A Treatment Planning Comparison of Passive-Scattering and Intensity-Modulated Proton Therapy for Typical Tumor Sites
A Treatment Planning Comparison of Passive-Scattering and Intensity-Modulated Proton Therapy for Typical Tumor Sites
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DOI：
10.1269/jrr.11136
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发表时间：
2012-03-01
影响因子：
2
通讯作者：
Murayama, Shigeyuki
中科院分区：
文献类型：
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作者：
Kase, Yuki;Yamashita, Haruo;Murayama, Shigeyuki
强度调制质子治疗（IMPT）有望改善治疗结果，副作用比其他质子治疗更少。本研究的目的是通过对被动散射质子治疗（PSPT）的典型病例进行IMPT计划，评估在相同射束计算条件下IMPT有效的肿瘤部位。我们选择了16例鼻腔癌、肺癌、肝癌和前列腺癌作为PSPT的典型肿瘤部位。将IMPT优化后的剂量分布和剂量体积直方图与PSPT优化后的结果进行了比较。我们特别注意到当PSPT被IMPT取代时，皮肤和危险器官（OAR）的剂量。此外，还进行了束角的改进，以获得更好的剂量分布在IMPT。对于鼻腔癌、肺癌、肝癌和前列腺癌，具有相同射束角度的IMPT导致皮肤的平均接近最大剂量的PSPT剂量的78%、64%、84%和99%。然而，难以改善靶体积的剂量均匀性。IMPT射束角度的改变可以减少鼻腔中OAR和皮肤的剂量，而在其他情况下效果有限。我们得出结论，IMPT在治疗鼻腔癌、肺癌、肝癌和前列腺癌时可有效降低某些OAR的剂量。光束角度的选择在IMPT优化中是重要的，特别是对于鼻腔癌。
Intensity-modulated proton therapy (IMPT) is expected to improve treatment results with fewer side effects than other proton therapies. The purpose of this study was to evaluate the tumor sites for which IMPT was effective under the same beam calculation conditions by planning IMPT for typical cases treated with passive scattering proton therapy (PSPT). We selected 16 cases of nasal cavity, lung, liver or prostate cancers as typical tumor sites receiving PSPT. The dose distributions and dose volume histograms optimized by the IMPT were compared with those optimized by the PSPT. We took particular note of the doses to the skin and organs at risk (OAR) when PSPT was replaced by IMPT. Furthermore, an improvement of the beam angles was also performed to obtain better dose distributions in the IMPT. The IMPT with the same beam angles resulted in near-maximum doses to the skin of average 78%, 64%, 84% and 99% of the PSPT doses for nasal cavity, lung, liver, and prostate cancers, respectively. However, it was difficult to improve the dose homogeneity of the target volume. The change of the IMPT beam angles could reduce the doses to OARs and skin in the case of the nasal cavity, while it had limited effect in the other cases. We concluded that IMPT was effective for reducing the doses to some OARs when treating nasal cavity, lung, liver and prostate cancers. The selection of beam angles was important in the IMPT optimization, especially for nasal cavity cancers.