Abstract:
:Clinical studies have established a strong benefit from adjuvant mild hyperthermia (HT) to radio- and chemotherapy for many tumor sites, including the head and neck (H&N). The recently developed HYPERcollar allows the application of local radiofrequency HT to tumors in the entire H&N. Treatment quality is optimized using electromagnetic and thermal simulators and, whenever placement risk is tolerable, assessed using invasively placed thermometers. To replace the current invasive procedure, we are investigating whether magnetic resonance (MR) thermometry can be exploited for continuous and 3D thermal dose assessment. In this work, we used our simulation tools to design an MR compatible laboratory prototype applicator. By simulations and measurements, we showed that the redesigned patch antennas are well matched to 50 Ω (S11<-10 dB). Simulations also show that, using 300 W input power, a maximum specific absorption rate (SAR) of 100 W kg(-1) and a temperature increase of 4.5 °C in 6 min is feasible at the center of a cylindrical fat/muscle phantom. Temperature measurements using the MR scanner confirmed the focused heating capabilities and MR compatibility of the setup. We conclude that the laboratory applicator provides the possibility for experimental assessment of the feasibility of hybrid MR-HT in the H&N region. This versatile design allows rigorous analysis of MR thermometry accuracy in increasingly complex phantoms that mimic patients' anatomies and thermodynamic characteristics.
journal_name
Phys Med Bioljournal_title
Physics in medicine and biologyauthors
Paulides MM,Bakker JF,Hofstetter LW,Numan WC,Pellicer R,Fiveland EW,Tarasek M,Houston GC,van Rhoon GC,Yeo DT,Kotek Gdoi
10.1088/0031-9155/59/9/2139subject
Has Abstractpub_date
2014-05-07 00:00:00pages
2139-54issue
9eissn
0031-9155issn
1361-6560journal_volume
59pub_type
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