Treatment planning with protons for pediatric retinoblastoma, medulloblastoma, and pelvic sarcoma: How do protons compare with other conformal techniques?
Treatment planning with protons for pediatric retinoblastoma, medulloblastoma, and pelvic sarcoma: How do protons compare with other conformal techniques?
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DOI：
10.1016/j.ijrobp.2005.01.060
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发表时间：
2005-10-01
影响因子：
7
通讯作者：
Smith, AR
中科院分区：
文献类型：
--
作者：
Lee, CT;Bilton, SD;Smith, AR
目的：计算治疗计划并比较光子三维适形放射治疗 (3D-CRT)、电子治疗、调强放射治疗 (IMRT) 和标准（非调强）质子治疗在三个儿科疾病部位的剂量分布和剂量体积直方图 (DVH)。 方法和材料：8 例患者的肿瘤体积（3 例视网膜母细胞瘤、2 例髓母细胞瘤和 3 例盆腔肿瘤）肉瘤）进行回顾性研究，比较质子治疗与 3D-CRT、电子治疗和 IMRT 的 DVH。在视网膜母细胞瘤中，分析了几种规划技术：将单个电子对位束与单个 3D-CRT 侧束、3D-CRT 前束与侧束配对、IMRT 和质子进行比较。在髓母细胞瘤中，分析了三种后颅窝照射技术：3D-CRT、IMRT 和质子。还评估了颅脊髓照射（由后颅窝和颅脊髓成分的复合计划组成），主要比较使用 3D-CRT 电子、3D-CRT 光子和质子的脊柱照射。最后，在盆腔肉瘤中，对 3D-CRT、IMRT 和质子计划进行了评估。结果：在视网膜母细胞瘤中，质子带来了最佳的靶区覆盖率和最多的眼眶骨保留（质子在 >= 5 Gy 照射下的平均眼眶骨体积为 10%，而 3D-CRT 电子为 25%，IMRT 为 69%，单次 3D 为 41%）侧束，带透镜块的 3D 前侧束为 51%，不带透镜块的 3D 前侧束为 65%）。单一对置电子场是次佳技术，其次是其他规划方法。在髓母细胞瘤中，对于后颅窝和颅脊髓照射，质子对耳蜗（仅在 >= 20 Gy 的后颅窝照射，质子照射的平均耳蜗体积为 34%，IMRT 为 87%，3D-CRT 为 89%）和下丘脑-垂体轴（仅在 >= 后颅窝照射）产生的剂量最小。 10 Gy，质子照射下丘脑-垂体的平均体积为 21%，IMRT 为 81%，3D-CRT 为 91%）；视交叉、眼睛、椎骨、下颌骨、甲状腺、肺、肾脏、心脏和肝脏的剂量进一步减少。调强放射治疗似乎是后颅窝照射的第二佳技术。对于脊柱照射，3D-CRT 电子优于 3D-CRT 光子，对甲状腺、心脏、肺、肾和肝脏的剂量较小。对于盆腔肉瘤，质子在消除对卵巢的任何剂量方面效果更佳（平均卵巢体积的 0% 用 >= 2 Gy 的质子进行照射），并在一定程度上消除了骨盆骨和椎骨。调强放疗确实比其他技术在盆腔肉瘤照射中显示出更多的膀胱剂量减少。结论：在所研究的疾病中，使用 3D-CRT、电子、IMRT 和质子等各种技术，质子在治疗视网膜母细胞瘤、髓母细胞瘤（后窝和颅脊髓）和盆腔肉瘤方面效果最佳。质子提供了卓越的目标剂量覆盖范围并保护正常结构。由于剂量体积参数预计与急性和晚期毒性相关，因此应认真考虑质子治疗作为治疗儿科肿瘤的首选技术。 (c) 2005 年爱思唯尔公司。
Purpose: To calculate treatment plans and compare the dose distributions and dose-volume histograms (DVHs) for photon three-dimensional conformal radiation therapy (3D-CRT), electron therapy, intensity-modulated radiation therapy (IMRT), and standard (nonintensity modulated) proton therapy in three pediatric disease sites.Methods and Materials: The tumor volumes from 8 patients (3 retinoblastomas, 2 medulloblastomas, and 3 pelvic sarcomas) were studied retrospectively to compare DVHs from proton therapy with 3D-CRT, electron therapy, and IMRT. In retinoblastoma, several planning techniques were analyzed: A single electron appositional beam was compared with a single 3D-CRT lateral beam, a 3D-CRT anterior beam paired with a lateral beam, IMRT, and protons. In medulloblastoma, three posterior fossa irradiation techniques were analyzed: 3D-CRT, IMRT, and protons. Craniospinal irradiation (which consisted of composite plans of both the posterior fossa and craniospinal components) was also evaluated, primarily comparing spinal irradiation using 3D-CRT electrons, 3D-CRT photons, and protons. Lastly, in pelvic sarcoma, 3D-CRT, IMRT, and proton plans were assessed.Results: In retinoblastoma, protons resulted in the best target coverage combined with the most orbital bone sparing (10% was the mean orbital bone volume irradiated at >= 5 Gy for protons vs. 25% for 3D-CRT electrons, 69% for IMRT, 41% for a single 3D lateral beam, 51% for a 3D anterolateral beam with a lens block, and 65% for a 3D anterolateral beam without a lens block). A single appositional electron field was the next best technique followed by other planning approaches. In medulloblastoma, for posterior fossa and craniospinal irradiation, protons resulted in the least dose to the cochlea (for only posterior fossa irradiation at >= 20 Gy, 34% was the mean cochlear volume irradiated for protons, 87% for IMRT, 89% for 3D-CRT) and hypothalamus-pituitary axis (for only posterior fossa irradiation at >= 10 Gy, 21% was the mean hypothalamus-pituitary volume irradiated for protons, 81% for IMRT, 91% for 3D-CRT); additional dose reductions to the optic chiasm, eyes, vertebrae, mandible, thyroid, lung, kidneys, heart, and liver were seen. Intensity-modulated radiotherapy appeared to be the second best technique for posterior fossa irradiation. For spinal irradiation 3D-CRT electrons were better than 3D-CRT photons in sparing dose to the thyroid, heart, lung, kidney, and liver. With pelvic sarcoma, protons were superior in eliminating any dose to the ovaries (0% of mean ovarian volume was irradiated at >= 2 Gy with protons) and to some extent, the pelvic bones and vertebrae. Intensity-modulated radiotherapy did show more bladder dose reduction than the other techniques in pelvic sarcoma irradiation.Conclusions: In the diseases studied, using various techniques of 3D-CRT, electrons, IMRT, and protons, protons are most optimal in treating retinoblastomas, medulloblastomas (posterior fossa and craniospinal), and pelvic sarcomas. Protons delivered superior target dose coverage and sparing of normal structures. As dose-volume parameters are expected to correlate with acute and late toxicity, proton therapy should receive serious consideration as the preferred technique for the treatment of pediatric tumors. (c) 2005 Elsevier Inc.