(Saturday, 4/4/2020) [Mountain Time (GMT-6)]
Purpose: Custom, manually fabricated lead shields are often used to reduce radiation doses to proximal healthy tissues during superficial radiation treatments. However, manually fabricating these lead shields is time-consuming, labor-intensive, and uncomfortable for patients. An alternative option is to 3D print patient-specific shields from a high-density bronze-based filament, which would alleviate these concerns. The purpose of this study was to measure the shielding and dosimetric characteristics of 3D-printed bronze (3DPB) shields and to demonstrate their clinical viability.
Methods: The attenuation of 6 and 9 MeV electron beams through varying thicknesses of 3DPB was first measured. Percent depth dose (PDD) and beam profile measurements were performed with flat 3DPB shields and equivalent lead shields to determine surface dose enhancement, output factors, and field widths. A 6 and 9 MeV 3DPB shield were designed and fabricated for an anthropomorphic phantom. Phantom measurements were performed using optically stimulated luminescence dosimeters (OSLD) and film with and without 3DPB shields. Finally, a 3DPB shield was used during the treatment of a patient’s left cheek tumor.
Results: 6 and 9 MeV electrons are attenuated by 95% through 10 and 15 mm of 3DPB, respectively. 3DPB and conventional lead shields had nearly identical beam widths (within 1%). Relative to an unshielded field, output factors averaged 1.007 for 3DPB shields and 1.015 for lead shields. 3DPB shields had surface dose enhancement that was 6.3% higher on average than for lead. Phantom measurements using 3DPB shields showed adequate attenuation of the primary beam (less than 3% transmission). The clinically used shield fit the patient as designed and was deemed clinically acceptable by the physician.
Conclusion: 3DPB shields are simpler and faster to produce, have similar shielding and dosimetric properties, and fit better than lead shields. 3DPB shields are a viable clinical option for patient-specific superficial shielding.
Contact Email
