Electromagnetic thermal therapy power optimization for multiple source applicators.

Area of Science:

• Medical Physics
• Biomedical Engineering
• Electromagnetics

Background:

• Electromagnetic (EM) thermal therapy requires precise power deposition for effective treatment.
• Optimizing power delivery is crucial to maximize therapeutic effects while minimizing damage to healthy tissues.

Purpose of the Study:

• To investigate and compare various objective functions for optimizing power deposition in EM thermal therapy.
• To identify the most effective strategy for enhancing target power absorption and minimizing hot spots.

Main Methods:

• A generalized mathematical formulation was used to define and examine several objective functions.
• Retrospective testing was performed on a database of 38 cancer patients using clinical EM phased array data.
• Finite element numerical models were created using CT/MRI data to represent patient anatomy and tissue properties.
• Power optimization was achieved by adjusting seven control parameters (four amplitudes, three phases) of the EM phased arrays.

Main Results:

• Different objective functions yielded site-dependent improvements in target power absorption compared to standard configurations.
• The strategy of maximizing target power absorption weighted by the target-to-non-target power absorption ratio showed superior performance.
• This weighted approach effectively balanced increased target absorption with controlled non-target heating.

Conclusions:

• The choice of objective function significantly impacts power deposition optimization in EM thermal therapy.
• Maximizing target power absorption, weighted by the target-to-non-target ratio, is a promising strategy for improving treatment efficacy.
• This optimization approach can lead to more effective and safer EM thermal therapy by enhancing therapeutic outcomes and reducing side effects.