Repairable-conditionally repairable damage model based on dual Poisson processes
Repairable-conditionally repairable damage model based on dual Poisson processes
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DOI：
10.1667/0033-7587(2003)160
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发表时间：
2003-09-01
影响因子：
3.4
通讯作者：
Brahme, A
中科院分区：
文献类型：
--
作者：
Lind, BK;Persson, LM;Brahme, A
调强放射治疗的出现使得当通过旨在最大化肿瘤治愈和最小化正常组织毒性的受控分级剂量分布照射大量正常组织时，准确地模拟响应变得越来越重要。这里提出的细胞存活模型是非常有用的和灵活的健康组织以及肿瘤在经典的和真正的放射生物学优化的放射治疗的反应的准确描述。可修复-有条件可修复（RCR）模型区分两种不同类型的损伤，即潜在可修复的损伤，其也可能是致命的，即如果未修复或错误修复，以及有条件可修复的损伤，其可以修复或如果未正确修复则可能导致细胞凋亡。当潜在可修复的损伤被修复时，例如通过非同源末端连接，有条件可修复的损伤可能另外需要通过同源修复的高保真校正。这两种类型的损伤的诱导被假定为描述泊松统计。所得的细胞存活表达具有独特的能力，能够很好地拟合低剂量（初始超敏范围）、中间剂量（存活曲线的肩部）和高剂量（存活曲线的准指数区域）下的大多数实验数据。完整的泊松表达式可以通过简单的双指数细胞存活表达式S（D）= e（-aD）+ bDe（-cD）很好地近似，其中第一项描述未受损细胞的存活，最后一项表示亚致死损伤完全修复后的存活。双指数表达使得容易导出Do、D、n和α、β值，以便于与经典细胞存活模型进行比较。(C)2003年，辐射研究协会。
The advent of intensity-modulated radiation therapy makes it increasingly important to model the response accurately when large volumes of normal tissues are irradiated by controlled graded dose distributions aimed at maximizing tumor cure and minimizing normal tissue toxicity. The cell survival model proposed here is very useful and flexible for accurate description of the response of healthy tissues as well as tumors in classical and truly radiobiologically optimized radiation therapy. The repairable-conditionally repairable (RCR) model distinguishes between two different types of damage, namely the potentially repairable, which may also be lethal, i.e. if unrepaired or misrepaired, and the conditionally repairable, which may be repaired or may lead to apoptosis if it has not been repaired correctly. When potentially repairable damage is being repaired, for example by nonhomologous end joining, conditionally repairable damage may require in addition a high-fidelity correction by homologous repair. The induction of both types of damage is assumed to be described by Poisson statistics. The resultant cell survival expression has the unique ability to fit most experimental data well at low doses (the initial hypersensitive range), intermediate doses (on the shoulder of the survival curve), and high doses (on the quasi-exponential region of the survival curve). The complete Poisson expression can be approximated well by a simple bi-exponential cell survival expression, S(D) = e(-aD) + bDe(-cD), where the first term describes the survival of undamaged cells and the last term represents survival after complete repair of sublethal damage. The bi-exponential expression makes it easy to derive Do, D, n and alpha, beta values to facilitate comparison with classical cell survival models. (C) 2003 by Radiation Research Society.