Calypso® 4D Localization System™ � Technology Overview

Five elements of the Calypso® 4D Localization System™ work in tandem to provide guidance to the radiology oncology clinician on the position and movement of the prostate gland during external beam radiation therapy.

The illustration below and the definitions provided for each element of the Calypso System will explain how the technology works together to monitor tumor motion accurately, continuously, in real-time, throughout external beam patient treatment by alerting the clinician in the event the tumor moves outside the radiation beam pathway.

The Five Elements of the Calypso System

  1. Beacon® electromagnetic transponder
  2. 4D Console™
  3. 4D Electromagnetic Array™
  4. 4D Tracking Station™
  5. Optical System

1) Beacon® electromagnetic transponder
The heart of the technology is the proprietary Beacon® electromagnetic transponder which is intended for permanent implantation in the prostate prior to external beam therapy. The Beacon® transponders transmit safe radiofrequency waves to the Calypso System to provide guidance to the clinician on the position and movement of the prostate. Clinicians use the motion data to guide radiation therapy setup and monitor the prostate position during treatment delivery. The Beacon® transponders and the Calypso System provide:

  • Continuous, real-time monitoring of the prostate
  • Objective guidance for managing organ motion
  • Accurate localization for maximum confidence
  • Non-ionizing technology for quick patient setup and no additional radiation dose  

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2) 4D Console™
The 4D Console™ is a component of the Calypso System, used to position the patient for radiation therapy treatment. It houses the 4D Electromagnetic Array™, processor module, power source, and the control panel and is located in the treatment room. It transfers data to the 4D Tracking Station™.

 

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3) 4D Electromagnetic Array™
The 4D Electromagnetic Array™ contains an AC electromagnetic energy source that excites the Beacon® transponders and receivers that detect the Beacon® transponder coordinates. The 4D array's position, relative to the room coordinate system, is determined by embedded infrared sensors that communicate with the infrared Optical System.

 

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4) 4D Tracking Station™
The 4D Tracking Station™ is located in the central room. Therapists use this to continuously monitor real-time tumor position information and generate daily reports.

 

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5) Optical System
The Optical System consists of three infrared cameras mounted in the ceiling of the radiation therapy suite. The Optical System works in tandem with the 4D Electromagnetic Array™ that is positioned over the patient during external beam therapy. The optical system is calibrated to the isocenter of the linear accelerator.

 

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Accurate Localization for Maximum Confidence

The accuracy of the Calypso System in clinical use has been demonstrated through phantoms under realistic conditions of use in daily quality assurance checks to ensure correct system operation. Based on phantom measurements under typical conditions of actual use, the Calypso System exhibits sub-millimeter1 electromagnetic localization accuracy.

 

1 Balter J. M., et al, Accuracy of a wireless localization system for radiotherapy. IJROBP Vol 61. No 3 pp 933-937, 2005.

The Beacon® electromagnetic transponder is ~8.5mm in length and is totally inactive until energized by the Calypso System.