Enhanced delivery of iodine for synchrotron stereotactic radiotherapy by means of intracarotid injection and bloodbrain barrier disruption:: Quantitative iodine biodistribution studies and associated dosimetry
Enhanced delivery of iodine for synchrotron stereotactic radiotherapy by means of intracarotid injection and bloodbrain barrier disruption:: Quantitative iodine biodistribution studies and associated dosimetry
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DOI：
10.1016/j.ijrobp.2004.12.026
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发表时间：
2005-03-15
影响因子：
7
通讯作者：
Elleaume, H
中科院分区：
文献类型：
--
作者：
Adam, JF;Biston, MC;Elleaume, H
目的：同步加速器立体定向放射治疗（SSR）是一种二元癌症治疗方式，涉及在肿瘤中选择性积累高Z元素，如碘，然后用来自同步加速器源的千伏X射线进行立体定向照射。SSR的成功与肿瘤中可获得的碘的绝对量直接相关。该临床前研究的目的是确定是否可以通过颈动脉内注射（有或没有高渗溶液）来增强碘向大鼠脑肿瘤模型的递送，并评估相应的吸收X射线剂量。实验在四组F98胶质瘤荷瘤大鼠上进行，其接受颈动脉内（IC）或静脉内（IV）输注与或不与瞬时血脑屏障开放剂（甘露醇）联合的碘化造影剂的混合物（12分钟内6 mL）。混合物体积比例分别为8/13的洛美隆（C = 350 mg/mL）与5113的甘露醇或生理盐水。通过单色计算机断层扫描在体内测量肿瘤、血液、对侧和同侧脑和肌肉中的绝对碘浓度动力学。通过计算每个区域的碘剂量增强因子（DEF）和构建剂量分布图，进行相关的剂量测定分析simulation.Results：甘露醇输注显着增强碘肿瘤摄取与对照值相比（p < 0.0001和p = 0.0138，分别为IC和IV协议）。碘和甘露醇给药后，平均碘浓度（C）达到20.5 +/- 0.98 mg/mL（DEF = 4.1），而i.c.给药后为4.1 +/- 1.2 mg/mL。血清（DEF 1.6）。颈静脉注射甘露醇后的肿瘤碘摄取（C = 4.4 +/- 2.1 mg/mL，DEF = 1.7）与IC注射碘（不含甘露醇）无显著差异（p = 0.8142）。碘与生理盐水的IV注射导致肿瘤中的碘浓度为1.2 ± 0.98 mg/mL，DEF为1.2。结论：本研究建立了通过IC注射结合血脑屏障开放剂（甘露醇）优化碘的递送显著增加F98大鼠胶质瘤的碘摄取。这种输注方案可能会提高SSR治疗的疗效，因为辐射剂量与照射床中存在的碘量成比例。(c)2005年爱思唯尔公司
Purpose: Synchrotron stereotactic radiotherapy (SSR) is a binary cancer treatment modality that involves the selective accumulation of a high Z element, such as iodine, in tumors, followed by stereotactic irradiation with kilovoltage X-rays from a synchrotron source. The success of SSR is directly related to the absolute amount of iodine achievable in the tumor. The purposes of this preclinical study were to determine whether the delivery of iodine to brain tumor models in rats could be enhanced by the means of its intracarotid injection with or without a hyperosmotic solution and to evaluate corresponding absorbed X-ray doses.Methods and Materials: Experiments were performed on four groups of F98 glioma-bearing rats, which received either intracarotid (IC) or intravenous (IV) infusions of a mixture (6 mL in 12 min) of an iodinated contrast agent associated or not with a transient blood-brain barrier opener (mannitol). The mixture volumetric proportions were 8/13 of lomeron (C = 350 mg/mL) for 5113 of mannitol or saline, respectively. Absolute iodine concentration kinetic was measured in vivo in the tumor, blood, contralateral and ipsilateral brain, and muscle by monochromatic computed tomography. Associated dosimetry was performed by computing the iodine dose enhancement factor (DEF) in each region and building dose distribution maps by analytical simulations.Results: Infusion of mannitol significantly enhanced iodine tumor uptake compared with the control values (p < 0.0001 and p = 0.0138, for IC and IV protocols, respectively). The mean iodine concentrations (C) reached 20.5 +/- 0.98 mg/mL (DEF = 4.1) after administration of iodine and mannitol vs. 4.1 +/- 1.2 mg/mL i.c. with serum (DEF 1.6). The tumor iodine uptakes after jugular injection with mannitol (C = 4.4 +/- 2.1 mg/mL, DEF = 1.7) were not significantly different from IC injection of iodine without mannitol (p = 0.8142). The IV injection of iodine with saline led to an iodine concentration in the tumor of 1.2 0.98 mg/mL and a DEF of 1.2.Conclusions: This study established that optimizing the delivery of iodine by means of IC injection combined with a blood-brain barrier opener (mannitol) significantly increases the iodine uptake of F98 rat gliomas. This infusion protocol could potentially enhance the efficacy of SSR treatment, because the radiation dose is proportional to the iodine amount present in the irradiation bed. (c) 2005 Elsevier Inc.