Related Experiment Video
Updated: Jul 30, 2025
Evaluating Regional Pulmonary Deposition using Patient-Specific 3D Printed Lung Models
Published on: November 11, 2020
Low-density 3D-printed boluses with honeycomb infill in radiotherapy
Edyta Dąbrowska-Szewczyk1, Anna Zawadzka2, Piotr Kowalczyk3
1Biomedical Physics Division, Faculty of Physics, University of Warsaw, 5 L. Pasteur Street, 02-093 Warsaw, Poland; Medical Physics Department, The Maria Skłodowska-Curie National Research Institute of Oncology in Warsaw, 5 WK Roentgen Street, 02-781 Warsaw, Poland.
Purpose:
Dosimetric characteristics of 3D-printed plates using different infill percentage and materials was the purpose of our study.
Methods:
Test plates with 5%, 10%, 15% and 20% honeycomb structure infill were fabricated using TPU and PLA polymers. The Hounsfield unit distribution was determined using a Python script. Percentage Depth Dose (PDD) distribution in the build-up region was measured with the Markus plane-parallel ionization chamber for an open 10x10 cm2 field of 6 MV. PDD was measured at a depth of 1 mm, 5 mm, 10 mm and 15 mm. Measurements were compared with Eclipse treatment planning system calculations using AAA and Acuros XB algorithms.
Results:
The mean HU for CT scans of 3D-printed TPU plates increased with percentage infill increase from -739 HU for 5% to -399 HU for 20%. Differences between the average HU for TPU and PLA did not exceed 2% for all percentage infills. Even using a plate with the lowest infill PDD at 1 mm depth increase from 44.7% (without a plate) to 76.9% for TPU and 76.6% for PLA. Infill percentage did not affect the dose at depths greater than 5 mm. Differences between measurements and TPS calculations were less than 4.1% for both materials, regardless of the infill percentage and depth.
Conclusions:
The use of 3D-printed light boluses increases the dose in the build-up region, which was shown based on the dosimetric measurements and TPS calculations.
