目的 比较基于等效均匀剂量生物优化与基于剂量-体积物理优化在直肠癌逆向调强治疗计划中的剂量学差异,探讨计划优化方法对计划质量的影响.方法 在已接受调强放疗的直肠癌患者中随机选取15例,采用VarianEc-lipse治疗计划系统,根据不同的优化方法分别制定三种逆向调强放疗计划,其中A组采用传统的剂量-体积(Dose-volume,DV)物理优化,B组采用等效匀剂量(Equivalent uniform dose,EUD)生物优化,C组优化是在物理优化基础上增加生物优化(DV+EUD),通过剂量学参数比较和评估三组优化方法的剂量学差异.结果 三组计划的靶区(PTV)剂量学指标无统计学差异(P＞0.05).在保护膀胱、股骨头方面,B和C组间无统计学差异(P＞0.05),两者均显著优于A组(P ＜ 0.01).在小肠方面,C组优于B组(P ＜ 0.05),B组显著优于A组(P ＜ 0.01),C组显著优于A组(P＜0.01).结论 直肠癌调强放疗计划设计时同时使用物理和生物优化,可以在满足靶区剂量要求的前提下,更好的保护危及器官.

目的 了解介入放射工作人员健康状况,及时发现健康损害,防止职业性放射性疾病的发生和发展.方法 选择山东省5所医院的介入放射工作人员156名为介入组,介入组根据工龄分为≤10、10～20、≥20年3个组,选择非放射工作人员134名为对照组,比较对照组和介入组及不同工龄组外周血淋巴细胞染色体畸变率、抗氧化功能和外周血细胞检测结果.结果 介入组染色体畸变率高于对照组,差异具有统计学意义(P＜0.05);不同工龄组染色体畸变率随工龄的增加逐渐升高,且差异具有统计学意义(P＜0.05).介入组SOD活性和GSH活性均低子对照组,且差异具有统计学意义(P＜0.05),MDA含量高于对照组,但差异无统计学意义(P＞0.05);不同工龄组SOD活性、GSH活性和MDA含量差异均无统计学意义(P＞0.05).介入组白细胞异常检出率和血红蛋白异常检出率均高于对照组,且差异具有统计学意义(P＜0.05);不同工龄组白细胞异常检出率隧工龄的增加逐渐升高,且差异具有统计学意义(P＜0.05).结论 低剂量电离辐射对介入放射工作人员的血液指标产生影响,应加强介入放射的辐射防护工作,定期进行职业健康检查.

目前,对较大或高剂量辐射所引起的生物学效应已经有了充分的认识,而对低剂量辐射所引起生物学效应的认识还很局限.研究表明适应性反应是低剂量辐射诱导细胞产生的效应之一,并涉及DNA损伤反应、免疫/炎症反应和抗氧化反应等多种机制.本文就低剂量辐射适应性反应机制的研究进展进行综述,为相关研究人员提供理论基础.

冠状动脉粥样硬化性心脏病是威胁健康的常见病之一,本研究选取我院2017年2月～2018年12月确诊的206例冠心病患者,其中急性冠脉综合征（acute coronary syndrome,ACS）患者114例（ACS组）、稳定型心绞痛（stable angina pectoris,SAP）患者92例（SAP组）,用双源CT血管造影技术检测患者的斑块性质,并检测了血清明胶酶B（MMP-9）、血小板活化因子（PAF）及脂蛋白相关磷脂酶2（Lp-PLA2）浓度,分析MMP-9、PAF及Lp-PLA2与斑块性质间的关系。结果显示,ACS组患者斑块面积和偏心指数均大于SAP组（P＜0.05）;ACS组患者血清MMP-9、PAF及Lp-PLA2的水平均高于SAP组（P＜0.05）;ACS组患者易损斑块的比例明显高于SAP组（P＜0.05）。所有易损斑块患者血清MMP-9、PAF及Lp-PLA2的水平均高于稳定斑块的患者,且差异具有统计学意义（P＜0.05）。患者冠状动脉斑块偏心指数与血清MMP-9、PAF及Lp-PLA2浓度呈正相关关系（P＜0.05）。因此,通过双源CT血管造影技术观察冠状动脉粥样硬化斑块性质,结合血清MMP-9、PAF及Lp-PLA2浓度,可以对患者的病情进行评估。血清MMP-9、PAF及Lp-PLA2浓度与斑块的性质及不稳定性有关,可为预测患者冠状动脉斑块性质提供参考。

目的 测量γ刀焦点计划剂量与实测剂量的相对偏差,分析产生偏差的原因,探讨提高放射治疗剂量准确性的方法.方法 使用PTW公司UNIDOS型剂量仪、31010型0.125cc电离室、60019型半导体探测器及山东省医学科学院放射医学研究所研制的RTP-H1型放射治疗质量控制检测模体,按照《X、γ射线立体定向放射治疗系统质量控制检测规范》(WS 582-2017)中的测量方法对1台奥沃公司生产的头部γ刀焦点计划剂量与实测剂量的相对偏差进行测量.焦点计划剂量与实测剂量的相对偏差在±5.O％以内的评价为合格.结果 该γ刀4个准直器焦点计划剂量与实测剂量的相对偏差为:-0.31％(18#准直器)、-1.58％(14#准直器)、-0.48％(8#准直器)和0.45％(4#准直器).结论 所检测的该γ刀4个准直器焦点计划剂量与实测剂量的相对偏差全部符合行业标准要求.根据国际原子能机构(IAEA)483号技术报告,使用电离室探测器测量吸收剂量时,电离室探测器有效收集体积的边界和被测照射野边界的距离应满足侧向带电粒子平衡的距离要求.

目的 了解光子放疗靶区计划剂量与实测结果相对偏差的现状,分析产生偏差的原因,促进放射治疗质量控制工作.方法 按照国际原子能机构(IAEA) 277号技术报告中的测量方法对8台医用电子加速器、8台头部伽玛刀、3台螺旋断层放射治疗装置、3台机械臂放射治疗装置的31个放射治疗计划靶区中心处的点剂量进行测量,使用的仪器设备包括PTW公司UNIDOS型剂量仪、31010型0.125cc电离室及山东省医学科学院放射医学研究所研制的RTP-HB1型放射治疗质量控制检测模体.靶点处相对偏差在±5.0％以内的测量结果评价为合格.结果 31个靶点剂量偏差总体合格率为90.3％.其中,加速器合格率为92.3％,头部伽玛刀合格率为87.5％,螺旋断层放射治疗装置及机械臂放射治疗装置合格率均为100％.结论 放射治疗靶区计划剂量与实测结果相对偏差的总体合格率较高,但仍有必要加强放射治疗的质量控制工作.

目的探讨 99 Tc m -MIBI SPECT/CT显像在原发性甲状旁腺功能亢进症（PHPT）中的诊断价值。方法回顾性分析为诊断PHPT而行 99 Tc m -MIBI SPECT/CT显像检查的57例患者的临床资料,以术后病理诊断为金标准,与高频超声、CT结果对比,分别统计三种检查方法的灵敏度、特异度、诊断符合率,将三种检查方法的灵敏度、特异度、诊断符合率加以对比分析。结果 57例病人经手术及病理检查共确诊76个PHPT病灶。 99 Tc m -MIBI SPECT/CT显像、高频超声、CT敏感度分别为75%、69.73%、50.94%;特异度分别为93.75%、96.07%、95.08%;诊断符合率分别为83.57%、80.31%、74.56%。 99 Tc m -MIBI SPECT/CT显像敏感度、诊断符合率高于CT（P＜0.05）, 99 Tc m -MIBI SPECT/CT显像对异位PHPT病灶诊断的敏感度为100%。结论 99 Tc m -MIBI SPECT/CT显像在PHPT病灶的定位中有较高的价值,是术前定位的较好方法。

The radioprotective effect of lactoferrin (LF) was studied in mice subjected to sublethal X-ray irradiation. The mice were randomly divided into the Control (non-irradiated mice fed a standard diet without LF), IR (irradiated mice fed a standard diet) and IR+LF (irradiated mice fed LF) groups. The mice were fed daily for 7 days prior to irradiation and for 30 continuous days following irradiation. The survival ratio of the mice in the IR+LF group was significantly increased compared with the IR group between days 15 and 30 after irradiation. The body weight of the mice in the IR+LF group was increased compared with the IR group, and the difference was statistically significant. Blood was collected from the mice via the tail vein on days 2, 7, 14, 21 and 30 following irradiation. The laboratory indicators, including leukocyte, erythrocyte and platelet counts recovered more rapidly following irradiation in the IR+LF group compared with the IR group. Treatment of the irradiated mice with LF significantly reduced the DNA damage. In the hepatic tissue the level of superoxide dismutase in the IR+LF group was significantly increased, while malondialdehyde was significantly decreased compared with the IR group. These findings indicate that LF may prevent radiation damage and may have potential as a treatment for patients with cancer who receive radiotherapy.

As a promising method for treating intractable epilepsy, the inhibitory effect of low-frequency stimulation (LFS) is well known, although its mechanisms remain unclear. Excessive levels of cerebral glutamate are considered a crucial factor for epilepsy. Therefore, we designed experiments to investigate the crucial parts of the glutamate cycle. We evaluated glutamine synthetase (GS, metabolizes glutamate), glutaminase (synthesizes glutamate), and glutamic acid decarboxylase (GAD, a γ-aminobutyric acid [GABA] synthetase) in different regions of the brain, including the dentate gyrus (DG), CA3, and CA1 subregions of the hippocampus, and the cortex, using western blots, immunohistochemistry, and enzyme activity assays. Additionally, the concentrations of glutamate, GABA, and glutamine (a product of GS) were measured using high-performance liquid chromatography (HPLC) in the same subregions. The results indicated that a transiently promoted glutamate cycle was closely involved in the progression from focal to generalized seizure. Low-frequency stimulation (LFS) delivered to the ventral hippocampus had an antiepileptogenic effect in rats exposed to amygdaloid-kindling stimulation. Simultaneously, LFS could partly reverse the effects of the promoted glutamate cycle, including increased GS function, accelerated glutamate-glutamine cycling, and an unbalanced glutamate/GABA ratio, all of which were induced by amygdaloid kindling in the DG when seizures progressed to stage 4. Moreover, glutamine treatment reversed the antiepileptic effect of LFS with regard to both epileptic severity and susceptibility. Our results suggest that the effects of LFS on the glutamate cycle may contribute to the antiepileptogenic role of LFS in the progression from focal to generalized seizure.

The aim of the present study was to investigate whether low-dose priming radiation induces antitumor immunity that can be augmented by the modulation of natural killer (NK) cell and cytokine activity using a mouse tumor model. Walker-256 cells were injected into the right flank of male BALB/c mice. At 7 days after inoculation, mice were divided into three groups, including group 1,2,3. In group 1 the mice were without radiation, in group 2 the mice were received 2 Gy radiation only, and in group 3 the mice were radiated with a priming dose of 75 mGy followed by 2 Gy radiation after 24 h. On day 21 following the radiation, the tumors were removed and the tumor index (tumor weight as a percentage of body weight) was calculated. At 1, 7, 14 and 21 days following the 2 Gy radiation, mouse splenocytes were isolated to analyze the NK activity and measure the production of the cytokines interleukin-1β, interferon-γ and tumor necrosis factor-α by ELISA. Apoptosis was also measured by flow cytometry. The results demonstrated that priming radiation significantly delayed the tumor growth and prolonged the median survival time to 38 days compared with the 31-day survival in the 2 Gy radiation group. The percentage of apoptotic cells was significantly higher in the mice that received 75 mGy + 2 Gy radiation compared with that in the mice that received 2 Gy alone; by contrast, mice that were not irradiated exhibited a relatively low level of apoptosis. The primed mice had a higher level of NK activity as compared with the mice exposed to 2 Gy radiation only or mice that were not irradiated. Furthermore, cytokine expression remained at a higher level in mice receiving priming dose of radiation compared that in the mice receiving only 2 Gy radiation. In conclusion, the results indicated that low-dose priming X-ray radiation may enhance the NK activity and the levels of cytokines, and that the immune response serves an important role in anticancer therapy, including radiotherapy.

Objective To study its influence on the 30th day suivival rate,the antioxidant in mice and to study the preventive effects of hLF on radiation damage as well as its possible mechanism.Methods The mice were randomly divided into three groups:normal control group 、radiated control group and human lactoferrin protection group.The normal and radiated control groups were given isotonic Na chloride,once a day in seven days pre-irradiation.But protection group was given hLF,Mice in radiated control and protection group were exposed to X-ray after the last adminstration.All indexes were measured in the 24 h after radiation.Indexes include the 30-day survival rate of mice,the content of MDA,the SOD activity.The hepatic histopathologic changes were observed by microscopy.Results hLF could raise the 30-days survival rate of mice,and minimize the increasing degree of MDA and the decreasing degree of the activities of SOD.About protection group,liver damage reduced.Conclusion hLF can raise survival rate of radiated mice,enhance the their antioxidant ability.So we can conclude that the hLF may have some preventive effects on mice exposed to radiation.

目的 探讨数字乳腺X射线机应用Mo/Mo、Mo/Rh、W/Rh 3种不同靶滤过组合对辐射剂量的影响,以便优化选择摄影技术参数,降低受检者的辐射损伤.方法 应用Siemens MAMMOMAT Inspiration数字乳腺X射线机,RaySafe X射线质量检测仪.首先使用全自动曝光模式对不同厚度的PMMA模体进行曝光并记录管电流量、管电压等摄影参数,然后采用相同的管电压、管电流量、压迫厚度在不同的靶滤过组合(Mo/Mo、Mo/Rh、W/Rh)模式下进行手动曝光,读取并记录体表入射剂量(ESD),计算平均腺体剂量(AGD).对不同模体厚度在使用3种不同靶滤过组合时产生的平均腺体剂量进行随机区组的方差分析,采用线性相关和回归观察不同靶滤过组合及不同厚度与AGD的相关性并列出直线回归方程.结果 3种靶滤过组合对不同厚度模体产生的AGD差异有统计学意义,Mo/Mo组合的AGD最高,W/Rh组合的AGD显著降低.使用不同靶滤过组合时模体厚度与AGD均呈显著正相关.结论 W/Rh组合AGD明显低于其他两种组合,乳腺X射线摄影时采用W/Rh组合是最佳选择,可显著降低受检者的辐射剂量.

Objective To test and analyze out-of-field organ dose in intracranial tumor radiotherapy with or without wedges and in different radiation field areas. Methods The absorbed doses of out-of-field organs were measured using a thermoluminescent dosimeter by intracranial tumor radiotherapy simulation in the domestic phantom. The tests were grouped according to radiation field areas and techniques. Common square field techniques do not use wedges, whereas 3D conformal radiotherapy(3D-CRT) uses wedges. The radiation field area was divided into 2 cm × 2 cm and 4 cm × 4 cm fields. Results The absorbed doses of out-of-field organs ranged from 0.13 mGy to 2.83 mGy per 100 cGy prescription dose. The doses of organs adjacent to the target area are higher after irradiation using the 4 cm × 4 cm field than after irradiation using the 2 cm × 2 cm field(t=-5.023, P=0.004);however, no statistically significant(t=-1.438, P=0.171) difference can be found in organs non-adjacent to the target area. The doses of organs are higher after irradiation using 3D-CRT with a wedge than after irradiation using common square field techniques without a wedge regardless of whether the organs are adjacent to the target area or not (t 头=-2.805, P=0.038;t 腹=-11.966, P=0.000). Conclusions The absorbed doses of out-of-field organs of the patients who received intracranial tumor radiotherapy are associated with radiation field areas and techniques. The doses of organs adjacent to the target area increase as the radiation field area increases in size. Given a uniform radiation field area and prescription dose, the absorbed doses of out-of-field organs irradiated by radiotherapy techniques with wedges are higher than those of organs irradiated by radiotherapy techniques without wedges.

目的 探讨小儿肠套叠在数字脉冲透视整复中的辐射剂量优化,为降低小儿在X射线透视整复中的辐射剂量提供一种切实可行的方法.方法 通过调研相关文献并结合研究的目的和原理,采用数字胃肠机低脉冲透视对小儿肠套叠胃肠整复治疗.结果 实验组(脉冲率=3P/s)60例,影像诊断的符合率为100％,空气灌肠整复的成功率为95％;对照组(脉冲率=7.5P/s)60例,影像诊断的符合率为100％,空气灌肠整复的成功率93.3％.两者在诊断符合率与整复成功率无明显差别,但在所接受辐射次数上实验组是对照组的39.25％.结论 降低数字胃肠机的透视脉冲率既可满足临床诊断和治疗需求,又可以降低肠套叠患儿的辐射剂量,值得在小儿肠套叠数字透视整复治疗中应用.

目的 分析全数字化钼靶摄影对于乳腺癌的诊断价值,提高钼靶摄影检查的准确率.方法 回顾性分析我院经手术及病理证实且临床资料完整的45例乳腺癌患者,对其临床、病理及影像资料进行分析,并对比全数字化钼靶摄影和B超对于乳腺癌的诊断符合率.结果 好发部位:外上象限26例,占57.8％,临床主要症状:触及肿块95.6％,病理类型:浸润性导管癌32例,导管内癌4例.术前钼靶诊断符合率为88.89％,误诊率为11.11％.B超诊断符合率为77.78％,误诊率为22.22％.结论 全数字化钼靶摄影是乳腺癌的重要检查方式,可以明显提高乳腺癌的诊断符合率.

The prognosis of patients exposed to a sub-threshold dose of a proconvulsant is difficult to establish. In this study, we investigated the effect of a single sub-threshold dose of the proconvulsant pilocarpine (PILO) on the progression of seizures that were subsequently induced by daily electrical stimulation (kindling) of the amygdaloid formation. Male Sprague–Dawley rats were each implanted with an electrode in the right basolateral amygdala and an indwelling cannula in the right ventricle. The animals were randomized into groups and were administered one of the following treatments: saline, PILO, saline+L-α-aminoadipic acid (L-AAA; one dosage tested), PILO+L-AAA, or PILO+L-methionine sulfoximine (three dosages tested). Amygdaloid stimulation and electroencephalography were performed once daily. We performed immunohistochemistry and western blot for glial fibrillary acidic protein and glutamine synthetase (GS). We also assayed the enzymic activity of GS in discrete brain regions. An intraperitoneal injection of a sub-threshold PILO dose enhanced the progression of amygdaloid-kindling seizures and was accompanied by an increase in reactive-astrocyte and GS (content and activity) in the hippocampus and piriform cortex. L-AAA and L-methionine sulfoximine, inhibitors of astrocytic and GS function, respectively, abolished the effect of PILO on amygdaloid-kindling seizures. We conclude that one sub-threshold dose of a proconvulsant may enhance the progression of subsequent epilepsy and astrocytic GS may play a role in this phenomenon. Thus, a future therapy for epilepsy could be inhibition of astrocytes and/or GS.

Objective To compare the single-shot fields irradiated by three focusing modes of γ-knife and explore the approaches for improving the quality of stereotactic radiosurgery.Methods GAFCHROMIC(R) EBT3 mode flushing-free film was used to measure the single-shot fields irradiated by multi-source static focusing modes,multi-source single-axis rotating focusing mode and single-source double-axis rotating focusing mode of γ-knife.Also the uniformity and penumbra of the single-shot fields were compared.Results The 2D dose distribution of the single-shot fields irradiated by three focusing modes of γ-knife was different.In the axis (x,y,z),the rang of penumbra axial length ratios of multisource static focusing modes,multi-source single-axis rotating focusing mode and single-source double-axis rotating focusing mode were 0.13-0.48,0.17-0.33 and 0.28-0.54,in the diagonal direction of the wings plane (NSD,PSD),were 0.31-0.39,0.38-0.43 and 0.54-0.72,respectively;the penumbra axial length ratio of single-source double-axis rotating focusing mode was bigger than in multi-source static focusing modes and multi-source single-axis rotating focusing mode.On the no-wings plane,the area ratios of 80％ dose curve enveloped and 50％ dose curve enveloped(A80％/A50％)were 0.40,0.47 and 0.19,on the wings plane,were 0.61,0.53 and 0.35,respectively.The field uniformity of multi-source static focusing modes and multi-source single-axis rotating focusing mode were superior to single-source doubleaxis rotating focusing mode.Conclusions Considering dose distribution of the single-shot fields,the multi-source static focusing modes devices and the multi-source single-axis rotating focusing mode devices should be preferred,when important tissues and organs are adjacent to the target areas.Compared with single-source double-axis rotating focusing mode,both multi-source static focusing modes and multi-source single-axis rotating focusing mode could make more target areas to be surrounded by high dose region.

目的 选取乳腺X射线摄影检出的BI-RADS4类微钙化病变56例,通过分析评估其X射线表现特点及对应的DCE-MRI表现特点,探讨动态对比增强磁共振成像对此类病变的诊断效能和对临床制订诊治方案的指导价值.方法 回顾性分析2013年11月至2015年8月由数字化乳腺X射线摄影检出的BI-RADS 4类微钙化56例,双乳动态对比增强磁共振成像均于穿刺活检术前完成,以病理诊断为金标准,对微钙化的X射线和MRI表现特点进行分析和评估,并按照ACR BI-RADS标准进行分类,后与相应的组织病理学表现进行对照分析.结果 56例由乳腺X射线摄影检出的BI-RADS 4类微钙化,BI-RADS 4A类病变,MRI多表现为点状强化和无强化;BI-RADS 4B及4C类病变,MRI多表现为肿块样强化和非肿块样强化.MRI强化方式和乳腺X射线摄影钙化的形态学和分布(BI-RADS分类)差异具有统计学意义.结论 中等可疑恶性钙化(BI-RADS 4类)是乳腺X射线摄影的诊断难点,结合MRI表现特点有助于其良恶性病变的鉴别诊断,对临床诊疗方案的制定具有较高的指导价值.

目的 调查医用电子加速器辐射野的半影状况,探讨提高放射治疗质量的措施.方法 使用GAFCHROMIC@EBT3型免冲洗胶片和固体水模对27台医用电子加速器的36个X射线辐射野及16个电子线辐射野进行半影检测.结果 X射线辐射野半影范围2.76 mm～5.95 mm;电子线辐射野半影范围8.70 mm～12.73 mm.医科达公司加速器X射线辐射野AB方向上半影大于GT方向上半影,差异有统计学意义(P＜0.05);瓦里安公司和西门子公司加速器X射线辐射野AB方向上半影小于GT方向上半影,差异有统计学意义(P＜0.05).结论 对医用电子加速器辐射野的半影应提出限值要求.不同厂家生产的加速器X射线辐射野的半影存在方向上的差别,了解这种差别有助于优化放疗计划,从而更好的保护靶区周围的组织器官.