Evaluation of a novel phantom for the quality assurance of a six-degree-of-freedom couch 3D-printed at multiple centres

This study aimed to validate a bespoke 3D-printed phantom for use in quality assurance (QA) of 6 degrees-of-freedom (6DoF) treatment couch. A novel design comprising main body with internal cube structures, was fabricated at five centres using Polylactic Acid (PLA) material, an additional produced incorporating PLA-stone hybrid material. Correctional setup shifts were determined image registration by 3D-3D matching high HU structures between obtained cone-beam computer tomography (CBCT) images reference CTs, containing cubes rotational offsets 3.5°, 1.5° and −2.5° rotation, pitch, roll, respectively. Average each phantom. The reproducibility 3D-printing probed comparing the size as well Hounsfield Units uniquely phantoms. For PLA phantoms, average rot, pitch roll correctional differences from −0.3 ± 0.2°, −0.2 0.5° 0.2 0.3° respectively, these −0.09 0.14°, 0.30 0.00° 0.03 0.10°. There found be no statistically significant difference printed (P < 0.05) one compared others attributed choice material density. work demonstrated capability producing 6DoF couch QA design, multiple centres, unique model capable sub-degree correction.