Daily adaptive proton therapy - the key to innovative planning approaches for paranasal cancer treatments
Daily adaptive proton therapy - the key to innovative planning approaches for paranasal cancer treatments
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DOI：
10.1080/0284186x.2019.1641217
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发表时间：
2019-07-27
期刊：
影响因子：
3.1
通讯作者：
Albertini, Francesca
中科院分区：
文献类型：
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作者：
Nenoff, Lena;Matter, Michael;Albertini, Francesca
背景：对于鼻翼肿瘤的质子治疗，通常使用磁场方向来避免在治疗过程中可能改变的体积。然而，如果在日常解剖上使用每日适应质子治疗（DAPT）优化计划，穿越鼻腔的磁场方向可能是可行的。在这项研究中，我们调查了DAPT在窄场治疗方法中的有效性。材料和方法：对于5例鼻旁肿瘤患者，代表了广泛的患者谱，计算了解剖学上健壮的4场星和窄场计划，并比较了它们在使用和不使用DAPT时对解剖学和设置不确定性的健壮性。基于标称计划ct，每个患者最多创建125个具有不同鼻腔填充物的模拟ct (simct)，并进一步模拟由于患者设置不确定性而导致的随机平移和旋转。在所有错误情况下重新计算或重新优化计划，分别代表非适应和DAPT部分。从中模拟了100种可能的治疗方法（60种GyRBE， 30种fx），并评估了总剂量、靶和危险器官（OARs）剂量的变化。结果：与4场星法相比，窄场法使总剂量降低29% ~ 56%。如果OARs没有与靶标重叠，OAR剂量也会减少。最后，在所有病例中，DAPT几乎可以完全恢复非适应性治疗中显著降低的目标覆盖率（平均V95降低高达34%）
Background: For proton therapy of paranasal tumors, field directions avoiding volumes that might change during therapy are typically used. If the plan is optimized on the daily anatomy using daily adapted proton therapy (DAPT) however, field directions crossing the nasal cavities might be feasible. In this study, we investigated the effectiveness of DAPT for enabling narrow-field treatment approaches. Material and methods: For five paranasal tumor patients, representing a wide patient spectrum, anatomically robust 4-field-star and narrow-field plans were calculated and their robustness to anatomical and setup uncertainties was compared with and without DAPT. Based on the nominal planning CTs, per patient up to 125 simulated CTs (simCTs) with different nasal cavity fillings were created and random translations and rotations due to patient setup uncertainties were further simulated. Plans were recalculated or re-optimized on all error scenarios, representing non-adapted and DAPT fractions, respectively. From these, 100 possible treatments (60 GyRBE, 30 fx) were simulated and changes in integral dose, target and organs at risk (OARs) doses evaluated. Results: In comparison to the 4-field-star approach, the use of narrow-fields reduced integral dose between 29% and 56%. If OARs did not overlap with the target, OAR doses were also reduced. Finally, the significantly reduced target coverage in non-adapted treatments (mean V95 reductions of up to 34%) could be almost fully restored with DAPT in all cases (differences