TY - JOUR
T1 - Improving locoregional hyperthermia delivery using the 3-D controlled AMC-8 phased array hyperthermia system: A preclinical study
AU - Crezee, J.
AU - van Haaren, P. M. A.
AU - Westendorp, H.
AU - de Greef, M.
AU - Kok, H. P.
AU - Wiersma, J.
AU - van Stam, G.
AU - Sijbrands, J.
AU - Zum Vörde Sive Vörding, P.
AU - van Dijk, J. D. P.
AU - Hulshof, M. C. C. M.
AU - Bel, A.
PY - 2009
Y1 - 2009
N2 - Background: The aim of this study is preclinical evaluation of our newly developed regional hyperthermia system providing 3D SAR control: the AMC-8 phased array consisting of two rings, each with four 70 MHz waveguides. It was designed to achieve higher tumour temperatures and improve the clinical effectiveness of locoregional hyperthermia. Methods: The performance of the AMC-8 system was evaluated with simulations and measurements aiming at heating a centrally located target region in rectangular (30 x 30 x 110 cm) and elliptical (36 x 24 x 80 cm) homogeneous tissue equivalent phantoms. Three properties were evaluated and compared to its predecessor, the 2-D AMC-4 single ring four waveguide array: (1) spatial control and (2) size of the SAR focus, (3) the ratio between maximum SAR outside the target region and SAR in the focus. Distance and phase difference between the two rings were varied. Results: (1) Phase steering provides 3-D SAR control for the AMC-8 system. (2) The SAR focus is more elongated compared to the AMC-4 system, yielding a lower SAR level in the focus when using the same total power. This is counter-balanced by (3) a superficial SAR deposition which is half of that in the AMC-4 system, yielding a more favourable ratio between normal tissue and target SAR and allowing higher total power and up to 30% more SAR in the focus for 3 cm ring distance. Conclusion: The AMC-8 system is capable of 3-D SAR control and its SAR distribution is more favourable than for the 2-D AMC-4 system. This result promises improvement in clinical tumour temperatures
AB - Background: The aim of this study is preclinical evaluation of our newly developed regional hyperthermia system providing 3D SAR control: the AMC-8 phased array consisting of two rings, each with four 70 MHz waveguides. It was designed to achieve higher tumour temperatures and improve the clinical effectiveness of locoregional hyperthermia. Methods: The performance of the AMC-8 system was evaluated with simulations and measurements aiming at heating a centrally located target region in rectangular (30 x 30 x 110 cm) and elliptical (36 x 24 x 80 cm) homogeneous tissue equivalent phantoms. Three properties were evaluated and compared to its predecessor, the 2-D AMC-4 single ring four waveguide array: (1) spatial control and (2) size of the SAR focus, (3) the ratio between maximum SAR outside the target region and SAR in the focus. Distance and phase difference between the two rings were varied. Results: (1) Phase steering provides 3-D SAR control for the AMC-8 system. (2) The SAR focus is more elongated compared to the AMC-4 system, yielding a lower SAR level in the focus when using the same total power. This is counter-balanced by (3) a superficial SAR deposition which is half of that in the AMC-4 system, yielding a more favourable ratio between normal tissue and target SAR and allowing higher total power and up to 30% more SAR in the focus for 3 cm ring distance. Conclusion: The AMC-8 system is capable of 3-D SAR control and its SAR distribution is more favourable than for the 2-D AMC-4 system. This result promises improvement in clinical tumour temperatures
U2 - https://doi.org/10.3109/02656730903213374
DO - https://doi.org/10.3109/02656730903213374
M3 - Article
C2 - 19848620
SN - 0265-6736
VL - 25
SP - 581
EP - 592
JO - International journal of hyperthermia
JF - International journal of hyperthermia
IS - 7
ER -