Spot scanning proton therapy minimizes neutron dose in the setting of radiation therapy administered during pregnancy.
Spot scanning proton therapy minimizes neutron dose in the setting of radiation therapy administered during pregnancy.
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DOI：
10.1120/jacmp.v17i5.6327
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发表时间：
2016-09-08
影响因子：
2.1
通讯作者：
Grosshans D
中科院分区：
文献类型：
--
作者：
Wang X;Poenisch F;Sahoo N;Zhu RX;Lii M;Gillin MT;Li J;Grosshans D
这是一个真实的案例研究，以尽量减少中子剂量当量（H）的胎儿使用点扫描质子束与有利的束流能量和角度。在中子H测量的指导下，通过迭代计划实现了胎儿的最小中子剂量暴露。计划采用两种高度适形治疗计划（每种计划均采用三个点扫描射束）治疗一名25岁的颅底侵袭性复发性脉络膜炎妊娠女性，该患者选择不进行终止妊娠。每项计划都安排在每隔一天交付，以实现强大的目标覆盖率。使用放置在患者模拟体模的胎儿位置处的REM 500中子测量仪测量胎儿的中子H。4.1两个初始计划的测量值分别为44.1和44.1。能量较高的顶点束流和靠近中心轴的胎儿位置是产生更高数量级中子H的计划的原因。用侧向束代替顶束，减少了中子H，使其与另一个计划相当。对于35次70戈伊的处方，基于单次的最终测量，估计胎儿的总中子H为0.35 mSv。相比之下，被动散射质子计划和光子计划在这种情况下的估计值分别为26和70 mSv。虽然应尽可能避免对妊娠患者进行放射治疗，但我们的工作表明，点扫描射束限制了胎儿的总中子H，其数量级低于建议的5 mSv调节阈值。它远比被动散射束有上级的优越性，仔细选择低能量的束流并使胎儿远离束流轴是最小化胎儿中子照射的关键。PACS编号：87.53.Bn、87.55.D‐、87.55.N‐
This is a real case study to minimize the neutron dose equivalent (H) to a fetus using spot scanning proton beams with favorable beam energies and angles. Minimum neutron dose exposure to the fetus was achieved with iterative planning under the guidance of neutron H measurement. Two highly conformal treatment plans, each with three spot scanning beams, were planned to treat a 25‐year‐old pregnant female with aggressive recurrent chordoma of the base of skull who elected not to proceed with termination. Each plan was scheduled for delivery every other day for robust target coverage. Neutron H to the fetus was measured using a REM500 neutron survey meter placed at the fetus position of a patient simulating phantom. 4.1 and 44.1 were measured for the two initial plans. A vertex beam with higher energy and the fetal position closer to its central axis was the cause for the plan that produced an order higher neutron H. Replacing the vertex beam with a lateral beam reduced neutron H to be comparable with the other plan. For a prescription of 70 Gy in 35 fractions, the total neutron H to the fetus was estimated to be 0.35 mSv based on final measurement in single fraction. In comparison, the passive scattering proton plan and photon plan had an estimation of 26 and 70 mSv, respectively, for this case. While radiation therapy in pregnant patients should be avoided if at all possible, our work demonstrated spot scanning beam limited the total neutron H to the fetus an order lower than the suggested 5 mSv regulation threshold. It is far superior than passive scattering beam and careful beam selection with lower energy and keeping fetus further away from beam axis are essential in minimizing the fetus neutron exposure. PACS number(s): 87.53.Bn, 87.55.D‐, 87.55.N‐
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DOI：
10.1016/s0360-3016(01)02826-7
发表时间：
2002-05-01
影响因子：
7
作者：
Schneider, U;Agosteo, S;Besserer, J
通讯作者：
Besserer, J
影响因子：
3.5
作者：
Jiang, HY;Wang, B;Paganetti, H
通讯作者：
Paganetti, H
影响因子：
1
作者：
Binns, PJ;Hough, JH
通讯作者：
Hough, JH
影响因子：
1.2
作者：
Jia, Sayyed Bijan;Hadizadeh, Mohammad Hadi;Loushab, Mandy Ebrahimi
通讯作者：
Loushab, Mandy Ebrahimi
影响因子：
1
作者：
Liu, JC
通讯作者：
Liu, JC