Developments in and experience of kilovoltage X-ray cone beam image-guided radiotherapy

This paper offers a realistic review of kilovoltage X-ray cone beam tomography integrated with the treatment machine for image-guided radiotherapy in the light of experience taking a commercial system from prototype development into clinical use. It shows that key practicalities cannot be ignored, in particular the regular characterization of mechanical flex during gantry rotation, the mapping of defects in flat panel image transducers and their response to X-ray exposure. The number of X-ray projections and the doses required for clinically useful cone beam reconstruction at different therapy sites are considered in the context of imaging that is fit for purpose. Three roles for cone beam tomography in radiotherapy are identified: patient setup in three dimensions (3D), where even low dose cone beam tissue detail is superior to megavoltage imaging; disease targeting where, despite wide field scatter and slow scanning, it is possible to generate images that are suitable for tumour delineation even at challenging sites; adaptive treatment planning, where calibrated cone beam images have been shown to provide sufficient target detail to support "plan of the day" selection and have the potential for planning with bulk corrections. With frequent use in mind, the need to limit patient dose during setup, yet maximize much needed image quality in the target zone, is considered. Finally, it is noted that the development of cone beam tomography for radiotherapy is far from complete, with X-ray source, image transducer, reconstruction algorithms and techniques for image profile collection still being researched.

An assessment of clinically optimal gold marker length and diameter for pelvic radiotherapy verification using an amorphous silicon flat panel electronic portal imaging device

Verification of target organ position is essential for the accurate delivery of conformal radiotherapy. Megavoltage electronic portal imaging with flat panel amorphous silicon detectors delivers high quality images that can be used for verification of bony landmark position. Gold markers implanted into the target organ can be visualized and used as a surrogate of actual organ position. On-line compensation for marker displacement, by adjusting patient position, can reduce geometric errors associated with radiation delivery. This study assesses the optimal marker length and diameter to be used with an amorphous silicon (a-Si) flat panel detector and electronic portal images (EPIs), prior to implementation of a clinical programme of gold marker insertion in prostate cancer patients. Seven marker sizes varying from 3 mm to 8 mm in length and 0.8 mm to 1.1 mm in diameter were investigated in a group of patients undergoing pelvic radiotherapy using an 8 MV Elekta SL20 linear accelerator. Markers were placed on the skin entry and exit sites of the treatment beam and EPIs in both lateral and anterior pelvic views were acquired. Three observers independently assessed visibility success and failure using a subjective scoring system. Markers less than 5 mm in length or 0.9 mm in diameter were poorly visualized (<70% visualization success in lateral EPIs). The marker measuring 0.9 mm x 5 mm appears to be clinically optimal in pelvic radiotherapy patients (80% visualization success in lateral EPIs) and will be used for actual organ implantation.

Recent advances in detrusor muscle function

Contractile activation of detrusor smooth muscle is initiated by the release of transmitters from motor nerves. Acetylcholine is a ubiquitous transmitter, as also is adenosine triphosphate (ATP) in many animal bladders and in people from several patient groups with pathological bladder function. In recent years there has been progress in explaining several cellular mechanisms that link transmitter release to contraction and these will be considered. The lifetime of ATP in the neuromuscular junction is finite and broken down ultimately to adenosine, which can exert modulatory control of contractile activation. Adenosine depresses nerve-mediated contractions and two sites of action have been proposed: an action on the motor nerves via A receptors to depress further transmitter release and a less well-defined depressant effect on the detrusor muscle. The Ca2+ ions that activate the contractile proteins are derived from intracellular stores, which releases their content via IP receptor activation and Ca2+-induced Ca2+ release. Filling of the stores in the rest interval is mediated via transmembrane flux of Ca2+through Ca2+ channels. Activation of the channels is regulated by the level of the intracellular [Ca2+], via activation and inactivation of Ca2+-sensitive K channels. Thus, Ca2+ store filling is regulated by intracellular [Ca2+] via a negative feedback process. The presence and physiological function of spontaneous contractions in detrusor remain contentious and little is known about their origin. One possibility is that they originate from random Ca2+ sparks, i.e. localized transient increases of [Ca2+] that may eventually progress to generate a cellular Ca2+ transient. Observations by confocal microscopy have revealed the presence of such sparks, especially near the cell membrane, and thus provide a cellular basis for spontaneous contractions. Finally, the questions arises as to whether detrusor smooth muscle is a functional syncitium. The demonstration of small gap junctions by electron microscopy and the demonstration of the gap junction protein connexin45 indicate that the muscle mass may indeed be functionally connected. The implications regarding the spread of excitation are discussed.

Evidence-based recommendations for the role of exercise in the management of osteoarthritis of the hip or knee--the MOVE consensus

OBJECTIVES

Exercise is an effective and commonly prescribed intervention for lower limb osteoarthritis (OA). Many unanswered questions remain, however, concerning the practical delivery of exercise therapy. We have produced evidence-based recommendations to guide health-care practitioners.

METHODS

A multidisciplinary guideline development group was formed from representatives of professional bodies to which OA is of relevance and other interested parties. Each participant contributed up to 10 propositions describing key clinical points regarding exercise therapy for OA of the hip or knee. Ten final recommendations were agreed by the Delphi technique. The research evidence for each was determined. A literature search was undertaken in the Medline, PubMed, EMBASE, PEDro, CINAHL and Cochrane databases. The methodological quality of each retrieved publication was assessed. Outcome data were abstracted and effect sizes calculated. The evidence for each recommendation was assessed and expert consensus highlighted by the allocation of two categories: (1) strength of evidence and (2) strength of recommendation.

RESULTS

The first round of the Delphi process produced 123 propositions. This was reduced to 10 after four rounds. These related to aerobic and strengthening exercise, group versus home exercise, adherence, contraindications and predictors of response. The literature search identified 910 articles; 57 intervention trials relating to knee OA, 9 to hip OA and 73 to adherence. The evidence to support each proposition is presented.

CONCLUSION

These are the first recommendations for exercise in hip and knee OA to clearly differentiate research evidence and expert opinion. Gaps in the literature are identified and issues requiring further study highlighted.

The random blood glucose level, a risk factor for mortality after acute myocardial infarction, in non-diabetic patients

The Correlation between blood glucose level and cardio-vascular events is well established in diabetic patients. In this study, fifty three non diabetic (M:30F:23), patients after acute myocardial infarction were studied for mortality in the following two years, retrospectively. Every patient had random venous glucose estimated on admission. This glucose level was correlated with all cause mortality. At the end of 2 years, 13 patients died and 40 remained alive. There was a significant difference of blood glucose between those who died and remained alive. The difference between the mean blood glucose level is between 0.6 mmol/L and 3.8 mmol/L higher for patients who died (mean = 8.62); compared with those that were still alive (mean = 6.69). This difference was particularly observed in the group of anterior wall infarction. The subgroup analysis also revealed that the difference between the mean blood glucose levels is 9 mmol/L for female patients with heart failure compared with those who did not suffer from heart failure (mean 6.8). The study concludes that, the higher glucose level is associated with increased all cause mortality in the following 2 years of first acute myocardial infarction.

Management of suspected cervical spine injuries--the paediatric perspective

Paediatric cervical spine immobilisation and management is one of the most difficult tasks to master in the paediatric trauma population. The Royal Children's Hospital--Melbourne has admitted 54 patients with diagnosed cervical spine injuries since January 1999. The management of such patients admitted to acute care facilities with suspected cervical spine injuries is inconsistent and at times sub-optimal. Management controversies centre around, application of cervical collars, clearance of the c-spine, patient movement and general care principles. In an endeavour to address these issues, the Royal Children's Hospital Trauma Service, in conjunction with the Emergency Department developed cervical spine guidelines. Teams consulted in the formulation of these guidelines included, Emergency Department, Intensive Care Unit, Orthopaedics, Neurosurgery, Radiology and General Surgery. These guidelines were developed as a clinical tool to guide management and standardise the approach of care for these patients. Specifically, the guidelines address: immobilisation of the paediatric cervical spine; radiology; clearing the cervical spine of injury; suspected or proven cervical spine injury; guidelines for times to fitting Philadelphia collar; ongoing care.

Power Doppler ultrasound assessment of rheumatoid hand synovitis

OBJECTIVE

To evaluate power Doppler ultrasound (PD) as a technique in assessing response to treatment with steroids in rheumatoid hand synovitis.

METHODS

Twelve patients with rheumatoid hand synovitis were assessed before and after treatment with steroids. Variables used to assess synovitis activity in each patient included patient visual analog scale (VAS) score for pain, physician assessment score (PAS), erythrocyte sedimentation rate (ESR), and PD of the metacarpophalangeal joints.

RESULTS

Nine female and 3 male patients were studied; mean age was 53.3+/-6.5 yrs and mean disease duration 6.5+/-4.5 yrs. All patients had a good clinical response to steroid treatment and there was a significant improvement in the synovitis activity assessments. Wilcoxon signed-rank test using the exact method was applied to the change in disease activity variables. For PD signal, p < 0.002; VAS, p < 0.0016; ESR, p < 0.031; PAS, p < 0.008.

CONCLUSION

PD quantifies synovitis and may be a useful adjunct to disease assessment and the response to treatment in RA.

Caribou reactions to provocation by snowmachines in Newfoundland

Caribou in Gros Morne National Park reacted to provocation by snowmachine with significant differences in their response between years. Upon exposure to snowmachines, caribou were displaced 60 to 237 m from their initial locations. Groups with calves allowed the snowmachines to approach more closely before responding (5 to 600 m) than adult-only groups (30 to 1300 m), and their overall flight distances were less. Time spent in locomotion and overall reaction time were greater for animals engaged in the most sedentary activities (eg. standing; mean = 239 s and mean = 262 s, and lying; mean = 166 s and mean = 273 s) than for animals already engaged in more dynamic activities such as walking (mean = 118 s and mean = 133 s), running (mean = 74 s and mean = 63 s) and feeding (mean = 118 s and mean = 133 s). Annual differences in the response of adult-only groups were not due to differences in the sex ratio of these groups, but may be related to annual variation in winter weather conditions.

An audit of the application of care aims across the south west Thames region

Care aims are a means of defining the purpose of intervention of health care. The Malcomess care aims model uses these labels to guide the planning, delivery and outcome measurement of care. Within speech and language therapy (SLT) this involves the use of one of seven labels which clarify and make explicit the purpose of each episode of care undertaken with a client. This relatively simple application has been shown to change the way SLTs work, clarifying expectations of many who use the service. In the South West Thames Region, a project was put in place for SLTs which included undertaking training, audit and support. The outcome of the audit showed that care aims had been adopted across the region in a sufficiently flexible way to meet local needs and offered therapists the tools to reflect on the types of interventions provided to clients.

Clinical uroselectivity: a 3-year follow-up in general practice. BPH Group in General Practice

The objectives of this open-labeled study were to assess the clinical uroselectivity of alfuzosin in a long-term follow-up study in general practice. A total of 3,228 patients with clinical benign prostatic hyperplasia (BPH) from 812 centers were included in a prospective 3-year open-labeled study and treated with alfuzosin (immediate-release formulation) at the recommended dosage. Symptom score (Boyarsky, modified) and a 20-item BPH-specific health related quality of life (HRQL) score (Urolife BPH QoL 20), which included three questions on sexuality, were self-administered at baseline, 3, 6, 12, 18, 24, 30 and 36 months. Symptom score was significantly reduced by 54% at 3 months and this reduction was maintained up to 36 months; the HRQL score was significantly improved by 45.4% at 12 months and this improvement was also maintained up to 36 months. Alfuzosin was well tolerated: the quantitative and qualitative distribution of adverse events (AEs) was similar to that previously observed in placebo-controlled studies. 4.2% of the patients dropped out due to AEs. This study confirms the long-term safety profile of alfuzosin in general practice and highlights the need to measure HRQL in the context of clinical uroselectivity.

Pain in young children attending an accident and emergency department

OBJECTIVES

To assess pain in young children presenting to an accident and emergency (A&E) department. To evaluate the use of the toddler-preschooler postoperative pain scale (TPPPS) and the use of analgesia in these children.

METHODS

100 children aged 1-5 years presenting to an A&E department were assessed for pain. Pain assessments were carried out using a modified form of the TPPPS; a visual analogue scale by parents and a numerical scale by nursing staff.

RESULTS

The majority of children were assessed as having pain: 60 by the TPPPS, 58 by the nurses and 63 by parents. Only 30 children, however, received analgesia. Children with the highest pain scores as assessed by nursing staff or using the TPPPS all received analgesia.

CONCLUSIONS

The pain scale appears suitable for use in young children in A&E departments. The subsequent management of pain in young children could be improved.

Selective ET(A) antagonists. 5. Discovery and structure-activity relationships of phenoxyphenylacetic acid derivatives

The fifth paper in this series describes the culmination of our investigations into the development of a potent and selective ET(A) receptor antagonist for the treatment of diseases mediated by ET-1. Receptor site mapping of several ET(A) antagonists prepared previously identified a common cationic binding site which prompted synthesis of phenoxyphenylacetic acid derivative 13a, which showed good in vitro activity (IC(50) 59 nM, rat aortic ET(A)). Optimization of 13a led to the identification of 27b, which exhibited an IC(50) of 4 nM. Although this did not translate into the expected in vivo potency, a compound of comparable in vitro activity, 27a (RPR118031A), showed a far better pharmacokinetic profile and in vivo potency (75 micromol/kg) and was duly proposed and accepted as a development candidate.

Sporadic chromosome abnormalities in human lymphocytes and previous exposure to chemicals

Sporadic abnormalities in lymphocyte cultures are often attributed to in vitro culture variations of no clinical significance. The data presented here compare the findings from 11,873 cells of 230 patients referred with histories of previous chemical exposure (usually to mixtures of solvents and/or pesticides) with 27,050 cells from 855 patients referred for other reasons. Detection of 0.38% or more, structural abnormalities (approximately 1 in 30 cells) was 27.2 times more likely in exposed persons than in controls and the finding of a single autosomal trisomic cell was 14.4 times more likely in exposed persons. These highly statistically significant findings were similar to the frequencies of abnormalities reported in other studies of persons exposed to benzene, pesticides, herbicides and irradiation. It is recommended that findings of sporadic abnormalities in lymphocytes be routinely recorded, and patients with positive findings followed up to discover whether there are past histories of significant exposures.

History of 7,093 patients with lower urinary tract symptoms related to benign prostatic hyperplasia treated with alfuzosin in general practice up to 3 years

OBJECTIVES

As we have previously published 4 articles reporting the treatment of 7,093 clinical benign prostatic hyperplasia (BPH) patients treated with alfuzosin in a 3-month open-labelled study which was subsequently extended to 12, 24, and 36 months, the objective of this article is to provide additional data on dropouts, acute urinary retention (AUR), progression to surgery, and safety under the natural conditions of general practice, paying special attention to the predictive factors.

METHODS

7,093 patients were initially enrolled by 1,812 centers for up to 3 months. Subsequently 1,508, 1,325, and 812 general practitioners agreed to extend the study up to 12, 24, and 36 months, respectively, which corresponds to 4 patient populations.

RESULTS

The baseline symptom profile of patients who completed the study was identical to that of patients who dropped out (because the center resigned or during treatment). In the 4 patient populations, the percentage of patients per month who dropped out, experienced adverse effects, AUR and surgery were 0. 6-1.6, 0.1-0.5, 0.01-0.03, and 0.1-0.3%, respectively. The classes of symptom severity were not predictive for dropouts: 3.5, 12.6, 20, and 14.3% of the severe patients dropped out during treatment versus 4.2, 13.7, 22.9, and 14.0% of the moderate patients who dropped out up to 3, 12, 24, and 36 months, respectively. Safety was satisfactory regarding the number of adverse events and blood pressure measurement. No retrograde ejaculation was reported.

CONCLUSION

Under the natural conditions of general practice the reasons for dropping out were not correlated with symptom severity.