针对射程不确定性的质子调强放疗鲁棒优化方法

目的 因治疗精度高、副作用小,质子调强放疗(IMPT)成为放疗领域的研究热点,但其精度对射程变化非常敏感。本研究提出一种针对射程不确定性的IMPT鲁棒优化方法用于减小射程偏差对放疗计划的影响。方法 首先建立鲁棒优化模型,目标函数采用二次型函数表达式,其中包含3种射程:射程增加、射程正常、射程缩短;每种射程对应的器官剂量贡献矩阵采用质子笔形束算法计算得到。对射程偏差进行离散化,每个射程的发生概率基于高斯分布函数得到。最后采用共轭梯度法优化出最优解,最优解使得靶区和危及器官实际剂量分布在射程偏差内尽量达到期望剂量。结果 采用AAPM TG-119号报告的3套模拟例题测试本研究方法的有效性:鼻咽癌病例、前列腺病例和“C”型病例。与常规IMPT优化结果对比,发现该方法对射程不确定性的敏感性更低。射程发生偏差时,鼻咽癌病例和前列腺病例的靶区和危及器官基本达到期望剂量,“C”型病例的靶区高剂量覆盖率和危及器官保护都有了提高。结论 针对射程不确定性,该方法可得到更高的靶区覆盖率,同时降低危及器官剂量。     

Respuesta a antiangiogénicos en el edema macular secundario a necrosis retiniana aguda

A 55 year-old female patient with unilateral Acute Retinal Necrosis (ARN) developed macular oedema (MO) after the resolution of her necrosis. The macular oedema (MO) was managed and controlled for four years with intravitreal anti-VEGF injections. Anti-VEGF therapy could be useful for the treatment of MO secondary to ARN, the same as for treating MO resulting from panuveitis, where its efficacy has been already demonstrated.     

Prevalence and risk factors of silent brain infarcts in patients with AF detected by 3T-MRI

Journal of Neurology - Silent brain infarcts (SBI), a finding on neuroimaging, are associated with higher risk of future stroke. Atrial Fibrillation (AF) has been previously identified as a cause...     

Research and development of anti-Alzheimer’s disease drugs: an update from the perspective of technology flows

Introduction: Today, over 20 million people suffer from Alzheimer’s disease (AD) worldwide. AD has become a critical issue to human health, especially in aging societies, and therefore it is a research hotspot in the global scientific community. The technology flow method differs from traditional reviews generating an informative overview of the research and development (R&D) landscape in a specific technological area. We need such an updated method to get a general overview of the R&D of anti-AD drugs in light of the dramatic developments in this area in recent years.

Areas covered: This study collects patent data from the Integrity database. A total of 399 patents with 821 internal citation pairs in the US from 1978 to 2017 were analyzed. Patent citation network analysis was used to visualize the technology relationship.

Expert opinion: For better production of anti-AD drugs, governments should emphasize the multi-target drug design, provide policy support for private companies, and encourage multilateral cooperation. The β-amyloid peptide (Aβ) theory leaves much to be desired; neurotransmitter and tau protein hypotheses are worth further examination. The use of old drugs for new indications is promising, as are traditional herbal medicines.