Clinical oxygen enhancement ratio of tumors in carbon ion radiotherapy: the influence of local oxygenation changes.
Clinical oxygen enhancement ratio of tumors in carbon ion radiotherapy: the influence of local oxygenation changes.
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DOI：
10.1093/jrr/rru020
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发表时间：
2014-09
影响因子：
2
通讯作者：
Toma-Dasu I
中科院分区：
文献类型：
--
作者：
Antonovic L;Lindblom E;Dasu A;Bassler N;Furusawa Y;Toma-Dasu I
碳离子放射治疗对乏氧肿瘤的效果最近受到质疑，因为在扩展布拉格峰（SOBP）的低线性能量转移（LET）值。本研究的目的是探讨缺氧和局部氧合变化（LOCs）在分次碳离子放疗中的作用。模拟缺氧亚体积的三维肿瘤，假设分次间LOCs。使用具有已知LET分布的临床相关治疗计划应用不同的分级。计算存活分数，考虑到氧分压，剂量和LET，使用可修复-有条件可修复（RCR）损伤模型的参数为人类唾液腺肿瘤细胞。临床氧增强比（OER）定义为缺氧和氧合良好肿瘤的肿瘤控制概率为50%所需的剂量比。所得OER远高于所有分馏的1。对于缺氧肿瘤，如果假设LOC，而不是静态氧合，则肿瘤控制概率相当高。LOC的有益效果随着组分的数量而增加。然而，对于非常低的分次剂量，与LOC相关的改善不能补偿肿瘤控制所需的总剂量增加。总之，我们的研究结果表明，缺氧可以影响结果的碳离子放疗，因为不可忽略的氧效应在低LETs的SOBP。然而，如果发生LOCs，对于低氧亚体积的肿瘤，采用大范围的分割方案可以实现相对高水平的肿瘤控制概率，但应谨慎进行超分割和低分割。
The effect of carbon ion radiotherapy on hypoxic tumors has recently been questioned because of low linear energy transfer (LET) values in the spread-out Bragg peak (SOBP). The aim of this study was to investigate the role of hypoxia and local oxygenation changes (LOCs) in fractionated carbon ion radiotherapy. Three-dimensional tumors with hypoxic subvolumes were simulated assuming interfraction LOCs. Different fractionations were applied using a clinically relevant treatment plan with a known LET distribution. The surviving fraction was calculated, taking oxygen tension, dose and LET into account, using the repairable–conditionally repairable (RCR) damage model with parameters for human salivary gland tumor cells. The clinical oxygen enhancement ratio (OER) was defined as the ratio of doses required for a tumor control probability of 50% for hypoxic and well-oxygenated tumors. The resulting OER was well above unity for all fractionations. For the hypoxic tumor, the tumor control probability was considerably higher if LOCs were assumed, rather than static oxygenation. The beneficial effect of LOCs increased with the number of fractions. However, for very low fraction doses, the improvement related to LOCs did not compensate for the increase in total dose required for tumor control. In conclusion, our results suggest that hypoxia can influence the outcome of carbon ion radiotherapy because of the non-negligible oxygen effect at the low LETs in the SOBP. However, if LOCs occur, a relatively high level of tumor control probability is achievable with a large range of fractionation schedules for tumors with hypoxic subvolumes, but both hyperfractionation and hypofractionation should be pursued with caution.
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碳离子辐射的氧细胞和缺氧细胞的let依赖性的放射生物学描述。
影响因子：
2
作者：
Antonovic L;Brahme A;Furusawa Y;Toma-Dasu I
通讯作者：
Toma-Dasu I
DOI：
10.1016/j.ijrobp.2005.03.049
发表时间：
2005-07-15
影响因子：
7
作者：
Ljungkvist, ASE;Bussink, J;van der Kogel, AJ
通讯作者：
van der Kogel, AJ
影响因子：
3.5
作者：
Dasu, A;Toma-Dasu, I;Karlsson, M
通讯作者：
Karlsson, M
影响因子：
3.4
作者：
Cromheecke, M;Piers, BA;Hoekstra, HJ
通讯作者：
Hoekstra, HJ
影响因子：
3.4
作者：
Horsman, M. R.;Overgaard, J.
通讯作者：
Overgaard, J.