Fabrication and Dosimetric Evaluations of a Dummy Eye Shield for Radiotherapy

Abstract

The purpose of this study was to fabricate a dummy eye shield by using a 3D scanner and 3D printer and to compare the dose distribution calculated using the computed tomography (CT) value assignment function in the commercial radiation treatment planning (RTP) system with the dummy eye shield to dose distribution measured with a metal shield by using EBT 2 film. The tungsten eye shield was scanned using a 3D scanner (GOM ATOS ScanBox; GOM, Braunschweig, Germany), and the designed dummy eye shield was printed with a 3D Printer (Stratasys Object 500 Connex; Stratasys Ltd., Minnesota, USA) using VeroWhite (Stratasys Ltd., Minnesota, USA). A 6-MeV electron beam from a 21EX-S linear accelerator (Varian Medical System, Palo Alto, USA) was used in this study. For a 6-MeV electron beam, the absolute doses at a 10-mm depth from RTP system calculations, EBT2 films, and TLD chips were 18.8, 32.4, and 35.6 cGy, respectively. The dummy eye shield could be adopted effectively to treat ocular tumors with electron radiotherapy; however, its use with a commercial RTP system for calculating the dose distribution was difficult.