PURPOSE: To describe the design, analysis and evaluation of a new antenna array system for microwave hyperthermia. The proposed antenna array was evaluated by the focusing method based on the time-reversal principle. MATERIALS AND METHODS: Power absorption distributions in a cylindrical homogeneous and inhomogeneous phantom were calculated for the frequency range 500-900 MHz. Two set-ups with 12 and 16 antennas were analysed by comparing the changes in focusing areas enclosed by the 50%, 75% and 90% iso-SAR contours. For a more quantitative evaluation of the results the average power absorption ratio and remaining tissue maximum index were calculated. RESULTS: The sharpest focusing area in the centre of the phantom, 151 mm(2) (9 x 20 mm) (90% iso-SAR), was obtained by using 16 antennas at frequency 900 MHz. The largest focusing area of 280 mm(2) (13 x 24 mm) (90% iso-SAR) was obtained by using 16 antennas at 500 MHz. The SAR focus was steered in the desired radial direction obtaining a 43 mm(2) 90% iso-SAR focus-width in a semi-three-dimensional neck phantom. The results showed qualitative agreement between three dimensions (3D) and two dimensions (2D) for the performance indicators. CONCLUSIONS: The conducted study confirms the feasibility of the time-reversal-based focusing methods for microwave hyperthermia. The proposed system shows promise and is suitable for further development in the treatment of head and neck tumours, and extremities application.
PURPOSE: To describe the design, analysis and evaluation of a new antenna array system for microwave hyperthermia. The proposed antenna array was evaluated by the focusing method based on the time-reversal principle. MATERIALS AND METHODS: Power absorption distributions in a cylindrical homogeneous and inhomogeneous phantom were calculated for the frequency range 500-900 MHz. Two set-ups with 12 and 16 antennas were analysed by comparing the changes in focusing areas enclosed by the 50%, 75% and 90% iso-SAR contours. For a more quantitative evaluation of the results the average power absorption ratio and remaining tissue maximum index were calculated. RESULTS: The sharpest focusing area in the centre of the phantom, 151 mm(2) (9 x 20 mm) (90% iso-SAR), was obtained by using 16 antennas at frequency 900 MHz. The largest focusing area of 280 mm(2) (13 x 24 mm) (90% iso-SAR) was obtained by using 16 antennas at 500 MHz. The SAR focus was steered in the desired radial direction obtaining a 43 mm(2) 90% iso-SAR focus-width in a semi-three-dimensional neck phantom. The results showed qualitative agreement between three dimensions (3D) and two dimensions (2D) for the performance indicators. CONCLUSIONS: The conducted study confirms the feasibility of the time-reversal-based focusing methods for microwave hyperthermia. The proposed system shows promise and is suitable for further development in the treatment of head and neck tumours, and extremities application.
Authors: Sara Salahi; Paolo F Maccarini; Dario B Rodrigues; Wiguins Etienne; Chelsea D Landon; Brant A Inman; Mark W Dewhirst; Paul R Stauffer Journal: Int J Hyperthermia Date: 2012-06-12 Impact factor: 3.914
Authors: Margarethus M Paulides; Paul R Stauffer; Esra Neufeld; Paolo F Maccarini; Adamos Kyriakou; Richard A M Canters; Chris J Diederich; Jurriaan F Bakker; Gerard C Van Rhoon Journal: Int J Hyperthermia Date: 2013-05-14 Impact factor: 3.914