April 8, 2010 - Lung tumors have been among the most challenging radiation therapy targets because the patient's breathing causes tumors to move.
While external skin surface markers or implanted markers are used to estimate lung tumor position during the breathing cycle, the physician can only apply the beam 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 beam delivery.
Elekta has introduced technology for stereotactic body radiation therapy (SBRT) for treating lung tumors. The solution is designed to enable doctors to use 4-D image guidance to confirm the tumor's location 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.
Elekta's XVI Symmetry provides tools to manage shifts in the relative positions of the tumor and organs-at-risk during the respiratory cycle. XVI Intuity is applied to ensure the position of the tumor is being tracked, and it accounts for the position of nearby healthy critical structures.
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.
The solutions account for baseline shifts and help physicians deliver treatment using reduced margins around the tumor.
XVI Intuity is designed to extend image guidance by enabling critical structure avoidance, which allows doctors to understand the positional relationship between the target and organs-at-risk. This provides for anatomical changes and corrections to set-up errors have not inadvertently put critical structures into the radiation beam's path.
For more information: www.elekta.com/lung-sbrt
September 30, 2025 
