ESTRO 2024 - Abstract Book

S204

Brachytherapy - General

ESTRO 2024

Keywords: Burnout, Brachytherapy, Survey

References:

Estimating the global cancer incidence and mortality in 2018: GLOBOCAN

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Digital Poster

3D printing of radioopaque polymer applied to brachytherapy implants and devices

Marc-Andre Fortin 1,2 , Theophraste Lescot 1 , Souheib Zekhraoui 1,2

1 CR-CHU de Québec - Université Laval, Regenerative Medicine, Québec, Canada. 2 Université Laval, Materials Engineering, Québec, Canada

Purpose/Objective:

Polyetheretherketone (PEEK) is a chemically resistant polymer with excellent thermal and mechanical properties. It is increasingly used in 3D printed orthopedic implants, as well as in radiotherapeutic applications requiring the insertion of permanent and non-permanents implants in the body. 1 Although PEEK is resistant to radiolysis – polymer degradation by ionizing radiation – it is a radiolucent material that expresses a poor capacity to block radiations (energetic photons, neutrons). However, many devices and tools in radiology, radiotherapy and in nuclear medicine, such as brachytherapy implants, shields, screens, and personalised radioprotection equipment, require a certain level of radiopacity in either one of their components that require radiation blocking. This works describes a novel procedure that allows the development of radioopaque polymer (PEEK) filaments for fused filament fabrication (FFF) 3D printing. Such filaments contain a homogeneous distribution of electron-dense particles that confer a high radiation blocking power to the printed objects. The material and 3D printing procedure is applied to the fabrication of episcleral plaques (EP) for eye brachytherapy. An original methodology allowing the optimal mixing of micrometric-sized metal particles (here: tungsten - W) with millimetric-sized PEEK pellets, was developed. The mixing process allowed to extruded W-loaded PEEK filaments in a continuous and robust manner. The filaments were characterized by electron microscopy (SEM; for W particle distribution) and X-ray fluorescence imaging (XRF; for W homogeneity) and elemental analysis (W concentration in PEEK). The filaments having reached a W concentration >5%v/v, were characterized for their fusion temperature, and used in a commercial FFF PEEK 3D-printer for the fabrication of radiopaque objects of various thicknesses (Figure 1A-C). The 3D printing resolution and the X-ray attenuation coefficients were evaluated and measured by X-ray radiography and computed tomography (CT). The possibility to 3D print EP of shapes similar to that of clinical brachytherapy implants, as well as the possibility to easily machine millimetric-size holes in the plaques, were demonstrated. Material/Methods:

Results: