Program Information
Design and Creation of a 3D Printed Custom Chest Wall Bolus From a Rubber-Like Material
D Vile1*, B Overshiner2 , H Ai1 , P Yearling3 , (1) Indiana University, Indianapolis, IN, (2) Indiana University Health, Indianapolis, IN, (3) Indiana University Purdue University Indianapolis, Indianapolis, IN
Presentations
SU-I-GPD-T-69 (Sunday, July 30, 2017) 3:00 PM - 6:00 PM Room: Exhibit Hall
Purpose: To define a process to create a 3D printed custom chest wall bolus from a patient’s planning CT scan using a rubber-like printing material.
Methods: An anthropomorphic phantom was scanned using a clinical CT protocol used for patient planning. The scan was then transferred to the treatment planning system, where a bolus was created covering the entire chest wall. Post-process smoothing was performed to account for the finite voxel size of the CT. The unsmoothed bolus was then directly 3D printed using the rubber-like TangoPlus (Stratsys, Eden Prairie, MN) while the smoothed bolus was printed in a rigid ABS material that is more readily available. A CT scan was performed to verify the fit.
Results: The precision of the 3D printer is stated as 16 microns, much smaller than the resolution of any planning CT. This caused a significant step artifact to be introduced to the 3D printed bolus. The artifact was prevalent even after using a 1 mm slice thickness, the smallest available. The end result was an air gap varying between 0-3 mm in a wave pattern. The smoothed bolus was able to give a better fit to the patient, though some air gaps still exist. It is believed that the flexibility of the rubber-like material will alleviate these gaps.
Conclusion: The flexibility of the rubber-like 3D printing material offers potential for a better patient bolus fit. The resolution of the CT hinders this ability and a post-process smoothing must be performed to overcome this limitation.
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