Dosimetric verification of brain and head and neck intensity-modulated radiation therapy treatment using EDR2 films and 2D ion chamber array matrix

Background: The evaluation of the agreement between measured and calculated dose plays an essential role in the quality assurance (QA) procedures of intensity-modulated radiation therapy (IMRT). Aim: The purpose of this study is to compare performances of the two dosimetric systems (EDR2 and I\u2032matriXX) in the verification of the dose distributions calculated by the TPS for brain and head and neck dynamic IMRT cases. Materials and Methods: The comparison of cumulative fluence by using Kodak extended dose rate (EDR2) and I\u2032matriXX detectors has been done for the evaluation of 10 brain, 10 head and neck IMRT cases treated with 6 MV beams. The parameter used to assess the quality of dose calculation is the gamma-index (g -index) method. The acceptance limits for g calculation we have used are 3% and 3 mm respectively for dose agreement and distance to agreement parameters. Statistical analyses were performed by using the paired, two-tailed Student t-test, and P< 0.01 is kept as a threshold for the significance level. Results: The qualitative dose distribution comparison was performed using composite dose distribution in the measurement plane and profiles along various axes for TPS vs. EDR2 film and TPS Vs I\u2032matriXX. The quantitative analysis between the calculated and measured dose distribution was evaluated using DTA and g-index. The percentage of pixels matching with the set DTA and g values are comparable for both with EDR2 film and I\u2032matriXX array detectors. Statistically there was no significant variation observed between EDR2 film and I\u2032matriXX in terms of the mean percentage of pixel passing g for brain cases (98.77 \ub1 1.03 vs 97.62 \ub1 1.66, P = 0.0218) and for head and neck cases (97.39 \ub1 2.13 vs 97.17 \ub1 1.52%, P = 0.7404). Conclusion: Due to simplicity and fast evaluation process of array detectors, it can be routinely used in busy departments without compromising the measurement accuracy

Physical activity monitoring to assess disability progression in multiple sclerosis

Background: Clinical outcome measurement in multiple sclerosis (MS) usually requires a physical visit. Remote activity monitoring (RAM) using wearable technology provides a rational alternative, especially desirable when distance is involved or in a pandemic setting. Objective: To validate RAM in progressive MS using (1) traditional psychometric methods (2) brain atrophy. Methods: 56 people with progressive MS participated in a longitudinal study over 2.5 years. An arm-worn RAM device measured activity over six days, every six months, and incorporated triaxial accelerometry and transcutaneous physiological variable measurement. Five RAM variables were assessed: physical activity duration, step count, active energy expenditure, metabolic equivalents and a composite RAM score incorporating all four variables. Other assessments every six months included EDSS, MSFC, MSIS-29, Chalder Fatigue Scale and Beck’s Depression Inventory. Annualized brain atrophy was measured using SIENA. Results: RAM was tolerated well by people with MS; the device was worn 99.4% of the time. RAM had good convergent and divergent validity and was responsive, especially with respect to step count. Measurement of physical activity over one day was as responsive as six days. The composite RAM score positively correlated with brain volume loss. Conclusion: Remote activity monitoring is a valid and acceptable outcome measure in MS

UK-Wide Surveillance of Neurological and Neuropsychiatric Complications of COVID-19: The First 153 Patients

Background: Increasingly neurological complications of COVID-19 are identified, mostly in small series. Larger studies have been limited by both geography and specialty. Consequently, the breadth of complications is not represented. Comprehensive characterization of clinical syndromes is critical to rationally select and evaluate potential therapies. / Methods: During the exponential pandemic phase, we developed coordinated online portals for rapid notification across the spectrum of major UK neuroscience bodies, representing neurology, stroke, psychiatry, and intensive care. Evidence of infection and clinical case definitions were applied prospectively. Cases were compared to overall Government Public Health COVID-19 reporting. / Findings: Within three weeks, 153 cases were notified, both geographically and temporally representative of overall COVID-19 Public Health reports. Median (range) age was 71 (23-94) years. 77 (62%) had a cerebrovascular event: 57 (74%) ischemic strokes, nine (12%) intracerebral hemorrhages, and one CNS vasculitis. The second most common group were 39 (31%) who had altered mental status, including 16 (41%) with encephalopathy of whom seven (44%) had encephalitis. The remaining 23 (59%) had a psychiatric diagnosis of whom 21 (92%) were new diagnoses; including ten (43%) with psychosis, six (26%) neurocognitive (dementia-like) syndrome, and 4 (17%) an affective disorder. Cerebrovascular events predominated in older patients. Conversely, altered mental status, whilst present in all ages, had disproportionate representation in the young. / Interpretation: This is the first nationwide, cross-specialty surveillance study of acute complications of COVID-19 in the nervous system. Alteration in mental status was common, reflecting encephalopathy/encephalitis and primary psychiatric diagnoses, often in young patients. These data provide valuable and timely information urgently needed by clinicians, researchers, and funders to inform immediate steps in COVID-19 neuroscience research and health policy throughout the areas of neurology and neuropsychiatry

UK-Wide Surveillance of Neurological and Neuropsychiatric Complications of COVID-19: The First 153 Patients

Background: Increasingly neurological complications of COVID-19 are identified, mostly in small series. Larger studies have been limited by both geography and specialty.Consequently, the breadth of complications is not represented. Comprehensive characterization of clinical syndromes is critical to rationally select and evaluate potential therapies.Methods: During the exponential pandemic phase, we developed coordinated online portals for rapid notification across the spectrum of major UK neuroscience bodies, representing neurology, stroke, psychiatry, and intensive care. Evidence of infection and clinical case definitions were applied prospectively. Cases were compared to overall Government Public Health COVID-19 reporting.Findings: Within three weeks, 153 cases were notified, both geographically and temporally representative of overall COVID-19 Public Health reports. Median (range) age was 71 (23-94) years. 77 (62%) had a cerebrovascular event: 57 (74%) ischemic strokes, nine (12%) intracerebral hemorrhages, and one CNS vasculitis.The second most common group were 39 (31%) who had altered mental status, including 16 (41%) with encephalopathy of whom seven (44%) had encephalitis. The remaining 23 (59%) had a psychiatric diagnosis of whom 21 (92%) were new diagnoses; including ten (43%) with psychosis, six (26%) neurocognitive (dementia-like) syndrome, and 4 (17%) an affective disorder. Cerebrovascular events predominated in older patients. Conversely, altered mental status, whilst present in all ages, had disproportionate representation in the young.Interpretation: This is the first nationwide, cross-specialty surveillance study of acute complications of COVID-19 in the nervous system. Alteration in mental status was common, reflecting encephalopathy/encephalitis and primary psychiatric diagnoses, often in young patients.These data provide valuable and timely information urgently needed by clinicians, researchers, and funders to inform immediate steps in COVID-19 neuroscience research and health policy throughout the areas of neurology and neuropsychiatry

The restorative role of annexin A1 at the blood–brain barrier

Annexin A1 is a potent anti-inflammatory molecule that has been extensively studied in the peripheral immune system, but has not as yet been exploited as a therapeutic target/agent. In the last decade, we have undertaken the study of this molecule in the central nervous system (CNS), focusing particularly on the primary interface between the peripheral body and CNS: the blood–brain barrier. In this review, we provide an overview of the role of this molecule in the brain, with a particular emphasis on its functions in the endothelium of the blood–brain barrier, and the protective actions the molecule may exert in neuroinflammatory, neurovascular and metabolic disease. We focus on the possible new therapeutic avenues opened up by an increased understanding of the role of annexin A1 in the CNS vasculature, and its potential for repairing blood–brain barrier damage in disease and aging

Variation of beam characteristics between three different wedges from a dual-energy accelerator

The use of megavoltage X-ray sources of radiation, with their skin-sparing qualities in radiation therapy, has been proved useful in relieving patient discomfort and allowing higher tumor doses to be given with fewer restrictions due to radiation effects in the skin. The purpose of this study was to compare the dosimetric characteristics of a physical and enhanced dynamic wedge from a dual-energy (6 and 18 MV) linear accelerator such as surfaces doses with different source to surface distances (SSD), half value layer (HVL) in water and peripheral doses for both available energies. At short SSD such as 85 cm, higher surface doses are produced by the lower wedges by the short wedge-to-skin distance. For physical wedged field, at heel edge side HVL value was high (17 cm) compared with the measured that of EDW (15.1 cm). It was noticed that, the HVL variation across the beam was significantly higher for 6 MV X-rays than for 18 MV X-rays. The lower wedge has the maximum variation of peripheral dose compared to other wedges. The three wedge systems discussed in this work possess vastly different dosimetric characteristics. These differences will have a direct impact on the choice of the wedge system to be used for a particular treatment. Complete knowledge of the dosimetric characterisitics, including the surface and peripheral doses, is crucial in proper choice of particular wedge systems in clinical use

Effect of fluence smoothening in intensity modulated radiotherapy planning and delivery

Objective: In Intensity Modulated Radiotherapy (IMRT) planning, optimization is a computational problem, potentially susceptible to noise and artifacts (high frequency spatial fluctuations) producing sharp fluence peaks and valleys in millimetric spatial scale. A solution to this problem is to smooth the beam profiles. Methods and Materials: In the Eclipse TPS, fluence smoothing is achieved within the objective function of the inverse treatment planning systems. Plans were developed for a 6 MV photon beam from a Varian Clinac-DHX equipped with a 120 leaves MLC. Total of 160 dose plans were compared and fed into the analysis process. The dose plan quality has been analysed in terms of Statistical computation by means of two-sided paired t-test between two smoothening levels (s25 and s75) in terms of Homogeneity-Index, Conformity-Index, Target dose coverage and OAR dose differences in terms of max, min and mean doses. Results: From our present study on the influence of smoothening of fluence levels in IMRT plans results, there was a reduction in total MU’s with no significant statistical variation in terms of mean differences of HI Index, CI index, PTV coverages, OAR doses. Moreover, the reduction in MU’s will help the less head leakage dose hence the lower whole-body dose, which will help the patient to reduce the chances for secondary malignancies. Conclusion: Hence, we conclude that, higher fluence smoothening levels with acceptable difference in target coverage and minimum variation of OAR should be selected for the execution

Comparison of Universal Plan Indices for Intensity Modulated Radiotherapy of Head and Neck Cancer treatment

Objective: Manual evaluation of IMRT plans for head-and-neck cancers has been especially challenging necessitating efficient and objective assessment tools. Based on previous clinical experience, the radiation oncologists prescribe the dose to the tumour after critical evaluation of the dose to critical structures. We have evaluated the IMRT plan using Universal Plan Indices and Quality factor. Methods and Materials: In the Eclipse Treatment Planning Systems, we have selected 15 head and neck cancer patients who underwent IMRT delivery in sliding window mode at Clinac DHX linear accelerator equipped with a 120 leaves MLC. All patients were treated using 6 MV photon beams. The UPI indices and Quality factor were calculated using HART software based on MATLAB background. Results: The mean conformity numbers for all fifteen patients were found as 0.92±0.05 and the mean target volume ratio was 1.02±0.04. Similarly the other indices like DG, NCI and modified HI index were 0.95±0.03, 1.08±0.06 and 0.94±0.02 respectively. The mean overall quality factor was found to be 1.01±0.02. The typical value of this factor also to be unity and above unity referred to be overdosed and below the unity referred as under dosage of the structures contoured volume in the corresponding plan. Conclusion: Hence, we have concluded that, evaluation of the IMRT plan of head and neck cancer patients using Universal plan Indices and Quality factor have been done successfully using HART softwar

Commissioning and validation of the electron Monte Carlo dose calculation at extended source to surface distance from a medical linear accelerator

Introduction: Radiotherapy is one of the major modality for cancer management playing curative, adjuvant, and palliative and sometimes has an alternative role to chemotherapy. Radiotherapy is practiced in two ways viz. External beam therapy and Brachytherapy. Electron beam therapy is widely used in the management of cancers. An electron beam is characterized by a finite range of penetration with a rapid dose fall off towards a slowly decaying x-ray background as the electrons traverse through tissues. The electron monte carlo (eMC) dose calculation algorithm for eclipse treatment system has been introduced by Varian Medical systems. The algorithm is commissioned and validated by comparing percentage depth dose (PDD) and gamma index. Methods: Percentage depth dose curves were generated for all the energies for 4x4 cm2 and 10x10 cm2 field sizes. The depth of maximum dose (R100), therapeutic depth (R85), depth of 50% isodose (R50) and the relative surface (Ds) were compared with the measured and calculated PDD curves. Results: The eMC calculated fluence and measured fluence were compared for all the energies and cones at nominal source to surface distance and extended distances. For 4x4 cm2 field size the maximum shift in R100 was 5 mm, R85 was 1.9 mm, R50 was 0.9 mm and the variation in the relative surface (DS) was about 25Gamma analysis shows excellent agreements with greater than 98% of the pixels passing the gamma requirements. Conclusion: We have successfully commissioned and validated the electron monte carlo dose calculation at extended source to surface distance

Children As Evaluators: Understanding Emotion Language Acquisition

This paper introduces a novel approach in the Child-Computer Interaction (CCI) field that examines how children’s feedback on experimental stimuli can enhance research design, using emotion research as a case study. Our study utilizes interactive vignettes where children act as ’emotion detectives’, providing insights into their emotional articulation, followed by elicited feedback on the stimuli and research process. This method refines emotional vocabulary elicitation techniques and empowers children by incorporating their perspectives into the experimental design. The core of this research lies in establishing a participatory framework for involving children as evaluators, thereby proposing changes within the realm of experimental methodologies. We hope that this could serve as a tool to researchers studying children using an experimental setup