Use of Virtual CT and On-Treatment MRI to Reduce Radiation Dose and Anesthesia Exposure Associated With the Adaptive Workflow in Pediatric Patients Treated With Intensity Modulated Proton Therapy.

Purpose: The purpose of this study was to determine whether virtual computed tomography (vCT) derived from daily cone beam computed tomography (CBCT), or on-treatment magnetic resonance imaging (MRI) can replace quality assurance computed tomography (qCT) in our clinical workflow to minimize imaging dose and potentially anesthesia exposure in patients requiring plan adaptation.

Methods And Materials: Pediatric patients (age <24 years) treated from 2020 to 2023 with intensity modulated proton therapy with at least 1 qCT during proton therapy were eligible. For cases that required plan adaptation, the dose was recalculated on vCT and compared with same-day qCT as well as the original planning computed tomography (pCT).

The Association of Linear Energy Transfer and Dose With Radiation Necrosis After Pencil Beam Scanning Proton Therapy in Pediatric Posterior Fossa Tumors.

Purpose: Proton therapy is the preferred treatment modality for most pediatric central nervous system tumors. The risk of radiation necrosis may be increased at the distal end of the beam because of an increase in linear energy transfer (LET) and relative biological effectiveness (RBE) dose. We report on the association of LET and dose with radiation necrosis after pencil beam scanning proton therapy in pediatric posterior fossa tumors using a case-control framework.

Chemical Exchange Saturation Transfer MRI: What Neuro-Oncology Clinicians Need To Know.

Chemical exchange saturation transfer (CEST) is a relatively novel magnetic resonance imaging (MRI) technique with an image contrast designed for in vivo measurement of certain endogenous molecules with protons that are exchangeable with water protons, such as amide proton transfer commonly used for neuro-oncology applications. Recent technological advances have made it feasible to implement CEST on clinical grade scanners within practical acquisition times, creating new opportunities to integrate CEST in clinical workflow. In addition, the majority of CEST applications used in neuro-oncology are performed without the use gadolinium-based contrast agents which are another appealing feature of this technique.

Skull phantom-based methodology to validate MRI co-registration accuracy for Gamma Knife radiosurgery.

Purpose: Target localization, for stereotactic radiosurgery (SRS) treatment with Gamma Knife, has become increasingly reliant on the co-registration between the planning MRI and the stereotactic cone-beam computed tomography (CBCT). Validating image registration between modalities would be particularly beneficial when considering the emergence of novel functional and metabolic MRI pulse sequences for target delineation. This study aimed to develop a phantom-based methodology to quantitatively compare the co-registration accuracy of the standard clinical imaging protocol to a representative MRI sequence that was likely to fail co-registration.

Chemical exchange saturation transfer MRI in central nervous system tumours on a 1.5 T MR-Linac.

Purpose: To describe the implementation and initial results of using Chemical Exchange Saturation Transfer (CEST) for monitoring patients with central nervous system (CNS) tumours treated using a 1.5 tesla MR-guided radiotherapy system.

Methods: CNS patients were treated with up to 30 fractions (total dose up to 60 Gy) using a 1.

A strategy to prevent a temperature-induced MRI artifact in warm liquid phantoms due to convection currents.

MRI phantom studies often fail to mimic the temperature of the human body, which can negatively impact accuracy. An artifact induced by increasing temperature in liquid phantoms was observed, presenting a significant challenge to temperature-controlled experiments. In this study we characterize and provide a solution to eliminate this temperature-induced MRI artifact.

In vitro characterization of the serotonin biosynthesis pathway by CEST MRI.

Purpose: The diagnosis of monoamine-related psychiatric disorders is based on the phenomenological evaluation of symptoms and behavior by trained clinicians. The CEST technique can be sensitive to monoamines such as serotonin. This study quantifies the CEST properties of the compounds in the serotonin biosynthesis pathway with the goal of developing noninvasive techniques aimed at advancing the diagnostic assessment of serotonin dysfunction.

Weakening of Indian Summer Monsoon Rainfall due to Changes in Land Use Land Cover.

Weakening of Indian summer monsoon rainfall (ISMR) is traditionally linked with large-scale perturbations and circulations. However, the impacts of local changes in land use and land cover (LULC) on ISMR have yet to be explored. Here, we analyzed this topic using the regional Weather Research and Forecasting model with European Center for Medium range Weather Forecast (ECMWF) reanalysis data for the years 2000-2010 as a boundary condition and with LULC data from 1987 and 2005.

Evaluating the psychometric properties of the CAHPS Patient-centered Medical Home survey.

Objective: The goal of this study was to evaluate the reliability and validity of the Consumer Assessment of Healthcare Providers and Systems (CAHPS) Patient-Centered Medical Home (PCMH) survey.

Methods: We conducted a field test of the CAHPS PCMH survey with 2740 adults. We collected information by mail (n = 1746), telephone (n = 672), and from the Web (n = 322) from 6 sites of care affiliated with a West Coast staff model health maintenance organization.

Expanded spatial extent of the Medieval Climate Anomaly revealed in lake-sediment records across the boreal region in northwest Ontario.

Multi-decadal to centennial-scale shifts in effective moisture over the past two millennia are inferred from sedimentary records from six lakes spanning a ~250 km region in northwest Ontario. This is the first regional application of a technique developed to reconstruct drought from drainage lakes (open lakes with surface outlets). This regional network of proxy drought records is based on individual within-lake calibration models developed using diatom assemblages collected from surface sediments across a water-depth gradient.

Inconsistencies between Pangean reconstructions and basic climate controls.

The supercontinent Pangea dominated our planet from the Permian into the Jurassic. Paleomagnetic reconstructions have been used to estimate the latitudinal position of Pangea during this 100-million-year period. Atmospheric circulation, recorded by eolian sandstones in the southwestern United States, shows a broad sweep of northeasterly winds over their northernmost extent, curving to become northwesterly in the south: This evidence is consistent with paleomagnetic reconstructions of the region straddling the equator in the Early Permian but is at odds with its northward movement to about 20 degrees N by the Early Jurassic.

Recruitment and retention benefits of EMT--paramedic utilization during ED nursing shortages.

ED nursing shortages have been widely documented in the literature; however, there has been little exploration of the benefits of using Emergency Medical Technicians-Paramedics (EMT-Ps) in the recruitment and retention of experienced ED registered nurses (RNs). This article will discuss the functionality of EMT-Ps in the nontraditional emergency care setting and the impact of their utilization against a background of nursing shortages. The proposed benefit from use of EMT-Ps in the emergency department will most certainly be lost without the input from the bedside RN.

Alveolar hemorrhage and pulmonary hypertension in systemic sclerosis: a continuum of scleroderma renal crisis?

Alveolar hemorrhage occurs as a complication of systemic inflammatory diseases. In addition to alveolar hemorrhage, patients with systemic sclerosis (SSc) may suffer from digital infarction, pulmonary hypertension, and renal crisis. Although a common pathogenesis of this disease that explains the variety of problems during a patient's illness has yet to be identified, the unique characteristics of SSc may alter our approach to alveolar hemorrhage in this patient population.

Large wind shift on the great plains during the medieval warm period.

Spring-summer winds from the south move moist air from the Gulf of Mexico to the Great Plains. Rainfall in the growing season sustains prairie grasses that keep large dunes in the Nebraska Sand Hills immobile. Longitudinal dunes built during the Medieval Warm Period (800 to 1000 years before the present) record the last major period of sand mobility.

New-onset gout after kidney transplantation: incidence, risk factors and implications.

Background: Although cyclosporine use has been associated with an increased risk of new-onset gout after renal transplantation, the incidence and risk factors for new-onset gout have not been reported in the era of modern immunosuppression.

Methods: We conducted a retrospective cohort study of Medicare primary renal transplant patients reported in the United States Renal Data System (USRDS), using Medicare claims data to determine the incidence of new-onset gout. Cox regression analysis was used to calculate adjusted hazard ratios (AHR) for cyclosporine (including separate analysis of Neoral) compared directly with tacrolimus, for the risk of new-onset gout, adjusted for baseline demographic factors and posttransplant renal function.

Maintenance immunosuppression use and the associated risk of avascular necrosis after kidney transplantation in the United States.

Background: Avascular necrosis (AVN) after renal transplantation has been largely attributed to the use of corticosteroids. However, other risk factors such as microvascular thrombosis and hyperlipidemia have been well described and may be of increased importance in the era of early steroid cessation and avoidance. We hypothesized that maintenance immunosuppressive medications known to be associated with these risk factors for AVN would also be associated with a higher risk of AVN.

A 36-year-old military recruit with recurrent myalgias and weakness.

The objective of this study was to discuss a comprehensive yet cost-effective approach to working up active duty patients with recurrent rhabdomyolysis. A 36-year-old male Army recruit was evaluated at Walter Reed Army Medical Center for recurrent rhabdomyolysis. This case illustrates a practical and cost-effective approach to this goal.

Lake sediments record large-scale shifts in moisture regimes across the northern prairies of North America during the past two millennia.

Six high-resolution climatic reconstructions, based on diatom analyses from lake sediment cores from the northern prairies of North America, show that shifts in drought conditions on decadal through multicentennial scales have prevailed in this region for at least the last two millennia. The predominant broad-scale pattern seen at all sites is a major shift in moisture regimes from wet to dry, or vice versa (depending on location), that occurred after a period of relative stability. These large-scale shifts at the different sites exhibit spatial coherence at regional scales.

Hospitalizations for total hip arthroplasty after renal transplantation in the United States.

The national incidence of and factors associated with total hip arthroplasty in renal transplant recipients has not been reported. We conducted an historical cohort study of 42096 renal transplant recipients in the United States between 1 July 1994 and 30 June 1998. Primary outcomes were associations with hospitalizations for a primary discharge code of total hip arthroplasty (ICD9 procedure code 81.