3D versus 2D steering in patient anatomies: A comparison using hyperthermia treatment planning

Purpose: In this study hyperthermia treatment planning is used to investigate whether the target temperature during hyperthermia treatment can be increased using the 3D AMC-8 instead of the 2D AMC-4 system (AMC: Academic Medical Center).Methods and materials: The heating ability of the AMC-4 and AMC-8 system was analysed for five patients with cervix uteri carcinoma. Dielectric and thermal models were generated, based on a hyperthermia planning computerised tomography (CT), at a resolution of 2.5 × 2.5 × 5.0 mm3. Calculation of the electric fields with the finite-difference time-domain method was followed by SAR- and temperature-based optimisation. The ability to correct for axial shifts of the patient by phase/amplitude steering was investigated for both systems. Finally, it was investigated whether adjusting the ring-to-ring distance of the AMC-8 system can be used for further optimisation.Results: An average increase in T90 of ∼0.5°C (0.2°–0.8°C) was found for the AMC-8 system compared to the AMC-4 sys...