A BIM-Based Algorithm for Real-Time Quantitative Monitoring of Temperature Distribution during Breast Hyperthermia Treatments
Microwave hyperthermia (MH) treatment for breast cancer is a research interest due to its capability to initiate cell necrosis in malignant tumor or to enhance the effect of other treatment modalities such as chemotherapy. The goal of MH treatment is to increase temperature of malignant tumor up to 45°C based on the treatment plan; however, microwave energy focusing is a challenging problem and may cause unwanted hotspots on healthy tissues. Therefore, there is a need to monitor the temperature to ensure that tumor and healthy tissues are at desired temperatures. In this paper, an iterative differential microwave imaging algorithm for temperature monitoring is presented. The algorithm is based on Born iterative method (BIM) and Tikhonov regularization. Feasibility of the algorithm is shown computationally using realistic digital breast phantoms via (i) TMz polarized 2-D scattered fields; and (ii) scattered fields calibrated from scattering parameters, which are obtained by a 3-D electromagnetic simulation program. An approach for selection of matching medium in hyperthermia monitoring applications is also presented. The reconstructions are performed with scattered field data collected at 11 discrete frequency points uniformly taken from the 0.5-1.5 GHz range. For a specific heating scenario, reconstruction error is lower than 0.3% with ±10% noise on reference dielectric property distribution and 35 dB signal to noise ratio (SNR). The results show that the proposed approach provides up to 3°C and 0.1°C resolution in temperature estimation with ±10\% noise on reference dielectric property distribution for 25 dB and 55 dB SNR values, respectively.
Email Address of Submitting Authoronalh@itu.edu.tr
Submitting Author's InstitutionIstanbul Technical University
Submitting Author's Country