Due to the physical properties of photon and electron radiation and surface “build-up”, a bolus device is often needed in radiation therapy for patients who require full prescription dosing to the skin. Tissue surfaces which display irregular topography can be challenging to consistently apply bolus reproducibly. Custom, digitally designed, and 3D printed bolus offsets allow a reproducible method for delivering radiotherapy. An inter-departmental 3D bolus design process for multiple head and neck patients with challenging anatomy requiring skin surface dosing has been implemented. During this process, a multitude of commercially available 3D printed materials across several of the 3D printing technologies have been evaluated. These 3D printed materials have also been compared to conventionally used materials. Traditional anterior-posterior 2-field photon radiation therapy with a dynamic arc intensity modulated radiation therapy plan to ensure dose fidelity across materials was compared. Simple dose statistics from a thermoluminescent dosimeter were used to confirm the material attenuates as expected based on its Hounsfield attenuation for each of the various substances at 0.5 cm and 1.0 cm depths.
- Understand the basic principles of bolus offsets.
- Understand advantages 3D printing can provide in the construction of bolus offsets.
- Know if the choice of different 3D printed materials will affect radiation dose.