Fluoroless Ureteroscopy: Experience in More Than 100 Patients

BACKGROUND

Ureteroscopy is becoming the primary treatment for ureteral stones. As a standard of care, ureteroscopy is performed under the supervision of fluoroscopy. Recent advances in endourological technology make the need for fluoroscopy questionable.

OBJECTIVES

To summarize our experience with a no-fluoroscopy technique for selected cases of ureteral stones.

METHODS

Patients were considered suitable for fluoroless ureteroscopy if they had one or two non-impacted stones, in any location in the ureter, 5-10 mm size, with a normal contralateral renal unit and no urinary tract infection. Procedures were performed using rigid scopes, nitinol baskets/forceps for stone retrieval, and Holmium:YAG laser for lithotripsy. Stents were placed per surgeon's decision.

RESULTS

During an 18-month period, 103 patients underwent fluoroless ureteroscopy. In 94 patients stones were removed successfully. In six, the stones were pushed to the kidney and treated successfully on a separate session by shock wave lithotripsy. In three patients no stone was found in the ureter. In five patients, miniature perforations in the ureter were noted and an indwelling double J stent was placed.

CONCLUSIONS

Fluoroless ureteroscopy resulted in a high rate of success. We believe that in selected cases it can be used with minimal adverse events.

Screening for Lung Cancer: CHEST Guideline and Expert Panel Report

BACKGROUND

Low-dose chest CT screening for lung cancer has become a standard of care in the United States, in large part because of the results of the National Lung Screening Trial (NLST). Additional evidence supporting the net benefit of low-dose chest CT screening for lung cancer, and increased experience in minimizing the potential harms, has accumulated since the prior iteration of these guidelines. Here, we update the evidence base for the benefit, harms, and implementation of low-dose chest CT screening. We use the updated evidence base to provide recommendations where the evidence allows, and statements based on experience and expert consensus where it does not.

METHODS

Approved panelists reviewed previously developed key questions using the Population, Intervention, Comparator, Outcome format to address the benefit and harms of low-dose CT screening, and key areas of program implementation. A systematic literature review was conducted using MEDLINE via PubMed, Embase, and the Cochrane Library on a quarterly basis since the time of the previous guideline publication. Reference lists from relevant retrievals were searched, and additional papers were added. Retrieved references were reviewed for relevance by two panel members. The quality of the evidence was assessed for each critical or important outcome of interest using the Grading of Recommendations, Assessment, Development, and Evaluation approach. Meta-analyses were performed when enough evidence was available. Important clinical questions were addressed based on the evidence developed from the systematic literature review. Graded recommendations and ungraded statements were drafted, voted on, and revised until consensus was reached.

RESULTS

The systematic literature review identified 75 additional studies that informed the response to the 12 key questions that were developed. Additional clinical questions were addressed resulting in seven graded recommendations and nine ungraded consensus statements.

CONCLUSIONS

Evidence suggests that low-dose CT screening for lung cancer can result in a favorable balance of benefit and harms. The selection of screen-eligible individuals, the quality of imaging and image interpretation, the management of screen-detected findings, and the effectiveness of smoking cessation interventions can impact this balance.

Radiation Reduction Strategies in Pediatric Orthopaedics

INTRODUCTION

Pediatric orthopaedic patients have the potential for significant radiation exposure from the use of imaging studies, such as computed tomography and bone scintigraphy. With the potential for long-term treatment, such as is required for scoliosis or osteogenesis imperfecta, patients are at even greater risk of radiation-induced carcinogenesis.

DISCUSSION

Although an association between radiation and cancer risk is evident, causation is difficult to prove because comorbidities or genetic predispositions may play a role in the higher baseline rates of malignancy later in life. Efforts have been made over the years to reduce exposure using more modern imaging techniques and simple radiation reduction strategies. Educational efforts and clinical practice guidelines are decreasing the rate of computed tomography scan use in pediatrics. Although considerable work is being done on the development of radiation-free imaging modalities, imaging that uses ionizing radiation will, in the near term, be necessary in specific circumstances to provide optimal care to pediatric orthopaedic patients.

CONCLUSION

Knowledge of the ionizing radiation exposure associated with commonly used tests as well as radiation-reduction strategies is essential for the optimal and safe care of pediatric orthopaedic patients.

The role of computed tomography scan in the diagnosis of COVID-19 pneumonia

PURPOSE OF REVIEW

To summarize current literature evidence on the role of computed tomography (CT) scan in the diagnosis and assessment of coronavirus disease 2019 (COVID-19) pneumonia.

RECENT FINDINGS

Recent guidelines on the use of CT scans in COVID-19 vary between countries. However, the consensus is that it should not be used as the first line; a notion supported by the WHO. Currently, several investigations are being used including reverse transcription PCR testing, chest radiographs, and ultrasound scans, and CT scans. They are ideally performed later during the disease process as the sensitivity and specificity are highest by that time. Typical COVID-19 features on CT scans vary but include vascular enlargement, ground-glass opacities, and ground glass opacification together with consolidation.

SUMMARY

Since COVID-19 was declared as a global pandemic, there was a push towards identifying appropriate diagnostic tests that are both reliable and effective. There is a general agreement that CT scans have a high sensitivity but low specificity in diagnosing COVID-19. However, the quality of available studies is not optimal, so this must always be interpreted with the clinical context in mind. Clinicians must aim to weigh up the practicalities and drawbacks of CT scans when considering their use for a patient. The ease and speed of use of CT scans must be balanced with their high radiation doses, and infection control considerations.

Behaviour and knowledge skill levels of orthopedic surgeons about radiation safety and fluoroscopy use: A survey analysis

OBJECTIVE

The aim of this study was to evaluate the behaviour and knowledge skill levels of Turkish orthopedic surgeons about fluoroscopy usage and radiation safety.

METHODS

The questionnaire, consisting of nineteen questions, was sent to orthopaedic surgeons and requested by a total of 323 surgeons online. The questions were about personal information, training and behaviours related to radiation and fluoroscopy usage, and the use of protective equipment.

RESULTS

A total of 277 individuals completed the questionnaire. The answers of 180 surgeons whose working duration was more than 1 year and also who participated in at least one fluoroscopy requiring operation per week, were analysed. 22 (12%) participants answered that they were trained on fluoroscopy usage. Sixty people (33.3%) reported that they did not use any protective equipment regularly. The most commonly used protection methods were lead aprons 123 (68.3%). Thyroid protectors were used by 92 participants (52.1%). There was no significant difference between the groups when comparing the use of protective equipment according to the academic title. Only 19 (10.6%) of the surgeons noted that they used dosimeter regularly, and 15 (83.3%) of them reported that they controlled their dosimeters.

CONCLUSION

In this study, Orthopedic surgeons were found not to be adequately trained about use and risks of fluoroscopy and also not to be equipped about methods for preventing radiation damage.

[Experience With Different Single-Stage Selective Arterial Catheterization Procedures During X-Ray Endovascular Interventions to Reduce a Radiation Dose for Patients]

OBJECTIVE

To evaluate the impact of single-stage selective arterial catheterizations during X-ray endovascular interventions to reduce obtained radiation doses in the treatment of patients.

MATERIAL AND METHODS

X-ray endovascular interventions were carried out in the operating room equipped with a flat detector digital angiography system (Axiom Artis dTA, Siemens Medical System). The impact of single-stage selective arterial catheterization procedures was analyzed during endovascular interventions for coronary heart disease and uterine myomas on the time course of changes in the collective effective radiation doses for patients in the period 2013 to 2015.

RESULTS

Analysis of the findings showed that single-stage selective coronary angiography using a universal (multipurpose) radial coronary catheter and single-stage X-ray endovascular uterine artery embolization techniques could reduce collective effective doses for patients from 5.86 persons-Sv in 2013 to 1.6 persons-Sv in 2015.

CONCLUSION

Different single-stage selective catheterization procedures used during endovascular interventions into the coronary and uterine arteries can reduce radiation doses for patients.

[Comparison of a Radiation Dose During Standard Digital Radiography, Tomosynthesis, and Multislice Spiral Computed Tomography in an Experimental Study of Pediatric Anthropomorphic Phantom]

OBJECTIVE

To compare a radiation dose obtained during standard digital radiography, tomosynthesis, and multislice spiral computed tomography (MSCT).

MATERIAL AND METHODS

Life-size full body pediatric anthropomorphic mannequin phantom was examined with a Fujifilm FDR Ac Selerate 200 X-ray diagnostic apparatus and a Toshiba Aquilion Prime 64 computed scanner using the Piranha dosimetry equipment, as well as Gammex planar target, for comparison of the resolution of the apparatus. The effective radiation doses were calculated for different anatomical regions with the formulas specified in the methodical instructions, using the coefficients K and Kd.

RESULTS

The tables and graphs comparing the radiation dose when using different radiation diagnostic techniques were presented. The resolution of standard digital radiography versus that of tomosynthesis was analyzed. Fluctuations of the doses obtained were associated with the difference in the volume of irradiated tissue and in the presence of the doses in the irradiated volume of organs with high radiosensitivity. Optimal physical and technical parameters of photography were proposed, which could reduce a dose load on the patient, without significantly losing the quality of films.

CONCLUSION

The effective doses of tomosynthesis were significantly higher than those of standard digital radiography (p < 0.05) while those of (MSCT) were above those of both X-ray and tomosynthesis, and the resolution of the latter was slightly lower.

A systems approach to evaluating ionizing radiation: six focus areas to improve quality, efficiency, and patient safety

Ionizing radiation is an essential component of the care process. However, providers and patients may not be fully aware of the risks involved, the level of ionizing radiation delivered with various procedures, or the potential for harm through incidental overexposure or cumulative dose. Recent high-profile incidents demonstrating the devastating short-term consequences of radiation overexposure have drawn attention to these risks, but applicable solutions are lacking. Although various recommendations and guidelines have been proposed, organizational variability challenges providers to identify their own practical solutions. To identify potential failure modes and develop solutions to preserve patient safety within a large, national healthcare system, we assembled a multidisciplinary team to conduct a comprehensive analysis of practices surrounding the delivery of ionizing radiation. Workgroups were developed to analyze existing culture, processes, and technology to identify deficiencies and propose solutions. Six focus areas were identified: competency and certification; equipment; monitoring and auditing; education; clinical pathways; and communication and marketing. This manuscript summarizes this comprehensive, multidisciplinary, and systemic analysis of risk and provides examples to illustrate how these focus areas can be used to improve the use of ionizing radiation. The proposed solutions, once fully implemented, may advance patient safety and care.

Radiation Exposure and Contrast Agent Reduction During Transcatheter Aortic Valve Implantation: An Ongoing Experience

OBJECTIVES

To determine the patient radiation exposure and contrast agent variation during transcatheter aortic valve implantation (TAVI) procedures resulting from technological improvements.

METHODS

TAVI procedures from January 2008 to July 2015 were analyzed in three different time periods: 1st period, when the angiography was equipped with an image intensifier technology; 2nd period, starting with the installation of a new angiography system with flat-panel detector (FPD) technology; and 3rd period, starting with the systematic use of preprocedural multidetector computed tomography (MDCT) to individualize optimal fluoroscopic projections for the aortic prosthesis implantation.

RESULTS

Significant differences were found in contrast volume (198 ± 99 mL vs 139 ± 74 mL; P<.001), kerma area product (211 ± 135 Gy•cm² vs 147 ± 120 Gy•cm²; P<.001) and effective dose (42 ± 27 mSv vs 29 ± 24 mSv; P<.001) between the 1st and 2nd periods, respectively. The reduction continued between the 2nd and 3rd periods for contrast volume (139 ± 74 mL vs 110 ± 61 mL; P<.001), kerma area product (147 ± 120 Gy•cm² vs 111 ± 69 Gy•cm²; P<.001), and effective dose (29 ± 24 mSv vs 22 ± 11 mSv; P<.001), respectively.

CONCLUSIONS

The present study suggests that the appropriate use of FPD technology and preprocedural MDCT to individualize fluoroscopic implant projections for TAVI temporally reduced the amount of radiation and contrast agent administered over time.

Overview of radiation dose to patients from medical X-ray examinations in Nigeria

OBJECTIVES

Medical Imaging accounts for the largest radiation exposure of population from artificial sources of radiation. The radiation dose rcceivedby patients from iedicail x-ray examinations in Nigeria has shown large variations within and among diagnostic centers for similar examinations. This could be traced to lack of imaging protocols and on avalability of local/national diagnostic reference, levels. Hence, the need to assess the trend of radiation doseto patients from radiological practice in Nigeria. Methocls:Entrance surface doses(ESDs) reported by, Nigerian authors for common x-ray examinations from 2000 - 2014 were extracted from articles published in peer reviewed journals, analyzed and compared with ifiternationally recommended Diagnostic Reference Levels (DkLs).

RESULTS

Among x-ray examinations, skull accounted for 32% followed by chest (22%), lumbar spine (13%), abdomen (12%), pelvis (8%), extremitics(8%), thorax and cervical spine(5%). The range of mean ESDs reported for various projections of x-ray examination are chest (2.28 - 3.70 mGy); Abdomen (4.42 - 7.22 mGy); Skull (3.81 - 5.19 mGy); Pelvis (5.93 mGy); Lumbar spine (5.73 - 10.98 mGy); Thorax (0.96 - 1.85 mGy); Cervical spine (1.45 - 1.49mGy) and Extremitics (0.31 -0.49 mGy). In this study, it was found that the mean ESDs received by patients from chest, skull and pelvis ex'aminations were higher than the published DRLs for similar x-ray examinations.

CONCLUSION

The results of this study showed that to harmonize radiation protection of patients and improve radiological practice in Nigeria there is need for development of comprehensive national diagnostic reference levels.

A safety radiation marker in the cardiac catheterization lab

OBJECTIVE

Nowadays, in order to deal with cardiovascular disease, coronary angiography (CRA) is the best tool and gold standard for diagnosis and assessment. CRA inevitably exposes both patient and operator to radiation. The purpose of this study was to calculate the radiation exposure in association with the radiation absorbed by interventional cardiologists, in order to estimate a safety radiation marker in the catheterization laboratory.

METHODS AND RESULTS

In 794 successive patients undergoing CRA and in three interventional cardiologists the following parameters were examined: radioscopy duration, radiation exposure during fluoroscopy, total radiation exposure and the number of stents per procedure. Every interventional cardiologist was exposed to 562,936 μGym2 of total radiation during CRA procedures, to 833,371 μGym2 during elective CRA + percutaneous coronary intervention (PCI) procedures and to 328,250 μGym2 during primary CRA + PCI. Hence, the total amount of radiation that every angiographer was exposed to amounted to 1,724,557.5 μGym2 (median values). During the same period, the average radiation that every angiographer absorbed was 15,253 while the average dose of radiation absorbed during one procedure was 0.06 mSv for each operator. Therefore, the ratio between radiation exposure and the radiation finally absorbed by every operator was 113:1 μGym2/mSv.

CONCLUSIONS

The present study, indicating the ratio above, offers a safety marker in order to realistically estimate the dose absorbed by interventional cardiologists, suggesting a specified number of permitted procedures and an effective level of radiation use protection tools.

Comparison of DXA Scans and Conventional X-rays for Spine Morphometry and Bone Age Determination in Children

Conventional lateral spine and hand radiographs are the standard tools to evaluate vertebral morphometry and bone age in children. Beside bone mineral density analyses, dual-energy X-ray absorptiometry (DXA) measurements with lower radiation exposure provide high-resolution scans which are not approved for diagnostic purposes. Data about the comparability of conventional radiographs and DXA in children are missing yet. The purpose of the trial was to evaluate whether conventional hand and spine radiographs can be replaced by DXA scans to diminish radiation exposure. Thirty-eight children with osteogenesis imperfecta or secondary osteoporosis or short stature (male, n=20; age, 5.0-17.0 yr) were included and assessed once by additional DXA (GE iDXA) of the spine or the left hand. Intraclass correlation coefficients (ICCs) were used to express agreement between X-ray and iDXA assessment. Evaluation of the spine morphometry showed reasonable agreement between iDXA and radiography (ICC for fish-shape, 0.75; for wedge-shape, 0.65; and for compression fractures, 0.70). Bone age determination showed excellent agreement between iDXA and radiography (ICC, 0.97). IDXA-scans of the spine in a pediatric population should be used not only to assess bone mineral density but also to evaluate anatomic structures and vertebral morphometry. Therefore, iDXA can replace some radiographs in children with skeletal diseases.

[Comparative survey of radiation doses to patients in computed tomography in a federal hospital]

OBJECTIVE

to analyze radiation exposure due to computed tomography (CT) of brain, chest, abdomen and pelvis in a large multi-field federal hospital and feasibility of low-dose CT-examinations.

MATERIAL AND METHODS

Retrospective analysis was performed using data from electronic patient records and PACS from a single multi-field hospital. Data were obtained from 1626 records of patients (794 men, 832 women; age range 17-93) scanned with 3 MDCT during one year. CT-examinations of good quality were selected, volumetric CT dose index (CTDI) and dose-length product (DLP) were collected for each of them. The effective doses (ED) were calculated using the normalized coefficients according to Russian Guidance. RESULTS. Number and structure of CT-examinations for the years 2012-2014 in a multi-field hospital were analyzed. The mean effective dose (M ± m) values with/without contrast medium (respectively), according to anatomical areas were as follows: brain--2.34 ± 0.03/3, 52 ± 0.23, chest--4.83 ± 0.11/11.02 ± 0.82, abdomen-pelvis--9.81 ± 0.40/36.6 ± 1.17, chest-abdomen-pelvis - 12.41 ± 0.79/35.63 ± 1.81 mSv. CONCLUSION. Results of this study give an example of CT dose values and distribution in a multi-field hospital. They are compa- rable with reference levels published of other authors. This expe- rience should be expanded for creation of CT national reference values and for co-operation with international initiatives (EUROSAFE projects).

[Robotic-enhanced percutaneous coronary revascularization]

Percutaneous revascularization (PCI) has made significant technological progress in the last four decades. Despite advances in the safety and efficacy of the coronary revascularization, interventional cardiologists have to cope with occupational hazards including exposure to radiation, cataract, and orthopedic problems. Robotic systems that enable distant navigation were developed to address the risks and challenges that are associated with percutaneous revascularization. The PRECISE multi-center study with robotic-enhanced PCI demonstrated technical success of 98.7% and clinical success of 97.5%. The use of the robotic-enhanced PCI system reduced operator radiation exposure by 95%. Patient benefits include precise segment measurements, improved stability of the intracoronary devices, and reduction of contrast media volume. Robotic-enhanced PCI is a promising advancement in interventional cardiology.

[ANALYSIS OF RADIATION IN THE DEPLOYMENT OF MILITARY UNITS OF THE MINISTRY OF DEFENSE OF UKRAINE]

There were observed radiation hazardous objects and zone of possibie rauioactive contaminationof the area with military units, and also possibility of influence of adverse factors (radiation) on the human organism. There is also available characteristic of Ukrainian nuclear Powers, number of population, that lives on the area with different pollution degree.

[Anatomic rationale and radiological experience in using an individual anatomical landmark during linear imaging of the human temporomandibular joint]

OBJECTIVE

To provide a rationale for determining the midsagittal plane of temporomandibular joint (TMJ) elements by the anatomical landmark for estimation of the individual depth of a tomographic section at targeted linear TMJ imaging.

MATERIAL AND METHODS

Cephalometry of 20 human skulls. Targeted linear TMJ imaging in the lateral projection in 176 patients.

RESULTS

The anatomical landmarks of the midsagittal plane of a tomographic section were determined and the latter's anatomical landmark (a reference searching point) was found to estimate the individual depth of the tomographic section at targeted linear TMJ imaging. There was an agreement between the midsagittal plane of the TMJ and that of the frontal process of the zygomatic bone (the lateral orbital wall). The latter was ascertained to be rightly used as a cephalometric point and taken as an individual anatomical landmark indicating the level of a tomographic section at targeted linear TMJ imaging. The individual anatomical landmark was used to examine 176 patients at targeted linear TMJ imaging. Six hundred and four tomography scans were studied. Excellent- and good-quality pictures were obtained in 94.2% of cases. The section depth was 2.0 to 3.0 cm in 86.7% of cases (2.5, 2.0, and 3.0 cm in 42.2, 21.6, and 22.9%, respectively).

CONCLUSION

The proposed procedure could exclude search samples and minimize the dose of radiation and the time of survey depth determination.

[Thyroid cancer: lessons of chernobyl and prognosis for Fukushima]

Results of epidemiological studies of thyroid cancer incidence in Russia following the Chernobyl accident are presented in the article. Child population in territories contaminated with radionuclides who got thyroid dose from incorporated (131)I above 100-150 mGy, should be referred to a group at radiation risk. Prognostic estimates of increase in thyroid cancer incidence among the population living in close vicinity of the Fukushima Daiichi NPP were made with account for the Chernobyl data and recommendations of the International Commission on Radiological Protection.

Radiological protection in medicine: work of ICRP Committee 3

Committee 3 of the International Commission on Radiological Protection (ICRP) is concerned with protection in medicine, and develops recommendations and guidance on the protection of patients, staff, and the public against radiation exposure in medicine. This paper presents an overview of the work of Committee 3 over recent years, and the work in progress agreed at the last annual meeting in Bethesda, MD in October 2011. The reports published by ICRP dealing with radiological protection in medicine in the last 10 years cover topics on: education and training in radiological protection; preventing accidental exposures in radiation therapy; dose to patients from radiopharmaceuticals; radiation safety aspects of brachytherapy; release of patients after therapy with unsealed radionuclides; managing patient dose in digital radiology and computed tomography; avoidance of radiation injuries from medical interventional procedures; pregnancy and medical radiation; and diagnostic reference levels in medical imaging. Three new reports will be published in the coming months dealing with aspects of radiological protection in fluoroscopically guided procedures outside imaging departments; cardiology; and paediatric radiology. The work in progress agreed by Committee 3 is also described.

[Modern possibilities of therapeutic aid in the time of mass sanitary losses of radiation profile]

Modern concept of medical-prophylactic measures in the time of mass radiation affection is presented in the present article. Moreover the past changes in organization-regular structure of medical service of the Armed Forces of the Russian Federation and appearance of new time-board equipment were taken into account. Recommendations about the rendering of all types of therapeutic aid on all stages of medical evacuation--first, premedical, medical assistance, qualified and specialized--are given.

[Occupational exposure and the reproductive health of man--personnel of the producing department of Smolensk NPP]

A study of the reproductive health of man--personnel of the producing department of Smolensk NPP did not determine the influence of occupational exposure on the indices of child-bearing and on the prevalence of the sterility of men. At the same time focuses attention the fact of the generation of children in more than 30% men of older than 30 years, at the age, to which are not extended the additional requirements of the limitation of irradiation, or the fact of child-bearing in man--personnel with the accumulated doses more than 100 mSv, with which increases the risk of genetic effects in descendants.

[Serum TNFalpha and its receptors in professionals after prolonged exposure to radiation in remote period]

The goal of this study was the detection of serum TNFalpha concentration and soluble receptors (sTNFRI and sTNFRII) in PA Mayak professionals in long-term after the prolonged radiation exposure, subject to cumulative dose. TNFalpha, sTNFRI, and sTNFRII concentration were investigated by ELISA in serum of 59 professionals. Cumulative external doses were within 0.21-7.72 Gy. 239Pu body burden was less than 1.48 kBk. Direct significant correlation was detected between TNFalpha concentration and external dose (0.21-3.(00) Gy; r = 0.41, p = 0.009, n = 40). Serum sTNFRI concentration rose significantly with increasing of cumulative dose. Significant increase of persons number with deviations of sTNFRI concentration from standards in groups with dose higher 1.00 Gy under comparison with control was discovered. The correlation was detected between external dose and serum sTNFRI concentration in long-term after radiation exposure (r = 0.36, p < 0.005). Significant positive correlation was detected between sTNFRI, and sTNFRII under increasing of cumulative external dose (r = 0.60, p = 0.0000004).

Appropriate radiation accident medical management: necessity of extensive preparatory planning

Despite the rareness of radiation accidents, their potential consequences can be very serious, and appropriate medical management requires sufficient preparatory planning. To identify necessary factors for sufficient preparatory planning, three different radiation accidents were analyzed, i.e. the accidents in Goiânia, Brazil, 1987; Lilo, Georgia, 1997; and Tokai-mura, Japan, 1999. These radiation accidents have been chosen specifically because they provide a wide spectrum of potential radiation accident scenarios. After a brief description of the accidents and the following medical management, the measures taken are analyzed in terms of diagnosing radiation-induced health damage, determining the cause, dealing with contamination/incorporation, pathophysiological and therapeutic principles, preparatory planning, national and international cooperation and training. Several important factors are identified that should be considered in preparatory planning, i.e. preventing delayed diagnosis and training of medical personnel. Due to limited national resources, an intensified international cooperation to manage medical radiation accidents is of great importance.

Radiological health risk evaluation of radium contaminated land: a real life implementation

A plot of land, currently used for dairy farming, has been contaminated over the years with radium due to the operation of one of the world's largest radium production plants. Within the framework of a global remediation approach for the plant surroundings, the land owner needed advice for a future destination of the land. Therefore, the radium contamination was accurately mapped, and on the basis of its severity a practically feasible subdivision of the land into four plots was proposed. For all four plots, the radiological risk was evaluated for the current type of land use and for possible alternative types. Hence a clear and useable advice could be formulated to the authorities reconciling public health, economic and practical issues.

The dirty bomb: management of victims of radiological weapons

A "dirty bomb," a conventional explosive packed with radioactive material, kills or injures through the initial blast and by airborne radiation and contamination. Adult-health nurses need an understanding of the consequences of blast injuries and radiation exposure, and the management of victims.

Ultrastructural apoptotic lesions induced in bone marrow after neptunium-237 contamination

This study describes the ultrastructure of lesions induced by neptunium-237 (237Np), a by-product of uranium in nuclear reactors, in the bone marrow. A group of rats were given a single injection of 237Np-nitrate solution in order to observe the acute toxicity effects of this actinide. Electron microscopy was used to describe the different lesions. Observations included the swelling of the cell membrane, nuclear membrane lyses, abnormal chromatin condensation or nucleus convolution. These ultrastructural alterations of the nucleus and the cellular membrane appeared shortly after treatment. This study demonstrates the toxic effects of neptunium and its implication in the induction of apoptosis in bone marrow.

Analysis of surface dose variation in CT procedures

An experimental and theoretical study has been made of the variations in air kerma-length product (AKLP) at the surface of a phantom exposed in a CT scanner, using clinical parameters. For the theoretical part, a computer simulation was developed, based on a simple analytical model, requiring information generic to the scanner model. The effects of patient size, position within the gantry plane and beam-shaping filter type were studied using three different elliptical phantoms. A dose reduction technique based on a sinusoidal tube current modulation system was also investigated. The surface AKLP was shown to be independent of phantom size (within experimental error) but decreases as the surface moves vertically away from the isocentre. The major contributor to this variation is the beam-shaping filter. A maximum difference of 19% between the values of surface AKLP was calculated for the two beam-shaping filters available. When the tube current modulation system was used, the maximum surface dose reduction was 18%. A maximum difference of 2% was found between measurements and computer simulations. It is therefore possible to predict the behaviour of AKLP using the analytical model. As the dose measured on the surface of a patient is simply related to AKLP, the model can be applied to data obtained from patient surface dose surveys and can be helpful in interpreting the sources of variation in the latter.