Repeated tumor pO2 measurements by multi-site EPR oximetry as a prognostic marker for enhanced therapeutic efficacy of fractionated radiotherapy
Repeated tumor pO2 measurements by multi-site EPR oximetry as a prognostic marker for enhanced therapeutic efficacy of fractionated radiotherapy
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DOI：
10.1016/j.radonc.2008.10.015
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发表时间：
2009-04-01
影响因子：
5.7
通讯作者：
Khan, Nadeem
中科院分区：
文献类型：
--
作者：
Hou, Huagang;Lariviere, Jean P.;Khan, Nadeem
目的：研究单次或分次放疗对皮下 RIF-1 肿瘤 pO(2) 的时间影响，并确定以肿瘤 pO(2) 指导分次时机时的治疗结果。方法：通过多部位电子顺磁共振 (EPR) 血氧测定法跟踪肿瘤 pO(2) 变化的时间过程。对肿瘤进行单次10、20和10 Gy x 2剂量治疗，并连续六天重复测量肿瘤pO(2)。在 10 Gy x 2 组中，在肿瘤相对充氧或缺氧时给予第二剂 10 Gy。跟踪肿瘤体积的变化九天以确定治疗结果。结果：10 Gy 照射后 24 小时观察到肿瘤 pO(2) 显着增加，而 20 Gy 导致照射后 72-120 小时肿瘤 pO(2) 显着增加。与缺氧 48 小时处理的肿瘤相比，在 24 小时进行第二次 10 Gy 剂量照射的肿瘤，当肿瘤缺氧时，肿瘤倍增时间 (DT) 显着增加 (p < 0.01)。结论：结果表明，肿瘤氧合时间取决于照射剂量，如果将照射安排在肿瘤氧合增加的时间，则可以优化放射治疗效果。体内多部位 EPR 血氧测定法可用于在分次方案中重复监测肿瘤 pO(2)，以优化放射治疗结果。该技术还可用于识别有反应和无反应的肿瘤，这将有助于在治疗过程的早期时间点设计针对无反应肿瘤的其他治疗方法。 (C) 2008 Elsevier Ireland Ltd. 保留所有权利。放射治疗与肿瘤学91（2009）126-131
Purpose: To investigate the temporal effects of single or fractionated radiotherapy on subcutaneous RIF-1 tumor pO(2) and to determine the therapeutic outcomes when the timing of fractionations is guided by tumor pO(2).Methods: The time-course of the tumor pO(2) changes was followed by multi-site electron paramagnetic resonance (EPR) oximetry. The tumors were treated with single 10, 20, and 10 Gy x 2 doses, and the tumor pO(2) was measured repeatedly for six consecutive days. In the 10 Gy x 2 group, the second dose of 10 Gy was delivered at a time when the tumors were either relatively oxygenated or hypoxic. The changes in tumor Volumes were followed for nine days to determine the therapeutic outcomes.Results: A significant increase in tumor pO(2) was observed at 24 h post 10 Gy, while 20 Gy resulted in a significant increase in tumor pO(2) at 72-120 h post irradiation. The tumors irradiated with a second dose of 10 Gy at 24 h, when the tumors were oxygenated, had a significant increase in tumor doubling times (DTs), as compared to tumors treated at 48 h when they were hypoxic (p < 0.01).Conclusion: Results indicate that the time of tumor oxygenation depends on the irradiation doses, and radiotherapeutic efficacy could be optimized if irradiations are scheduled at times of increased tumor oxygenation. In vivo multi-site EPR oximetry could be potentially used to monitor tumor pO(2) repeatedly during fractionated schemes to optimize radiotherapeutic outcome. This technique could also be used to identify responsive and non-responsive tumors, which will facilitate the design of other therapeutic approaches for non-responsive tumors at early time points during the course of therapy. (C) 2008 Elsevier Ireland Ltd. All rights reserved. Radiotherapy and Oncology 91 (2009) 126-131