Design and test of microwave interstitial applicators with improved longitudinal heating pattern.

Area of Science:

• Biomedical Engineering
• Medical Physics
• Oncology

Background:

• Interstitial hyperthermia is often used with radiation therapy to improve tumor treatment.
• Conventional microwave applicators can cause overheating in surrounding normal tissues.
• A need exists for improved applicator designs that provide more targeted and controlled heating.

Purpose of the Study:

• To design and evaluate a novel microwave applicator for interstitial hyperthermia.
• To compare the heating patterns of the new applicator with conventional designs.
• To assess the clinical potential of the new applicator for precise thermal therapy.

Main Methods:

• A new microwave applicator for interstitial hyperthermia was designed.
• Temperature distributions were measured in phantom materials and in the hind legs of anesthetized pigs.
• Two applicators were inserted in parallel, 2 cm apart and 6 cm deep.
• Heating patterns from the new design were compared to conventional applicators.

Main Results:

• The new microwave applicator demonstrated improved heating patterns in both phantom and animal studies.
• The heating pattern produced by the new applicators was shifted towards the applicator tip.
• This targeted heating reduces thermal dose to normal tissues surrounding the tumor.

Conclusions:

• The novel microwave applicator offers a more precise and effective heating pattern for interstitial hyperthermia.
• The design allows for targeted heating without applicator penetration into normal tissues, enhancing safety.
• This advancement holds significant clinical importance for combined radiation and hyperthermia treatments.