Quality assurance in various radiative hyperthermia systems applying a phantom with LED matrix

Area of Science:

• Medical Physics
• Biomedical Engineering
• Oncology

Background:

• Deep-body hyperthermia is an emerging cancer treatment modality.
• Accurate dosimetry, specifically measuring specific absorption rate (SAR), is crucial for effective hyperthermia treatment.
• Existing methods for visualizing SAR distribution can be limited in scope and application.

Purpose of the Study:

• To evaluate the performance of four clinical radiative deep-body hyperthermia systems using the Amsterdam phantom with an LED matrix.
• To demonstrate the utility of this phantom for visualizing and analyzing SAR distribution.
• To investigate the influence of key parameters on SAR patterns.

Main Methods:

• Utilized the Amsterdam phantom with an LED matrix to test four radiative deep-body hyperthermia systems: BSD-1000, BSD-2000, Coaxial TEM applicator, and Four-waveguide-array.
• Captured photographs of the LED matrix to visualize RF power deposition (SAR) in the aperture midplane.
• Analyzed the impact of applicator phase/amplitude relations and frequency on SAR patterns.

Main Results:

• The LED phantom successfully visualized SAR distribution for all tested hyperthermia systems.
• Adjusting applicator phase relations enabled the creation and directional control of a central SAR focus.
• SAR patterns varied based on applicator phase/amplitude settings.
• Frequency dependency was observed for the BSD-1000 and BSD-2000.
• Water bolus dimensions affected SAR values in the Coaxial TEM applicator.

Conclusions:

• The Amsterdam phantom with an LED matrix is a valuable tool for assessing and optimizing radiative deep-body hyperthermia systems.
• Precise control over SAR distribution is achievable through applicator parameter adjustments.
• This phantom facilitates a deeper understanding of factors influencing hyperthermia treatment efficacy.