Investigation of the effects of spinal surgical implants on radiotherapy dosimetry: A study of 3D printed phantoms

Purpose The use of three-dimensional (3D) printing to develop custom phantoms for dosimetric studies in radiotherapy is increasing. process allows production designed evaluated specific geometries, patients, or patient groups with a defining feature. ability print bone-equivalent has, however, proved challenging. purpose this work was 3D series three similar spine containing no surgical implants, implants made titanium, and carbon fiber, future imaging studies. Phantoms were (a) tissue bone equivalence, (b) geometric accuracy compared design, (c) similarity one another. Methods Sample blocks PLA, HIPS, StoneFil PLA-concrete different infill densities printed evaluate equivalence. samples used CT physical (PD) effective relative electron density (REDeff) conversion curves define the settings phantoms. scans obtained assess geometry achieved. Mean distance agreement (MDA) DICE coefficient (DSC) values calculated between contours materials, from design like phantom modules. HU determine PD REDeff subsequently Results objects showed linear relationships both PLA StoneFil. using clinical not accurate required. 90% found have 1.11 ± 0.03 g.cm?3 1.04 0.02 selected tissue- equivalent elements. 100% 1.35 1.24 0.04 Upon evaluation final phantoms, elements displayed range 1.10 g.cm?3–1.13 1.02 0.03–1.06 0.03. 1.43 g.cm?3–1.46 1.31 0.04–1.33 0.04. shown MDA ?1.00 mm DSC ?0.95 ?0.48 ?0.91 ?0.44 ?0.98 ?0.43 ?0.92 Conclusions which radiologically produced high level even higher When conjunction derived they are suitable evaluating effects spinal varying material construction.