Moldable tissue equivalent bolus for high-energy photon and electron therapy

Area of Science:

• Medical Physics
• Radiation Oncology
• Biomaterials

Background:

• Radiation therapy often requires treating irregular patient surfaces with electron and photon beams.
• Achieving uniform doses at depth and proper surface dose buildup necessitates surface smoothing using bolus material.
• Effective bolus materials must be tissue-equivalent and capable of filling irregular voids for accurate dose delivery.

Purpose of the Study:

• To evaluate moldable materials, specifically those used in dental clinics, as potential tissue-equivalent bolus for radiation therapy.
• To identify a cost-effective, readily available bolus material that provides adequate surface smoothing and dose buildup.
• To assess the suitability of Polyflex, a hydrocolloid, for use as a bolus material in radiation oncology.

Main Methods:

• Evaluation of several moldable materials, with a focus on those previously or currently used in dental settings.
• Assessment of material properties for tissue equivalence, particularly for electron and photon beams.
• Consideration of material availability and durability over time.

Main Results:

• Polyflex, a hydrocolloid, demonstrated near water equivalence for both electron and photon beams.
• The material proved to be inexpensive and readily available.
• Polyflex exhibited good durability and stability over time.

Conclusions:

• Polyflex is a suitable and effective tissue-equivalent bolus material for radiation therapy applications.
• Its properties make it ideal for achieving uniform doses on irregular surfaces with electron and photon beams.
• The material's cost-effectiveness and availability further support its use in clinical settings.