Control of phased-arrays for hyperthermia using tomographic temperature feedback

Phased-array hyperthermia applicators are attractive for their ability to selectively heat cancerous tissues while minimally damaging nearby healthy tissue. Determining driving phases and amplitudes of an array which actually achieve this, however, is not a trivial problem. This is primarily due to the patient-specific electrical inhomogeneity encountered in the path between each array element and the target volume. Radiofrequency hyperthermia monitored in real-time with magnetic resonance imaging (MRI) has been demonstrated, however no attempt has been made to use thermometric information to optimize the phases of the array elements. In this work, a method for controlling both the shape of the power deposition pattern and the temperatures at various points is proposed. Numerical simulations are used to illustrate the importance of proper model structure in the control scheme as well as demonstrate the scheme´s ability to control the temperature despite measurement noise.