3D打印胸壁硅胶bolus制作及临床前研究

Fabrication and pre-clinical application of patient-specific 3D sificone rubber bolus for chest wall

目的 探讨利用3D打印技术用于制作胸壁个性化硅胶组织补偿物与常规bolus及直接3D打印的PLA材料（3D-PLA材料）bolus的优势并验证其临床特性.方法 基于定位CT图像获取2例乳腺癌改良根治术后放疗患者的胸壁数据,使用3D打印硅胶倒模的设计方法,建立制作胸壁3D打印硅胶bolus（3D-SRB）.分别验证3D-SRB、常规bolus和3D-PLA与胸壁的贴合性,通过Eclipse计划系统比较虚拟计划和使用3种组织补偿物后的剂量学参数.结果 本研究成功设计并制作了一套硬度与常规bolus类似的3D-SRB.3D打印的组织补偿物（3D-SRB和3D-PLA）无论是在胸壁贴合性方面还是实际计划剂量分布方面均优于常规bolus;且3D-SRB在重复性、患者舒适性及胸壁贴合性方面优于3D-PLA.在剂量学方面,3D-SRB组与虚拟计划重复性最好,其次是3D-PLA,最后是常规bolus.结论 应用间接法3D打印的胸壁硅胶bolus在实际操作中是可行,具有较高的临床应用价值.

 Objective To apply 3D printing technology to fabricate patient-specific silicone tissue compensators for the chest wall and compare the advantages and clinical characteristics between conventional bolus and 3D-printed PLA materials. Methods The chest wall data of two breast cancer patients undergoing mastectomy were obtained based upon the CT images. A patient-specific 3D printing silicone rubber bolus （3D-SRB） was designed and fabricated. The conformability of 3D-SRB,3D-PLA and conventional bolus to the chest wall were validated. Ecipse8. 6 planning system was adopted to statistically compare the dosimetric parameters of virtual plan with those after using three tissue compensators. Results The 3D-SRB was successfully designed and fabricated with a similar hardness to conventional bolus. During the process of validating conformability and radiotherapy planning,3D-SRB and 3D-PLA were superior to conventional bolus in terms of conformability to chest wall and planning dosimetric distribution.3D-SRB was advantageous in repeatability, conformability and comfortable experience compared with 3D-PLA. Regarding dosimetric parameters,3D-SRB yielded the highest repeatability with the virtual plan, followed by 3D-PLA and conventional bolus. Conclusion It is applicable to utilize 3D-SRB as the patient-specific compensators for the chest wall,which is of significance in clinical practice.