Lizondo M, Lorenzo Á, Adell-Gómez N, Navarro D, Colomer M, Ambroa E, Valdivielso T, Garcia-Miguel J, Infestas Á, Ramírez A, Valls-Esteve A
Physics Unit, Consorci Sanitari Terrassa, Ctra. de Torrebonica s/n, 08227 Terrassa, Spain.
Physics Unit, Consorci Sanitari Terrassa, Ctra. de Torrebonica s/n, 08227 Terrassa, Spain.
Phys Med. 2025 Jun;134:104987. doi: 10.1016/j.ejmp.2025.104987. Epub 2025 May 7.
3D-printing is increasingly used in radiotherapy for precise bolus fabrication. While materials like ABS and PLA are common, flexible 3D-printing materials may better adapt to anatomical variations. However, a comprehensive evaluation of these flexible materials remains limited.
A breast silicone phantom (Phantom) was designed based on a small-breast model and printed. To simulate treatment-related swelling, a second phantom with a 3 mm expansion (PhantomExp) was also created. A virtual bolus (0.5 mm thick) was designed and 3D-printed using twelve materials, including direct printing (ABS, PLA, TPU, MED610, Biomed Flex 80, Biomed Elastic 50, Elastic 50, Flexible 80, ElasticClear, AmSil silicone) and casting (Dragon-Skin 30 and Silbione silicones). Three tests were conducted: 1. Bolus Characterization: Printing cost and time, CT image analysis, and print fidelity were evaluated. 2. Adaptability Test: Air volume between the bolus and Phantom was measured using CT images, and compared to the air volume between the bolus and PhantomExp to assess adaptability. 3. Dosimetric Test: Film dosimetry was used to compare the planned and measured surface doses on the Phantom with each bolus.
Most of the materials achieve high printing accuracy (<0.3 mm). Air volume was greater with PhantomExp due to expansion, but silicone materials and BiomedElastic50 adapted well to the shape changes. Dosimetric differences were under 3 %, confirming that the bolus effect was achieved.
Silicone-based options produced through casting are the most favourable when time constraints are not critical.
3D打印在放射治疗中越来越多地用于精确制作等效物。虽然ABS和PLA等材料很常见，但柔性3D打印材料可能更能适应解剖学变异。然而，对这些柔性材料的全面评估仍然有限。
基于小乳房模型设计并打印了一个乳腺硅胶体模（体模）。为了模拟与治疗相关的肿胀，还制作了一个膨胀3毫米的第二个体模（膨胀体模）。设计了一个虚拟等效物（0.5毫米厚），并使用十二种材料进行3D打印，包括直接打印（ABS、PLA、TPU、MED610、生物医学柔性80、生物医学弹性50、弹性50、柔性80、弹性透明、AmSil硅胶）和浇铸（Dragon-Skin 30和Silbione硅胶）。进行了三项测试：1. 等效物特性分析：评估打印成本和时间、CT图像分析以及打印保真度。2. 适应性测试：使用CT图像测量等效物与体模之间的空气体积，并与等效物与膨胀体模之间的空气体积进行比较，以评估适应性。3. 剂量学测试：使用胶片剂量学比较每个等效物在体模上的计划表面剂量和测量表面剂量。
大多数材料实现了高打印精度（<0.3毫米）。由于膨胀，膨胀体模的空气体积更大，但硅胶材料和生物医学弹性50能很好地适应形状变化。剂量学差异在3%以下，证实实现了等效物效应。
在时间限制不严格的情况下，通过浇铸生产的基于硅胶的材料是最有利的。
