Avelino Samuel R, Silva Luis Felipe O, Miosso Cristiano J
Biomedical Engineering Department, University of Brasília, Gama, DF Brazil.
Annu Int Conf IEEE Eng Med Biol Soc. 2012;2012:5718-21. doi: 10.1109/EMBC.2012.6347293.
Intensity-Modulated Radiotherapy (IMRT) is an important tool for cancer treatment. It concentrates high radiation doses in complex target volumes, while sparing the surrounding tissues. IMRT is traditionally performed using Multileaf Collimators (MLC) or Compensator Blocks. The conventional way used to manufacture IMRT compensator blocks, which uses milling machines, is an important drawback over the MLC method, due to high operational and production costs. In this research, we developed a simpler alternative method to manufacture an IMRT compensator block from a fluency map generated by a commercial treatment planning system (TPS). This map was converted into a mold, and then printed using a 3D printer. The final IMRT compensator block was achieved by filling the mold with cerrobend alloy. To validate this method a quality assurance was performed using dosimetric films to compare the measured dose distributions to those predicted by the TPS system. This comparison showed a good agreement among 8 dose profiles from each situation, with a maximum RMS error of 8.84 % for the tested profiles. This suggests that the 3D printers can be effectively used to manufacture IMRT compensator blocks. The main advantage to this approach is that it can be fully conducted inside a radiotherapy facility, which results in lower costs and production times.
调强放射治疗（IMRT）是癌症治疗的一项重要工具。它能将高剂量辐射集中于复杂的靶区，同时保护周围组织。传统上，IMRT是使用多叶准直器（MLC）或补偿器挡块来进行的。由于操作和生产成本高昂，用于制造IMRT补偿器挡块的传统方法（使用铣床）相较于MLC方法存在一个重大缺陷。在本研究中，我们开发了一种更简单的替代方法，可根据商业治疗计划系统（TPS）生成的通量图制造IMRT补偿器挡块。该通量图被转换为模具，然后使用3D打印机进行打印。通过用铈镓合金填充模具，最终制成了IMRT补偿器挡块。为验证此方法，使用剂量测定胶片进行了质量保证，以将测量的剂量分布与TPS系统预测的剂量分布进行比较。这种比较显示，每种情况下的8个剂量剖面之间具有良好的一致性，测试剖面的最大均方根误差为8.84%。这表明3D打印机可有效地用于制造IMRT补偿器挡块。这种方法的主要优点在于它可以在放射治疗设施内部完全完成，从而降低成本和缩短生产时间。
