Albantow Christine, Hargrave Catriona, Brown Amy, Halsall Christopher
Radiation Therapy, Townsville Cancer Centre, Townsville Hospital and Health Service, Townsville, Queensland, Australia.
Radiation Oncology, Princess Alexandra Hospital - Raymond Tce Campus, South Brisbane, Queensland, Australia.
J Med Radiat Sci. 2020 Mar;67(1):54-63. doi: 10.1002/jmrs.378. Epub 2020 Feb 3.
Three-dimensional printing technology has the potential to streamline custom bolus production in radiotherapy. This study evaluates the volumetric, dosimetric and cost differences between traditional wax and 3D printed versions of nose bolus.
Nose plaster impressions from 24 volunteers were CT scanned and planned. Planned virtual bolus was manufactured in wax and created in 3D print (100% and 18% shell infill density) for comparison. To compare volume variations and dosimetry, each constructed bolus was CT scanned and a plan replicating the reference plan fields generated. Bolus manufacture time and material costs were analysed.
Mean volume differences between the virtual bolus (VB) and wax, and the VB and 18% and 100% 3D shells were -3.05 ± 11.06 cm , -1.03 ± 8.09 cm and 1.31 ± 2.63 cm , respectively. While there was no significant difference for the point and mean doses between the 100% 3D shell filled with water and the VB plans (P> 0.05), the intraclass coefficients for these dose metrics for the 100% 3D shell filled with wax compared to VB doses (0.69-0.96) were higher than those for the 18% and 100% 3D shell filled with water and the wax (0.48-0.88). Average costs for staff time and materials were higher for the wax ($138.54 and $20.49, respectively) compared with the 3D shell prints ($10.58 and $13.87, respectively).
Three-dimensional printed bolus replicated the VB geometry with less cost for manufacture than wax bolus. When shells are printed with 100% infill density, 3D bolus dosimetrically replicates the reference plan.
三维打印技术有潜力简化放射治疗中定制 bolus 的生产。本研究评估了传统蜡制鼻用 bolus 与 3D 打印鼻用 bolus 在体积、剂量学和成本方面的差异。
对 24 名志愿者的鼻石膏印模进行 CT 扫描并制定计划。将计划的虚拟 bolus 用蜡制作，并以 3D 打印（100%和 18%的壳填充密度）制作，以进行比较。为了比较体积变化和剂量学，对每个制作好的 bolus 进行 CT 扫描，并生成一个复制参考计划野的计划。分析了 bolus 的制作时间和材料成本。
虚拟 bolus（VB）与蜡制 bolus 之间，以及 VB 与 18%和 100%的 3D 壳之间的平均体积差异分别为 -3.05 ± 11.06 cm³、-1.03 ± 8.09 cm³ 和 1.31 ± 2.63 cm³。虽然填充水的 100% 3D 壳与 VB 计划之间的点剂量和平均剂量没有显著差异（P > 0.05），但与 VB 剂量相比，填充蜡的 100% 3D 壳的这些剂量指标的组内系数（0.69 - 0.96）高于填充水的 18%和 100% 3D 壳以及蜡的组内系数（0.48 - 0.88）。与 3D 壳打印（分别为 10.58 美元和 13.87 美元）相比，蜡制 bolus 的工作人员时间和材料平均成本更高（分别为 138.54 美元和 20.49 美元）。
3D 打印 bolus 复制了 VB 的几何形状，且制造成本低于蜡制 bolus。当以 100%的填充密度打印壳时，3D bolus 在剂量学上复制了参考计划。
