Room: AAPM ePoster Library
Purpose: To report on the first use of a software technology for the design and production of silicone bolus individualized to complex patient anatomy, and to demonstrate utility via a clinical case study.
Methods: 3D printed silicone mold technology was used in the treatment preparation for an 81-year-old male presenting with both a basal cell carcinoma of the scalp and a squamous cell carcinoma of the left ear and pre-auricular area. Because of the complex anatomy of the treatment sites as well as the potential sensitivity of the patient using a rigid bolus, we employed a new FDA 510(k) cleared software technology (3Dbolus 3.0, Adaptiiv Medical) for the generation of a 3D printed mold to be filled with a skin-safe silicone. The application interfaced directly with the treatment planning system (Eclipse13.6, Varian Medical) to automatically generate a 3D object incorporating a two-part shell surrounding a 1 cm-thick cavity. User-positioned custom guides on the mating surfaces ensured precise alignment and sealing of shell surfaces. Treatment planning was performed using 6 MV photons and a VMAT approach for both sites, prescribing 50 Gy/20 fractions.
Results: The process of software mold design required approximately 15 minutes each for the scalp and pre-auricular boluses. Fused deposition modeling 3D printing, pouring, setting and removal of the silicone boluses was completed within one day. The soft boluses were well tolerated by the patient and placement was straightforward by the therapists. Subsequent CT and CBCT imaging during the treatment course demonstrated excellent fit of both boluses with minimal air gapping for both sites, including for the complex anatomy of the ear.
Conclusion: The software technology presented in this exemplary case study provides a viable option for efficient design of bolus that provides the flexibility of conventional vinyl sheet boluses, yet allows for close conformity to complex surfaces.
Funding Support, Disclosures, and Conflict of Interest: This work was supported by Adaptiiv Medical. Author JR holds a position on the Board of Directors of this venture.
Not Applicable / None Entered.
Not Applicable / None Entered.