title: A clinical water-coated antenna applicator for MR-controlled deep-body hyperthermia: a comparison of calculated and measured 3-D temperature data sets.
abstract: A magnetic resonance (MR)-compatible three-dimensional (3-D) hyperthermia applicator was developed and evaluated in the magnetic resonance (MR) tomograph Siemens MAGNETOM Symphony 1.5 T. Radiating elements of this applicator are 12 so-called water coated antenna (WACOA) modules, which are designed as specially shaped and adjustable dipole structures in hermetically closed cassettes that are filled by deionized water. The WACOA modules are arranged in the applicator frame in two transversal antenna subarrays, six antennas per subarray. As a standard load for the applicator an inhomogeneous phantom was fabricated. Details of applicator's realization are presented and a 3-D comparison of calculated and measured temperature data sets is made. A fair agreement is achieved that demonstrates the numerically supported applicator's ability of phase-defined 3-D pattern steering. Further refinement of numerical models and measuring methods is necessary. The applicator's design and the E-field calculations were performed using the finite-difference time-domain (FDTD) method. The calculation and optimization of temperature patterns was obtained using the finite element method (FEM). For MR temperature measurements the proton resonance frequency (PRF) method was used.
authors.affiliation: Charité Universitätsmedizin Berlin, Campus Virchow Klinikum, Klinik für Strahlenheilkunde, Augustenburger Platz 1, 13353 Berlin, Germany. jacek.nadobny@charite.de
authors.forename: Jacek
authors.initials: J
authors.lastname: Nadobny
authors.forename: Waldemar
authors.initials: W
authors.lastname: Wlodarczyk
authors.forename: Lothar
authors.initials: L
authors.lastname: Westhoff
authors.forename: Johanna
authors.initials: J
authors.lastname: Gellermann
authors.forename: Roland
authors.initials: R
authors.lastname: Felix
authors.forename: Peter
authors.initials: P
authors.lastname: Wust
mesh_terms: D003198:Computer Simulation; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006801:Humans; D006979:Hyperthermia, Induced / Q000295:instrumentation* / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000295:instrumentation* / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000295:instrumentation* / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000295:instrumentation* / Q000379:methods; D008954:Models, Biological; D019047:Phantoms, Imaging; D000078702:Radiofrequency Therapy; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013813:Therapy, Computer-Assisted / Q000379:methods; D013817:Thermography / Q000295:instrumentation* / Q000379:methods; D014159:Transducers