Microwave leakage during patient treatment

Area of Science:

• Biomedical Engineering
• Medical Physics
• Radiation Oncology

Background:

• The Bureau of Radiological Health (BRH) proposed a draft standard for microwave leakage at 10 mW/cm2.
• Accurate measurement of microwave leakage is essential for patient safety during therapeutic applications.

Purpose of the Study:

• To compare microwave leakage measurements under static phantom conditions versus during actual patient treatments.
• To assess if current phantom-based measurements accurately predict real-world microwave exposure.

Main Methods:

• Microwave leakage was measured using a tissue-equivalent phantom, varying net forward power and aperture-to-skin distance (SSD).
• Leakage was also measured on patients undergoing microwave hyperthermia treatments at various anatomical locations.

Main Results:

• Microwave leakage during patient treatments was significantly higher than predicted by static phantom measurements.
• Anatomical site and treatment conditions appear to influence the extent of microwave leakage.

Conclusions:

• Static phantom models may underestimate microwave leakage during clinical hyperthermia.
• Further research is needed to refine safety standards and measurement protocols for microwave hyperthermia to account for in-vivo conditions.