Calypso Medical’s Real-Time Tracking Technology in Radiation Therapy Highlighted in 23 Clinical Presentations at the 50th Annual ASTRO Scientific Sessions

Seattle, Wash. and Boston, Mass. – September 20, 2008 – Calypso Medical Technologies, Inc. today announced that 23 abstracts highlighting the use of the Calypso® 4D Localization System™ will be presented this week at the 50th Annual Meeting of the American Society for Therapeutic Radiology and Oncology (ASTRO) at the Boston Convention and Exhibition Center. The studies report on a wide range of benefits of the Calypso System.

The Calypso System is the only real-time target tracking system used to manage tumor motion during treatment delivery. The ability to manage motion during radiation therapy is a critical advancement that assures the clinician and the patient that the radiation treatment prescribed is delivered to the cancerous tissue while avoiding adjacent healthy organs. Known as GPS for the Body®, the Calypso System utilizes implanted Beacon® electromagnetic transponders, smaller than a grain of rice, to enable continuous tracking of the prostate during radiation treatment.

The results of a study entitled “Geometric Accuracy and Latency of an Integrated 4D IMRT Delivery System Using Real-Time Internal Position Monitoring and Dynamic MLC (multileaf collimator) Tracking” will be presented by Dr. Amit Sawant of Stanford University. Dr. Sawant’s research focuses on using dynamic MLC technology to respond to respiratory motion during therapy. This research demonstrates that the Calypso System is capable of guiding the delivery of radiation to moving tumors with sub-millimeter accuracy by tracking a target in real-time.

A significant amount of research has been performed assessing the utility of the Calypso System in managing prostate motion. Among the highlights is a study (“Prostate Patient Setup Error and Organ Motion Error for Conventional and Hypo-Fractionated Radiation Therapy”) by Dr. Zhong Su, et al., demonstrating the high probability of inter-fraction set-up errors that could be eliminated with Calypso-guided online setup. Dr. J. R. Olson, et al., in “Individual Margin Determination for Prostate Cancer Patients Undergoing Real-Time Tracking” showed the importance of monitoring patient-specific rotation because it can lead to inadequate PTV coverage.

The importance of real-time tracking was also evaluated in new clinical areas. The results of a study conducted by Dr. M. L. Mayse, et al., entitled “Development of a Non-Migrating Electromagnetic Transponder System for Lung Tumor Tracking” showed the feasibility of using stabilized transponders in the lung. The potential of using transponders to monitor lung motion could prove to be an essential factor in lung cancer radiation therapy management. In “Feasibility of AC Electromagnetic Localization for External Beam Partial Breast Irradiation” by Dr. Stephen Eulau, et al., the Calypso System was used to localize and continuously track the lumpectomy cavity during partial breast radiation therapy. The authors concluded Calypso’s technology provides an efficient means to correct setup errors and manage intrafractional motion, even after couch kicks. In addition, they pointed out that continuous tracking could potentially enable the use of tighter treatment margins.

“It is very encouraging to see the large and growing body of scientific work demonstrating the many advantages of the Calypso System," said Eric R. Meier, CEO and President of Calypso Medical. “As the evidence shows, continuously tracking the position of the prostate or other vital organs during radiation treatment provides clear clinical benefits for physicians and their patients." 

2008 ASTRO Abstracts