Abstract
Purpose: A system has been developed for patient positioning based on real-time localization of implanted electromagnetic transponders (beacons). This study demonstrated the accuracy of the system before clinical trials. Methods and Materials: We describe the overall system. The localization component consists of beacons and a source array. A rigid phantom was constructed to place the beacons at known offsets from a localization array. Tests were performed at distances of 80 and 270 mm from the array and at positions in the array plane of up to 8 cm offset. Tests were performed in air and saline to assess the effect of tissue conductivity and with multiple transponders to evaluate crosstalk. Tracking was tested using a dynamic phantom creating a circular path at varying speeds. Results: Submillimeter accuracy was maintained throughout all experiments. Precision was greater proximal to the source plane (σx = 0.006 mm, σy = 0.01 mm, σz = 0.006 mm), but continued to be submillimeter at the end of the designed tracking range at 270 mm from the array (σx = 0.27 mm, σy = 0.36 mm, σz = 0.48 mm). The introduction of saline and the use of multiple beacons did not affect accuracy. Submillimeter accuracy was maintained using the dynamic phantom at speeds of up to 3 cm/s. Conclusion: This system has demonstrated the accuracy needed for localization and monitoring of position during treatment.
Original language | English (US) |
---|---|
Pages (from-to) | 933-937 |
Number of pages | 5 |
Journal | International Journal of Radiation Oncology Biology Physics |
Volume | 61 |
Issue number | 3 |
DOIs | |
State | Published - Mar 1 2005 |
Externally published | Yes |
Keywords
- Electromagnetic localization
- Target localization
- Tracking
ASJC Scopus subject areas
- Radiation
- Oncology
- Radiology Nuclear Medicine and imaging
- Cancer Research