Simulation guided design of the MRcollar: a MR compatible applicator for deep heating in the head and neck region
Language English Country Great Britain, England Media print
Document type Journal Article, Research Support, Non-U.S. Gov't
- Keywords
- Antenna, SAR, head and neck, magnetic resonance, phased array,
- MeSH
- Head diagnostic imaging MeSH
- Hyperthermia, Induced * MeSH
- Neck diagnostic imaging MeSH
- Humans MeSH
- Magnetic Resonance Spectroscopy MeSH
- Magnetic Resonance Imaging MeSH
- Heating * MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
PURPOSE: To develop a head and neck hyperthermia phased array system compatible with a 1.5 T magnetic resonance (MR) scanner for noninvasive thermometry. METHODS: We designed a dielectric-parabolic-reflector antenna (DiPRA) based on a printed reflector backed dipole antenna and studied its predicted and measured performance in a flat configuration (30 mm thick water bolus and muscle equivalent layer). Thereafter, we designed a phased array applicator model ('MRcollar') consisting of 12 DiPRA modules placed on a radius of 180 mm. Theoretical heating performance of the MRcollar model was benchmarked against the current clinical applicator (HYPERcollar3D) using specific (3D) head and neck models of 28 treated patients. Lastly, we assessed the influence of the DiPRA modules on MR scanning quality. RESULTS: The predicted and measured reflection coefficients (S11) of the DiPRA module are below -20 dB. The maximum specific absorption rate (SAR) in the area under the antenna was 47% higher than for the antenna without encasing. Compared to the HYPERcollar3D, the MRcollar design incorporates 31% less demineralized water (-2.5 L), improves the predicted TC25 (target volume enclosed by 25% iso-SAR contour) by 4.1% and TC50 by 8.5%, while the target-to-hotspot quotient (THQ) is minimally affected (-1.6%). MR experiments showed that the DiPRA modules do not affect MR transmit/receive performance. CONCLUSION: Our results suggest that head and neck hyperthermia delivery quality with the MRcollar can be maintained, while facilitating simultaneous noninvasive MR thermometry for treatment monitoring and control.
Department of Electrical Engineering Eindhoven University of Technology Eindhoven The Netherlands
Hyperthermia Unit Department of Radiotherapy Erasmus MC Cancer Institute Rotterdam The Netherlands
Imaging and Bioelectronic Technologies GE Global Research Centre Niskayuna NY USA
References provided by Crossref.org
