(Tuesday, 7/31/2018) 10:00 AM - 10:30 AM
Room: Exhibit Hall | Forum 3
Purpose: The dosimetric properties of several 3D printed materials were investigated with an Ir-192 source.
Methods: Several rectangular blocks were created using a commercially available 3D printer composed of the following materials (and their printed density): acrylonitrile butadiene styrene (ABS) (1.0 g/cc), polyactic acid (PLA) (1.2 g/cc), calcium carbonate-infused PLA (1.4 g/cc), copper-infused PLA (3.4 g/cc) and tungsten-infused ABS (3.7 g/cc). Blocks with infills of 25%, 50%, 75% and 100% were used for some materials. A block was also fabricated from Cerrobend using a 3D printed mold. Blocks were designed so an Ir-192 HDR source would be centered, at a depth of 2 cm, between two blocks when adjoined with the material of interest paired with a 100% ABS block on the side away from the measurements; solid water was placed around the blocks for full scatter. Radiation transmissions through the materials were measured at 3 cm from the source with ionization chambers and radiochromic film. All transmission measurements were normalized to a 100% ABS block.
Results: For ABS and PLA, transmission was within 4% of the 100% ABS regardless of the infill. For each infill, the two materials showed a maximum difference of 2%. Relative transmission of 100% infill copper and tungsten infused plastic was 79% and 39%, respectively. The relative transmission through Cerrobend was 6%. Varying the percent infill of the metal infused plastics resulted in greater variation in transmission than the other plastics.
Conclusion: Good agreement of radiation transmission of an Ir-192 HDR source was observed for ABS and PLA despite differences in chemical composition and material density. Metal infused plastics showed greater attenuation and variation in transmission with variation in infill than ABS or PLA. This could possibly allow custom modulation of a single Ir-192 dose distribution in the future.
Keywords
Brachytherapy, HDR, Ir-192 Source
Taxonomy
TH- Brachytherapy: Development (new technology and techniques)
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