3D打印胸壁硅胶bolus制作及临床前研究

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。

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

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.