鼻咽癌Ib区放疗研究进展

放疗可显著改善鼻咽癌患者的预后,但不少患者放疗后出现明显口干,可能与颌下腺的照射有关。颌下腺位于颈部Ib区,目前鼻咽癌Ib区预防性照射指征及靶区勾画尚存争议,该文就鼻咽癌Ib区放疗相关研究作一综述。

鼻咽癌调强放疗Ib区剂量分析

目的:通过分析50例鼻咽癌调强放疗的TPS资料中Ib区、颌下腺的剂量分布特点,为个体化制定鼻咽癌调强放疗计划提供依据。方法:50例于2011年1月至2011年6月接受调强放射治疗(IMRT)的初治鼻咽癌患者被纳入研究。收集所有患者IMRT计划的TPS数据,分析其Ib区、颌下腺计划外受照射体积剂量特点。结果:50例TPS数据中双侧Ib区平均体积为9.03 mm3±2.22 mm3,平均剂量达52.42 Gy±4.30 Gy,V30、V35、V40、V45、V50、V55、V60的百分比分别为99.4%、83.1%,94%、83.1%、64.3%、58.1%、35.5%、21.6%。双侧颌下腺平均体积为7.03 mm3±1.05 mm3,平均剂量为58.51 Gy±5.35 Gy,接受30 Gy、40 Gy、50 Gy、60 Gy的体积分别为100%、99.1%、89.7%、71.2%。结论:在鼻咽癌调强放射治疗中,即使Ib区不予预防照射,Ib区和颌下腺均已接受较高的计划外照射。颌下腺的计划外剂量已经超出其功能保全剂量。

本质安全型电路试验等效电路分析

以本质安全型无源救灾电话电路为例,分析了该电路在不同本质安全试验电气原理等效图下的安全火花试验过程,指出火花试验装置应接入被试电路中可能产生最大火花能量的试验点上,才能保证本质安全型电路通过火花试验后有足够的安全系数。

本质安全型电路的消火花电路分析

消除电感电路放电火花是研究本质安全电路的重要内容。通过对本质安全型电路的消火花电路分析,提出了保护方式和设计方法。结合实例分析不同消火花电路的特点,有助于优化保护电路,提高防爆产品的安全可靠性能。

影响本质安全型电路安全性能因素的实例分析

为保证非本质安全型电路不会对本质安全型电路产生不利影响,以一个矿用隔爆兼本质安全型控制器电路为例,通过对本质安全火花试验要求和影响本质安全防爆性能因素的分析,有助于设计人员理解标准和优化电路设计,以提高防爆产品的安全性能。

Lymph nodes of the perimandibular area: from anatomical classification to pathological role in cancer of the oral cavity, oropharynx and skin

Lymph node status of the neck is the most important prognostic factor in head and neck cancer.Neck dissection,which consists of the systematic excision of the neck nodes,represents the gold standard of surgical treatment in clinically positive necks.In cases in which metastases to lymph nodes of the neck are not detectable,the decision to perform an elective neck dissection depends on the stage and the site of the primary tumor.This narrative review focuses on the anatomical description and oncological role of a group of lymph nodes of the neck that historically has not been well defined.Over the years,several authors have described the groups of lymph nodes that lie where the facial vein crosses the mandible,but to date,no unique definition or a clear view of their oncological role has been proposed.Recently,the term“perimarginal nodes”was coined to refer to this group of lymph nodes,and emphasis was placed on the risk of leaving them undissected during neck dissection.This paper aims to provide a surgical-anatomical classification of these lymph nodes and describe their oncological role on the basis of a review of the relevant literature.