A margin-based analysis of the dosimetric impact of motion on step-and-shoot IMRT lung plans

PURPOSE: Intrafraction motion during step-and-shoot (SNS) IMRT is known to affect the target dosimetry by a combination of dose blurring and interplay effects. These effects are typically managed by adding a margin around the target. A quantitative analysis was performed, assessing the relationship between target motion, margin size, and target dosimetry with the goal of introducing new margin recipes. METHODS: A computational algorithm was used to calculate 1,174 motion-encoded dose distributions and DVHs within the patient’s CT dataset. Sinusoidal motion tracks were used simulating intrafraction motion for nine lung tumor patients, each with multiple margin sizes. RESULTS: D(95%) decreased by less than 3% when the maximum target displacement beyond the margin experienced motion less than 5 mm in the superior-inferior direction and 15 mm in the anterior-posterior direction. For target displacements greater than this, D(95%) decreased rapidly. CONCLUSIONS: Targets moving in excess of 5 mm outside the margin can cause significant changes to the target. D(95%) decreased by up to 20% with target motion 10 mm outside the margin, with underdosing primarily limited to the target periphery. Multi-fractionated treatments were found to exacerbate target under-coverage. Margins several millimeters smaller than the maximum target displacement provided acceptable motion protection, while also allowing for reduced normal tissue morbidity

Relationship between cerebral oxygenation, cardiac output, and blood pressure during transitional period in extremely low gestational age neonates

ObjectiveTo describe the relationship between cerebral oxygenation, cardiac output, arterial blood pressure (BP), and cerebral blood flow velocity in extremely low gestational age neonates (ELGANs) during transition.MethodsThis study comprises secondary analyses from a prospective observational study conducted at a tertiary Neonatal Intensive Care Unit. Recruited ELGANs underwent cerebral saturation (CrSO2) monitoring and serial echocardiography during 72 h from birth. Correlative analyses of CrSO2 and cerebral fractional tissue oxygen extraction (CFTOE) with left (LVO) and right ventricular output (RVO), superior vena cava (SVC) flow, middle cerebral artery blood flow mean velocity (MCA.MV), systolic (SBP), diastolic (DBP), and mean (MBP) BP were conducted.ResultsFifty ELGANs with median (range) gestational age of 25.9 (23.1–27.9) weeks were recruited. Echocardiography was performed sequentially at a median (range) age 5.0 (3.8–6.6), 17.3 (15.4–19.4), 31.0 (27.0–34.1), and 53.7 (49.3–58.3) hours. RVO, LVO, CrSO2, and SBP increased over time but no changes in MBP, DBP, CFTOE, MCA.MV or SVC flow were noted. A weak correlation was identified between CrSO2 and SBP (r2 = 0.11, p = 0.047) and MBP (r2 = 0.12, p = 0.04) at 17.3 (15.4–19.4) hours. No correlation of either CrSO2 or CFTOE with any measures of blood flow was identified.ConclusionThere is a weak correlation between measures of cardiac output, BP, and MCA.MV with both CrSO2 and CFTOE in ELGANs during transition. Whether this finding suggests intact cerebral autoregulation requires prospective evaluation in a cohort of sick ELGANs

Hyperimmune immunoglobulin for hospitalised patients with COVID-19 (ITAC): a double-blind, placebo-controlled, phase 3, randomised trial

BACKGROUND: Passive immunotherapy using hyperimmune intravenous immunoglobulin (hIVIG) to SARS-CoV-2, derived from recovered donors, is a potential rapidly available, specific therapy for an outbreak infection such as SARS-CoV-2. Findings from randomised clinical trials of hIVIG for the treatment of COVID-19 are limited. METHODS: In this international randomised, double-blind, placebo-controlled trial, hospitalised patients with COVID-19 who had been symptomatic for up to 12 days and did not have acute end-organ failure were randomly assigned (1:1) to receive either hIVIG or an equivalent volume of saline as placebo, in addition to remdesivir, when not contraindicated, and other standard clinical care. Randomisation was stratified by site pharmacy; schedules were prepared using a mass-weighted urn design. Infusions were prepared and masked by trial pharmacists; all other investigators, research staff, and trial participants were masked to group allocation. Follow-up was for 28 days. The primary outcome was measured at day 7 by a seven-category ordinal endpoint that considered pulmonary status and extrapulmonary complications and ranged from no limiting symptoms to death. Deaths and adverse events, including organ failure and serious infections, were used to define composite safety outcomes at days 7 and 28. Prespecified subgroup analyses were carried out for efficacy and safety outcomes by duration of symptoms, the presence of anti-spike neutralising antibodies, and other baseline factors. Analyses were done on a modified intention-to-treat (mITT) population, which included all randomly assigned participants who met eligibility criteria and received all or part of the assigned study product infusion. This study is registered with ClinicalTrials.gov, NCT04546581. FINDINGS: From Oct 8, 2020, to Feb 10, 2021, 593 participants (n=301 hIVIG, n=292 placebo) were enrolled at 63 sites in 11 countries; 579 patients were included in the mITT analysis. Compared with placebo, the hIVIG group did not have significantly greater odds of a more favourable outcome at day 7; the adjusted OR was 1·06 (95% CI 0·77–1·45; p=0·72). Infusions were well tolerated, although infusion reactions were more common in the hIVIG group (18·6% vs 9·5% for placebo; p=0·002). The percentage with the composite safety outcome at day 7 was similar for the hIVIG (24%) and placebo groups (25%; OR 0·98, 95% CI 0·66–1·46; p=0·91). The ORs for the day 7 ordinal outcome did not vary for subgroups considered, but there was evidence of heterogeneity of the treatment effect for the day 7 composite safety outcome: risk was greater for hIVIG compared with placebo for patients who were antibody positive (OR 2·21, 95% CI 1·14–4·29); for patients who were antibody negative, the OR was 0·51 (0·29–0·90; pinteraction=0·001). INTERPRETATION: When administered with standard of care including remdesivir, SARS-CoV-2 hIVIG did not demonstrate efficacy among patients hospitalised with COVID-19 without end-organ failure. The safety of hIVIG might vary by the presence of endogenous neutralising antibodies at entry. FUNDING: US National Institutes of Health

Intestinal pseudo-obstruction – An under-recognized presentation of systemic lupus erythematosus

Intestinal pseudo-obstruction (IPO), characterized by obstruction without an identifiable anatomic cause, is a rare and poorly understood entity that may occur as a primary condition or secondary to other autoimmune disorders such as systemic lupus erythematosus (SLE). A12-year-old female child was brought with abdominal distension, vomiting, and fever for 15 days. Examination showed height and weight less than the third centile for age, tachypnea, tachycardia, and hypertension with severe abdominal distension, copious bilious aspirate, and very sluggish bowel sounds. Abdominal X-ray showed multiple air fluid levels. Ultrasound abdomen and unenhanced computed tomography (CT) scan revealed thickened dilated bowel loops, ascites, and pleural effusion. In view of multisystem nature of the disease, Koch's abdomen or autoimmune disease was suspected and emergency laparotomy procedure was deferred. She was evaluated and diagnosed to have SLE with lupus nephritis class V as per the International Society of Nephrology/Royal Pathology Society. She was managed conservatively with nasogastric decompression, immunosuppressive therapy and supportive hemodialysis

Role of C- reactive protein in diabetic retinopathy

Introduction: Diabetes mellitus is a major medical problem throughout the world. Diabetes causes an array of long-term systemic complications that have considerable impact on the patient as well as society, as the disease typically affects individuals in their most productive years. C Reactive Protein is an acute phase reactant and an inflammatory mediator involved in the pathogenesis of Diabetic Retinopathy. Aim: The aim of this study is to determine the correlation of C-reactive protein with diabetic retinopathy and different grades of retinopathy. Methods: The study was done on 200 diabetic patients attending the ophthalmology outpatient department, who were selected by purposive sampling. The patients were subjected to a complete ocular examination. Based on the fundus examination patients were categorized into the respective study groups: - 1) Controls 2) Diabetics without Diabetic Retinopathy 3) NPDR 4) PDR 5) CSME. The patients were then subjected to C- reactive protein estimation via laboratory analysis (Turbidometry Technique). Results: The study showed that the mean CRP levels in diabetics were found to be 3mg/dl which is well within normal limits. The CRP levels were relatively higher in the PDR and CSME groups with it being elevated in 30% and 20% patients in the groups respectively. Conclusion: CRP levels in our study did not show significant correlation with diabetes mellitus. Although higher grades of retinopathy had higher CRP levels, the correlation was not significant and consistent. Hence C- reactive protein cannot be used as a reliable screening tool for diabetic retinopathy

Multiple Thrombotic Events in a 67-Year-Old Man 2 Weeks After Testing Positive for SARS-CoV-2: A Case Report

BACKGROUND Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the viral pathogen responsible for coronavirus disease 2019 (COVID-19), a pandemic respiratory illness. While many patients experience mild to moderate symptoms, severely affected patients often progress to acute respiratory distress syndrome (ARDS). Specific to COVID-19, abnormal coagulability appears to be a principal instigator in the progression of disease severity and mortality. In this report we summarize a case of COVID-19 in which extreme thrombophilia led to patient demise. CASE REPORT A 67-year-old man in New York presented to the hospital 14 days after testing positive for SARS-CoV-2 at an outpatient site. His initial presenting symptoms included sore throat, headache, fever, and diarrhea. He was brought in by his wife after developing sudden onset confusion and dysarthria. The patient\u27s clinical picture, which was unstable on presentation, further deteriorated to involve significant desaturations, generalized seizure activity, and cardiac arrest requiring resuscitation. Upon return to spontaneous circulation, the patient required intensive care unit admission, mechanical ventilation, and vasopressor increases. Comprehensive workup uncovered coagulopathy with multiple thrombotic events involving the brain and lungs as well as radiographic evidence of severe lung disease. In the face of an unfavorable clinical picture, the family opted for comfort care measures. CONCLUSIONS In this case report on a 67-year-old-man with COVID-19, we present an account of extreme hypercoagulability that led to multiple thrombotic events eventually resulting in the man\u27s demise. Abnormal coagulation 14 days from positive testing raises the question of whether outpatients with COVID-19 should be screened for hypercoagulability and treated with prophylactic anticoagulation/antiplatelet agents

Benchmarking of five commercial deformable image registration algorithms for head and neck patients

Benchmarking is a process in which standardized tests are used to assess system performance. The data produced in the process are important for comparative purposes, particularly when considering the implementation and quality assurance of DIR algorithms. In this work, five commercial DIR algorithms (MIM, Velocity, RayStation, Pinnacle, and Eclipse) were benchmarked using a set of 10 virtual phantoms. The phantoms were previously developed based on CT data collected from real head and neck patients. Each phantom includes a start of treatment CT dataset, an end of treatment CT dataset, and the ground‐truth deformation vector field (DVF) which links them together. These virtual phantoms were imported into the commercial systems and registered through a deformable process. The resulting DVFs were compared to the ground‐truth DVF to determine the target registration error (TRE) at every voxel within the image set. Real treatment plans were also recalculated on each end of treatment CT dataset and the dose transferred according to both the ground‐truth and test DVFs. Dosimetric changes were assessed, and TRE was correlated with changes in the DVH of individual structures. In the first part of the study, results show mean TRE on the order of 0.5 mm to 3 mm for all phantoms and ROIs. In certain instances, however, misregistrations were encountered which produced mean and max errors up to 6.8 mm and 22 mm, respectively. In the second part of the study, dosimetric error was found to be strongly correlated with TRE in the brainstem, but weakly correlated with TRE in the spinal cord. Several interesting cases were assessed which highlight the interplay between the direction and magnitude of TRE and the dose distribution, including the slope of dosimetric gradients and the distance to critical structures. This information can be used to help clinicians better implement and test their algorithms, and also understand the strengths and weaknesses of a dose adaptive approach. PACS number(s): 87.57.nj, 87.55.dk, 87.55.Q