NO对放射性肠炎的影响

目的 研究一氧化氮（NO）对放射性肠炎的影响。确定NO是否参与了放射性肠损伤。方法 用硝酸还原酶特异性地将NO3^-还原为NO2^-。通过显色深浅测定其浓度的高低，从而判断肠组织匀浆中NO的含量。并观察组织形态学变化。结果 放射性肠损伤后，肠组织匀浆NO的含量明显高于正常，并且肠绒毛紊乱，炎性细胞增多，粘膜厚度变薄，腺体被破坏。结论 NO与放射性肠炎的发生发展有关。硝酸还原酶法在放射性肠炎的临床诊断中有一定的应用价值。     

心导管检查所致幼儿患者辐射剂量的研究

本文用热释光剂量、人形模体实验数据结合实际检查条件等方法，对心导管检查所致幼儿甲状腺剂量和入射皮肤剂量进行测量，并以此对有效剂量进行了估算。心导管检查所致幼儿患者左、右甲状腺剂量均值分别为８７４和１３７６ｍＧｙ；入射皮肤剂量均值为８４７ｃＧｙ；有效剂量均值为６９９ｍＳｖ，最高为１３８１ｍＳｖ。在心导管检查中，透视和微缩摄影所用电流时间积均值分别为２２９和６１６１ｍＡ·ｍｉｎ，微缩摄影用电流时间积为透视的１０５～８９２倍，平均为３４０倍。按ＩＣＲＰ６０号出版物给出的随机性效应标称概率系数估算，幼儿接受一次心导管检查所致随机性效应危险度达５１×１０－３。     

飞行人员宇宙辐射受照剂量计算机估算系统

目的为了保障机组人员健康和飞行安全,研究开发宇宙辐射剂量计算机估算系统.方法先通过模拟和测量数据,根据给定日期、地理坐标和海拔计算剂量率,然后按照飞行信息计算航程有效剂量.结果用该系统计算的剂量率和航线剂量的数值结果满足国际放射防护委员会60号出版物的精度要求.结论该计算机宇宙辐射剂量估算系统适用于航空公司辐射防护管理.     

Results of A trial with topotecan dose escalation and concurrent thoracic radiation therapy for locally advanced, inoperable nonsmall cell lung cancer

: To conduct a dose escalation clinical study with topotecan and concurrent standard dose thoracic irradiation to assess its feasibility and toxicity in the treatment of patients with locally advanced, inoperable nonsmall cell lung cancer (NSCLCA).

: Between April 1993 and August 1994, 12 patients with inoperable, loco-regionally advanced NSCLCA were entered in a prospective dose escalation trial and assigned to receive concurrent thoracic radiotherapy and topotecan. Patients received thoracic irradiation to a total tumor dose of 60 Gy in 30 fractions. Initial fields were to encompass the gross disease plus the mediastinum. Topotecan was delivered by bolus injection days 1 through 5, and days 22 through 26, beginning on the same day as the radiation therapy. The initial dose level was 0.5 mg/m². Two additional dose levels of 0.75 mg/m² and 1.0 mg/m² were tested.

: Six patients were accessioned to the 0.5 mg/m² dose level, three patients to the 0.75 mg/m² dose level, and three patients to the 1.0 mg/m² dose level. At the 0.5 mg/m² dose level, zero of six patients had ≥Grade 4 hematologic toxicity. One of the six had Grade 3 esophagitis. At the 0.75 mg/m² dose level, two of three patients had ≥Grade 3 nonhematologic toxicity including anorexia, fatigue, nausea, vomiting, and weakness; zero patients experienced ≥Grade 4 hematologic toxicity. At the 1.0 mg/m² dose level one of three patients had ≥Grade 3 esophagitis, and two of three patients experienced Grade 4 neutropenia. With a follow-up of 12 to 24 months, two patients are alive and free of disease, three patients are alive with disease (two with distant metastasis, one with local disease and distant metastasis), and the remaining seven patients are dead of disease.

: The combination of topotecan and thoracic radiotherapy for nonsmall lung cancer, in the manner given by this protocol, could be safely given at a dose level of only 0.5 mg/m² days 1 to 5 and 22 to 26 with 60 Gy of external beam radiotherapy. Higher doses of topotecan were associated with high hematologic and gastrointestinal toxicity. Distant metastasis was the primary pattern of failure.     

辐射诱发胸腺淋巴瘤中包含易位的染色体畸变

为了研究包含易位的染色体畸变在辐射诱发淋巴瘤过程中的作用，作者分析了供体型Ｔ淋巴瘤细胞的染色体Ｇ带核型。结果观察到，在供体派生的Ｔ细胞淋巴瘤中，有许多数目和结构畸变。有意义的是：几乎在每组淋巴瘤中都发现了含有易位的共同畸变。如：Ｄ组中１１号和１２号染色体的易位；Ｅ组中１２号和１５号钵体的易位；Ａ组和Ｆ组中还有共同的１５号染色体三体。这些结果表明：包含易位的染色体畸变在辐射诱发淋巴瘤过程中可能是重要     

Informed consent in radiation oncology: is consenting easier than informing?

The patient’s right to be informed has been universally recognized and reflected in the legal system of many countries. This right to correct and complete information on behalf of the patient and his admission to proceed with the recommended diagnostic or therapeutic procedure is formalized in the document commonly known as informed consent. Although the legal and bioethical considerations regarding this document have been exhaustively discussed and consensuated, its content continues to create certain doubts and uncertainties. The formal content and the manner in which the consent is obtained are the most difficult aspects. In this article, we analyze what should be included in the written informed consent, with regard to the totality of the information which the patient receives, who should inform, and how the consent should be obtained, as well as how to reflect the different aspects of the variety of radiotherapeutic procedures in the informed consent.     

双源CT前瞻性心电门控序列扫描冠状动脉成像准确性的多中心研究

Objective To investigate the accuracy of low-dose dual-source computed tomography (DSCT) coronary angiography in the step-and-shoot (SAS) mode for the diagnosis of coronary artery stenosis in comparison with conventional coronary angingraphy (CCA).Methods Prospective multiple-center study, 46 patients[mean age(58±9) years;bedy mass index(BMI) (25±3) kg/m2]underwent both DSCT in the SAS mode and CCA within 14 days.The inclusion criteria for contrast-enhanced CT: (1) heart rate less than 65 times/rain (bpm).(2) regular sinus rhythm, heart rate fluctuations within the range of 6 bpm. (3) holding breath well, breath-hold time is about 12-15 s.The exclusion criteria:(1) allergy to iodinecontaining contrast medium, nephropathy (serum creatinine level 120 μmol/L), heart failure and serious arrhythmias.(2) patients with coronary stents or bypass grafts.(3) heart rate can not be controlled very well (4)the patient could not take nitroglycerin.(5)BMI 30 kg/m2.(6) other heart disease: carcliomyopathy, valvular disease etc.Sensitivity, specificity, negative (NPV) and positive predictive value (PPV) were determined with CCA as standard of reference.The Kappa value between the two modalities and the two observers was calculated.Radiation dose values were measured.Results Mean heart rate during scanning was (61±6)bpm.99.19% (614/619) coronary segments were depicted with a diagnostic image quality. The vessel-based sensitivity, specificity, PPV, and NPV for the diagnosis of coronary artery stenosis were 96.2% (75/78), 88.2% (60/68), 90.4% (75/83), and 95.2% (60/63), respectively.The Kappa value between the two modalities was 0.848 (P=0.000).The mean effective dose of the SAS-CTCA was (2.95± 0.96) rosy(1.26-4.32 mSy).Conclusion In selected patients, DSCT coronary angiography in the SAS mode have good image quality, which allows for the accurate diagnosis of coronary stenosis at a low radiation dose.     

Radiofrequency shielding of surface coils at 4.0 t

Because radiation loss associated with a radiofrequency (RF) coil increases as roughly the fourth power of the frequency, this loss mechanism may become important in high-field studies above 2.0 T. In this study, the contribution of radiation losses at 4.0 T were determined in a rectangular surface coil using an RF shield to modify the radiation losses. The effect of this shield was determined on coil Q, B₁ distribution, and signal to noise as a function of distance between the coil and the shield. Phantoms and human tissue were evaluated to characterize the loss mechanisms. The results demonstrate a large radiation loss in the unshielded surface coil. However, the radiation losses in vivo were not dominant owing to a large inductive loss occurring from dielectric currents in the body at 170 MHz.     

MEBO治疗4例放射性顽固性溃疡的体会

目的：寻求简单有效治疗放射性顽固性溃疡方法。方法：全程应用湿润暴露疗法(MEBT)。结果：4例放射性顽固溃疡创面全部愈合。结论：烧伤湿润暴露疗法，对放射性顽固性溃疡治疗效果满意。     

γ源放射事故受照者呕吐开始时间与全身剂量关系

目的探讨γ源放射事故受照者呕吐开始时间与全身吸收剂量之间的关系。方法采用STATA统计软件包对39例γ源放射事故受照者资料进行回顾性分析。结果全身吸收剂量等于或大于1Gy的受照者呕吐发生率(2227)显著大于剂量在1Gy以下的受照者(112,P<0.001)。出现呕吐的受照者,呕吐开始时间(TD,以h表示)与全身吸收剂量D(Gy)之间的关系符合幂函数模型,其方程式可描述为:TD=(17.45±1.77)D-(2.21±0.30)(n=23,F=50.01,P<0.01,经校正的R2=0.8099)。受照后呕吐开始时间在2h以内的P25、P50和P75剂量分别为4.1、7.6和11Gy;呕吐开始时间大于2h的P25、P50和P75剂量分别为2.0、2.4和2.6Gy。结论在突发核或放射事件可能涉及大量患者的情形下,呕吐开始时间可作为早期分类的一个快速而实用的观察指标,但应注意其局限性。