Intensity Modulated Radiotherapy (IMRT) Phantom Fabrication Using Fused Deposition Modeling (FDM) 3D Printing Technique

Design and fabrication of patient-specific radiotherapy phantom is now more accessible and cost-effective using 3D printing technology. This study fabricates a 3D printed radiotherapy phantom for quality assurance of Intensity Modulated Radiotherapy (IMRT). Using an IMRT Thorax anthropomorphic phantom (CIRS) as a substitute for an actual patient, a 3D printed radiotherapy phantom was designed based on a patient computed tomography (CT) scan during treatment planning. Before printing the phantom, the tissue equivalence of Acrylonitrile Butadiene Styrene (ABS) and Polylactic Acid (PLA) polymers used in 3D printing was characterized by quantifying its CT number and relative electron density to water. In the 3D printed phantom fabricated, it was shown that soft tissue and lungs can be simulated using PLA 100% infill (rho(130kv)(e,w) = 0.99) and 20% infill plastic (rho(130kv)(e,w) = 0.20).