(Sunday, 7/12/2020) [Eastern Time (GMT-4)]
Room: AAPM ePoster Library
Purpose:
The 3D-range-modulator (3D-RM), could be a viable instrument for the very fast treatment of moving targets with a high-degree of dose conformity/homogeneity. The use of a single energy leads to a significant decrease of irradiation time, thus mitigating interplay-effects. This work investigates the feasibility of an aluminium(Al) alloy 3D-RM for a real tumour form and compares the simulated dose distribution with one from a PMMA-like resin.
Methods:
Using a high-quality 3D metal-printing-machine a test model with 3x3 fine pyramid-shaped base-structures (pins) was manufactured. 3D imaging with a µCT proved the high degree of production accuracy, suggesting that the manufacturing of a complex 3D-RM is possible.
A complex 3D-RM for a lung tumour, previously designed for PMMA-like resin and 151.77 MeV 1H, was scaled for the Al alloy. The modulator consists of many pins with a 3x3 mm2 base area and different heights.
The FLUKA Monte-Carlo package was used to simulate the resulting dose distributions from the original PMMA-like RM and the newly optimised one.
Results:
The simulations show homogeneous/conformal dose distributions and very good agreement between PMMA-like and Al modulators. The dose distribution resulting from the Al RM does not show deterioration of the DVH or broader lateral penumbra.
Conclusion:
A state-of-the-art metal 3D printing machine can be a viable method to manufacture complex 3D-RMs from Al with high accuracy, mechanical stability and dosimetric properties similar to PMMA.
Keywords
Not Applicable / None Entered.
Taxonomy
Not Applicable / None Entered.
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