Deterioration of 3D printed multicomponent radiotherapy dosimetry phantom’s properties upon high energy irradiation

Abstract

Accuracy and realization of the prescribed dose in radiotherapy is one of the crucial ways to ensure the quality of the treatment, which usually is closely related to the use of different types of phantoms. Nowadays 3D printing technology is a promising methodology for the fabrication of phantoms, mimicking different biological tissues. Therefore, analysis of the structural properties of materials and their deterioration due to the irradiation is an important issue. This study is aimed to assess radiation-induced changes of the physical and mechanical properties of 3D printed materials used in the construction of the advanced multicomponent dosimetry phantom for radiotherapy when high energy (6 MeV) X-ray photons were applied for irradiation. Irradiation dose of 70 Gy, representing total dose delivered to the target during the whole treatment procedure prescribed for a patient was applied. Composites filaments with TiO2 additive were extruded using a 3D Devo filament extruder and experimental samples were printed using 3D printer Zortrax M300. Attenuation properties of the samples were simulated using the XCOM database, while mechanical tests were performed using the ElectroPuls® E10000 Linear-Torsion machine. It was observed that 6 MeV photons irradiation of the investigated composites (polyethylene terephthalate glycol (PETG), Polylactic acid (PLA), High Impact Polystyrene (HIPS), ULTRAT ABS and GLASS) and PLA containing various concentrations of TiO2 additives (0 %, 0.5 %, 1.0 % and 2.0 %)) has not induce d significant deterioration of samples’ attenuation and mechanical properties, indicating variations within interval of 5 % − 10 %. However, performed investigation also revealed some improvement of structural and mechanical properties of 3D printed PLA composites with incorporated TiO2.