ESTRO 2021 Abstract Book

S459

ESTRO 2021

SP-0594 Publishing interdisciplinary science M. Leech 1 1 Applied Radiation Therapy Trinity College , Trinity St. James's Cancer Institute, Radiation Therapy, Dublin, Ireland Abstract Text Interdisciplinarity is the cornerstone of radiation oncology practice. However the publication of interdisciplinary science can prove to be a conundrum for many authors, with difficulties in determining which academic journal's scope best fits their work. This presentation will discuss these perceived difficulties and how they can be overcome. The current status of interdisciplinary publication in our field will also be evaluated. PH-0595 Radiation dose to tissue inside 3D printed titanium and PEEK scaffolds: Monte Carlo simulation G. Katsifis 1 1 University of Sydney, School of Physics, Sydney, Australia Purpose or Objective Bone prostheses have typically been constructed as solid metal objects, but now, customised 3D printed porous structures have become available to reduce the effective stiffness of the implant and to allow for increased osseointegration. The radiation dose to the implant, including the ossifying cells within the scaffold structure may cause necrosis and impede osseointegration. Radiotherapy patients frequently present with metallic implants. Here we examine the dose to the scaffold and to the tissue within its structure for two types of materials, titanium and PEEK in three designs (Table 1). Materials and Methods The dose distribution was calculated in GATE using the Geant4 library for a Varian Truebeam TM 6MV photon beam. The STLs for three implant designs were unfolded and positioned at a depth of 5cm in a 30 cm cube of water. The dose to the tissue in the pores of the implants was determined by applying a 3D binary mask to the 3D dose distribution of the implant. The integrated dose was calculated for each design in titanium and in PEEK and were compared to the dose calculated in the absence of the implant. The doses within the pores of each implant were calculated at specific depths within the implant volume. Results Table 1 shows the dose heatmaps for each implant at a depth of 5 cm. The dose within the pores of the implants is higher for the titanium implants compared to PEEK. For the titanium implants, the maximum dose enhancements found within the pores were 12.5, 11.7 and 13.4% for the rings, reconstruction plate and the woodpile respectively. For the PEEK implants, the corresponding dose perturbations of 1.1, -1.5 and 0.8 % were calculated. Analysis of the dose distribution within the pores of the ringed reconstruction frame, reported a 15% higher dose along the surface compared to an 8% enhancement at the centre of the pores. For PEEK, the enhancement remained less than 2.5% throughout the entire volume. Poster highlights: Poster Highlights 22: Dosimetry 2