Can particle beam therapy be improved using helium ions? - a planning study focusing on pediatric patients
Can particle beam therapy be improved using helium ions? - a planning study focusing on pediatric patients
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DOI：
10.3109/0284186x.2015.1125016
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发表时间：
2016-01-01
期刊：
影响因子：
3.1
通讯作者：
Georg, Dietmar
中科院分区：
文献类型：
--
作者：
Knaeusl, Barbara;Fuchs, Hermann;Georg, Dietmar
目的探讨扫描氦离子束治疗（He-4）与质子治疗在儿科患者中的比较计划研究的潜力。这是由于He-4的上级生物学和物理特性。材料和方法对11例神经母细胞瘤（NB）、9例霍奇金淋巴瘤（HL）、5例肾母细胞瘤（WT）、5例室管膜瘤（EP）和4例尤文肉瘤（EW）患者制定了质子和He-4的治疗计划。计划靶区（PTV）的剂量处方为21 Gy [相对生物学有效性（RBE）]（NB）、19.8 Gy（RBE）（HL）、WT增强区25.2 Gy（RBE）和EP和EW患者54 Gy（RBE）。质子（常数RBE=1.1）和He-4的笔形束算法在治疗计划系统中实现。对于He-4，采用基于不同线性能量传递区域的“带状”模型计算相对生物学效应（RBE）。对于NB患者，除高剂量体积外，在所有剂量体积区域均观察到肾脏和肝脏的差异。接受高达12.6Gy（RBE）的身体体积与He-4相比减少了10%。对于WT患者，当使用He-4时，肝脏的平均和高剂量体积得到改善。对于EP，使用He-4降低正常组织剂量，其中12.7%的体素使用质子接收更高剂量。对于HL和EW肉瘤患者，大PTV体积与危及器官（OAR）位置的结合消除了两种粒子种类之间的差异，而心脏靠近PTV的患者可以受益于He-4。结论与质子计划相比，He-4计划的治疗计划质量有所提高，但OAR保留的优势取决于适应症和肿瘤几何形状。这些扫描He-4治疗的第一批结果激发了对He-4的全面研究，包括获取实验数据以改进He-4的建模。
Aim To explore the potential of scanned helium ion beam therapy (He-4) compared to proton therapy in a comparative planning study focusing on pediatric patients. This was motivated by the superior biological and physical characteristics of He-4.Material and methods For eleven neuroblastoma (NB), nine Hodgkin lymphoma (HL), five Wilms tumor (WT), five ependymoma (EP) and four Ewing sarcoma (EW) patients, treatment plans were created for protons and He-4. Dose prescription to the planning target volume (PTV) was 21Gy [relative biological effectiveness (RBE)] (NB), 19.8Gy (RBE) (HL), 25.2Gy (RBE) for the WT boost volume and 54Gy (RBE) for EP and EW patients. A pencil beam algorithm for protons (constant RBE=1.1) and He-4 was implemented in the treatment planning system Hyperion. For He-4 the relative biological effectiveness (RBE) was calculated with a zonal' model based on different linear energy transfer regions.Results Target constraints were fulfilled for all indications. For NB patients differences for kidneys and liver were observed for all dose-volume areas, except the high-dose volume. The body volume receiving up to 12.6Gy (RBE) was reduced by up to 10% with He-4. For WT patients the mean and high-dose volume for the liver was improved when using He-4. For EP normal tissue dose was reduced using He-4 with 12.7% of the voxels receiving higher doses using protons. For HL and EW sarcoma patients the combination of large PTV volumes with the position of the organs at risk (OARs) obliterated the differences between the two particle species, while patients with the heart close to the PTV could benefit from He-4.Conclusion Treatment plan quality improved with He-4 compared to proton plans, but advantages in OAR sparing were depending on indication and tumor geometries. These first results of scanned He-4 therapy motivate comprehensive research on He-4, including acquisition of experimental data to improve modeling of He-4.