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A wireless implantable passive microdosimeter for radiation oncology
1School of Electrical and Computer Engineering, Purdue University, West Lafayette, IN 47907, USA. cson@purdue.edu
IEEE Transactions on Bio-Medical Engineering
|August 22, 2008
Summary
This study developed a novel implantable passive LC transponder for accurate in situ radiation dose measurement in oncology. The sensor detects ionizing radiation by measuring resonance frequency shifts, offering a cost-effective solution for radiation therapy quality control.
Area of Science:
- Medical Physics
- Biomedical Engineering
- Radiation Oncology
Background:
- Accurate in situ measurement of ionizing radiation is crucial for dose verification in radiation oncology.
- Active electronic sensors are vulnerable to damage from high radiation levels, necessitating passive alternatives.
- Passive sensors offer potential for reduced fabrication costs and improved durability in harsh radiation environments.
Purpose of the Study:
- To develop an implantable, micro-machined, passive LC transponder for real-time, in situ radiation dose measurement.
- To enable reliable dose verification and quality control during radiation therapy.
- To create a cost-effective and robust sensor solution for internal dosimetry.
Main Methods:
- Designed and fabricated a micro-machined passive LC tank circuit using a movable plate capacitor partially filled with a Teflon electret.
- Integrated the LC transponder into an implantable glass capsule (2.5 mm diameter, 2.8 cm length).
- Measured resonance frequency changes in response to ionizing radiation exposure from a Cobalt-60 (Co60) source.
Main Results:
- The passive LC transponder demonstrated a measurable resonance frequency shift upon exposure to ionizing radiation.
- A dose of 30 Gray (Gy) resulted in a 1.46 MHz frequency shift.
- The developed sensor exhibited a sensitivity of 49 kHz/Gy, indicating its potential for precise dose monitoring.
Conclusions:
- The developed implantable micro-machined passive LC transponder is a promising technology for in situ radiation dose measurement.
- This passive sensor design overcomes limitations of active electronics in high-radiation environments.
- The technology offers a viable approach for enhancing quality control and dose verification in radiation oncology.
