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Updated: Apr 25, 2026
08:58
Cerebral Blood Oxygenation Measurement Based on Oxygen-dependent Quenching of Phosphorescence
Published on: May 4, 2011
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Cherenkov excited phosphorescence-based pO2 estimation during multi-beam radiation therapy: phantom and simulation
Robert W Holt1, Rongxiao Zhang1, Tatiana V Esipova2
1Department of Physics & Astronomy, Dartmouth College Hanover NH 03755.
Physics in Medicine and Biology
|August 23, 2014
Summary
This study introduces Cherenkov Excited Phosphorescence Oxygen imaging (CEPhOx) to measure oxygen levels in tumors during radiation therapy. The method successfully differentiated oxygenated and deoxygenated tissues in phantoms, paving the way for non-invasive tumor monitoring.
Area of Science:
- Medical Physics
- Biomedical Optics
- Radiation Oncology
Background:
- External Beam Radiotherapy (EBRT) utilizes megavoltage radiation beams.
- These beams induce Cherenkov light emission in biological tissues and phantoms.
- Oxygen levels (pO2) in tumors are critical for radiotherapy efficacy and patient outcomes.
Purpose of the Study:
- To develop and validate a novel method for non-invasive, real-time pO2 monitoring during EBRT.
- To utilize Cherenkov light emission to excite an oxygen-sensitive phosphorescent probe (PtG4).
- To tomographically reconstruct pO2 distributions in tissue-equivalent phantoms.
Main Methods:
- Excitation of the phosphorescent probe PtG4 using Cherenkov light generated by megavoltage radiation beams.
- Acquisition of phosphorescence emission using an intensifier-gated CCD camera synchronized with radiation pulses.
- Tomographic reconstruction of pO2 distribution using data from multiple beam angles and spatial information of target regions.
Main Results:
- Successful tomographic reconstruction of pO2 distribution in phantoms with varying oxygen levels.
- Accurate differentiation between oxygenated and deoxygenated inclusions within phantoms.
- Simulation indicates potential for measuring pO2 in human brain tumors within 15 mmHg at depths < 10-20 mm.
Conclusions:
- The Cherenkov Excited Phosphorescence Oxygen imaging (CEPhOx) method, using PtG4, enables non-invasive pO2 monitoring during EBRT.
- This technique can provide crucial information about tumor oxygenation during treatment.
- CEPhOx has the potential to optimize radiotherapy by allowing real-time adjustments based on tumor oxygen status.
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