Dose-response effect of human equivalent radiation in the murine mandible: Part II. A biomechanical assessment.
Dose-response effect of human equivalent radiation in the murine mandible: Part II. A biomechanical assessment.
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DOI：
10.1097/prs.0b013e31822b67ae
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发表时间：
2011-11
影响因子：
3.6
通讯作者：
Buchman SR
中科院分区：
文献类型：
--
作者：
Tchanque-Fossuo CN;Monson LA;Farberg AS;Donneys A;Deshpande SS;Razdolsky ER;Halonen NR;Goldstein SA;Buchman SR
尽管头颈部癌症的辅助放射治疗被广泛使用，但对底层骨的损伤程度还不清楚。然而，患者可能会遭受严重的临床后果，包括病理性骨折、骨不连和放射性骨坏死。作者的具体目标是客观地量化辐射对小鼠下颌骨生物力学特性的人体等效辐射剂量反应效应。将12只Sprague-Dawley大鼠随机分为3个辐射剂量组-低（5.91戈伊）、中（7戈伊）和高（8.89戈伊），每天分5次给药。分次治疗方案分别约为人类在常规头颈癌治疗中接受的生物等效剂量的75%、100%和150%。辐照后五十六天，以0.5 mm/s的速度在单轴拉伸条件下加载半下颌骨直至失效。分析屈服载荷和断裂载荷的载荷位移曲线，认为p < 0.05时的值具有统计学显著性。作者的数据表明，屈服和断裂载荷指标在统计学上显著降低。作者报告的低、中和高辐射剂量的平均值分别为162、136和69 N（产量）; 215、211和141 N（断裂载荷）。这两种定量生物力学特性都以剂量-反应模式减少。在这篇文章中，作者报告了分次人体等效辐射后下颌骨生物力学性能退化的剂量反应效应。作者的发现和模型现在可以用来制定治疗方法，旨在补救这些影响，并在头颈部癌症患者的辅助放疗后增强骨再生和愈合。
Despite the widespread use of adjuvant irradiation for head and neck cancer, the extent of damage to the underlying bone is not well understood. However, patients can suffer serious clinical consequences, including pathologic fractures, nonunion, and osteoradionecrosis. The authors’ specific aim was to objectively quantify the human equivalent radiation dose-response effect of radiation on the biomechanical properties of the murine mandible. Twelve Sprague-Dawley rats were randomized into three radiation dosage groups—low (5.91 Gy), middle (7 Gy), and high (8.89 Gy)—delivered in five daily fractions. The fractionation regimen was used to approximate 75, 100, and 150 percent, respectively, of the bioequivalent dose humans receive in conventional head and neck cancer treatment. Fifty-six days after irradiation, hemimandibles were loaded to failure in a uniaxial tension at 0.5 mm/second. Load displacement curves were analyzed for yield and breaking load, and values were considered statistically significant at p < 0.05. The authors’ data demonstrated a statistically significant decrease in the yield and breaking load metrics. The authors’ reported averages for low, middle, and high radiation dosages were 162, 136, and 69 N, respectively, for yield; and 215, 211, and 141 N, respectively, for breaking load. Both of these quantitative biomechanical properties were diminished in a dose-response pattern. In this article, the authors report a dose-response effect in the degradation of the biomechanical properties of the mandible after fractionated human equivalent radiation. The authors’ findings and model can now be used to formulate therapies aimed at remediating those effects and augmenting bone regeneration and healing after adjuvant radiotherapy in head and neck cancer patients.