Improving Complex Brachytherapy Efficiency in the Current Financial Climate

PURPOSE/OBJECTIVE(S)

To optimize multidisciplinary collaboration in the setting of limited resources to increase the efficiency of complex brachytherapy workflow for patients with locally advanced cervical cancer.

MATERIALS/METHODS

High Dose Rate (HDR) brachytherapy is a critical component in the treatment of women with locally advanced cervical cancer. The completion of HDR brachytherapy to provide a complete treatment of concurrent chemoradiation and brachytherapy of <56 days has been well established. A quality improvement (QI) initiative was born out of the need to accommodate an increasing volume of patients with locally advanced cervical cancer. The challenges addressed were: different location of the operating room (OR), HDR brachytherapy suite, MR scanner; Inconsistent OR days; Post-Anesthesia Care Unit (PACU)/transportation delays; Anesthesiology staffing constraints. The QI initiative required multidisciplinary collaboration. A new protocol was finalized which provided protected OR time, and changed analgesia from general anesthesia requiring prolonged monitoring in PACU, to a pre-procedural epidural with moderate sedation. Additionally, a dedicated anesthesiologist was assigned to discuss process improvement, and the medical history for these complex patients as it relates to anesthesia safety. The streamlined process allows the patients' physical time in PACU to be bypassed; a dedicated brachytherapy nurse competent in moderate sedation recovery accompanies the patient to CT simulation. An MR protocol was established with tentative slots secured. The primary metric was the change in the number of interstitial cases performed. Additional metrics included: total case time, anesthesiology delay, MR delay, and number of OR days where 2 complex cases are performed.

RESULTS

Prior to initiation of QI initiative, from 01/2022-09/2022 there were 27 cases, average 3.0/month. After implementation of QI project, from 10/2022-02/2023 there were 32 cases, average 6.4/month, a 113.3% increase. Total case time decreased from baseline 9.3 hours to average 6 hours (Range: 3.8-10.6). Anesthesiology related delays were on average 18.5 minutes (Range: -15-35). MR related delays were on average 87.6 minutes (Range: 35-275). These changes now permit the flexibility of performing 2 complex interstitial cases per day, instead of one. The average days per month where two interstitial cases are performed increased from 0.4 to 1.4.

CONCLUSION

As hospital systems continue to face economic constraints, it is critical that we leverage our existing resources in order to provide timely care to our patients. This QI initiative shows that despite the limitation in brachytherapy operations, systems can be changed through multidisciplinary collaboration to improve efficiencies and increase capacities while working within financial workforce constraints to provide optimal patient care.

Duration of Heightened Risk of Acute Ischemic Stroke After Hospitalization for Acute Systolic Heart Failure

Background The duration and magnitude of increased stroke risk after a hospitalization for acute systolic heart failure (HF) remains uncertain. Methods and Results The authors performed a retrospective cohort study using claims (2008-2018) from a nationally representative 5% sample of Medicare beneficiaries aged ≥66 years. Cox regression models were fitted separately for the groups with and without acute systolic HF to examine its association with the incidence of ischemic stroke after adjustment for demographics, stroke risk factors, and Charlson comorbidities. Corresponding survival probabilities were used to compute the hazard ratio (HR) in each 30-day interval after discharge. The authors stratified patients by the presence of atrial fibrillation (AF) before or during the hospitalization for acute systolic HF. Among 2 077 501 eligible beneficiaries, 94 641 were hospitalized with acute systolic HF. After adjusting for demographics, stroke risk factors, and Charlson comorbidities, the risk of ischemic stroke was highest in the first 30 days after discharge from an acute systolic HF hospitalization for patients with AF (HR, 2.4 [95% CI, 2.1-2.7]) and without AF (HR, 4.6 [95% CI, 4.0-5.3]). The risk of stroke remained elevated for 60 days in patients with AF (HR, 1.4 [95% CI, 1.2-1.6]) and was not significantly elevated afterward. The risk of stroke remained significantly elevated through 330 days in patients without AF (HR, 2.1 [95% CI, 1.7-2.7]) and was no longer significantly elevated afterward. Conclusions A hospitalization for acute systolic HF is associated with an increased risk of ischemic stroke up to 330 days in patients without concomitant AF.

Abstract WMP85: Postpartum Risk Of Cerebral Venous Thrombosis

Background: The postpartum state is associated with a heightened risk of thrombosis. The duration of heightened risk for postpartum cerebral venous thrombosis (CVT) is uncertain.

Methods: Using claims data from the Healthcare Cost and Utilization Project (HCUP) from all emergency departments and acute care hospitalizations in Florida from 2005-2015 and New York from 2006-2015, we identified women aged ≥18 years old who were hospitalized for labor and delivery. CVT was ascertained using previously validated International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM), diagnosis codes. For women with multiple labor-related hospitalizations during a single 40-week period, we excluded cases of false labor by identifying delivery as the latest hospitalization during that time. Patients with claims for CVT before their first recorded delivery, and women with a second delivery during the follow-up period were also excluded. We compared the likelihood of a first-ever recorded CVT during postpartum days 0-41 compared with the same period 1 year later. We repeated this crossover-cohort analysis for consecutive 6-weeks periods after delivery, as compared with the corresponding 6-week period 1 year later. We used McNemar's to calculate odds ratios for each 6-week interval.

Results: Among the 1,406,447 women with a first recorded delivery, the risk of CVT was markedly higher within the 6 weeks after delivery than in the same period 1 year later (22 versus 3 CVTs per million deliveries). This corresponded to an absolute risk difference of 19 events per million (95% confidence interval [CI], 11-27) and an odds ratio of 10.0 (95% CI, 3.1-51.2). There was no significant increase in the risk of CVT during the period of 7 to 12 weeks after delivery as compared with the same period 1 year later with an absolute risk difference of 6.0 events (95% CI, 0-11) per million deliveries and an odds ratio of 3.0 (95% CI, 0.9-12.8).

Conclusion: There appears to be a heightened risk of CVT for 6 weeks after delivery.

The association of parental involvement with adolescents' well-being in Oman: evidence from the 2015 Global School Health Survey

BACKGROUND

The parent-adolescent relationship plays a key role in adolescent development, including behaviour, physical health, and mental health outcomes. Studies on the parental factors that contribute to an adolescent's dietary habits, exercise, mental health, physical harm and substance use are limited in the Middle East and North Africa region, with none in Oman. This study aims to investigate the association between parental involvement and adolescent well-being in Oman.

METHODS

Cross-sectional data from the 2015 Global School Health Survey for Oman was analysed. The dataset consisted of 3468 adolescents. Adolescents reported on their parental involvement (checking to see if they did their homework, understanding their problems, knowing what they are doing in their free time and not going through their things without permission). Parental involvement was scored on a 20-point scale. Associations with the following dependent variables: nutrition, exercise, hygiene, physical harm, bullying, substance use, tobacco use and mental health well-being were done using Spearman's correlations, linear and logistic regressions.

RESULTS

The surveyed population was 48% male, 65% aged 15 to 17 years old and 5% reported that they "most of the time or always" went hungry. Parental involvement was positively correlated with each of the dependent variables. Adolescents with higher parental involvement had significantly higher odds of good nutrition (1.391), hygiene (1.823) and exercise (1.531) and lower odds of physical harm (0.648), being bullied (0.628), poor mental health (0.415), tobacco use (0.496) and substance use (0.229).

CONCLUSIONS

Parental involvement plays a positive role in all aspects of adolescents' well-being in Oman. Awareness campaigns and interventions aimed to help improve the well-being of adolescents should incorporate such positive role in their designs.

Real-world experience of ocrelizumab in multiple sclerosis in an Arab population

Objective

Pivotal clinical trials revealed good clinical efficiency of ocrelizumab while having a good safety profile in the management of multiple sclerosis (MS). However, real-world data of ocrelizumab in daily clinical practice remain scarce. The aim of this study was to evaluate the preliminary safety profile and effectiveness of ocrelizumab treatment for MS in an Arab population in a real-world clinical setting.

Methods

In this retrospective single-center observational study in Qatar, we reviewed the medical records and analyzed the clinical and MRI data of all patients with relapsing-remitting MS (RRMS) and active secondary progressive MS (aSPMS)—between October 2017 through December 2020—who had received at least one infusion of ocrelizumab (Q-OCRE).

Results

A total of 60 MS patients were included (57 with RRMS, three SPMS). The Median follow-up period was 19 months (range, 1–32). The most common reason for switching to ocrelizumab was increased disease activity and three-quarters of the patients were on a previous disease-modifying drug (DMD). No evidence of disease activity (NEDA) status at year 1 was achieved in 73% of the cohort. Mild infusion-related reactions (IRR) and infections were reported (mainly upper respiratory tract infections followed by urinary tract infection) with a declining percentage over the follow-up applications. No severe side effects were observed.

Conclusion

Our real-world experience confirms good efficacy, tolerability, and safety of ocrelizumab in our Arab population.

Racial Differences in Atrial Cardiopathy Phenotypes in Patients With Ischemic Stroke

OBJECTIVE

To test the hypothesis that thrombogenic atrial cardiopathy may be relevant to stroke-related racial disparities, we compared atrial cardiopathy phenotypes between Black vs White patients with ischemic stroke.

METHODS

We assessed markers of atrial cardiopathy in the Greater Cincinnati/Northern Kentucky Stroke Study, a study of stroke incidence in a population of 1.3 million. We obtained ECGs and reports of echocardiograms performed during evaluation of stroke during the 2010/2015 study periods. Patients with atrial fibrillation (AF) or flutter (AFL) were excluded. Investigators blinded to patients' characteristics measured P-wave terminal force in ECG lead V1 (PTFV1), a marker of left atrial fibrosis and impaired interatrial conduction, and abstracted left atrial diameter from echocardiogram reports. Linear regression was used to examine the association between race and atrial cardiopathy markers after adjustment for demographics, body mass index, and vascular comorbidities.

RESULTS

Among 3,426 ischemic stroke cases in Black or White patients without AF/AFL, 2,391 had a left atrial diameter measurement (mean, 3.65 ± 0.70 cm). Black race was associated with smaller left atrial diameter in unadjusted (β coefficient, -0.11; 95% confidence interval [CI], -0.17 to -0.05) and adjusted (β, -0.15; 95% CI, -0.21 to -0.09) models. PTFV1 measurements were available in 3,209 patients (mean, 3,434 ± 2,525 μV*ms). Black race was associated with greater PTFV1 in unadjusted (β, 1.59; 95% CI, 1.21-1.97) and adjusted (β, 1.45; 95% CI, 1.00-1.80) models.

CONCLUSIONS

We found systematic Black-White racial differences in left atrial structure and pathophysiology in a population-based sample of patients with ischemic stroke.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that atrial cardiopathy phenotypes differ in Black people with acute stroke compared to White people.

Acute sensorineural hearing loss as atypical presentation of typhoid fever in adult patient

Salmonella Typhi is the main cause of an acute febrile, sometimes fatal, multisystemic illness called typhoid fever. The diverse presentations of this disease make it a diagnostic challenge in some patients. Involvement of the neurological system, including cochleovestibular system, is very rare with less than a handful of reported cases. This case report describes the condition of a previously healthy 23-year-old Pakistani man with acute onset of hearing loss associated with fever, headache, and disorientation. The most likely differential diagnoses were bacterial or viral meningoencephalitis, and other bacterial infections, such as Rickettsial and spirochetal diseases. Salmonella Typhi grew on blood culture; thus, treatment with intravenous antibiotics and systemic steroids was provided with excellent response. Hearing loss gradually improved and almost completely resolved within 3 to 4 weeks.

Abstract WP265: Racial Differences in Left Atrial Size Among Patients With Ischemic Stroke

Introduction: Blacks in the U.S. face twice the risk of ischemic stroke as whites, and this disparity is not fully explained by established stroke risk factors. Although atrial fibrillation (AF) is a major risk factor for stroke, blacks are less often diagnosed with AF than whites. It is unclear whether this paradox exists because AF is less thoroughly ascertained in blacks compared to whites or because blacks have less predisposing substrate and thus a truly lower risk of AF.

Hypothesis: Based on our prior work, we hypothesized that black patients with ischemic stroke less often have left atrial enlargement, a major predisposing factor for AF.

Methods: We compared left atrial size in black versus white patients in the Greater Cincinnati/Northern Kentucky Stroke Study, a study of racial disparities in stroke incidence in a nationally representative population of 1.3 million. We obtained reports of echocardiograms performed for stroke evaluation among patients in the 2010 and 2015 study periods. Patients with known AF or atrial flutter were excluded. Investigators blinded to patients’ characteristics abstracted left atrial diameter from echocardiogram reports. Linear regression was used to examine the association between race and left atrial diameter after adjustment for demographics, body mass index, and comorbidities.

Results: Among 2,980 cases of ischemic stroke without AF, the median age was 66 years, 52% were female, and 30% were black. The overall mean left atrial diameter was 3.65 (±0.69) cm. Despite a higher burden of vascular risk factors and comorbidities, blacks had significantly smaller left atrial diameters (mean difference, -0.10 cm; 95% CI, -0.04 to -0.17 cm). This difference persisted after adjustment for demographics, comorbidities, and body mass index (adjusted mean difference, -0.15 cm; 95% CI, -0.09 to -0.21 cm).

Conclusions: In a population-based sample, we found that black patients with ischemic stroke had smaller left atrial size than white patients. Our results suggest that the paradox of greater stroke risk but lower AF risk in blacks compared with whites at least partly stems from a lesser degree of AF substrate in blacks.

Abstract WP205: Seasonal Variation in Stroke Incidence in Black versus White Medicare Beneficiaries

Introduction: The increased risk of ischemic stroke in black versus white U.S. residents is not fully explained by known risk factors. Influenza has been implicated as a stroke risk factor, and studies have shown that blacks less often receive influenza vaccination than whites. We investigated whether there is an increased black-white racial disparity in stroke incidence during flu season.

Methods: We performed a retrospective cohort study using inpatient and outpatient claims between 2008-2015 from a nationally representative 5% sample of Medicare beneficiaries. We included patients of black or white race who were ≥66 years old. The outcomes were ischemic stroke outside of influenza season versus during influenza season, defined as December through March based on reports of peak influenza activity from the Centers for Disease Control and Prevention. We calculated incidence rates and used Cox regression models adjusted for demographics and vascular risk factors to examine the association between black race and ischemic stroke.

Results: Among 1,511,393 white and 138,026 black beneficiaries, blacks were slightly younger (mean age, 72.7 vs 73.5), more often female (60.5% vs 56.9%), and less likely to have atrial fibrillation but more likely to have hypertension, diabetes, heart failure, and chronic kidney disease. During a 4.7 (±2.2) years of follow-up, 61,188 patients experienced a stroke. During influenza season, stroke incidence was 1.08 (95% CI, 1.02-1.11) per 100 person-years in blacks versus 0.72 (95% CI, 0.69-0.72) per 100 person-years in whites. Outside of influenza season, stroke incidence was 1.22 (95% CI, 1.19-1.26) per 100 person-years in blacks versus 0.80 per 100 person-years in whites (95% CI, 0.80-0.81). Blacks had a similarly increased hazard of stroke both during influenza season (HR, 1.58; 95% CI, 1.52-1.66) and outside of influenza season (HR, 1.58; 95% CI, 1.53-1.63).

Conclusion: In a cohort of elderly U.S. patients, we found that the black-white disparity in stroke risk was not more pronounced during influenza season. Our findings do not support the hypothesis that influenza contributes to the black-white disparity in stroke risk.

Detection and characterization of intermittent complexity variations in cardiac arrhythmia

OBJECTIVE

A frequent observation during cardiac fibrillation is a fluctuation in complexity where the irregular pattern of the fibrillation is interrupted by more regular phases of varying length.

APPROACH

We apply different measures to sliding windows of raw ECG signals for quantifying the temporal complexity. The methods include permutation entropy, power spectral entropy, a measure for the extent of the set of reconstructed states and several wavelet measures.

MAIN RESULTS

Using these methods, variations of fibrillation patterns over time are detected and visualized.

SIGNIFICANCE

These quantifications can be used to characterize different phases of the ECG during fibrillation and might improve diagnosis and treatment methods for heart diseases.

Mechanisms of vortices termination in the cardiac muscle

We propose a solution to a long-standing problem: how to terminate multiple vortices in the heart, when the locations of their cores and their critical time windows are unknown. We scan the phases of all pinned vortices in parallel with electric field pulses (E-pulses). We specify a condition on pacing parameters that guarantees termination of one vortex. For more than one vortex with significantly different frequencies, the success of scanning depends on chance, and all vortices are terminated with a success rate of less than one. We found that a similar mechanism terminates also a free (not pinned) vortex. A series of about 500 experiments with termination of ventricular fibrillation by E-pulses in pig isolated hearts is evidence that pinned vortices, hidden from direct observation, are significant in fibrillation. These results form a physical basis needed for the creation of new effective low energy defibrillation methods based on the termination of vortices underlying fibrillation.

Incidence of lower limb motor weakness in patients receiving postoperative epidural analgesia and factors associated with it: An observational study

Introduction and Aim:

Epidural analgesia is an effective technique for postoperative pain relief following thoracoabdominal surgeries. Lower limb motor weakness is a well-known complication of epidural analgesia with local anesthetics and delays postoperative rehabilitation. Our aim in conducting this observational study was to assess the frequency of lower limb motor weakness in patients receiving epidural analgesia following upper abdominal surgery and the factors associated with it.

Materials and Methods:

All adult patients, aged 20-70 years, who underwent upper abdominal surgery and received postoperative analgesia with an epidural infusion of bupivacaine with fentanyl, were included. Data were collected over 4 months from notes entered by acute pain service after each round. Data collected included level of epidural placement, drug solution and volume, degree of lower limb motor weakness and measures taken to relieve it. Bromage scale was used to assess motor weakness.

Results:

Data were collected on 123 patients. Bupivacaine 0.1% with fentanyl 2 μg/mL was used in 113 (92%) patients. Lower limb motor weakness developed in 45 patients (36.5%). The highest frequency was seen in patients with epidural at L2-L3 level. The common management steps were a change of patient's position or decrease in concentration of local anesthetic. These measures produced improvement in 39 (87%) patients whereas the local anesthetic was stopped temporarily in the remaining six patients.

Conclusion:

Lower limb motor weakness occurred in 36.5% patients. It was more common with a lumbar epidural. It was successfully managed in all patients. Lower thoracic epidurals are recommended for abdominal surgeries.

Parallel transmit excitation at 1.5 T based on the minimization of a driving function for device heating

PURPOSE

To provide a rapid method to reduce the radiofrequency (RF) E-field coupling and consequent heating in long conductors in an interventional MRI (iMRI) setup.

METHODS

A driving function for device heating (W) was defined as the integration of the E-field along the direction of the wire and calculated through a quasistatic approximation. Based on this function, the phases of four independently controlled transmit channels were dynamically changed in a 1.5 T MRI scanner. During the different excitation configurations, the RF induced heating in a nitinol wire immersed in a saline phantom was measured by fiber-optic temperature sensing. Additionally, a minimization of W as a function of phase and amplitude values of the different channels and constrained by the homogeneity of the RF excitation field (B1) over a region of interest was proposed and its results tested on the benchtop. To analyze the validity of the proposed method, using a model of the array and phantom setup tested in the scanner, RF fields and SAR maps were calculated through finite-difference time-domain (FDTD) simulations. In addition to phantom experiments, RF induced heating of an active guidewire inserted in a swine was also evaluated.

RESULTS

In the phantom experiment, heating at the tip of the device was reduced by 92% when replacing the body coil by an optimized parallel transmit excitation with same nominal flip angle. In the benchtop, up to 90% heating reduction was measured when implementing the constrained minimization algorithm with the additional degree of freedom given by independent amplitude control. The computation of the optimum phase and amplitude values was executed in just 12 s using a standard CPU. The results of the FDTD simulations showed similar trend of the local SAR at the tip of the wire and measured temperature as well as to a quadratic function of W, confirming the validity of the quasistatic approach for the presented problem at 64 MHz. Imaging and heating reduction of the guidewire were successfully performed in vivo with the proposed hardware and phase control.

CONCLUSIONS

Phantom and in vivo data demonstrated that additional degrees of freedom in a parallel transmission system can be used to control RF induced heating in long conductors. A novel constrained optimization approach to reduce device heating was also presented that can be run in just few seconds and therefore could be added to an iMRI protocol to improve RF safety.