the clinician's confidence in aggressively treating cancer, while limiting undue exposure to healthy tissues. The results can lead to better patient outcomes and quality of life.

XVI Symmetry and XVI Intuity are feature sets of version 4.5 of Elekta's X-ray Volume Imaging (XVI) package of software solutions for Image Guided Radiation Therapy (IGRT). XVI 4.5 recently received 510(k) clearance and CE marking, to enable sales and distribution in the United States and Europe.

XVI Symmetry-Managing Respiratory Motion
"Traditional external markers in lung cancer radiation therapy don't account for baseline shifts of the tumor throughout the course of the treatment sessions," says NKI-AvL's Jan-Jakob Sonke, Ph.D., who with his colleagues developed the technology behind Symmetry.1-4 "Symmetry captures image data during the breathing phase and performs sophisticated computations to provide 4D data. This data helps to visualize the tumor position in each phase of the respiratory cycle to arrive at an average position of the tumor for each treatment."

The benefits are accounting for baseline shifts and the ability of the physician to treat using reduced "margins" (i.e. better fit of dose) around the tumor-by virtue of enhanced knowledge of the tumor's position on a day to day basis.

XVI Intuity-Image Guidance for Both Tumors and Critical Structures

The key to safe, effective radiation therapy is often to maximize the dose to the tumor, and to minimize the dose to critical structures, or organs-at-risk. Imaging technology integrated in Elekta IGRT systems has revolutionized the physician's ability to achieve this goal.

XVI Intuity extends image guidance by better enabling critical structure avoidance, which allows doctors to understand the positional relationship between the target and organs-at-risk. This ensures that anatomical changes and corrections to set-up errors have not inadvertently put critical structures into the radiation beam's path.

For more information on Elekta's next generation SBRT visit: www.elekta.com/lung-sbrt

References
1. VARIABILITY OF FOUR-DIMENSIONAL COMPUTED TOMOGRAPHY PATIENT MODELS JAN-JAKOB SONKE, PH.D., JOOS LEBESQUE, PH.D., M.D., AND MARCEL VAN HERK,
PH.D. Int. J. Radiation Oncology Biol. Phys., Vol. 70, No. 2, pp. 590-598, 2008

2. RESPIRATORY CORRELATED CONE BEAM CT, SONKE JJ, ZIJP L, REMEIJER P, VAN HERK M, MED PHYS. 2005 APR;32(4):1176-86.

3. CORRELATION OF LUNG TUMOUR MOTION WITH EXTERNAL SURROGATE INDICATORS OF RESPIRATION. JEREMY D.P. HOISAK, KATHARINA E. SIXEL, ROMEO TIRONA, PATRICK C.F. CHEUNG, JEAN-PHILIPPE PIGNOL. Int. J. Radiation Oncology Biol. Phys., Vol. 60, No. 4, pp. 1298-1306, 2004

4. COMPARISON OF DIFFERENT STRATEGIES TO USE FOUR-DIMENSIONAL COMPUTED TOMOGRAPHY IN TREATMENT PLANNING FOR LUNG CANCER PATIENTS. JOCHEM W. H. WOLTHAUS, M.SC., JAN-JAKOB SONKE, PH.D., MARCEL VAN HERK, PH.D., JOSE´[<00B4>][<00B4>][<00B4>][<00B4>] S. A. BELDERBOS, M.D., PH.D., MADDALENA M. G. ROSSI, D.C.R. (R.), R.T.T., JOOS V. LEBESQUE, M.D., PH.D., AND EUGE`NE M. F. DAMEN, PH.D. Int. J. Radiation Oncology Biol. Phys., Vol. 70, No. 4, pp. 1229-1238, 2008

About Elekta
Elekta is a human care company pioneering significant innovations and clinical solutions for treating cancer and brain disorders. The company develops sophisticated, state-of-the-art tools and treatment planning systems for radiation therapy and radiosurgery, as well as workflow enhancing software systems across the spectrum of cancer care.

Stretching the boundaries of science and technology, providing intelligent and resource-efficient solutions that offer confidence to both healthcare providers and patients, Elekta aims to improve, prolong and even save patient lives, making the future possible today.

Today, Elekta solutions in oncology and neurosurgery are used in over 5,000 hospitals globally, and every day more than 100,000 patients receive diagnosis, treatment or follow-up with the help of a solution from the Elekta Group.

Elekta employs around 2,500 employees globally. The corporate headquarter is located in Stockholm, Sweden, and the company is listed on the Nordic Exchange under the ticker EKTAb. For more information about Elekta, please visit www.elekta.com .