Search for exotic decays of the Higgs boson to a pair of pseudoscalars in the μμbb and ττbb final states

A search for exotic decays of the Higgs boson (H ) with a mass of 125Ge V to a pair of light pseudoscalars a 1 is performed in final states where one pseudoscalar decays to two b quarks and the other to a pair of muons or τ leptons. A data sample of proton-proton collisions at s = 13 Te V corresponding to an integrated luminosity of 138fb - 1 recorded with the CMS detector is analyzed. No statistically significant excess is observed over the standard model backgrounds. Upper limits are set at 95% confidence level (CL ) on the Higgs boson branching fraction to μ μ b b and to τ τ b b , via a pair of a 1 s. The limits depend on the pseudoscalar mass m a 1 and are observed to be in the range (0.17-3.3) × 10 - 4 and (1.7-7.7) × 10 - 2 in the μ μ b b and τ τ b b final states, respectively. In the framework of models with two Higgs doublets and a complex scalar singlet (2HDM+S), the results of the two final states are combined to determine upper limits on the branching fraction B ( H → a 1 a 1 → ℓ ℓ b b ) at 95% CL , with ℓ being a muon or a τ lepton. For different types of 2HDM+S, upper bounds on the branching fraction B ( H → a 1 a 1 ) are extracted from the combination of the two channels. In most of the Type II 2HDM+S parameter space, B ( H → a 1 a 1 ) values above 0.23 are excluded at 95% CL for m a 1 values between 15 and 60Ge V .

Emergence of Long-Range Angular Correlations in Low-Multiplicity Proton-Proton Collisions

This Letter presents the measurement of near-side associated per-trigger yields, denoted ridge yields, from the analysis of angular correlations of charged hadrons in proton-proton collisions at sqrt[s]=13  TeV. Long-range ridge yields are extracted for pairs of charged particles with a pseudorapidity difference of 1.4<|Δη|<1.8 and a transverse momentum of 1 Collapse

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First Measurement of the |t| Dependence of Incoherent J/ψ Photonuclear Production

The first measurement of the cross section for incoherent photonuclear production of J/ψ vector mesons as a function of the Mandelstam |t| variable is presented. The measurement was carried out with the ALICE detector at midrapidity, |y|<0.8, using ultraperipheral collisions of Pb nuclei at a center-of-mass energy per nucleon pair of sqrt[s_{NN}]=5.02  TeV. This rapidity interval corresponds to a Bjorken-x range (0.3-1.4)×10^{-3}. Cross sections are given in five |t| intervals in the range 0.04<|t|<1  GeV^{2} and compared to the predictions by different models. Models that ignore quantum fluctuations of the gluon density in the colliding hadron predict a |t| dependence of the cross section much steeper than in data. The inclusion of such fluctuations in the same models provides a better description of the data.

Handling 'carbon footprint' in orthopaedics

INTRODUCTION

The National Health Service contributes 4%-5% of England and Wales' greenhouse gases and a quarter of all public sector waste. Between 20% and 33% of healthcare waste originates from a hospital's operating room, and up to 90% of waste is sent for costly and unneeded hazardous waste processing. The goal of this study was to quantify the amount and type of waste produced during a selection of common trauma and elective orthopaedic operations, and to calculate the carbon footprint of processing the waste.

METHODS

Waste generated for both elective and trauma procedures was separated primarily into clean and contaminated, paper or plastic, and then weighed. The annual carbon footprint for each operation at each site was subsequently calculated.

RESULTS

Elective procedures can generate up to 16.5kg of plastic waste per procedure. Practices such as double-draping the patient contribute to increasing the quantity of waste. Over the procedures analysed, the mean total plastic waste at the hospital sites varied from 6 to 12kg. One hospital site undertook a pilot of switching disposable gowns for reusable ones with a subsequent reduction of 66% in the carbon footprint and a cost saving of £13,483.89.

CONCLUSIONS

This study sheds new light on the environmental impact of waste produced during trauma and elective orthopaedic procedures. Mitigating the environmental impact of the operating room requires a collective drive for a culture change to sustainability and social responsibility. Each clinician can have an impact upon the carbon footprint of their operating theatre.

Study of High-Transverse-Momentum Higgs Boson Production in Association with a Vector Boson in the qqbb Final State with the ATLAS Detector

This Letter presents the first study of Higgs boson production in association with a vector boson (V=W or Z) in the fully hadronic qqbb final state using data recorded by the ATLAS detector at the LHC in proton-proton collisions at sqrt[s]=13  TeV and corresponding to an integrated luminosity of 137  fb^{-1}. The vector bosons and Higgs bosons are each reconstructed as large-radius jets and tagged using jet substructure techniques. Dedicated tagging algorithms exploiting b-tagging properties are used to identify jets consistent with Higgs bosons decaying into bb[over ¯]. Dominant backgrounds from multijet production are determined directly from the data, and a likelihood fit to the jet mass distribution of Higgs boson candidates is used to extract the number of signal events. The VH production cross section is measured inclusively and differentially in several ranges of Higgs boson transverse momentum: 250-450, 450-650, and greater than 650 GeV. The inclusive signal yield relative to the standard model expectation is observed to be μ=1.4_{-0.9}^{+1.0} and the corresponding cross section is 3.1±1.3(stat)_{-1.4}^{+1.8}(syst)  pb.

Observation of WWγ Production and Search for Hγ Production in Proton-Proton Collisions at sqrt[s]=13 TeV

The observation of WWγ production in proton-proton collisions at a center-of-mass energy of 13 TeV with an integrated luminosity of 138  fb^{-1} is presented. The observed (expected) significance is 5.6 (5.1) standard deviations. Events are selected by requiring exactly two leptons (one electron and one muon) of opposite charge, moderate missing transverse momentum, and a photon. The measured fiducial cross section for WWγ is 5.9±0.8(stat)±0.8(syst)±0.7(modeling)  fb, in agreement with the next-to-leading order quantum chromodynamics prediction. The analysis is extended with a search for the associated production of the Higgs boson and a photon, which is generated by a coupling of the Higgs boson to light quarks. The result is used to constrain the Higgs boson couplings to light quarks.

New Structures in the J/ψJ/ψ Mass Spectrum in Proton-Proton Collisions at sqrt[s]=13 TeV

A search is reported for near-threshold structures in the J/ψJ/ψ invariant mass spectrum produced in proton-proton collisions at sqrt[s]=13  TeV from data collected by the CMS experiment, corresponding to an integrated luminosity of 135  fb^{-1}. Three structures are found, and a model with quantum interference among these structures provides a good description of the data. A new structure is observed with a local significance above 5 standard deviations at a mass of 6638_{-38}^{+43}(stat)_{-31}^{+16}(syst)  MeV. Another structure with even higher significance is found at a mass of 6847_{-28}^{+44}(stat)_{-20}^{+48}(syst)  MeV, which is consistent with the X(6900) resonance reported by the LHCb experiment and confirmed by the ATLAS experiment. Evidence for another new structure, with a local significance of 4.7 standard deviations, is found at a mass of 7134_{-25}^{+48}(stat)_{-15}^{+41}(syst)  MeV. Results are also reported for a model without interference, which does not fit the data as well and shows mass shifts up to 150 MeV relative to the model with interference.

Measurement of the Centrality Dependence of the Dijet Yield in p+Pb Collisions at sqrt[s_{NN}]=8.16 TeV with the ATLAS Detector

ATLAS measured the centrality dependence of the dijet yield using 165  nb^{-1} of p+Pb data collected at sqrt[s_{NN}]=8.16  TeV in 2016. The event centrality, which reflects the p+Pb impact parameter, is characterized by the total transverse energy registered in the Pb-going side of the forward calorimeter. The central-to-peripheral ratio of the scaled dijet yields, R_{CP}, is evaluated, and the results are presented as a function of variables that reflect the kinematics of the initial hard parton scattering process. The R_{CP} shows a scaling with the Bjorken x of the parton originating from the proton, x_{p}, while no such trend is observed as a function of x_{Pb}. This analysis provides unique input to understanding the role of small proton spatial configurations in p+Pb collisions by covering parton momentum fractions from the valence region down to x_{p}∼10^{-3} and x_{Pb}∼4×10^{-4}.

Cryopreservation and assessment of genetic fidelity Acorus calamus Linn., an endangered medicinal plant

BACKGROUND

Acorus calamus Linn. is a medicinally valuable monocot plant belonging to the family Acoraceae. Over-exploitation and unscientific approach towards harvesting to fulfill an ever-increasing demand have placed it in the endangered list of species.

OBJECTIVE

To develop vitrification-based cryopreservation protocols for A. calamus shoot tips, using conventional vitrification and V cryo-plate.

MATERIALS AND METHODS

Shoot tips (2 mm in size) were cryopreserved with the above techniques by optimizing various parameters such as preculture duration, sucrose concentration in the preculture medium, and PVS2 dehydration time. Regenerated plantlets obtained post-cryopreservation were evaluated by random amplified polymorphic DNA (RAPD) to test their genetic fidelity.

RESULTS

The highest regrowth of 88.3% after PVS2 exposure of 60 min was achieved with V cryo-plate as compared to 75% after 90 min of PVS2 exposure using conventional vitrification. After cryopreservation, shoot tips developed into complete plantlets in 28 days on regrowth medium (0.5 mg/L BAP, 0.3 mg/L GA3, and 0.3 mg/L ascorbic acid). RAPD analysis revealed 100% monomorphism in all cryo-storage derived regenerants and in vitro donor (120-days-old) plants.

CONCLUSION

Shoot tips of A. calamus that were cryopreserved had 88.3% regrowth using V cryo-plate technique and the regerants retained genetic fidelity. https://doi.org/10.54680/fr24210110412.

Right ventricular assessment of the adolescent footballer's heart

INTRODUCTION

Athletic training can result in electrical and structural changes of the right ventricle that may mimic phenotypical features of arrhythmogenic right ventricular cardiomyopathy (ARVC), such as T-wave inversion and right heart dilatation. An erroneous interpretation may have consequences ranging from false reassurance in an athlete vulnerable to cardiac arrhythmias, to unnecessary sports restriction in a healthy individual. The primary aim of this study was to define normal RV dimension reference ranges for academy adolescent footballers of different ethnicities. Secondary aims include analysis of potential overlap between this adolescent group with ARVC criteria and comparison with normal adult ranges.

RESULTS

Electrocardiographic (ECG) and echocardiographic data of 1087 academy male footballers aged between 13 and 18 years old (mean age 16.0 ± 0.5 years), attending mandatory cardiac screening were analysed. Ethnicity was categorised as white (n = 826), black (African/Caribbean; n = 166) and mixed-race (one parent white and one parent black; n = 95). Arrhythmogenic right ventricular cardiomyopathy major criteria for T-wave inversion was seen in 3.3% of the cohort. This was more prevalent in black footballers (12%) when compared to mixed race footballers (6.3%) or white footballers (1%), P < 0.05. Up to 59% of the cohort exceeded adult reference ranges for some of the right ventricular parameters, although values were similar to those seen in adult footballers. There were no differences in right ventricular dimensions between ethnicities. In particular, the right ventricular outflow tract diameter would fulfil major criteria for ARVC dimension in 12% of footballers. Overall, 0.2% of the cohort would fulfil diagnosis for 'definite' arrhythmogenic right ventricular cardiomyopathy and 2.2% would fulfil diagnosis for 'borderline' arrhythmogenic right ventricular cardiomyopathy for RV dimensions and ECG changes. This was seen more frequently in black footballers (9.9%) than mixed race footballers (3.9%) or white footballer (0.6%), P < 0.05. Among athletes meeting definite or borderline arrhythmogenic right ventricular cardiomyopathy criteria, no cardiomyopathy was identified after comprehensive clinical assessment, including with cardiac magnetic resonance imaging, exercise testing, ambulatory electrocardiograms and familial evaluation.

CONCLUSION

Right heart sizes in excess of accepted adult ranges occurred in as many as one in two adolescent footballers. Structural adaptations in conjunction with anterior T-wave inversion may raise concern for ARVC, highlighting the need for evaluation in expert settings.

Prevalence and Clinical Significance of Electrocardiographic Complete Right Bundle Branch Block in Young Individuals

BACKGROUND AND AIMS

There is limited information on the clinical significance of complete right bundle branch block (CRBBB) in young individuals. The aim of this study was to determine the prevalence and significance of CRBBB in a large cohort of young individuals aged 14-35 years old.

METHODS

From 2008 to 2018, 104,369 consecutive individuals underwent a cardiovascular assessment with a health questionnaire, electrocardiogram, clinical consultation, and selective echocardiography. Follow-up was obtained via direct telephone consultations. Mean follow-up was 7.3 ± 2.7 years.

RESULTS

CRBBB was identified in 154 (0.1%) individuals and was more prevalent in males compared with females (0.20% vs. 0.06%; p<0.05) and in athletes compared with non-athletes (0.25% vs. 0.14%; p<0.05). CRBBB-related cardiac conditions were identified in 7 (5%) individuals (4 with atrial septal defect, 1 with Brugada syndrome, 1 with progressive cardiac conduction disease and 1 with atrial fibrillation). Pathology was more frequently identified in individuals with non-isolated CRBBB compared with individuals with isolated CRBBB (14% vs 1%; p < 0.05) and in individuals with a QRS duration of ≥130 milliseconds (ms) compared with individuals with a QRS of <130ms (10% vs 1%; p<0.05).

CONCLUSION

The prevalence of CRBBB in young individuals was 0.1% and was more prevalent in males and athletes. CRBBB-related conditions were identified in 5% of individuals and were more common in individuals with non-isolated CRBBB and more pronounced intraventricular conduction delay (QRS duration of ≥130ms). Secondary evaluation should be considered for young individuals with CRBBB with symptoms, concerning family history, additional electrocardiographic anomalies or significant QRS prolongation (≥130ms).

Search for New Phenomena in Two-Body Invariant Mass Distributions Using Unsupervised Machine Learning for Anomaly Detection at sqrt[s]=13 TeV with the ATLAS Detector

Searches for new resonances are performed using an unsupervised anomaly-detection technique. Events with at least one electron or muon are selected from 140  fb^{-1} of pp collisions at sqrt[s]=13  TeV recorded by ATLAS at the Large Hadron Collider. The approach involves training an autoencoder on data, and subsequently defining anomalous regions based on the reconstruction loss of the decoder. Studies focus on nine invariant mass spectra that contain pairs of objects consisting of one light jet or b jet and either one lepton (e,μ), photon, or second light jet or b jet in the anomalous regions. No significant deviations from the background hypotheses are observed. Limits on contributions from generic Gaussian signals with various widths of the resonance mass are obtained for nine invariant masses in the anomalous regions.

Search for Scalar Leptoquarks Produced via τ-Lepton-Quark Scattering in pp Collisions at sqrt[s]=13 TeV

The first search for scalar leptoquarks produced in τ-lepton-quark collisions is presented. It is based on a set of proton-proton collision data recorded with the CMS detector at the LHC at a center-of-mass energy of 13 TeV corresponding to an integrated luminosity of 138  fb^{-1}. The reconstructed final state consists of a jet, significant missing transverse momentum, and a τ lepton reconstructed through its hadronic or leptonic decays. Limits are set on the product of the leptoquark production cross section and branching fraction and interpreted as exclusions in the plane of the leptoquark mass and the leptoquark-τ-quark coupling strength.

ψ(2S) Suppression in Pb-Pb Collisions at the LHC

The production of the ψ(2S) charmonium state was measured with ALICE in Pb-Pb collisions at sqrt[s_{NN}]=5.02  TeV, in the dimuon decay channel. A significant signal was observed for the first time at LHC energies down to zero transverse momentum, at forward rapidity (2.5 Collapse

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Search for Inelastic Dark Matter in Events with Two Displaced Muons and Missing Transverse Momentum in Proton-Proton Collisions at sqrt[s]=13 TeV

A search for dark matter in events with a displaced nonresonant muon pair and missing transverse momentum is presented. The analysis is performed using an integrated luminosity of 138  fb^{-1} of proton-proton (pp) collision data at a center-of-mass energy of 13 TeV produced by the LHC in 2016-2018. No significant excess over the predicted backgrounds is observed. Upper limits are set on the product of the inelastic dark matter production cross section σ(pp→A^{'}→χ_{1}χ_{2}) and the decay branching fraction B(χ_{2}→χ_{1}μ^{+}μ^{-}), where A^{'} is a dark photon and χ_{1} and χ_{2} are states in the dark sector with near mass degeneracy. This is the first dedicated collider search for inelastic dark matter.

Observation of WZγ Production in pp Collisions at sqrt[s]=13 TeV with the ATLAS Detector

This Letter reports the observation of WZγ production and a measurement of its cross section using 140.1±1.2  fb^{-1} of proton-proton collision data recorded at a center-of-mass energy of 13 TeV by the ATLAS detector at the Large Hadron Collider. The WZγ production cross section, with both the W and Z bosons decaying leptonically, pp→WZγ→ℓ^{'}^{±}νℓ^{+}ℓ^{-}γ (ℓ^{(^{'})}=e, μ), is measured in a fiducial phase-space region defined such that the leptons and the photon have high transverse momentum and the photon is isolated. The cross section is found to be 2.01±0.30(stat)±0.16(syst)  fb. The corresponding standard model predicted cross section calculated at next-to-leading order in perturbative quantum chromodynamics and at leading order in the electroweak coupling constant is 1.50±0.06  fb. The observed significance of the WZγ signal is 6.3σ, compared with an expected significance of 5.0σ.

Luminosity determination using Z boson production at the CMS experiment

The measurement of Z boson production is presented as a method to determine the integrated luminosity of CMS data sets. The analysis uses proton-proton collision data, recorded by the CMS experiment at the CERN LHC in 2017 at a center-of-mass energy of 13Te V . Events with Z bosons decaying into a pair of muons are selected. The total number of Z bosons produced in a fiducial volume is determined, together with the identification efficiencies and correlations from the same data set, in small intervals of 20pb - 1 of integrated luminosity, thus facilitating the efficiency and rate measurement as a function of time and instantaneous luminosity. Using the ratio of the efficiency-corrected numbers of Z bosons, the precisely measured integrated luminosity of one data set is used to determine the luminosity of another. For the first time, a full quantitative uncertainty analysis of the use of Z  bosons for the integrated luminosity measurement is performed. The uncertainty in the extrapolation between two data sets, recorded in 2017 at low and high instantaneous luminosity, is less than 0.5%. We show that the Z boson rate measurement constitutes a precise method, complementary to traditional methods, with the potential to improve the measurement of the integrated luminosity.

Measurement of the production cross section for a W boson in association with a charm quark in proton-proton collisions at s=13TeV

The strange quark content of the proton is probed through the measurement of the production cross section for a W boson and a charm (c) quark in proton-proton collisions at a center-of-mass energy of 13Te V . The analysis uses a data sample corresponding to a total integrated luminosity of 138fb - 1 collected with the CMS detector at the LHC. The W bosons are identified through their leptonic decays to an electron or a muon, and a neutrino. Charm jets are tagged using the presence of a muon or a secondary vertex inside the jet. The W + c production cross section and the cross section ratio R c ± = σ ( W + + c ¯ ) / σ ( W - + c ) are measured inclusively and differentially as functions of the transverse momentum and the pseudorapidity of the lepton originating from the W boson decay. The precision of the measurements is improved with respect to previous studies, reaching 1% in R c ± = 0.950 ± 0.005 (stat) ± 0.010 (syst) . The measurements are compared with theoretical predictions up to next-to-next-to-leading order in perturbative quantum chromodynamics.

A prospective case-control study on the evaluation of oxidative stress in renal stone formers

Association of increased oxidative stress (OS) with the pathophysiology of renal stone formation has not been explored greatly in the field of urolithiasis. In this prospective case-control study, we measured 24-h urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels in patients with urolithiasis and compared them with matched healthy controls. We also measured 24-h urinary uric acid, calcium, oxalate, and citrate levels in patients with renal stone disease and studied their relation with urinary 8-OHdG levels. Seventy-five cases of renal stone disease and 75 well-matched controls were included. Median 24-h urinary 8-OHdG levels were significantly higher in cases compared to controls (7.6 vs. 3.7 µg/g of creatinine; p < 0.000). Receiver-operating curve (ROC) analysis for 8-OHdG between cases and controls revealed an area under the curve of 0.90. At 8-OHdG (µg/g of creatinine) value of 5 or more, a sensitivity and a specificity of 84% each were obtained. A positive correlation between 8-OHdG (µg/g of creatinine) and 24-h urinary oxalate level was noted (r = 0.461, p = 0.000). No correlation between 8-OHdG (µg/g of creatinine) and other variables was noted. On multivariate linear regression analysis, we noted 24-h urinary oxalate levels to be an independent predictor of urinary 8-OHdG levels. OS is significantly higher in patients with renal stone diseases compared to healthy controls. Urinary oxalate levels were significantly correlated with urinary 8-OHdG levels.

Probing Small Bjorken-x Nuclear Gluonic Structure via Coherent J/ψ Photoproduction in Ultraperipheral Pb-Pb Collisions at sqrt[s_{NN}]=5.02 TeV

Quasireal photons exchanged in relativistic heavy ion interactions are powerful probes of the gluonic structure of nuclei. The coherent J/ψ photoproduction cross section in ultraperipheral lead-lead collisions is measured as a function of photon-nucleus center-of-mass energies per nucleon (W_{γN}^{Pb}) over a wide range of 40 Collapse

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Combined Measurement of the Higgs Boson Mass from the H→γγ and H→ZZ^{*}→4ℓ Decay Channels with the ATLAS Detector Using sqrt[s]=7, 8, and 13 TeV pp Collision Data

A measurement of the mass of the Higgs boson combining the H→ZZ^{*}→4ℓ and H→γγ decay channels is presented. The result is based on 140  fb^{-1} of proton-proton collision data collected by the ATLAS detector during LHC run 2 at a center-of-mass energy of 13 TeV combined with the run 1 ATLAS mass measurement, performed at center-of-mass energies of 7 and 8 TeV, yielding a Higgs boson mass of 125.11±0.09(stat)±0.06(syst)=125.11±0.11  GeV. This corresponds to a 0.09% precision achieved on this fundamental parameter of the Standard Model of particle physics.

Search for Dark Photons in Rare Z Boson Decays with the ATLAS Detector

A search for events with a dark photon produced in association with a dark Higgs boson via rare decays of the standard model Z boson is presented, using 139  fb^{-1} of sqrt[s]=13  TeV proton-proton collision data recorded by the ATLAS detector at the Large Hadron Collider. The dark boson decays into a pair of dark photons, and at least two of the three dark photons must each decay into a pair of electrons or muons, resulting in at least two same-flavor opposite-charge lepton pairs in the final state. The data are found to be consistent with the background prediction, and upper limits are set on the dark photon's coupling to the dark Higgs boson times the kinetic mixing between the standard model photon and the dark photon, α_{D}ϵ^{2}, in the dark photon mass range of [5, 40] GeV except for the ϒ mass window [8.8, 11.1] GeV. This search explores new parameter space not previously excluded by other experiments.

Effect of impaction on third molar development and age estimation-A study in a Lebanese population

BACKGROUND

The effect of impaction on third molar development is disputable as the scientific literature is not uniform. In parallel, population-specific studies have been encouraged in dental age estimation. This study aimed to investigate the effect of impaction on third molar formation in a sample of Lebanese individuals.

MATERIALS AND METHODS

The sample consisted of 518 panoramic radiographs of females (n=229) and males (n=289) between 15 and 23.9 years. Mandibular third molars were classified based on their position as non-impacted and impacted (with horizontal, vertical, mesioangular, and distoangular impaction). Dental development was classified according to Demirjian's 8-level staging system.

RESULTS

Most teeth presented mesioangular impaction (#38=29.7%, #48=33%). Developing third molars were predominantly distributed between stages D and G. The mean age of most developmental stages was higher among impacted teeth, meaning that third molar mineralization could be slower in the presence of impaction. In general, the delayed dental development did not have statistically significant effects (P<0.05). However, descriptive data pointed out differences between (impacted and non-impacted) mean ages of >12 months-suggesting a potential clinical significance (despite the lack of a statistical one). Furthermore, differences changed based on sex and side (#38/#48).

CONCLUSION

Therefore, dental age estimation from third molars in the selected Lebanese population should preferably be performed in non-impacted third molars whenever available.

Species-differences in the in vitro biotransformation of trifluoroethene (HFO-1123)

1,1,2-Trifluoroethene (HFO-1123) is anticipated for use as a refrigerant with low global warming potential. Inhalation studies on HFO-1123 in rats indicated a low potential for toxicity (NOAELs ≥ 20,000 ppm). In contrast, single inhalation exposure of Goettingen® minipigs (≥ 500 ppm) and New Zealand white rabbits (≥ 1250 ppm) resulted in severe toxicity. It has been suggested that these pronounced species-differences in toxicity may be attributable to species-differences in biotransformation of HFO-1123 via the mercapturic acid pathway. Therefore, the overall objective of this study was to evaluate species-differences in glutathione (GSH) dependent in vitro metabolism of HFO-1123 in susceptible versus less susceptible species and humans as a basis for human risk assessment. Biotransformation of HFO-1123 to S-(1,1,2-trifluoroethyl)-L-glutathione (1123-GSH) and subsequent cysteine S-conjugate β-lyase-mediated cleavage of the corresponding cysteine conjugate (1123-CYS) was monitored in hepatic and renal subcellular fractions of mice, rats, minipigs, rabbits, and humans. While 1123-GSH formation occurred at higher rates in rat and rabbit liver S9 compared to minipig and human S9, increased β-lyase cleavage of 1123-CYS was observed in minipig kidney cytosol as compared to cytosolic fractions of other species. Increased β-lyase activity in minipig cytosol was accompanied by time-dependent formation of monofluoroacetic acid (MFA), a highly toxic compound that interferes with cellular energy production via inhibition of aconitase. Consistent with the significantly lower β-lyase activity in human cytosols, the intensity of the MFA signal in human cytosols was only a fraction of the signal obtained in minipig subcellular fractions. Even though the inconsistencies between GSH and β-lyase-dependent metabolism do not allow to draw a firm conclusion on the overall contribution of the mercapturic acid pathway to HFO-1123 biotransformation and toxicity in vivo, the β-lyase data suggest that humans may be less susceptible to HFO-1123 toxicity compared to minipigs.

Insights from neuroradiology in acute disseminated encephalomyelitis

Acute disseminated encephalomyelitis (ADEM) is a rare immune-mediated demyelinating disorder primarily observed in children, typically triggered by recent vaccination or viral infection. Although uncommon, there have been reports of ADEM occurring in adults, with varying radiological findings compared to pediatric cases. Distinguishing ADEM from other demyelinating disorders, such as multiple sclerosis (MS) and neuromyelitis optica (NMO), can pose a diagnostic challenge. We present a case report of an 18-year-old male with a history of polysubstance use who was successfully treated with corticosteroids and highlight the neuroradiological presentation of ADEM, emphasizing the importance of accurate diagnosis and management in both pediatric and adult populations.

Measurements of Groomed-Jet Substructure of Charm Jets Tagged by D^{0} Mesons in Proton-Proton Collisions at sqrt[s]=13 TeV

Understanding the role of parton mass and Casimir color factors in the quantum chromodynamics parton shower represents an important step in characterizing the emission properties of heavy quarks. Recent experimental advances in jet substructure techniques have provided the opportunity to isolate and characterize gluon emissions from heavy quarks. In this Letter, the first direct experimental constraint on the charm-quark splitting function is presented, obtained via the measurement of the groomed shared momentum fraction of the first splitting in charm jets, tagged by a reconstructed D^{0} meson. The measurement is made in proton-proton collisions at sqrt[s]=13  TeV, in the low jet transverse-momentum interval of 15≤p_{T}^{jet ch}<30  GeV/c where the emission properties are sensitive to parton mass effects. In addition, the opening angle of the first perturbative emission of the charm quark, as well as the number of perturbative emissions it undergoes, is reported. Comparisons to measurements of an inclusive-jet sample show a steeper splitting function for charm quarks compared with gluons and light quarks. Charm quarks also undergo fewer perturbative emissions in the parton shower, with a reduced probability of large-angle emissions.

Observation of Single-Top-Quark Production in Association with a Photon Using the ATLAS Detector

This Letter reports the observation of single top quarks produced together with a photon, which directly probes the electroweak coupling of the top quark. The analysis uses 139  fb^{-1} of 13 TeV proton-proton collision data collected with the ATLAS detector at the Large Hadron Collider. Requiring a photon with transverse momentum larger than 20 GeV and within the detector acceptance, the fiducial cross section is measured to be 688±23(stat) _{-71}^{+75}(syst)  fb, to be compared with the standard model prediction of 515_{-42}^{+36}  fb at next-to-leading order in QCD.

[Protein Repeats Show Clade-Specific Volatility in Aves]

Protein repeats are a source of rapid evolutionary and functional novelty. Repeats are crucial in development, neurogenesis, immunity, and disease. Repeat length variability and purity can alter the outcome of a pathway by altering the protein structure and affecting the protein-protein interaction affinity. Such rampant alterations can facilitate species to rapidly adapt to new environments or acquire various morphological/physiological features. With more than 11000 species, the avian clade is one of the most speciose vertebrate clades, with near-ubiquitous distribution globally. Explosive adaptive radiation and functional diversification facilitated the birds to occupy various habitats. High diversity in morphology, physiology, flight pattern, behavior, coloration, and life histories make birds ideal for studying protein repeats' role in evolutionary novelty. Our results demonstrate a similar repeat diversity and proportion of repeats across all the avian orders considered, implying an essential role of repeats in necessary pathways. We detected positively selected sites (PSS) in the polyQ repeat of RUNX2 in the avian clade; and considerable repeat length contraction in the Psittacopasserae. The repeats show a species-wide bias towards a contraction in Galloanseriformes. Interestingly, we detected the length contrast of polyS repeat in PCDH20 between Galli-formes and Anseriformes. We speculate the length variability of serine repeat and its interaction with β-catenin in the Wnt/β-catenin signaling pathway could have facilitated fowls to adapt to their respective environmental conditions. We believe our study emphasizes the role of protein repeats in functional/morphological diversification in birds. We also provide an extensive list of genes with considerable repeat length contrast to further explore the role of length volatility in evolutionary novelty and rapid functional diversification.

Measurement of Suppression of Large-Radius Jets and Its Dependence on Substructure in Pb+Pb Collisions at sqrt[s_{NN}]=5.02 TeV with the ATLAS Detector

This letter presents a measurement of the nuclear modification factor of large-radius jets in sqrt[s_{NN}]=5.02  TeV Pb+Pb collisions by the ATLAS experiment. The measurement is performed using 1.72  nb^{-1} and 257  pb^{-1} of Pb+Pb and pp data, respectively. The large-radius jets are reconstructed with the anti-k_{t} algorithm using a radius parameter of R=1.0, by reclustering anti-k_{t} R=0.2 jets, and are measured over the transverse momentum (p_{T}) kinematic range of 158 Collapse

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Measurement of the top quark mass using a profile likelihood approach with the lepton + jets final states in proton-proton collisions at s=13TeV

The mass of the top quark is measured in 36.3fb - 1 of LHC proton-proton collision data collected with the CMS detector at s = 13 Te V . The measurement uses a sample of top quark pair candidate events containing one isolated electron or muon and at least four jets in the final state. For each event, the mass is reconstructed from a kinematic fit of the decay products to a top quark pair hypothesis. A profile likelihood method is applied using up to four observables per event to extract the top quark mass. The top quark mass is measured to be 171.77 ± 0.37 Ge V . This approach significantly improves the precision over previous measurements.

Measurement of the Sensitivity of Two-Particle Correlations in pp Collisions to the Presence of Hard Scatterings

A key open question in the study of multiparticle production in high-energy pp collisions is the relationship between the "ridge"-i.e., the observed azimuthal correlations between particles in the underlying event that extend over all rapidities-and hard or semihard scattering processes. In particular, it is not known whether jets or their soft fragments are correlated with particles in the underlying event. To address this question, two-particle correlations are measured in pp collisions at sqrt[s]=13  TeV using data collected by the ATLAS experiment at the LHC, with an integrated luminosity of 15.8  pb^{-1}, in two different configurations. In the first case, charged particles associated with jets are excluded from the correlation analysis, while in the second case, correlations are measured between particles within jets and charged particles from the underlying event. Second-order flow coefficients, v_{2}, are presented as a function of event multiplicity and transverse momentum. These measurements show that excluding particles associated with jets does not affect the measured correlations. Moreover, particles associated with jets do not exhibit any significant azimuthal correlations with the underlying event, ruling out hard processes contributing to the ridge.

A search for decays of the Higgs boson to invisible particles in events with a top-antitop quark pair or a vector boson in proton-proton collisions at s=13TeV

A search for decays to invisible particles of Higgs bosons produced in association with a top-antitop quark pair or a vector boson, which both decay to a fully hadronic final state, has been performed using proton-proton collision data collected at s = 13 Te V by the CMS experiment at the LHC, corresponding to an integrated luminosity of 138fb - 1 . The 95% confidence level upper limit set on the branching fraction of the 125Ge V Higgs boson to invisible particles, B ( H → inv ) , is 0.54 (0.39 expected), assuming standard model production cross sections. The results of this analysis are combined with previous B ( H → inv ) searches carried out at s = 7 , 8, and 13Te V in complementary production modes. The combined upper limit at 95% confidence level on B ( H → inv ) is 0.15 (0.08 expected).

Observation of τ Lepton Pair Production in Ultraperipheral Pb-Pb Collisions at sqrt[s_{NN}]=5.02 TeV

We present an observation of photon-photon production of τ lepton pairs in ultraperipheral lead-lead collisions. The measurement is based on a data sample with an integrated luminosity of 404  μb^{-1} collected by the CMS experiment at a center-of-mass energy per nucleon pair of sqrt[s_{NN}]=5.02  TeV. The γγ→τ^{+}τ^{-} process is observed for τ^{+}τ^{-} events with a muon and three charged hadrons in the final state. The measured fiducial cross section is σ(γγ→τ^{+}τ^{-})=4.8±0.6(stat)±0.5(syst)  μb, where the second (third) term corresponds to the statistical (systematic) uncertainty in σ(γγ→τ^{+}τ^{-}) in agreement with leading-order QED predictions. Using σ(γγ→τ^{+}τ^{-}), we estimate a model-dependent value of the anomalous magnetic moment of the τ lepton of a_{τ}=0.001_{-0.089}^{+0.055}.

Observation of an Excess of Dicharmonium Events in the Four-Muon Final State with the ATLAS Detector

A search is made for potential ccc[over ¯]c[over ¯] tetraquarks decaying into a pair of charmonium states in the four muon final state using proton-proton collision data at sqrt[s]=13  TeV, corresponding to an integrated luminosity of 140  fb^{-1} recorded by the ATLAS experiment at LHC. Two decay channels, J/ψ+J/ψ→4μ and J/ψ+ψ(2S)→4μ, are studied. Backgrounds are estimated based on a hybrid approach involving Monte Carlo simulations and data-driven methods. Statistically significant excesses with respect to backgrounds dominated by the single parton scattering are seen in the di-J/ψ channel consistent with a narrow resonance at 6.9 GeV and a broader structure at lower mass. A statistically significant excess is also seen in the J/ψ+ψ(2S) channel. The fitted masses and decay widths of the structures are reported.

Observation of the γγ→ττ Process in Pb+Pb Collisions and Constraints on the τ-Lepton Anomalous Magnetic Moment with the ATLAS Detector

This Letter reports the observation of τ-lepton-pair production in ultraperipheral lead-lead collisions Pb+Pb→Pb(γγ→ττ)Pb and constraints on the τ-lepton anomalous magnetic moment a_{τ}. The dataset corresponds to an integrated luminosity of 1.44  nb^{-1} of LHC Pb+Pb collisions at sqrt[s_{NN}]=5.02  TeV recorded by the ATLAS experiment in 2018. Selected events contain one muon from a τ-lepton decay, an electron or charged-particle track(s) from the other τ-lepton decay, little additional central-detector activity, and no forward neutrons. The γγ→ττ process is observed in Pb+Pb collisions with a significance exceeding 5 standard deviations and a signal strength of μ_{ττ}=1.03_{-0.05}^{+0.06} assuming the standard model value for a_{τ}. To measure a_{τ}, a template fit to the muon transverse-momentum distribution from τ-lepton candidates is performed, using a dimuon (γγ→μμ) control sample to constrain systematic uncertainties. The observed 95% confidence-level interval for a_{τ} is -0.057 Collapse

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Comparative studies of the sensitivities of sparse and full geometries of Total-Body PET scanners built from crystals and plastic scintillators

BACKGROUND

Alongside the benefits of Total-Body imaging modalities, such as higher sensitivity, single-bed position, low dose imaging, etc., their final construction cost prevents worldwide utilization. The main aim of this study is to present a simulation-based comparison of the sensitivities of existing and currently developed tomographs to introduce a cost-efficient solution for constructing a Total-Body PET scanner based on plastic scintillators.

METHODS

For the case of this study, eight tomographs based on the uEXPLORER configuration with different scintillator materials (BGO, LYSO), axial field-of-view (97.4 cm and 194.8 cm), and detector configurations (full and sparse) were simulated. In addition, 8 J-PET scanners with different configurations, such as various axial field-of-view (200 cm and 250 cm), different cross sections of plastic scintillator, and multiple numbers of plastic scintillator layers (2, 3, and 4), based on J-PET technology have been simulated by GATE software. Furthermore, Siemens' Biograph Vision has been simulated to compare the results with standard PET scans. Two types of simulations have been performed. The first one with a centrally located source with a diameter of 1 mm and a length of 250 cm, and the second one with the same source inside a water-filled cylindrical phantom with a diameter of 20 cm and a length of 183 cm.

RESULTS

With regards to sensitivity, among all the proposed scanners, the ones constructed with BGO crystals give the best performance ([Formula: see text] 350 cps/kBq at the center). The utilization of sparse geometry or LYSO crystals significantly lowers the achievable sensitivity of such systems. The J-PET design gives a similar sensitivity to the sparse LYSO crystal-based detectors while having full detector coverage over the body. Moreover, it provides uniform sensitivity over the body with additional gain on its sides and provides the possibility for high-quality brain imaging.

CONCLUSION

Taking into account not only the sensitivity but also the price of Total-Body PET tomographs, which till now was one of the main obstacles in their widespread clinical availability, the J-PET tomography system based on plastic scintillators could be a cost-efficient alternative for Total-Body PET scanners.

Review of management practices of sinogenic intracranial abscesses in children

OBJECTIVE

This study aimed to evaluate the management practices and outcomes in children with sinogenic intracranial suppuration.

METHOD

This was a retrospective cohort study in a single paediatric tertiary unit that included patients younger than 18 years with radiologically confirmed intracranial abscess, including subdural empyema and epidural or intraparenchymal abscess secondary to sinusitis. Main outcomes studied were rate of return to the operating theatre, length of hospital stay, death in less than 90 days and neurological disability at 6 months.

RESULTS

A cohort of 39 consecutive patients presenting between 2000 and 2020 were eligible for inclusion. Subdural empyema was the most common intracranial complication followed by extradural abscess and intraparenchymal abscess. Mean length of hospital stay was 42 days. Sixteen patients were managed with combined ENT and neurosurgical interventions, 15 patients underwent ENT procedures alone and 4 patients had only neurosurgical drainage. Four patients initially underwent non-operative management. The rates of return to the operating theatre, neurological deficits and 90-day mortality were 19, 9 and 3, respectively, and were comparable across the 4 treatment arms. In the univariate logistic regression, only the size of an intracranial abscess was found be associated with an increased likelihood of return to the operating theatre, whereas combined ENT and neurosurgical intervention did not result in improved outcomes.

CONCLUSION

Sinogenic intracranial abscesses are associated with significant morbidity and mortality. The size of an intracranial abscess has a strong association with a need for a revision surgery.

Intrafraction Dosimetric Evaluation of Biology-Guided Radiotherapy to a Target Under Respiratory Motion

PURPOSE/OBJECTIVE(S)

To evaluate the reproducibility and variability of biology-guided radiotherapy (BgRT) treatments using a large anthropomorphic phantom modeling the motion amplitude of a lung tumor.

MATERIALS/METHODS

RefleXion X1 is equipped with two opposing 90 degrees PET detector arcs to capture the radionuclide emissions and direct the 6MV Linac to treat the lesions in real time. A custom-built phantom filled with a liquid [¹⁸F]Fluorodeoxyglucose (FDG) solution was used. Fillable target and OAR structures were 3D printed and attached to motion stages. The GTV = CTV was matched to the spherical 22 mm diameter target, and the PTV was a 5 mm expansion from the CTV volume. The Biology Tracking Zone (BTZ) was generated after adding 5 mm margin to the motion extent of the CTV. The OAR was a large C-shape annulus (emulating a heart) that was approximately 3 cm from the target. The 3D independent motion trajectory of the target was designed to mimic lung motion: range of +5.8 mm to -4.9 mm in LR, range of +14.4 mm to -11.3 mm in SI, and range of +5.2 mm to -5.1 mm in AP directions. The OAR motion waveform used a 1D sinusoidal pattern with a 5 mm amplitude in SI direction. The target and the OAR were filled with 40 kBq/mL while the background had 5 kBq/mL FDG. A BgRT Modeling (imaging-only) PET acquisition was performed using RefleXion X1 and used to generate a 4-fraction BgRT treatment plan prescribing 10 Gy/fraction to PTV. For each delivery, target, OAR and background were filled with the same FDG concentrations as in the BgRT Modeling PET planning scan. Dosimetry to the target and OAR were both measured using an ion-chamber (Exradin A14SL) and film in the coronal plane through the center of the GTV for all 4 fractions.

RESULTS

The mean activity concentration within the (BTZ) was 7.4 ± 0.8 kBq/mL. The calculated signal-to-noise ratio metric (Normalized Target Signal) within the BTZ was 4.0 ± 0.3. Total treatment times were all less than 35 minutes (34.3 ± 0.2). Prescription dose coverage to the CTV for all 4 fractions was 100%. Ion chamber measurements in the CTV were -1.6 ± 1.3% relative to the planned dose over the active area of the ion-chamber. Minimum and maximum doses to the CTV, measured on film, were -7.7 ± 2.2% and 1.3 ± 1.4%, calculated relative to the planned dose distribution, respectively. The OAR maximum point dose measured on film was -8.7 ± 2.9%, calculated relative to the maximum OAR dose predicted on the bounded dose-volume histogram.

CONCLUSION

Based on this initial study, accurate and reproducible dosimetry can be achieved for targets under respiratory motion using biology-guided radiotherapy over the course of a complete course of treatment. Further studies are needed to evaluate the intrafraction dosimetry of BgRT delivery under various motion models and tumor sizes.

Decay Series Dose Delivery Validation of a Biology-Guided Radiotherapy (BgRT) Methodology

PURPOSE/OBJECTIVE(S)

In this work, we compared the accuracy between the planned dose estimated by a commercial BgRT treatment planning system to the measured delivered dose by the BgRT treatment delivery device. The dose delivered was measured with the Sun Nuclear ArcCHECK device containing a customized phantom filled with fluorodeoxyglucose F18 (FDG) with a fixed target to background activity concentration ratio. The BgRT approach was evaluated for its capacity to accurately deliver a planned dose to a phantom target of an increasingly limited PET signal due to radioactive decay.

MATERIALS/METHODS

The Sun Nuclear ArcCHECK is a helical detector assembly of 1,386 diodes around a 15 cm diameter cavity designed for quality assurance of linear accelerator (LINAC) driven therapies. In this work, the ArcCHECK was loaded with a cylindrical phantom containing a 22 mm diameter homogenous ball and a C-shape insert. The ball target was designated as an organ at risk (OAR) with appropriate dose constraints applied, and the C-shaped insert was designated as the target. The C-shaped target was used to simulate a tumor with a necrotic core. A cylindrical planning/gross tumor volume was placed around the C-shape, providing a test case of delivery to a partially PET-avid target. The target and OAR were filled with 58.46 kBq/mL of FDG and the background with 7.30 kBq/mL, giving an approximate target to background ratio of 8:1. A kVCT localization scan, a short PET pre-treatment scan, and a LINAC treatment sequence (1000 cGy per fraction) were performed each run with four runs performed over a duration of ∼3.5 hours (1.9 half-lives). The ArcCHECK measured the delivered dose during each LINAC treatment sequence and compared it to the plan predicted dose. The relative dose (RD) and absolute dose (AD) gamma values were then calculated for each run using Sun Nuclear's proprietary software with a gamma pass rate criterion of 3mm/3%.

RESULTS

The PET scans for runs 1-4 were completed with background activity concentrations of 5.49 kBq/ml, 3.95 kBq/ml, 2.79 kBq/ml, and 2.02 kBq/ml, respectively. The scans further reported 17.48 kBq/ml, 12.26 kBq/ml, 7.93 kBq/ml, and 6.95 kBq/ml as the mean activity concentrations for the cylindrical gross tumor volume of the planned treatment. After treatment delivery, the resulting RD gamma values were 98%, 94%, 93%, and 95% and AD gamma values were 98%, 93%, 92%, and 94% for runs 1-4.

CONCLUSION

Results from this study demonstrated treatment delivery stability with consistent repeatability in the 8:1 target to background contrast condition even with diminishing PET signal from the phantom target as the activity decayed. This work shows that BgRT is capable of delivering to a cylindrical target volume that is very different from the PET avid C-shaped that was used for the plan and delivery.

2 Pathways to detection of non-infectious childhood uveitis in the UK: findings from the UNICORN cohort study

INTRODUCTION

Prompt detection of childhood uveitis is key to minimising negative impact. From an internationally unique inception cohort, we report pathways to disease detection.UNICORNS is a national childhood non-infectious uveitis study with longitudinal collection of a standardised clinical dataset and patient reported outcomes. Descriptive analysis of baseline characteristics are reported.Amongst 150 recruited children (51% female, 31% non-white ethnicity) age at detection ranged from 2-18yrs (median 10). In 69%, uveitis was diagnosed following onset of symptoms: time from first symptoms to uveitis detection ranged from 0-739days (median 7days), with longer time to detection for those presenting initially to their general practitioner. Non symptomatic children were detected through JIA/other disease surveillance (16%), routine optometry review (5%) or child visual health screening (1%). Commonest underlying diagnoses at uveitis detection were JIA (17%), TINU (9%, higher than pre-pandemic reported UK disease frequency) and sarcoid (1%). 60% had no known systemic disease at uveitis detection. At disease detection, in at least one eye: 34% had structural complications (associated with greater time to detection - 17 days versus 4 days for uncomplicated presentation).The larger relative proportions of children with non-JIA uveitis reported here increase the importance of improving awareness of childhood uveitis amongst the wider clinical communities. There is scope for improvement of pathways to detection. Forthcoming analysis on the full cohort (251 recruited to date across 33 hospitals and 4 nations) will provide nationally representative data on management and the determinants of visual and broader developmental/well-being outcomes.

Dosimetric Accuracy of Multi-Target Biology-Guided Radiotherapy Treatments in a Single Session

PURPOSE/OBJECTIVE(S)

We present the first dosimetric measurements of single session, multi-target BgRT deliveries using a clinically realistic motion phantom on a research-only version of the RefleXion X1 system.

MATERIALS/METHODS

A custom-made anthropomorphic phantom of a human torso with embedded fillable targets mimicking 18F-FDG-avid lesions was used. From the three embedded spherical targets, Target 1 was 26 mm in diameter coupled with a 3D independent respiratory motion with 22 mm range, whereas Target 2 and 3 were 22 mm in diameter and moved with a 1D 5 mm maximum sinusoidal motion. The 18F-FDG concentration in the background cavity of the phantom was 5 kBq/ml, and the targets were loaded with 10:1, 8:1 and 6:1 contrast relative to the background for Targets 1, 2, 3, respectively. Spherical structures were contoured as GTVs (CTV = GTV) and a 5 mm margin was added to create PTVs. Motion extent of the tumors were captured to create biological tracking zones for each target. Treatment plans were generated using a research version of the Reflexion treatment planning software to deliver 8 Gy/fx to the PTVs. The treatment delivery was repeated 2 times, and each time the phantom was refilled according to the plan. PET image evaluation metrics for each of the three targets were also recorded. Target dosimetry was measured using a combination of radiographic film and ion chamber. The maximum distance between the 97% prescription isodose line from the plan and the film measurements was used to characterize the dosimetric accuracy of the tracked deliveries. CTV and PTV min, max, and mean doses measured on film were also recorded for each target.

RESULTS

Treatment plans were successfully created with 100% prescription dose coverage to each target loaded with different FDG ratios. Total treatment times for the single-plan, three-target deliveries were less than 80 minutes. PET evaluation metrics at imaging-only and pre-scan, and planning and film dosimetry to the GTV and PTV for each of the three targets is shown in table below (mean ± standard deviation of both deliveries). The CTV dose coverage was maintained for all targets. The shrinkage distance of the 97% prescription dose isodose line on the film plane for all three targets was less than 3 mm for both tests, and ranged from -0.4 to -2.34 mm.

CONCLUSION

These results demonstrate that high tracking accuracy and dosimetric accuracy can be achieved in single session, multi-target deliveries over a range of target-to-background 18F-FDG concentrations and target motion patterns.

Defining the Oligometastatic State and Predicting Overall Survival in Uterine Cancers using a Recursive Partitioning Analysis: A National Cancer Database Analysis

PURPOSE/OBJECTIVE(S)

Oligometastatic disease is an intermediate state between locoregional disease and widely metastatic disease. Studies have shown an overall survival advantage in oligometastatic patients treated aggressively in multiple cancers. However, few studies have explored this relationship in oligometastatic gynecological cancers. In this study, we sought to identify if an oligometastatic state with improved overall survival exists in uterine cancer and whether treatment patterns, or patient factors play a role in survival.

MATERIALS/METHODS

The National Cancer Database was retrospectively analyzed in patients diagnosed with uterine cancer between 2004-2019. We excluded patients with non-metastatic disease at diagnosis, lack of metastatic sites listed, multiple primaries and missing survival data. Survival analyses were performed using Cox proportional hazards analyses and the Kaplan-Meier method and differences between groups were evaluated with log-rank tests. Recursive partitioning analysis (RPA) was performed using the rpart package in R.

RESULTS

Amongst 641,276 women with uterine cancer, 17,343 were ultimately in our study population after exclusion who had a median age of 64 (range 18-90), median overall survival of 11.1 months, and a total of 24,337 metastases that represented the following metastatic sites: lung (35%), other (24%) (sites "other" than bone, brain liver or lung), liver (15%), bone (12%), distant lymph nodes (10%), brain (3%) and carcinomatosis (1%). Multivariate cox proportional hazards analysis identified the following variables as significantly associated with survival, which were then used for RPA: one metastatic site, treatment, grade, age, race, Charlson-Deyo score. The data was split 70/30% for training and validation, respectively. A survival model was built using RPA on the training data with 10-fold cross-validation and had accuracy of 76.25% (p = 3.393e-0.5). Survival prediction was performed on the internal validation data set with 76.69% accuracy (p = 0.004). RPA stratified 4 groups with the following median survivals: 5.9, 8.6, 29.5, and 43.8 months (log-rank test p<0.0001). The group with the best overall survival was defined by 1 metastatic site (carcinomatosis, distant lymph nodes and "other"), combination treatment with systemic therapy and radiation or surgery and low-grade histology.

CONCLUSION

An oligometastatic state with involvement of one metastatic site does exist with improved survival in uterine cancer. The RPA defined groups may aid in identifying patients that are best suited for aggressive definitive combination therapy versus those that would be better suited for comfort care. Analysis is ongoing and will further delineate the relationship between specific treatment modalities and overall survival in patients with one metastatic site. This study may set the foundation for a prospective clinical trial.

Hippocampal Avoidance Whole BRAIN Radiotherapy (HA-WBRT) with Simultaneous Integrated BOOST (SIB) vs. HA-WBRT in Multiple Brain Metastases: A Dosimetric Comparison

PURPOSE/OBJECTIVE(S)

There has been a paradigm shift in managing multiple brain metastases. Various options include SRS, WBRT, and WBRT with Hippocampal avoidance (HA-WBRT). There is no consensus for the treatment of multiple brain metastases (>3 brain metastases). A new technique that has proven feasible is dose escalation in the form of simultaneous integrated boost. The aim of this study was to compare the dosimetry parameters of HA-WBRT plus simultaneous integrated boost versus HA-WBRT alone in multiple brain metastases.

MATERIALS/METHODS

In a prospective trial,16 patients with multiple brain metastasis (≥ 3) from various primaries with good performance scores (ECOG PS ≤ 2) are recruited. All patients underwent CT simulation (1.5 mm slice thickness) and RT plans for HA-WBRT with (SIB) and HA-WBRT alone were made. A 5 mm margin was given to the bilateral hippocampus for Hippocampal Avoidance. In the HA-WBRT plan for the PTV i.e., whole brain plus 3 mm margin minus hippocampal avoidance region (H.A.), a dose of 30 Gy in 10 fractions is prescribed over two weeks. In HA-WBRT with SIB, a dose of 30 Gy in 10 fractions over two weeks is prescribed for the PTV, which is the clinical target volume, minus the hippocampal avoidance region (H.A.) minus the PTV Mets (1 mm margin to the GTV). A simultaneous Integrated Boost of 42.5 Gy in 10 # over two weeks is prescribed for PTVmets. Planning was done using a VMAT technique with 6MV F.F.F. beam energy in a treatment planning software.

RESULTS

The mean B/L hippocampus volume is 3.47 cc. The mean dose of PTV D98% in HA-WBRT plans is 27.45 Gy, whereas in HA-WBRT with S.I.B. is 27.36 Gy (p = 0.90). V30 mean dose in HA-WBRT plans is 93.35%, and the mean dose in HA-WBRT SIB is 91.87% (p = 0.12). PTV D2% mean dose in HA-WBRT Is 36.06 Gy, and in HA-WBRT -S.I.B., it is 40.58 (p< 0.001). The mean bilateral hippocampus Dmax in HA-WBRT is 14.85 Gy, and in HA-WBRT-SIB is 14.25 Gy (p = 0.35). The mean Bilateral hippocampus D100% is 9.14 Gy in HA-WBRT and 9.01 Gy in HA-WBRT-SIB (p = 0.54). The mean brainstem Dmax in HA-WBRT is 36.82 Gy compared to 38.55 Gy in HA-WBRT-SIB (p = 0.02).

CONCLUSION

In patients planned for a simultaneous boost along with hippocampal sparing whole brain radiotherapy, the mean dose to the hippocampal region did not increase. The Dmax of Brainstem, optic chiasma is significantly higher in HA-WBRT-). Our study, the mean dose to PTVmets is more than 45 Gy and more than 50 Gy to GTV with a BED of more than 65 Gy (α/ß = 10) to the metastases, which is equivalent to some ablative dose regimens. Simultaneous integrated boost along with hippocampal sparing radiotherapy thus helps in sparing the hippocampus and delivering higher doses to the metastases and intermediate doses to the rest of the brain, addressing the microscopic disease.

Prognostic Impact of a Negative Central Pelvic Biopsy after Definitive Chemoradiotherapy (CRT) for Locally Advanced Cervical Cancer (LACC)

PURPOSE/OBJECTIVE(S)

Central pelvic biopsies are occasionally performed during post-treatment surveillance of locally advanced cervical cancer (LACC) after a change in symptoms, abnormal pelvic exam, pap smear or imaging. Although it is established that a positive result is considered disease recurrence, it is unclear the prognostic impact of a negative biopsy. Here, we investigated the characteristics and the clinical course of patients with negative biopsy, focusing on central pelvic recurrence.

MATERIALS/METHODS

Our institutional database of female patients with diagnosis of cervical cancer treated with definitive CRT was retrospectively reviewed (2013-2022). The central pelvic region was subdivided in: I) cervix, II) endocervix/endometrium, III) vagina, IV) vulva, V) bladder and VI) rectum. Each subsite sampled was considered a distinct biopsy event, but multiple samples from one subsite at the same procedure were considered one biopsy event. We calculated the rate of initial negative and positive biopsies. The central pelvic control (local recurrence rate [LCRR]) for patients with negative biopsy was estimated with Kaplan Meier method.

RESULTS

Two hundred and twenty-five consecutive patients were included (initial FIGO 2018 staging: 30% I/II and 70% III-IVA). Of these, 66 (29.3%) underwent 112 central pelvic biopsies (average 1.7 per patient) during a median follow up time of 27.1 months [range: 0.2-94.0], with median time from treatment to first biopsy of 7.0 months [range: 1.0-41.7]. Biopsies were triggered by: symptoms/physical exam in 83 (73.4%), imaging abnormalities in 21 (18.6%), and abnormal pap smear in 9 (8%). The most common structures biopsied were: cervix (53.6%, n = 60), vagina (17.9%, n = 20), endocervix/endometrium (11.6%, n = 13), rectum/sigmoid (11.6%, n = 13), bladder (4.5%, n = 5) and vulva (0.9%, n = 1). Overall, 13.6% cases (9/66) had an initial positive biopsy, while 86.4% (57/66) had an initial negative biopsy. Of these patients with negative biopsies, 84.2% (48/57) remained without evidence of local recurrence and 15.8% (9/57) were subsequently diagnosed with local disease recurrence (1y post-biopsy LCRR 15.0% [95% CI 4.8-24.0]).

CONCLUSION

Although most (>85%) post-treatment central pelvic biopsies are negative, these patients are still at considerable risk of early local recurrence thereafter (post-biopsy 1y-LCRR 15%). Strategies to intensify surveillance may be beneficial in the first year after a negative biopsy.

Role of Stereotactic Body Radiation Therapy in Portal Vein Tumor Thrombosis in Hepatocellular Carcinoma: A Prospective Single Institute Experience

PURPOSE/OBJECTIVE(S)

Patients diagnosed with Hepatocellular carcinoma (HCC) complicated with portal vein tumor thrombosis (PVTT) have a limited number of treatment options available and are associated with an overall poor prognosis. With the recent developments in the field of radiation therapy, the role of radiotherapy particularly Stereotactic Body radiotherapy (SBRT) has increased as a loco-regional therapy for HCC. This study was planned to evaluate the role of SBRT in Locally advanced HCC complicated with PVTT and its role as loco-regional therapy.

MATERIALS/METHODS

We conducted a prospective study that included patients diagnosed with HCC complicated with PVTT Child-Turcotte Pugh (CTP) Class A/B with a maximum score of 7, diagnosed on triple phase Contrast-Enhanced - MRI unsuitable for other ablative procedures. Patients with Bilirubin levels > 4 mg/dl, active Hepatitis, CTP score >7, normal liver volume <700cc or history of prior radiotherapy were excluded from the study. Patients underwent a contrast enhanced 4D-CT simulation with abdominal compression and were planned for SBRT using VMAT technique. Patients were followed-up as per Institute protocol. CECT or MRI for a radiological response was done for response assessment using mRECIST criteria version 1.1. A baseline MRI was done at one-month post-SBRT to understand any RT changes in the liver and to differentiate from tumor progression during the response assessment at three months.

RESULTS

A total of 22 patients with HCC were recruited and received SBRT to PVTT, with a dosage between 30-42 Gy over 6 fractions treated on alternate days. Patients were assessed post-treatment with triphasic CE-MRI every 3 months as per institute protocol. Five patients had achieved Complete response in form of Portal vein recanalization. Three patients had Partial response to the treatment. Seven patients maintained stable disease status whereas six patients had disease progression during the entire course of treatment. The response rate (CR+PR) to treatment was 36.3% at the time of analysis. The Overall Response rate (CR+PR+SD) was 69%. No grade 3 or 4 toxicities were observed and treatment was tolerated well by patients. Kaplan-Meier method was applied to calculate the survival probability at various follow-up intervals. The median time for overall survival was 25 months ((95% CI: 15-35). Out of the 22 subjects included in the study, 6 patients died. There was a 78% survival probability at 12 months and a 68% survival probability at 18 months of follow-up.

CONCLUSION

This prospective single-arm study demonstrated the vital role of SBRT in the treatment of Hepatocellular carcinoma with Portal vein tumor thrombosis and its efficacy in terms of achieving excellent local control with relatively lesser toxicities compared with existing treatment modalities. Patients have shown benefit post-treatment in terms of thrombus reduction and restoration of Portal vein flow making them suitable for further treatment like Resection or TACE.

Radiation Toxicity Profile Difference in p16+ vs. p16- Oropharyngeal Cancer Patients

BACKGROUND

p16+ oropharyngeal squamous cell carcinoma is radiosensitive and has better prognosis than p16-ve. However, the correlation between p16 reactivity and radiation toxicity profile in these patients has not been studied. Edmonton Symptom Assessment System (ESAS) is a generic patient reported symptom scale validated for patient reported outcome (PRO) assessments in head and neck cancer patients. We sought to review the ESAS and its psychometric properties in oropharyngeal cancer patients treated with concurrent chemoradiation (CCRT) stratified by their HPV status.

PURPOSE/OBJECTIVE(S)

To evaluate differences in magnitude and temporal trends in PRO before, during and after radiation treatments in both p16+ and p16-ve oropharyngeal cancer patients using ESAS scores.

MATERIALS/METHODS

Prospectively collected ESAS scores for oropharyngeal cancer patients treated at a safety net hospital with CCRT were analyzed. Longitudinal variation in pain, depression, appetite and family distress scores before, during and up to 36 weeks after CCRT were evaluated at seven time points: prior to treatment, 1-3, 4-6, 7-10, 11-15, 16-20 and 20-36 weeks. Statistical analysis focused on data collected through repeated measurements for patients using ANOVA mixed regression analysis using p16 status as between subjects factor for each symptom.

RESULTS

Three hundred fifty-five ESAS assessments were analyzed for each symptom for 64 oropharyngeal cancer patients treated with CCRT. Subsites identified were 21 (32.8%) tonsil, 15 (23.4%) base of tongue, 22 (34.4%) soft palate, and 6 (9.4%) oropharynx not specified. We identified 35 (54.7%) p16+ and 29 (45.3%) p16-ve patients. The median age of the cohort was 60 (range: min 39 - max 88); the median age was 59 for p16+ and 61 for p16-ve. Median total radiation dose was 6996 Gy. Pain scores peaked at 7-10 weeks for both groups but p16-ve had delayed peak 11-15 weeks as well. Depression scores stayed <4 for both populations but family distress, pain and appetite scores peaked for p16-ve between 11-15 weeks.

CONCLUSION

Mean pain scores were similar for both populations and peak during CCRT for both however p16-ve patients have another peak after completion of CCRT. Family distress and decreased appetite also heighten during this post CCRT time for p16-ve patients which warrants a planned early intervention at 11-15 weeks for these patients to improve their quality of life.