Medium‐dose‐rate brachytherapy for cancer of the cervix: Preliminary results of a designed schedule

Aim: This retrospective analysis aims to report results from patients with cervical cancer treated by external beam radiation (EBR) with telecobalt and medium‐dose‐rate (MDR) brachytherapy and to establish the magnitude of brachytherapy dose reduction. Methods: Between June 2003 and September 2005, 77 patients with histological diagnosis of cervical carcinoma were treated with cobalt for external beam radiation, followed by one or two insertions of MDR with a dose rate from 220 ± 10 cGy/h. Median dose of EBR at whole pelvis was 50 Gy and the planned MDR schedule consisted of 1 or 2 insertions with 10–12 Gy to point A. Results: 77 patients were followed for median of 15 months (range: 1–33 months). Local control was achieved in 63 patients 81.8%. Local failure and overall failure rates were 11.7% and 19.5%, respectively. Overall incidence of rectal and bladder complication was 9.0% (7/77) and 7.8% (6/77), respectively. Conclusion: Results of this series suggest that use of telecobalt for EBR together with MDR brachytherapy with a dose reduction around 20% in comparison with low‐dose‐rate (LDR) brachytherapy can be an acceptable technique, especially in developing countries.     

The Operational Multiple Dosing Half-life: A Key to Defining Drug Accumulation in Patients and to Designing Extended Release Dosage Forms

Half-life (t _1/2) is the oldest but least well understood pharmacokinetic parameter, because most definitions are related to hypothetical 1-compartment body models that don’t describe most drugs in humans. Alternatively, terminal half-life (t _1/2,z) is utilized as the single defining t _1/2 for most drugs. However, accumulation at steady state may be markedly over predicted utilizing t _{1/2, z}. An apparent multiple dosing half-life (t _{1/2, app}) was determined from peak and trough steady-state ratios and found to be significantly less than reported terminal t _1/2s for eight orally dosed drugs with t _1/2,z values longer than one day. We define a new parameter, “operational multiple dosing half-life” (t _{1/2, op}), as equal to the dosing interval at steady-state where the maximum concentration at steady-state is twice the maximum concentration found for the first dose. We demonstrate for diazepam that the well-accepted concept that t _1/2,z representing the great majority of the AUC will govern accumulation can be incorrect. Using oral diazepam, we demonstrate that t _{1/2, op} is remarkably sensitive to the absorption t _1/2, even when this absorption t _1/2 is much less than t _1/2,z, and describe the relevance of this in designing extended release dosage forms. The t _{1/2, op} is compared with previously proposed half-lives for predicting accumulation.     

Hypofractionated Whole-Breast Radiotherapy: Impact on Departmental Waiting Times and Cost

Conventionally fractionated breast radiation therapy is delivered over 5–6 weeks. Randomised evidence has shown that hypofractionated whole-breast radiotherapy (HWBRT) over 3 weeks results in similar local control without increased toxicity. HWBRT is not standard practice in Australia for all eligible women. We examined the effect of using HWBRT (for eligible patients) on waiting lists and monetary costs. We identified factors associated with prescribing HWBRT. The Princess Alexandra Hospital Radiation Oncology Database was searched for all women with breast cancer treated with adjuvant radiotherapy in 2008. Included patients had undergone breast conserving surgery and had T1-2N0 tumours with negative margins. Women with large breasts and those receiving nodal irradiation were excluded. The outcome evaluated was fractionation schedule. Patient, tumour and treatment factors associated with the use of HWBRT were examined. The impact on departmental resources and health-care costs were calculated assuming the entire cohort received HWBRT. Two hundred seventy-nine patients met the inclusion criteria. Sixty-seven (24%) of these patients were treated with HWBRT. Compared with the conventionally fractionated breast radiation therapy group, the HWBRT group were older (median 69 vs. 54 years; P < 0.001) and more likely to have smaller tumours (12 mm vs. 15 mm; P = 0.02). Had all eligible patients received HWBRT an extra 14 patients each month could be treated and health-care costs would be reduced by 24%. HWBRT was more frequently prescribed in older women with small tumours. More widespread use of HWBRT would allow significantly more patients to be treated each month with considerable cost savings.     

我国天然环境电离辐射外照射剂量的调查与评价

本文介绍了我国天然辐射外照射水平及其所致的居民剂量。测量仪器是国产FD-7l型闪烁辐射仪和美制RSS-111型高压电离室。室外调查点共38611个, 室内点共53952个,道路共37727个。相应的天然γ辐射水平人口加权平均值分别为8.03×10^-3Gyh^-1、11.95×10^-3Gyh^-1和7.95×10^-3膏Gyh^-1室外宇宙射线电离成分空气吸收剂量率人口加权平均值为3.30×10^-3Gyh^-1,室内为3.00×10^-3Gyh^-1.天然外照射所致居民人均年有效剂量当量为952μsv,集体年有效剂量当量为9.6×10^-3man·sv,天然γ辐射对有效剂量当量的贡献占72%,宇宙射线电离成分占28%。     

非均匀人形体模及医用诊断X线工作人员的有效剂量当量估算

本文根据ICRP有效剂量当量的概念,应用所研制的人干骨,干粉模拟软组织非均匀人形体模,求出了胃肠检查和胸透时医用诊断X线工作人员的器官剂量、有效剂量当量与个人剂量计读数的比值,也计算了它们与工作人员所在位置自由空气照射量率的比值。得出男女性别不同的医用诊断X线工作人员的有效剂量当量与佩戴在左胸的个人剂量计读数的比值,胃肠检查时分别为0.52和0.43,胸透时分别为0.32和0.21。应用这些比值和个人剂量监测数据估算了该类人员的有效剂量当量。     

瑞芬太尼镇痛镇静辅助用于局麻和区域麻醉的临床观察

目的观察瑞芬太尼在局麻和区域麻醉中辅助镇痛镇静的作用。方法观察局麻或区域神经阻滞患者术前、术中泵注小剂量0．05～0．1μg／（kg·min）时各生命体征的变化、呼吸抑制情况的变化和镇痛效果。结果实验组镇痛效果好（P〈0．05），实验组和对照组各生命体征的变化和呼吸抑制变化无统计学意义。结论小剂量瑞芬太尼泵注可安全用于局麻和区域麻醉辅助镇痛、镇静。     

用动力学公式评价静滴给药方案

本文系近期对住院病人抗感染治疗用药方案的调查分析报道。调查抗感染治疗病历 2 1 0份 ,对治疗中反复出现频率较高的静脉滴注给药方案 2 3组。用动力学公式 [Ch=K0vdk( 1 -e-kt]进行回顾性评价。发现血药浓度 (Cmax) >有效血药浓度 (Ceff)者 1 5组 ;接近有效浓度者 2组 ;超过中毒浓度 (Ps)者 1组 ;<有效血药浓度者 5组 ;给药间期合理者 1 9组 ,不合理者 4组 ,剂量合理者 2 1组 ;剂量偏高者 2组 ,笔者认为不仅是剂量决定血药浓度 ,而且应重视剂量与滴注速度的整体治疗方案的实施。通过动力学公式的评价为临床选择有效、安全、合理、经济的静脉给药方案提供了科学依据 ,有利于推进我院临床药学的发展 ,促进医疗质量的提高。     

Barbiturates in severe head injuries?

Possible mechanisms for the therapeutic effects of barbituric acid derivatives in severe head injuries have been discussed for half a century. In the following, a survey of the literature, and a discussion of three controlled clinical studies available until now is presented. A proven effect in terms of a beneficial long-term outcome for all injured patients has not been established.On the other hand there might be a subgroup of patients with an intact CO₂ reactivity of the brain vessels who may profit from barbiturates administered after head trauma.Dedicated to Marianne and Gerhard Winkler     

室内氡的危害研究进展

阐述了人类赖以生存的环境中氡的来源、性质、进入人体的途径及致病机制和主要危害。同时介绍了世界各国在氡研究领域中的现状和最新进展情况。资料表明：随着经济的发展，住宅的条件逐步得到改善，特别是家庭空调的使用，以及不适当建筑材料或装饰材料的使用，已经使室内氡的问题成为人人都要面临的普遍性问题。介绍了过去10年各国对氡的研究情况，包括室内空气中氡的浓度，它给人们带来的内照射剂量，以及为减少氡所带来的危害要采取的补救措施和降低室内氡的主要技术方法。