Does one size fit all? Adaptive radiotherapy for bladder cancer: A feasibility study

IntroductionAdaptive techniques to deliver radiotherapy to the bladder may ensure treatment accuracy whilst sparing organs at risk. This study assesses the frequency of when an alternative plan to the current standard may be beneficial and establish the treatment resource implications of adaptive techniques. Assess the variation in accuracy of skeletal surrogate compared to the target. Additionally describes a training package for therapeutic radiographers evaluating CBCT datasets for adaptive techniques.MethodsA library of three plans was created for each patient, small, standard and large. Weekly CBCT and planar imaging data were acquired from 10 bladder cancer patients receiving radical radiotherapy. Bladder volumes from weekly CBCT were compared to the planning scan. Image registration was performed using bone and soft tissue structures on the CBCT images. A database of images was created to develop competency assessment and a training package.ResultsMatching to a skeletal surrogate may under estimate movement of the target. Bladder volume can vary significantly during the course of treatment, even in the presence of bladder preparation protocols. The additional time required to implement this technique is 4 min per fraction compared to standard treatment with planar imaging.ConclusionsThis feasibility study is a useful process to facilitate the implementation of adaptive techniques. However a limitation of this study is the low number of CBCT datasets evaluated. The advent of IGRT and adaptive techniques gives increased confidence to reduce margins, consequently facilitating hypo-fractionation, and may provide a gain in linear accelerator efficiency and reduce the number of hospital visits for the patient. CBCT paired with a development programme for therapeutic radiographers is an effective and efficient means of implementing adaptive radiotherapy.     

M EDICAL D IRECTION AND M EDICAL C ONTROL OF A IR M EDICAL S ERVICES Position statement of the Air Medical Physician Association

Abstract

Introduction. Traumatic injury is a leading cause of morbidity and mortality, but these can be minimized by timely transport to definite care. Helicopter emergency medical services (HEMS) provide timely transport and can influence survival. However, accident analyses indicate that landing at an unsecured landing zone (LZ), particularly at night, increases the risk of aviation accidents. To ensure safety, some HEMS operations land only at designated, secured LZs. Objective. This study utilized geographic information systems (GISs) to compare locations of scene call requests and secure LZs. The goal was to determine the optimal placement of new helipads as a strategy to improve access while mitigating the risk of aviation accidents. Methods. Call request data from a large air medical transport service were used to determine the geographic locations of all requests for scene responses in 2006. Request locations were compared with the locations of existing helipads, and straight-line distances between scene and helipad were determined using the GIS application. The application was then used to determine potential locations for new helipads. Results. During the study period, 748 requests for scene calls and 269 helipads were available. There were 476 (52.4%) requests at least 10 kilometers from a helipad and 356 (36.6%) requests at least 15 kilometers from a helipad. One particular region, Southwestern Ontario, was identified as having the highest number of requests >15 kilometers from the closest helipad. Conclusion. GISs can be used to determine potential locations for new helipad construction using historical call request data. This evidence-based approach can improve HEMS access while mitigating operational risk.     

Left ventricular volume and ejection fraction response to exercise in chronic congestive heart failure: difference between dilated cardiomyopathy and previous myocardial infarction

To determine if cause influences the left ventricular (LV) volume and ejection fraction (EF) response to exercise, 24 patients with chronic congestive heart failure (CHF) (13 dilated cardiomyopathy [DC], CHF-DC group; 11 previous myocardial infarction [MI], CHF-MI group) and 6 age-matched control subjects underwent simultaneous hemodynamic monitoring and radionuclide ventriculography during semiupright bicycle exercise. Both CHF groups had similar hemodynamic values, LV volumes and EF at rest. Exercise hemodynamics were also similar, but LV volume and EF responses to exercise were different. In the CHF-DC group LV end-diastolic volume increased by 15% during exercise, significantly less (p less than 0.01) than the 44% increase in CHF-MI group. During exercise, EF increased in CHF-DC group, but did not change in CHF-MI group because of a larger increase in end-systolic volume. The slope of mean pulmonary wedge pressure-LV end-diastolic volume relation was steeper in CHF-DC group than in CHF-MI group (p less than 0.01). The study suggests that LV volume and EF response to exercise in patients with CHF depends on the origin of the CHF.     

Muscle damage and soreness after endurance exercise of the elbow flexors

PURPOSE: This study investigated changes in indirect markers of muscle damage after endurance exercise of the elbow flexors and compared the changes with those after maximal eccentric actions (Max-ECC) of the elbow flexors. METHODS: Eighteen male students rhythmically lifted (1 s) and lowered (1 s) a light dumbbell (1.1-1.8 kg: 9% of MIF) in 60-180 degrees of elbow joint angle for 2 h (2-h Ex). Maximal isometric force (MIF), relaxed (RANG) and flexed elbow joint angles (FANG), upper-arm circumference (CIR), muscle soreness (SOR), B-mode ultrasound (US), and plasma creatine kinase (CK) activity were assessed before and immediately after, and up to 96 h after exercise. RESULTS: All measures were altered significantly (P < 0.05) after 2-h Ex in a similar time course to Max-ECC; however, changes in RANG, FANG, CIR, US, and CK (peak: 356 +/- 121 IU.L-1) were significantly (P < 0.05) smaller compared with those after Max-ECC. SOR developed immediately after 2-h Ex and peaked 24-48 h after exercise. MIF dropped to 44.1% of the preexercise level, which was significantly (P < 0.05) lower than that after Max-ECC (58.1%), immediately postexercise. MIF recovered to 79.8% at 24 h, and 97.8% at 96 h postexercise, which was a significantly (P < 0.05) faster recovery compared with that of Max-ECC (73.1% at 96 h). CONCLUSION: These results showed low-intensity continuous muscle contractions (3600 times) resulted in muscle damage; however, the magnitude of the muscle damage was less severe, and the recovery was faster compared with 12 maximal eccentric muscle actions.     

Cognitive state following mild stroke: A matter of hippocampal mean diffusivity

The hippocampus is known to play a vital role in learning and memory and was demonstrated as an early imaging marker for Alzheimer's disease (AD). However, its role as a predictor for mild cognitive impairment and dementia following stroke is unclear. The main purpose of this study was to examine the associations between hippocampal volume, mean diffusivity (MD) and connectivity and cognitive state following stroke. Eighty three consecutive first ever mild to moderate stroke or transient ischemic attack (TIA) survivors from our ongoing prospective TABASCO (Tel Aviv Brain Acute Stroke Cohort) study underwent magnetic resonance imaging scans within 7 days of stroke onset. Hippocampal volume was measured from T1 weighted images, hippocampal mean diffusivity was calculated from diffusion tensor imaging and connectivity was calculated from resting state fMRI. Global cognitive assessments were evaluated during hospitalization and 6 and 12 months later using a computerized neuropsychological battery. Multiple linear regression analysis was used to test which of the hippocampi measurements best predict cognitive state. All three imaging parameters were significantly correlated to each other (|r's| >0.3, P's < 0.005), and with cognitive state 6 and 12 months after the event. Multiple regression analyses demonstrated the predictive role of hippocampal mean diffusivity (β = ?0.382, P = 0.026) on cognitive state, above and beyond that of volume and connectivity of this structure. To our knowledge, the combination of hippocampal volume, mean diffusivity and connectivity in first ever post stroke or TIA patients has not yet been considered in relation to cognitive state. The results demonstrate the predictive role of hippocampal mean diffusivity, suggesting that these changes may precede and contribute to volumetric and connectivity changes in the hippocampi, potentially serving as a marker for early identification of patients at risk of developing cognitive impairment or dementia. © 2015 Wiley Periodicals, Inc.     

The United Kingdom and Ireland Trauma & Orthopaedic eLogbook-An evidence base for enhancing training

The United Kingdom and Ireland Trauma and Orthopaedic (T&O) eLogbook was originally conceived over ten years ago in order to provide individual surgeon support and allow national analysis of surgical training experience. Since 2003 every trainee in T&O has been required to submit data recording their operative experience throughout the six years of higher specialist training. We describe how orthopaedic surgeons are using the evidence from the eLogbook to improve training, set operative standards and support consultant (post-specialist registration) revalidation.