质子治疗机房的屏蔽设计方案国内外比较

目的 探讨国内外不同辐射防护标准对质子治疗机房屏蔽设计的影响。方法 以一个多室质子中心机房为例,分别根据美国国家辐射防护与测量委员会（NCRP）151号报告、新加坡辐射防护法案、英国ACoP指南以及国家标准GBZ/T 201.5-2015规定的辐射防护限值,得到相应的屏蔽方案。比较各个机房间隔墙和机房与控制室间隔墙厚度,在保持各个机房设计尺寸不变的前提下,从机房有效使用面积、建设成本等方面讨论上述4种屏蔽方案的差异性。结果 由NCRP 151号报告计算得到的各机房墙体（A~F）厚度最薄,由国家标准计算得到的墙体厚度最厚,其中两个旋转治疗室间隔墙厚度增加了1倍以上,总的治疗室使用面积减少17.69%,总建筑材料成本增加44万元。结论 通过比较不同屏蔽标准对质子治疗机房设计的影响,发现与其他国际法规或标准相比,我国现行的质子机房辐射屏蔽标准远高于其他国家,这会显著增加机房的屏蔽墙厚度,对国内的质子治疗技术的发展及将来升级到超高剂量率治疗模式都有一定影响。建议参考质子治疗技术相对成熟的国家标准和经验,适当放宽瞬时剂量率限值条件,增加更能反映现实治疗工况的时间平均剂量率（time averaged dose rate,TADR）限值条件,以更好地实现机房屏蔽设计的最优化原则。     

A practical guide to targeted therapy for bone pain palliation

Targeted radionuclide therapy is an effective and cost efficient treatment for multi-site metastatic bone pain. This paper discusses the physical characteristics of the licensed radiopharmaceuticals (153)Sm ethylenediamine-N,N,N',N'-tetrakis(methylene phosphonic acid) ((153)Sm-EDTMP), (186)Re 1,1-hydroxyethylidenediphosphonate ((186)Re-HEDP) and (89)SrCl(2) and considers the factors influencing treatment choice in specific clinical settings. The advantages and practical limitations of this approach are discussed, with emphasis on defining criteria for patient selection and response monitoring. Opportunities for future research and development are outlined.     

Tumour regression during radiation treatment as a guide to prognosis

The response to radiation treatment was studied in 110 patients with head and neck cancer with a minimum follow-up of two years. If the tumour had disappeared by the mid-point of treatment (3000 rad), a significantly more favourable prognosis was found in early (T1-2N0) tumours. On the other hand, whether these tumours had disappeared or were persisting at the end of treatment, there was no difference in the recurrence during the observation time of two years. In advanced tumours there was no significant relationship between disappearance by the mid-point of treatment and recurrence up to two years. But when an advanced tumour had disappeared at the end of treatment, the prognosis was significantly more favourable. The unpredictability and often impossibility of judging the prognosis in individual cases encourages the authors to stress the importance of executing the original individual surgical plan irrespective of radiation response.     

子宫颈癌术后调强放疗照射野设计的探讨

目的 通过对子宫颈癌调强放疗各种布野方案的比较,探讨符合临床要求的最佳照射方案。方法 对10例子宫颈癌患者采用调强治疗方案,处方剂量为46 Gy,分次量为2 Gy。每位患者做6个不同的治疗计划,分别为5野、7野、9野均分照射,初始入射角度选用0°和180°。分别计算比较靶区的覆盖度、均匀性、适形度各项指标。结果 7野和9野的靶区适形度基本一致,7野的均匀性最好,5野靶区覆盖度也能达到要求,但适形度和均匀度都次于7、9野;9野IMRT计划与5野IMRT计划相比没有减少正常组织的受照剂量,但增加了子野数和照射的总跳数,延长了治疗时间。结论 在子宫颈癌的调强放疗中,综合考虑各种物理和生物因素,建议在设计照射野时尽量选择7野照射。     

Medical management of radiation enteritis--an algorithmic guide

An algorithmic guide to the differential diagnosis and management of late radiation enteritis is proposed. The proposition is based on physiological principles and clinical experience rather than on published reports. Too few patients with late radiation enteritis are seen in most oncology centres for a large prospective trial of the algorithm to be set up, but we hope it will stimulate further investigation.     

A daily radiation therapy record form

This communication reviews one institution's experience in developing a reliable and accurate radiation therapy record form. The design of a daily record is highly subjective. With the subjectivity of this process in mind, the purpose of this presentation is to describe the advantages of our form and to acquaint the reader with the literature useful in preparing a therapy record that fulfills their facility's requirements.     

A multi-platform approach to image guided radiation therapy (IGRT).

Siemens Medical Solutions, Oncology Care Systems Group (SMSOCSG) is supporting the development of several technologies that enable image acquisition and decision making processes required for IGRT in various clinical settings. Four such technologies are presented including: (i) the integration of a traditional multi-slice computed tomography (CT) scanner "on rails" with a C-arm gantry linear accelerator; (ii) the development of a high sensitivity, fast, megavoltage (MV) electronic portal imaging device capable of clinical MV Conebeam CT (MVCBCT) reconstruction and fluoroscopy mounted on a C-arm gantry linear accelerator; (iii) the modification of a mobile C-arm with flat panel kilovoltage (kV) diagnostic imager; and (iv) the development of an in-line megavoltage and kilovoltage flat panel imaging system that has the potential to image both anatomical and dosimetric information in "real-time" utilizing the traditional C-arm gantry linear accelerator geometry. Each method of IGRT has unique as well as complementary qualities which are discussed from both a clinical and technical perspective.     

A visual guide to PACS

Picture archiving and communication systems (PACS) is a complex and vast subject, about which much has been written. A Visual Guide to PACS is an overview of the subject presented as an efficient reference for hospital and department administrators planning for and implementing PACS. A Visual Guide to PACS is adapted from presentation materials developed by Integration Resources/GORCA to capsulize issues relating to PACS. The authors aim to communicate the broad parameter and some of the complexity of the subject.     

A virtual radiation therapy workflow training simulation

AimSimulation forms an increasingly vital component of clinical skills development in a wide range of professional disciplines. Simulation of clinical techniques and equipment is designed to better prepare students for placement by providing an opportunity to learn technical skills in a “safe” academic environment. In radiotherapy training over the last decade or so this has predominantly comprised treatment planning software and small ancillary equipment such as mould room apparatus. Recent virtual reality developments have dramatically changed this approach. Innovative new simulation applications and file processing and interrogation software have helped to fill in the gaps to provide a streamlined virtual workflow solution. This paper outlines the innovations that have enabled this, along with an evaluation of the impact on students and educators.MethodVirtual reality software and workflow applications have been developed to enable the following steps of radiation therapy to be simulated in an academic environment: CT scanning using a 3D virtual CT scanner simulation; batch CT duplication; treatment planning; 3D plan evaluation using a virtual linear accelerator; quantitative plan assessment, patient setup with lasers; and image guided radiotherapy software.ResultsEvaluation of the impact of the virtual reality workflow system highlighted substantial time saving for academic staff as well as positive feedback from students relating to preparation for clinical placements. Students valued practice in the “safe” environment and the opportunity to understand the clinical workflow ahead of clinical department experience.ConclusionSimulation of most of the radiation therapy workflow and tasks is feasible using a raft of virtual reality simulation applications and supporting software. Benefits of this approach include time-saving, embedding of a case-study based approach, increased student confidence, and optimal use of the clinical environment. Ongoing work seeks to determine the impact of simulation on clinical skills.     

A questionnaire about radiation safety management of the draining-water system at nuclear medicine facilities

We conducted a questionnaire survey about radiation-safety management condition in Japanese nuclear medicine facilities to make materials of proposition for more reasonable management of medical radioactive waste. We distributed a questionnaire to institutions equipped with Nuclear Medicine facilities. Of 1,125 institutions, 642 institutes (52.8%) returned effective answers. The questionnaire covered the following areas: 1) scale of an institution, 2) presence of enforcement of radiotherapy, 3) system of a tank, 4) size and number of each tank, 5) a form of draining-water system, 6) a displacement in a radioactive rays management area, 7) a measurement method of the concentration of medical radioactive waste in draining water system, 8) planned and used quantity of radioisotopes for medical examination and treatment, 9) an average displacement of hospital for one month. In most institutions, a ratio of dose limitation of radioisotope in draining-water system was less than 1.0, defined as an upper limitation in ordinance. In 499 hospitals without facilities of hospitalization for unsealed radioisotope therapy, 473 hospitals reported that sum of ratios of dose limits in a draining-water system was less than 1.0. It was calculated by used dose of radioisotope and monthly displacement from hospital, on the premise that all used radioisotope entered in the general draining-water system. When a drainage including radioactivity from a controlled area join with that from other area before it flows out of a institution, it may be diluted and its radioactive concentration should be less than its upper limitation defined in the rule. Especially, in all institutions with a monthly displacement of more than 25,000 m3, the sum of ratio of the concentration of each radionuclide to the concentration limit dose calculated by used dose of radioisotope, indicated less than 1.0.     

A practical guide to fad diets

This discussion of fad diets may be concluded by comparing the 14 selected diets with the standards previously outlined for desirable weight reducing plans. Many of the popular diets supply large quantities of saturated fat and cholesterol, which are dietary components that have been associated with cardiovascular disease. Ketogenic diets are not appropriate for athletes because of problems with secondary dehydration and hyponatremia. Almost all of the diets are nutritionally inadequate. The rate of anticipated weight loss will vary according to the age, sex, weight, basal energy requirement, and activity level of an individual. However, it is expected that weight loss will be excessively rapid if a competitive athlete consumes a diet of less than 1000 calories per day. These hypocaloric diets cannot meet the training demands of athletes and will promote loss of lean body mass and carbohydrate stores. Many of the ketogenic diets do not restrict calories; therefore, weight loss will depend upon individual daily caloric consumption. The Cambridge Diet and starvation diets produce weight loss far in excess of that desired for an athlete in training. Long-term eating patterns to maintain weight loss are not encouraged in any of the 14 selected fad diets. In fact, most of these diets promote patterns of poor nutrition. Not one of the diets provides options or choices for dieters to use in accommodating food preference and lifestyle patterns. Some of the diets are fairly easy to comply with and others require special foods and supplements. None of the 14 diets reviewed fulfull all of the standards for a sound weight reduction diet plan.(ABSTRACT TRUNCATED AT 250 WORDS)