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.

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.

Economic evaluation of the Very Early Rehabilitation in SpEech (VERSE) intervention

INTRODUCTION

There is limited evidence on the costs and outcomes of patients with aphasia after stroke. The aim of this study was to estimate costs in patients with aphasia after stroke according to the aphasia therapies provided.

METHODS

A three-arm, prospective, randomized, parallel group, open-label, blinded endpoint assessment trial conducted in Australia and New Zealand. Usual ward-based care (Usual Care) was compared to additional usual ward-based therapy (Usual Care Plus) and a prescribed and structured aphasia therapy program in addition to Usual Care (the VERSE intervention). Information about healthcare utilization and productivity were collected to estimate costs in Australian dollars for 2017-18. Multivariable regression models with bootstrapping were used to estimate differences in costs and outcomes (clinically meaningful change in aphasia severity measured by the WAB-R-AQ).

RESULTS

Overall, 202/246 (82%) participants completed follow-up at 26 weeks. Median costs per person were $23,322 (Q1 5,367, Q3 52,669, n = 63) for Usual Care, $26,923 (Q1 7,303, Q3 76,174, n = 70) for Usual Care Plus and $31,143 (Q1 7,001. Q3 62,390, n = 69) for VERSE. No differences in costs and outcomes were detected between groups. Usual Care Plus was inferior (i.e. more costly and less effective) in 64% of iterations, and in 18% was less costly and less effective compared to Usual Care. VERSE was inferior in 65% of samples and less costly and less effective in 12% compared to Usual Care.

CONCLUSION

There was limited evidence that additional intensively delivered aphasia therapy within the context of usual acute care provided was worthwhile in terms of costs for the outcomes gained.

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.

Associations of meeting 24-h movement guidelines and metabolic syndrome in Korean adults during the COVID-19 pandemic

OBJECTIVES

This study aimed to investigate the association between adherence to 24-h movement guidelines and metabolic syndrome (MetS) before and during the COVID-19 pandemic.

STUDY DESIGN

Repeated cross-sectional design.

METHODS

We selected 10,882 adults (2019: n = 5710; 2020: n = 5172) aged ≥20 years from the Korea National Health and Nutrition Examination Survey. Domain-specific physical activity and sedentary behavior were assessed using a global physical activity questionnaire. We also measured the typical sleep duration (h/day) on weekdays and weekends. MetS was defined as the presence of more than three risk factors.

RESULTS

During the COVID-19 pandemic, transportation-related physical activity decreased, while the prevalence of abdominal obesity (+3.3 %) and low HDL-C levels (+3.1 %) increased significantly. An elevated risk of MetS was observed in the lower aerobic (odds ratio [OR], 1.28; 95% confidence interval [CI], 1.04-1.58; P = 0.019) and muscular exercise (OR, 1.31; 95% CI, 1.04-1.66; P = 0.023) groups and in the high sedentary behavior (OR, 1.23; 95% CI, 1.00-1.51; P = 0.049) during the pandemic. Sensitivity analysis stratified by sex showed similar patterns with more pronounced changes in MetS components in males. The models also showed significant associations between aerobic physical activity, strength exercises, and sedentary behavior with MetS in males and females.

CONCLUSIONS

Although sedentary behavior and sleep time remained unchanged, a significant decrease in transportation-related physical activity was observed during the pandemic. Moreover, our findings revealed that aerobic physical activity, strength exercise, and sedentary time during the pandemic were associated with an increased MetS risk. These results highlight the importance of promoting physical activity, particularly during periods of social restriction, to mitigate the pandemic's negative effects on metabolic health.

Outcomes and outcome measures utilised in randomised controlled trials of postoperative caesarean delivery pain: a scoping review

BACKGROUND

Inadequately treated postoperative pain following caesarean delivery can delay recovery and the ability to care for a newborn. Effectiveness studies of interventions to treat postoperative caesarean delivery pain measure different outcomes, limiting data pooling for meta-analysis. We performed a comprehensive review of existing outcomes with the aim of recommending core outcomes for future research.

METHODS

A scoping review to identify all outcomes reported in randomised controlled trials (RCTs) and clinical trial registries of interventions to treat or prevent postoperative caesarean delivery pain, with postoperative pain as a primary outcome measure. We searched PubMed, Web of Science, CINAHL, LILACS, Embase, CDSR and CRCT for studies from May 2016 to 2021. Outcomes were extracted and frequencies tabulated.

RESULTS

Ninety RCTs and 11 trial registries were included. In total, 392 outcomes (375 inpatient and 17 outpatient) were identified and categorised. The most reported outcome domain was analgesia (n = 242/375, 64.5%), reported in 96% of inpatient studies, with analgesic consumption accounting for 108/375, 28.8% of analgesia outcomes. The second most common domain was pain intensity (n = 120/375, 32%), reported in 97% of inpatient studies, using the visual analogue scale (68/120, 59%) and the numerical reporting scale (37/120, 25%). Maternal and neonatal adverse effects accounted for 65/375 (17.3%) and 19/375 (5.1%) of inpatient outcomes, respectively.

CONCLUSIONS

Outcomes reported in RCTs for postoperative caesarean delivery pain vary widely. The results of this review suggest that standardisation is needed to promote research efficiency and aid future meta-analyses to identify optimal postoperative caesarean delivery pain management.

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.

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.

CT findings of inferior vena cava trauma according to the level of injury: a retrospective analysis of 19 cases in a single trauma centre

AIM

To analyse the clinicoradiological characteristics of traumatic inferior vena cava (IVC) injury level on preoperative computed tomography (CT).

MATERIALS AND METHODS

This retrospective study evaluated patients from a single trauma centre treated for traumatic IVC injury between January 2014 and January 2021. Data on demographics, mechanism of injury, Injury Severity Score, radiological findings on CT and angiography, IVC injury level in surgical findings, complications, and clinical outcomes were collected.

RESULTS

During the 8-year study period, 36 patients presented with traumatic IVC injury: 19 underwent preoperative CT with 17 (89%) blunt and two (11%) penetrating injuries. The most common primary CT sign was contour abnormality (53%, n=10), followed by intraluminal flap and active extravasation (21%, n=4). Among the secondary signs, hepatic laceration (53%, n=10) and retroperitoneal haemorrhage (53%, n=10) were the most common. Frequencies of primary and secondary signs were higher in the infrarenal and suprarenal than in the retrohepatic vena cava injuries. Diagnostic capability of preoperative CT for IVC injury differed according to the IVC level. The detection rate was the highest for an infrarenal vena cava injury at 100% (n=4), followed by that for a suprarenal, suprahepatic, and retrohepatic vena cava injuries at 75% (n=3), 43% (n=3), and 25% (n=1), respectively.

CONCLUSION

CT findings of traumatic IVC injuries may vary depending on the mechanism and anatomical site of injury. Familiarity with IVC injury imaging features may help in diagnosis and surgical treatment planning.

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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Nesting chinstrap penguins accrue large quantities of sleep through seconds-long microsleeps

Microsleeps, the seconds-long interruptions of wakefulness by eye closure and sleep-related brain activity, are dangerous when driving and might be too short to provide the restorative functions of sleep. If microsleeps do fulfill sleep functions, then animals faced with a continuous need for vigilance might resort to this sleep strategy. We investigated electroencephalographically defined sleep in wild chinstrap penguins, at sea and while nesting in Antarctica, constantly exposed to an egg predator and aggression from other penguins. The penguins nodded off >10,000 times per day, engaging in bouts of bihemispheric and unihemispheric slow-wave sleep lasting on average only 4 seconds, but resulting in the accumulation of >11 hours of sleep for each hemisphere. The investment in microsleeps by successfully breeding penguins suggests that the benefits of sleep can accrue incrementally.

Search for Boosted Dark Matter in COSINE-100

We search for energetic electron recoil signals induced by boosted dark matter (BDM) from the galactic center using the COSINE-100 array of NaI(Tl) crystal detectors at the Yangyang Underground Laboratory. The signal would be an excess of events with energies above 4 MeV over the well-understood background. Because no excess of events are observed in a 97.7  kg·yr exposure, we set limits on BDM interactions under a variety of hypotheses. Notably, we explored the dark photon parameter space, leading to competitive limits compared to direct dark photon search experiments, particularly for dark photon masses below 4 MeV and considering the invisible decay mode. Furthermore, by comparing our results with a previous BDM search conducted by the Super-Kamionkande experiment, we found that the COSINE-100 detector has advantages in searching for low-mass dark matter. This analysis demonstrates the potential of the COSINE-100 detector to search for MeV electron recoil signals produced by the dark sector particle interactions.

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.

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.

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}.

Ptth regulates lifespan through innate immunity pathway in Drosophila

The prothoracicotropic hormone (Ptth) is well-known for its important role in controlling insect developmental timing and body size by promoting the biosynthesis and release of ecdysone. However, the role of Ptth in adult physiology is largely unexplored. Here we show that Ptth null mutants (both males and females) show extended lifespan and healthspan, and exhibit increased resistance to oxidative stress. Transcriptomic analysis reveals that age-dependent upregulation of innate immunity pathway is attenuated by Ptth mutants. Intriguingly, we find that Ptth regulates the innate immunity pathway, specifically in fly oenocytes, the homology of mammalian hepatocytes. We further show that oenocyte-specific overexpression of Relish shortens the lifespan, while oenocyte-specific downregulation of ecdysone signaling extends lifespan. Consistently, knocking down torso, the receptor of Ptth in the prothoracic gland also promotes longevity of the flies. Thus, our data reveal a novel function of the insect hormone Ptth in longevity regulation and innate immunity in adult Drosophila.

The Landscape of Genetic Alterations Associated with Metachronous Metastasis in Patients with Pancreatic Ductal Adenocarcinoma and Its Prognostic Significance

PURPOSE/OBJECTIVE(S)

Metachronous metastasis is one of the major pathologic processes which significantly increases the mortality of patients with pancreatic ductal adenocarcinoma (PDA) who completed initial curative treatment. Genetic signatures that drive the metachronous mutations are not well investigated. In this study, we aimed to identify the landscape of genetic alterations associated with metachronous metastasis in patients with PDA and its prognostic significance.

MATERIALS/METHODS

We retrospectively identified patients with histologically confirmed PDA who underwent next-generation sequencing using a panel of 324 pre-specified genes. The landscape of somatic mutations was stratified by metastasis types [no metastasis (nMet) vs. de novo metastasis (dMet) vs. metachronous metastasis (mMet)]. Outcomes of interest included overall survival (OS), local recurrence (LR) following radiotherapy, and association of CA 19-9 level with metastasis types. The OS was calculated using the Kaplan-Meier estimates and log-rank test, and LR was measured using cumulative incidence. A multivariate cox-regression analysis was performed to identify prognostic factors. Pathway analysis of mMet exclusive genes was performed using DAVID (Database for Annotation, Visualization, and Integrated Discovery).

RESULTS

A total of 328 patients with PDA were included. Among them, 56 (17%), 145 (44%), and 127 (39%) patients had nMet, dMet, and mMet, respectively. The median follow up was 21.6 months (range 0.7 -136 months). The median age at the time of diagnosis was 65.5 years (range 26.77 -87.31 years). ANOVA test showed that CA 19-9 level was associated with metastasis types (p = 0.034). The median OS was 48.4 (95% CI 28.3-NA), 27.4 (95% CI 23.3-33.9), and 15 (95% CI 13.9-17.8) months for patients with nMet, mMet, and dMet, respectively (p<0.0001). The multivariate analysis (MVA) revealed that KRAS mutation (HR 2.31; 95% CI 1.37-3.9; p = 0.001), mMet (HR 0.45; 95% CI 0.34-0.61; p<0.0001), nMet (HR 0.27; 95% CI 0.16-0.45; p<0.0001), age (HR 1.01; 95% CI 1-1.02; p = 0.03), and male gender (HR 1.5; 95% CI 1.15-2.01; p = 0.002) were associated with OS. Mutations in other PDA driver genes (TP53, SAMD4, CDKN2A) were not associated with OS (p>0.05). The LR rate at 12 months post-radiotherapy was 28% and 27% for nMet and mMet, respectively (p = 0.5). Heatmap analysis identified 31 genes that were exclusively mutated in patients with mMet. These genes were enriched in pathways of transcription regulation by RNA polymerase II promoter binding, a negative regulator of apoptosis, and telomerase maintenance.

CONCLUSION

This study identified metachronous metastasis-associated genetic alterations and molecular pathways. Future prospective studies incorporating whole exome sequencing are warranted to validate these findings.

Utility of Stereotactic Body Radiation Therapy (SBRT) in Establishing Local Control for Invasive Breast Cancer Patients Not Undergoing Definitive Surgery

PURPOSE/OBJECTIVE(S)

Breast cancer (BC) treatment involves a multi-modal approach where surgical resection is the backbone of therapy. However, due to medical comorbidities precluding surgery, unresectable disease, or patient preference, some patients do not undergo surgery. In the absence of resection, it is paramount to improve local control (LC) of the primary tumor. To that end, this study explored the role of ablative RT dose delivered with SBRT.

MATERIALS/METHODS

Between 2015-2022, 21 patients (10 metastatic, 11 stage IA-IIIC) received 23 SBRT courses to primary BC lesions without planned surgery at our institution. One patient had undergone whole breast RT 20 years prior to SBRT. 7 patients were analyzed retrospectively; 15 are currently enrolled in a prospective study. SBRT dose was 40 Gy/5 fractions delivered every other day. Follow-up imaging (PET, CT, MRI, MMG/US) was reviewed to evaluate the response. CTCAE v.3 was used to document any acute (≤3 months) and late toxicities. Kaplan-Meier curves were used to estimate local control (LC) and overall survival (OS).

RESULTS

Median age was 78.4 (45.9-97.3) years. Median follow-up was 14.7 (3.3-70.3) months after RT completion. Initial post-treatment imaging was available for all cases and was performed at a median of 4.0 (0.6-11.9) months after SBRT. The median pre-SBRT index lesion size was 3.1 (0.5-14.5) cm and PTV was 32.4 (11.5-522.4) cc. At a median 4 months post-SBRT, the median decrease in index lesion size was 20.8 (0-100) % and SUV reduction was 65.2 (20.8-100) %. Further improvement was seen on the 2nd follow-up scans at a median 7.8 months post-SBRT, with 62 (0-100) % and 88 (33.3-100) % median reduction in the tumor size and SUV, respectively, compared to pre-SBRT values. The estimated LC rate was 100% at 6 months and 93.3% at 12 months. The sole case of local progression occurred 9.5 months after SBRT, after an initial interval decrease in the primary lesion. Among the patients with available systemic follow-up scans, regional progression occurred in 4 (17.4%) cases at a median 18.6 (5.2-22.7) months post-SBRT. Six (37.5%) patients developed distant progression at a median 4.8 (0.9-16.2) months, all of whom had metastatic disease at diagnosis. The estimated OS was 85.7% at 6 months and 63.8% at 12 months. Most patients tolerated the treatment well. There was no grade 4 toxicity. Complete acute toxicity data is presented in Table 1. Only one patient experienced late grade 2 breast edema.

CONCLUSION

Based on our preliminary results, definitive SBRT to the primary BC appears to have a role in providing LC in the treatment of non-surgical patients and is well-tolerated. Since the disease progression tends to occur outside the treated primary tumor, additional approaches to improve regional and distant control should be investigated.

Impact of carbapenem-targeted antimicrobial stewardship interventions: an interrupted time-series analysis

BACKGROUND

The development of carbapenem-resistant Gram-negative bacilli (CR-GNB) is largely favoured by indiscriminate and prolonged carbapenem use, which is a significant contributing factor.

AIM

To evaluate the impact of two carbapenem antibiotic stewardship programme interventions on both carbapenem prescriptions and the clinical isolation rates of CR-GNBs, using interrupted time-series analysis.

METHODS

A time-series analysis was performed using data for carbapenem usage from a tertiary hospital in South Korea from January 2017 to July 2022. Two carbapenem antibiotic stewardship programme interventions were implemented sequentially: (i) a prospective audit and feedback (PAF) from November 2018 to April 2020 (intervention 1), and (ii) preauthorization from May 2020 to August 2020 (intervention 2). Monthly carbapenem usage and incidence of CR-GNB before and after each intervention were compared using an autoregressive integrated moving average model.

FINDINGS

Implementation of PAF resulted in a significant reduction in carbapenem consumption, followed by an additional decrease after the preauthorization was implemented. The incidence of carbapenem-resistant Escherichia coli and Klebsiella pneumoniae increased after intervention 1, but there was a significant change from an increasing trend to a stationary trend after intervention 2. The incidence of carbapenem-resistant Pseudomonas aeruginosa, which had increased during the baseline period, became stationary after intervention 1. A significant decrease was observed in the incidence of carbapenem-resistant Acinetobacter baumannii during the implementation of intervention 1 and 2.

CONCLUSION

This study emphasizes the importance of adopting comprehensive antibiotic management and rigorous infection control to prevent infections caused by antibiotic-resistant bacteria.

Mapping the Anatomical Distribution of MRI-Identified Locoregional Recurrence following Robotic-Assisted Laparoscopic Prostatectomy for Prostate Adenocarcinoma

PURPOSE/OBJECTIVE(S)

The pattern of locoregional recurrence specifically after robotic-assisted laparoscopic prostatectomy (RALP) for prostate adenocarcinoma is still unknown. In this study, we reviewed pelvic magnetic resonance images (MRI) after postoperative biochemical recurrence (BCR) and drew a map of locoregional recurrence to support evidence of determining the optimal target volume of salvage radiotherapy in a post-RALP BCR scenario.

MATERIALS/METHODS

We have retrospectively searched 7,583 prostate adenocarcinoma patients who have received RALP in our institution between January 2010 and December 2021, and found a pool of highly selected patients with gross tumor recurrence confirmed by post-BCR pelvic MRIs and did not have other histories of malignancy. BCR was defined as the serum PSA more or equal to 0.2 ng/mL, or three consecutive increases. Patients with serum PSA nadir more or equal to 0.2 ng/mL on the 90th postoperative day (POD 90) were excluded to guarantee successful tumor removal. We have reviewed serum PSA levels using R codes, MRI and pathological reports using Excel, and descriptive statistics using SPSS 25. The gross lesions were contoured on the correlating MRIs using MIM Maestro 7.1. The RT structure DICOM files were merged into a map using MATLAB 2022b. In addition, we have conducted Fisher exacted test, Mann-Whitney U test, and logistic regression to identify risk factors for regional recurrence.

RESULTS

A total of 173 patients were identified with locoregional recurrence from post-BCR pelvic MRIs, and 139 (80.3%) patients were in the high-risk group or very-high-risk group according to the NCCN guidelines: 57 (32.9%) patients with histological grade group 5, 50 (28.9%) patients with initial PSA over 20 ng/mL, 114 (65.9%) patients with extracapsular extension, 55 (31.8%) patients with seminal vesicle invasion, and 15 (9%) patients with pN1. The median follow-up was 4.7 (IQR 2.8-6.9) years for pelvic MRIs and 5.8 (IQR 4.0-8.6) years for serum PSA. The BCF survival was median of 10.7 (IQR 4.6-19.1) months, and the locoregional recurrence-free survival was median of 24.6 (IQR 9.7-49.4) months for this subgroup of patients. At first locoregional recurrence, 148 (85.5%) patients were local only, 20 (11.6%) patients were regional only, and 5 (2.9%) patients were both local and regional. Out of the 25 patients with regional recurrence, the incidence of gross tumor recurrence differed by nodal sites: 3 (12%) in perirectal space, 5 (20%) in internal iliac, 7 (28%) in obturator, 13 (52%) in external iliac, and 6 (24%) in common iliac lymph nodes.

CONCLUSION

We have found 173 patients and were able to map reliable gross tumor recurrence sites after RALP and confirmed by pelvic MRIs following BCR. The map supports evidence of using the existing consensus pelvic clinical target volume of salvage radiotherapy, in a post-RALP BCR scenario.

Comparison of Early Outcomes of Stereotactic Accelerated Partial Breast Irradiation vs. Volumetric Modulated Arc Therapy-Based FAST-FORWARD Whole Breast Irradiation for Breast Cancer

PURPOSE/OBJECTIVE(S)

Despite evidence supporting APBI from 8 published prospective randomized trials enrolling over 10,000 women, the uptake of APBI in clinical practice is surprisingly low. This is being exacerbated by a new, convenient, and safe shortened WBI schedule. Here, we report the dosimetric and early outcome analyses of the first >1000 patients treated at our institution since the first adoption of stereotactic APBI and the ultra-hypofractionated WBI regimen.

MATERIALS/METHODS

From 2016 to 2022, 801 women with breast cancers in the suitable or cautionary categories according to the ASTRO APBI consensus panel guidelines, received 30 Gy in 5 fractions (92%) either using a robotic stereotactic radiation system (83%) or stereotactic volumetric-based arc therapy (VMAT, 17%). Between 2020 and 2022, 468 women, who were not candidates for APBI and not undergoing any regional irradiation received 26 Gy in 5 fractions using VMAT to the whole breast with the addition of cardiac sparing technique in left-sided breast cancer patients. Tumor bed boosts were delivered in 99% of FF-WBI patients. We evaluated dose-volume histogram parameters for target volumes and organs-at-risk and radiation-related toxicities during RT or within 6 months after the end of RT.

RESULTS

Target volume coverage was acceptable in both groups, with mean 96% of the target volumes receiving 95% of the prescribed doses and 0 cm3 within target volumes exceeding 105% of the prescribed doses. S-APBI resulted in small, but statistically significant, reductions in the radiation dose delivered to the ipsilateral breast, contralateral breast, lungs, heart, and coronary artery compared with FF-WBI. Comparing WBI to APBI, the mean contralateral breast dose, ipsilateral lung V20 Gy, mean contralateral lung dose, and mean heart dose, were reduced by 89%, 78%, 73%, and 29%, respectively. With median follow-up periods of 32 months for s-APBI and 19 months for FF-WBI, acute toxicity was assessable in all patients. The risks of any grade acute toxicity were 21% for s-APBI and 25% for FF-WBI (p = .117). Among them, grade 2 rates were 1.3% in both groups and no severe toxicity has been reported.

CONCLUSION

We found s-APBI and VMAT-based FF WBI were associated with favorable dosimetric and acute toxicity profiles. However, considering significantly less irradiated volume in the breast, lungs, and heart, APBI with advanced available technique options should be considered over any WBI-based approach for patients at low risk for local recurrence.

Plasma EBV DNA in Nasopharyngeal Cancer (NPC) Treated with Definitive Radiotherapy (RT)

PURPOSE/OBJECTIVE(S)

EBV DNA has well-studied roles in NPC including early detection and surveillance. There are limited North American data on EBV DNA testing. Our center has used EBV DNA testing since 2010. We hypothesized: (1) higher first post-RT EBV DNA level is associated with worse prognosis, and (2) surveillance EBV DNA is specific for recurrence at a low detection threshold.

MATERIALS/METHODS

We retrospectively reviewed all patients with non-metastatic (TNM-7 stage I-IVB) NPC treated with definitive RT/chemoRT (CRT) ± adjuvant chemotherapy (AC) between 2010-2017. EBV DNA was assayed by quantitative PCR in a CAP/CLIA-certified laboratory and reported in copies/mL of plasma. Pre-RT is defined as 0-90 days before the first RT fraction and post-RT within one year after RT. We report log odds ratios (LOR) from a linear model of T- and N-category with log-adjusted EBV DNA as the response variable. Survival outcomes were analyzed with log-rank tests and Cox multivariate analyses (MVA) adjusted for age, stage, and treatment, reporting hazard ratios (HR). A total of 95% confidence intervals of LOR and HR are reported. The detection threshold that maximized the F1 accuracy score was considered optimal.

RESULTS

Of 271 patients in the study window, 179 had pre-RT +/- post-RT EBV DNA testing. Six received RT, 43 CRT, and 130 CRT+AC. With 7-yr median follow-up, 37 recurred and 37 died. Detectable pre-RT EBV DNA was found in 154 (86%) with a median of 928 copies/mL (range: 1-239214). EBV DNA level correlated with higher N category (LOR: 0.28, 0.15-0.42, p<0.001), but not T category (0.04, -0.06-0.13, p = 0.5). Above-median pre-RT EBV DNA was associated with worse recurrence-free survival (RFS) by log-rank test (p = 0.016) and Cox MVA (HR: 2.2, 1.1-4.8, p = 0.03) along with N category, age, and no AC. Post-RT EBV DNA was available in 99 patients at a median of 54 days. RFS, progression-free survival (PFS), and overall survival (OS) were worse in patients with detectable post-RT EBV DNA (Table). RFS and PFS drop further to 20% if EBV DNA was detectable after the full treatment (RT±AC, n = 71). In Cox MVA, post-RT EBV DNA remained independently prognostic (Table). EBV DNA was performed within 30 days of recurrence in 30 patients, and 24 were detectable (80% sensitivity). Conversely, of 152 patients without recurrence and at least 3-yr follow-up, 95 had post-RT EBV DNA testing and 84 were undetectable (88% specificity). An EBV DNA threshold of 31 copies maximized F1 accuracy metric, yielding 74% sensitivity and 97% specificity.

CONCLUSION

Pre-RT EBV DNA is prognostic and associated with higher N-category. Post-RT EBV DNA is a strong, independent predictor of RFS, PFS, and OS; 31 copies/mL may be a useful threshold to detect recurrence.

Combination of Radiotherapy and Atezolizumab plus Bevacizumab in Patients with Advanced Hepatocellular Carcinoma: A Pilot Study

PURPOSE/OBJECTIVE(S)

Following the results of the IMbrave150 study, Atezolizumab plus bevacizumab (Atezo/beva) became the first-line treatment in patients with advanced hepatocellular carcinoma (HCC). However, its real-world efficacy has been less satisfied. In this study, we investigated the efficacy of radiotherapy (RT) combined with Atezo/beva in patients with advanced HCC.

MATERIALS/METHODS

Twenty patients received combination of RT and Atezo/beva between December 2021 and December 2022 at our institution. RT was administered in 10 fractions of 5 Gy between Atezo/beva cycles. Tumor response were evaluated on both imaging and tumor marker basis. The iRECIST guideline was used to assess treatment response after the combination treatment of RT and Atezo/beva. Primary endpoints were disease control rate (DCR) and overall response rate (ORR), and secondary endpoint was treatment related toxicity.

RESULTS

All patients were BCLC C with advanced tumors associated with lymph node metastasis (7, 35%) or distant metastasis (8, 40%). Patients received RT between cycles of Atezo/beva, mostly (14, 70%) between 2nd and 3rd cycles. After a median follow-up of 3.2 months, DCR was 65% and ORR was 20%. Significant decrease in tumor marker of over 2-fold was shown in 10 patients (50%). Regarding treatment related toxicity, only 1 patient (5%) showed grade 3 neutropenic fever, and no grade 4 or 5 toxicity was seen.

CONCLUSION

Combination of radiotherapy and Atezo/beva showed high response rate with tolerable treatment related toxicity in advanced HCC patients. Further prospective studies with larger patient cohort are warranted.

Comprehensive Genomic Analysis Stratified by KRAS Status in Patients with Pancreatic Adenocarcinoma and Its Prognostic Significance

PURPOSE/OBJECTIVE(S)

KRAS mutations (MUT) are one of the major drivers in pancreatic ductal adenocarcinoma (PDA) with over 90% of patients having alterations. However, the genetic landscape of PDA based on KRAS status is not well studied. The aim of this study is to investigate genomic alterations based on KRAS status and to identify driver mutations in patients with KRAS wild type (WT).

MATERIALS/METHODS

Next-generation sequencing with 324 pre-specified genes was performed on patients with histologically confirmed PDA. The landscape of somatic mutations was stratified by KRAS status. Outcomes of interest included overall survival (OS), local failure (LF) following radiotherapy, time to metastasis, and CA 19-9 level. All outcomes were stratified by KRAS status. Genetic alterations exclusive to patients with KRAS WT were analyzed. OS was calculated using the Kaplan-Meier estimates and log-rank test, and LF was measured using cumulative incidence. A multivariate cox-regression analysis (MVA) was performed to identify prognostic factors for survival. Gene ontology analysis of KRAS WT exclusive genes was performed via DAVID (Database for Annotation, Visualization, and Integrated Discovery).

RESULTS

A total of 272 patients with metastatic PDA were included. The median age at diagnosis was 65.4 (range, 26.77-83.21) years. The median follow-up was 15.7 (0.06-136.7) months. 91% percent (n = 248) of patients were found to be KRAS MUT. The chi-square test showed that the primary tumor site (p = 0.027) and perineural invasion (p = 0.006) were associated with KRAS status. The median CA 19-9 was 143.6 (15.5-27996) U/ml and 341.15 (0-100000) U/ml for KRAS WT and KRAS MUT, respectively (p = 0.23). The median OS for KRAS WT and MUT was 31.4 (95% CI 25.1-NA) and 13.3 (95% CI 11.3-14.5) months, respectively (p = 0.0008). In patients with metachronous recurrence, the median time to metastasis was 22.4 (1.37-52.97) months and 12.8 (1.8-84.97) months for KRAS WT and KRAS MUT, respectively (p = 0.057). KRAS MUT types including G12 and Q21 were not associated with OS (p = 0.58). On MVA, including KRAS status, age, sex, and metastatic types (de novo vs. metachronous), only KRAS mutation was associated with worse OS [HR 2.64; 95% CI 1.53 to 4.56; p = 0.0004]. In patients treated with radiation, the LF rate at 12 months was 12.5% in patients with KRAS WT and 33.8% in KRAS MUT (p = 0.13). Heatmap analysis identified that RAD50, ALK, BCORL1, BRAF, CDC73, FAM123B, NF2, ERBB4, and ERCC4 were exclusively mutated in patients with KRAS WT. These genes were enriched in pathways associated with tyrosine kinase catalytic domain activity, ubiquitination, and nuclear localization signal.

CONCLUSION

This study identified driver mutations in patients with KRAS WT. KRAS status was associated with pathologic features and disease prognosis after treatment. Further study leveraging more powered cohorts is warranted.

Outcomes after Contemporary Definitive Radiotherapy Alone in Patients with TNM-7 Stage III/IV Head and Neck Squamous Cell Carcinoma

PURPOSE/OBJECTIVE(S)

This study was undertaken to determine outcomes and prognostic factors of definitive intensity-modulated radiotherapy (IMRT) alone for patients with TNM-7 stage III/IV HNSCC who did not receive concurrent chemotherapy.

MATERIALS/METHODS

We evaluated TNM-7 stage III/IV HNSCC patients treated with definitive IMRT alone in our institution from 2004-2019. Patients were reclassified according to TNM-8 staging. Stage II HPV+ oropharyngeal cancers (OPC) were subdivided into T1-2N2 and T3N0-2 for analysis. The rationale for chemotherapy omission was obtained retrospectively from clinical documentation. Recurrence-free survival (RFS) and overall survival (OS) were estimated stratified by HPV status (determined by p16 staining, sometimes supplemented by HPV DNA testing). Multivariable analysis (MVA) identified prognostic factors for RFS and OS, taking into account stage and IMRT regimen. Age, performance status, and smoking were also examined for OS.

RESULTS

A total of 1083 patients were included (460 HPV+ and 623 HPV-). Reasons for omission of chemotherapy were: age >70 years or frailty (n = 551, 51%), cisplatin contraindication (n = 241, 22%), patient refusal (n = 106, 10%), and clinician's decision (n = 185, 17%). Median age was 67 years for HPV+ and 70 years for HPV- cohorts. IMRT mostly utilized altered fractionation regimens (n = 1016, 94%): moderately accelerated (Acc) (70 Gy/35 fractions [f]/6 weeks [w], 55%), hypofractionated (Hypo) (60 Gy/25f/5w, 14%), and hyperfractionated-accelerated (Hyper) (64 Gy/40f/4w, 25%). Median follow-up was 5 years. Five-year RFS and OS for HPV+ TNM-8 stage I/T1-2N2/T3N0-N2/III were 89%/86%/76%/52% and 83%/80%/64%/33% respectively (p<0.01). The same outcomes for HPV- TNM-8 stage III/IVA/IVB were 58%/52%/39% and 47%/27%/13%, respectively (p<0.01). MVA confirmed that HPV+ T3N0-2 subset within stage II and stage III (vs stage I) had lower RFS, and HPV- stage IVA and IVB (vs stage III) carried worse RFS and OS (Table).

CONCLUSION

Despite the retrospective nature and inherent selection bias, this large single institutional study shows that altered fractionated IMRT alone is an acceptable alternative for elderly, frail or cisplatin ineligible patients with HPV+ stage I/IIA (T1-2N2) OPC. Patients with HPV+ T3N0-2/stage III OPC and HPV- stage III/IV HNSCC have poor outcomes with IMRT alone and may benefit from alternative strategies.

Deep Learning vs. Handcrafted Radiomics to Predict Chemoradiotherapy Response for Locally Advanced Cervical Cancer

PURPOSE/OBJECTIVE(S)

To predict CRT response in locally advanced cervical cancer (LACC) with handcrafted radiomics (HCR) and deep learning radiomics (DLR) using pretreatment MRI. Furthermore, we investigate whether the incorporation of clinical factors improves prediction performance.

MATERIALS/METHODS

Two hundred and fifty-two patients with LACC are enrolled. All patients are treated with external beam radiotherapy, followed by high-dose-rate intracavitary brachytherapy with concurrent cisplatin. The patients are randomly divided into two independent groups for the training (167 patients) and test datasets (85 patients). Contrast-enhanced T1- and T2-weighted MR scans are obtained. Patients in the training and test sets have similar characteristics in terms of age, tumor size, FIGO stage, HPV infection status, or CRT response. For HCR analysis, 1890 imaging features are extracted and a support vector machine classifier with a five-fold cross-validation is trained using training dataset to predict CRT response and validated using test dataset. For DLR analysis, a 3-dimensional convolutional neural network was trained and validated using test dataset.

RESULTS

A comparison of the DLR and HCR models reveals that the DLR model exhibits better prediction performance than the HCR model for the test dataset (AUC = 0.721 vs. 0.597, p = 0.097). The incorporation of clinical factors could improve performance in both DLR and HCR models.

CONCLUSION

The DLR models outperform the HCR models in predicting CRT responses in patients with LACC. Combining clinical factors and MRI may improve the prediction performance in both HCR and DLR analyses.

Predictive Value of Dynamic Tumor Volume Changes in Stage III Non-Small Cell Lung Cancer Treated with Chemoradiation and Consolidative Immunotherapy

PURPOSE/OBJECTIVE(S)

Concurrent chemoradiation (CRT) followed by Immunotherapy is standard of care in unresectable, locally advanced, non-small cell lung cancer (NSCLC). We hypothesize that on-treatment dynamic changes in tumor volume may predict oncologic outcome in Stage III NSCLC.

MATERIALS/METHODS

Stage III NSCLC patients who were treated with definitive CRT of 60 Gy in 30 fractions over 6 weeks with concurrent platinum-based concurrent chemotherapy followed by consolidative immunotherapy were retrospectively reviewed. We manually delineated the gross tumor volumes (GTV) of patients on cone beam computed tomography (CBCT) acquired on day 1, 15, 29 and 43. GTV reduction was quantified as the percent difference in volume on each CBCT as compared to CBCT Day 1. Mid-treatment response (MTR) and End of treatment response (ETR) was defined at day 29 (at 40 Gy) and day 43 (at 60 Gy), respectively. Loco-regional control (LRC) and overall survival (OS) was evaluated by Kaplan-Meier analysis, with log-rank test for groups stratified as per treatment response. Multivariate Cox regression analysis was performed to identify additional prognostic factors.

RESULTS

We evaluated 24 consecutively treated patients from 01/2016 to 08/2019, with a median follow-up of 30.5 months. Median age was 69 years (range 51-84). Adenocarcinoma histology was present in 58 % and squamous cell carcinoma in 42% patients. The tumor stage IIIA in 38% and Stage IIIB in 62% patients. All patients received definitive CRT with at least 2 cycles of immunotherapy (median 8 cycles). The median ETR at CBCT43 was 49.5% (range, 1%-84.7%). 1-year cumulative incidence of loco-regional failure (LRF) was 27% versus 10% in patients with ETR <49.5% as compared to patients with greater ETR (p = 0.31). The median MTR at CBCT29 was 32.7% (range, 1%-81%). 1-year cumulative incidence of LRF was 28% versus 9% in patients MTR <32.7% as compared to patients with higher response (p = 0.03). The 3-year actuarial LRC of all patients was 51% which was significantly better in higher MTR (70% vs 30%; p = 0.02, log-rank) as compared to lower MTR. The 3-year actuarial OS for all patients was 45% which was 54% in patients with higher MTR verses 37% in low responders (p = 0.09). On multivariate analysis, age and T-stage were significant factors associated with LRC. Histologic subtype showed no impact on our findings.

CONCLUSION

Stage III NSCLC patients with approximately one-third (33%) reduction of GTV on mid-treatment CBCT during CRT have significantly improved LRC and a trend towards improved OS. This approach may justify early adaptive intensification of RT or application of additional therapies in patients with non-optimal response. Additional large prospective study of CBCT is needed to determine whether treatment can be tailored based on tumor response, to improve outcomes.

Predictive Value of Tumor Volume on Local Control in Hepatocellular Carcinoma Treated with Image Guided Hypofractionated Radiation Treatment

PURPOSE/OBJECTIVE(S)

External beam radiation treatment (EBRT) is an important local treatment in liver-confined hepatocellular carcinoma (HCC) patients who are not candidates for curative therapy. EBRT dose, technique and prognostic factors are evolving. We hypothesized that tumor volume to liver volume ratio can be a predictor of local control (LC) in patients treated with hypo-fractionated radiation (HFRT) in HCC MATERIALS/METHODS: We retrospectively reviewed 50 patients of HCC treated with HFRT at our institution. HFRT schedule was chosen such that the radiation dose to the remaining liver and other organs at risk (OAR) met the standard dosimetric constraints. Image guided techniques were used for motion management, internal target volume (ITV) and planning target volume (PTV) delineation. Tumor to Liver Ratio (TLR) was defined as ratio of PTV volume to whole liver volume. TLR ≤ 0.3 was considered as low volume disease and TLR > 0.3 was considered as high-volume disease. The radiation dose ranged from 45 Gy to 67.5 Gy in 5 - 15 fractions. The biologically equivalent dose (BED) for tumor ranged from 58.5 Gy10 to 100 Gy10. Local control (LC) was evaluated by Kaplan-Meier analysis, with log-rank test for groups stratified as per TLR. Multivariate Cox regression analysis was performed to identify additional prognostic factors.

RESULTS

The mean duration of follow-up was 24 months. The median age was 69 years (range 50 - 90) and 76% were males. 32 patients had CP-A class cirrhosis while 17 had CP-B and 1 had CP-C class. BCLC stage A, B, C and D was seen in 2, 14, 33 and 2 patients, respectively. Portal vein thrombosis was present in 9 patients and prior trans-arterial chemo embolization (TACE) was done in 23 patients. The median volume of PTV was 551 cc (range 52 - 1990 cc). The TLR ranged from 0.04 - 0.67 with a median of 0.29. The median BED radiation dose was 78.4 Gy10 (range - 58.5 Gy10 to 100 Gy10). Nine patients had local recurrence with overall LC rate of 82%. The LC was better in low volume tumors, with the TLR cut-off of 0.3 as a significant factor associated with LC (p = 0.007). The 1-year actuarial LC with TLR ≤ 0.3 was 88% as compared 61% in TLR of > 0.3 (p = 0.007). BED ≥60 Gy10 was associated with better 1 year LC as compared to BED < 60 Gy10 (89% vs 62%; p = 0.11). ALBI grade 1 was associated with better 1 year LC as compared to ALBI grade 2 (80% versus 75%; p = 0.40). On multivariate analysis, high volume disease and TLR >0.3 were significant prognostic factor for LC.

CONCLUSION

HFRT has good 1-year local control of 82% in carefully selected unresectable HCC. Radiation with BED greater than 60 Gy10 and ALBI grade 1 showed a trend towards better LC. Smaller tumors had better LC with a PTV to liver ratio (TLR) of < 0.3. This information can help in identifying the poor responders, intensifying the radiation treatment and adding additional therapy to improve the oncological outcomes.

The Prognostic and Predictive Value of Pre-Treatment Total Lymphocyte Count in HPV+ Oropharyngeal Carcinoma Receiving Definitive (Chemo-) Radiation

PURPOSE/OBJECTIVE(S)

Evidence of prognostic importance of pre-radiotherapy (RT) total lymphocyte counts (TLC) and interaction with addition of cisplatin (CRT) in HPV-positive oropharyngeal carcinoma (HPV+OPC) is conflicting. Recent data suggest patients with high TLC may not benefit from the addition of chemotherapy (Price et al, JCO 2022). We assess the prognostic and predictive value of TLC in a large single center HPV+OCP cohort.

MATERIALS/METHODS

All HPV+OPC patients treated at a single academic center with definitive RT/CRT between 2005-2018 were included. Pre-treatment TLC up to 6 weeks prior to RT start were considered. Multivariable analysis (MVA) was applied to assess the prognostic importance of TLC (continuous variable), adjusted for age, gender, performance status, TNM-8 stage, and smoking status in the CRT and RT subgroups. The actuarial rates of locoregional control (LRC), distant control (DC), and overall survival (OS) were calculated using Kaplan-Meier and competing risk methods, stratified by low vs high TLC (determined using Contal and O'Quigley method for optimal cutoff).

RESULTS

Among 1153 eligible patients, 707 (61%) were treated with CRT. Median age was 59.7 (range 22.7-92.2) years. 526 patients were (46%) TNM-8 stage I, 366 (32%) stage II and 261 (23%) stage III. Median TLC was 1.6 x 109/L (range 0.1-8.5). Median follow-up was 5.5 years. On MVA, TLC was prognostic for patients receiving CRT (OS [adjusted hazard ration (aHR) 0.55 (0.38-0.79), p = 0.002], DC [aHR 0.57 (0.37-0.88), p = 0.011], LRC [aHR 0.57 (0.36-0.89), p = 0.014]) but not RT (OS [aHR 1.04 (0.82-1.31), p = 0.74], LRC [aHR 1.26 (0.86-1.85), p = 0.23], DC [aHR 0.87 (0.64-1.19), p = 0.4)]. The optimal TLC cut-off for OS with CRT was 1.9 x 109/L. Low vs high TLC patients receiving CRT had significantly inferior 5-year DC (87% vs 93%, p = 0.017) and OS (84% vs 90%, p = 0.026). The benefit of higher TLC was most evident in stage II disease (table 1). CRT vs RT improved OS for stage II/III disease at high and low TLC.

CONCLUSION

Pre-treatment TLC is prognostic in a large cohort of HPV+OPC patients receiving CRT but not RT alone. Further investigation of the interaction of cisplatin and immune response during RT is warranted. The omission of chemotherapy based on TLC is not supported.

Prediction of Lymphopenia and Survival with Baseline Absolute Lymphocyte Count and Irradiated Dose to Immune Cells in Patients with Non-Small Cell Lung Cancer Treated with Concurrent Chemoradiotherapy

PURPOSE/OBJECTIVE(S)

This study aimed to investigate the effect of effective dose to immune cell (EDIC) combined with pre-radiotherapy (RT) absolute lymphocyte count (ALC) on treatment-related lymphopenia during RT and treatment outcome in patients with locally advanced non-small cell lung cancer (NSCLC). A subgroup analysis in patients who received consolidation immunotherapy was also conducted.

MATERIALS/METHODS

Between August 2008 and December 2021, 517 patients with locally advanced NSCLC treated with definitive concurrent chemoradiotherapy (CRT) were retrospectively analyzed. All patients had serial complete-blood-count tests at pre-, and during-CRT. Severe lymphopenia was defined as ALC < 0.5x109cells/L during RT. EDIC was calculated according to mean doses of the lung, heart and the total body. The patients were grouped according to high and low EDIC and pre-RT ALC and was assessed for its correlation with radiation induced lymphopenia and survival outcomes.

RESULTS

Of 517 eligible patients, most of the patients received weekly paclitaxel with carboplatin (90.3%) and 195 patients (37.7%) received consolidation immunotherapy following CRT. A median radiation dose of 63 Gy (IQR, 60-64.5) was delivered in 30 fractions. The optimal cutoff value of EDIC and pre-RT ALC for predicting severe lymphopenia were 2.89 Gy and 2.03x109cells/L, respectively. High risk group was defined as EDIC ≥ 2.89 Gy and pre-RT ALC < 2.03x109cells/L, low risk group as EDIC <2.89 Gy and pre-RT ALC ≥ 2.03x109cells/L, and intermediate group as EDIC ≥ 2.89 Gy and pre-RT ALC ≥ 2.03x109cells/L or EDIC < 2.89 Gy and pre-RT ALC < 2.03x109cells/L. The incidence of severe lymphopenia during RT in high, intermediate, and low risk group was 90.1%, 77.1%, and 52.3%, respectively (p<0.001). The risk groups were independent predictors for both progression-free survival (PFS) (p<0.001) and overall survival (OS) (p<0.001). The high-risk group had higher incidence of locoregional and distant recurrences (p<0.001). In the subset of patients who were treated with consolidation immunotherapy, the risk groups were predictive of severe lymphopenia (p = 0.001), PFS (p = 0.004), and OS (p = 0.012).

CONCLUSION

This study demonstrated that the combination of EDIC and pre-RT ALC is a predictor for severe lymphopenia during RT, recurrence, and survival in patients with locally advanced NSCLC who received CRT. Moreover, the combination of EDIC and pre-RT ALC may serve as a potential biomarker for the benefit of maintenance immunotherapy.

BLZ8 activates a plastidial peroxiredoxin and a ferredoxin to protect Chlamydomonas reinhardtii against oxidative stress

Reactive oxygen species (ROS) cause damage to various cellular processes in almost all organisms, in particular photosynthetic organisms that depend on the electron transfer chain for CO2 fixation. However, the detoxifying process to mitigate ROS damage has not been studied intensively in microalgae. Here, we characterized the ROS detoxifying role of a bZIP transcription factor, BLZ8, in Chlamydomonas reinhardtii. To identify downstream targets of BLZ8, we carried out comparative genome-wide transcriptomic profiling of BLZ8 OX and its parental CC-4533 under oxidative stress conditions. Luciferase reporter activity assays and RT-qPCR were performed to test whether BLZ8 regulates downstream genes. We performed an in silico functional gene network analysis and an in vivo immunoprecipitation assay to identify the interaction between downstream targets of BLZ8. Comparative transcriptomic analysis and RT-qPCR revealed that overexpression of BLZ8 increased the expression levels of plastid peroxiredoxin1 (PRX1) and ferredoxin-5 (FDX5) under oxidative stress conditions. BLZ8 alone could activate the transcriptional activity of FDX5 and required bZIP2 to activate transcriptional activity of PRX1. Functional gene network analysis using FDX5 and PRX1 orthologs in A. thaliana suggested that these two genes were functionally associated. Indeed, our immunoprecipitation assay revealed the physical interaction between PRX1 and FDX5. Furthermore, the complemented strain, fdx5 (FDX5), recovered growth retardation of the fdx5 mutant under oxidative stress conditions, indicating that FDX5 contributes to oxidative stress tolerance. These results suggest that BLZ8 activates PRX1 and FDX5 expression, resulting in the detoxification of ROS to confer oxidative stress tolerance in microalgae.

Optimal Planning Target Margin for Prostate Radiotherapy Based on Interfractional and Intrafractional Variability Assessment during 1.5T MR-Guided Radiotherapy

PURPOSE/OBJECTIVE(S)

MR-guided radiotherapy (MRgRT) provides superior soft-tissue contrast over CT-based image guidance. We collected and analyzed daily pre-treatment (PRE) and real-time motion-monitoring (MM) MR images of patients receiving prostate radiotherapy to assess interfractional and intrafractional variability of prostate using two localization methods: pelvic bony anatomy (bone) and prostate during online adaptive radiotherapy (ART).

MATERIALS/METHODS

PRE and MM MRIs for the first five fractions of twenty prostate cancer patients who received definitive MRgRT with 1.5T MRI were collected. Using MIM software, rigid registration between PRE MRI and planning CT images based on pelvic bony anatomy and prostate reproduced bone localization and online ART, respectively. To determine interfractional setup margin (SM), prostate was delineated on all PRE MRIs registered after bone and prostate localizations by a radiation oncologist, and centroid values of prostate contours between planning CT and PRE MRIs were compared. To determine interobserver variability, another radiation oncologist, a medical physicist, and a radiotherapist contoured prostate for both localization methods. For internal margin (IM) assessment, we used MM MRIs of the five patients who had all three sets of coronal, sagittal, and axial cine images and determined the maximum contour displacement using in-house MATLAB-based software converting binary image files to 2D cine images with a superimposed grid of 1 mm spacing.

RESULTS

A total of 100 PRE and 25 MM MRIs were analyzed. Four hundred prostate contours were delineated on MR images registered with planning CT based on both bony anatomy and prostate. After bone localization, SM was 0.57±0.42 mm in left-right (LR), 2.45±1.98 mm in anterior-posterior (AP), and 2.28±2.08 mm in superior-inferior (SI) directions, and IO was 1.06±0.58 mm in LR, 2.32±1.08 mm in AP, and 3.30±1.85 mm in SI directions. After prostate localization, SM was 0.76±0.57 mm in LR, 1.89±1.60 mm in AP, and 2.2±1.79 mm in SI directions, and IO was 1.11±0.55 mm in LR, 2.13±1.07 mm in AP, and 3.53±1.65 mm in SI directions. Average IM was 2.12±0.86 mm, 2.24±1.07 mm, and 2.84±0.88 mm in LR, AP, and SI directions, respectively.

CONCLUSION

Using daily MRIs from MRgRT, we showed that movements in the SI direction were the largest source of variability in prostate definitive RT. In addition, interobserver variability was a non-negligible source of margin. Optimal PTV margin should also consider internal margin, especially in the SI direction.

Choosing Wisely between Radiotherapy Dose-Fractionation Schedules: The Molecular Graded Prognostic Assessment (molGPA) for Elderly Glioblastoma (eGBM-molGPA)

PURPOSE/OBJECTIVE(S)

This study aimed to develop a graded prognostic assessment (GPA) model integrating genomic characteristics in patients with elderly glioblastoma (eGBM), and compare the efficacy between conventionally fractionated radiotherapy (CFRT) vs. hypofractionated radiotherapy (HFRT) in each risk group.

MATERIALS/METHODS

Patients aged ≥65 years who underwent surgical resection followed by radiotherapy (RT) with or without temozolomide (TMZ) for newly diagnosed IDH-wildtype eGBM between 2006 and 2021 were included in this multicenter cohort study. Patients who were planned for a ≥6-week or ≤4-week radiotherapy were regarded as being treated with CFRT or HFRT, respectively. Based on the prognostic factors significantly identified through multivariate analysis for overall survival (OS), we developed the molecular GPA for eGBM (eGBM-molGPA) and assigned 0.0, 0.5, and 1.0 points in proportion to the corresponding hazard ratio (HR) of each factor. Then, the survival outcomes by treatment groups were evaluated according to the eGBM-molGPA scores.

RESULTS

A total of 334 and 239 patients who underwent CFRT and HFRT were included, respectively, and 86% of patients were treated with TMZ-based chemoradiation. With a median follow-up of 17.4 months for survivors, the median OS was 18.7 months for CFRT plus TMZ group, 15.1 months for HFRT plus TMZ group, and 10.4 months for RT alone group, respectively (all p<0.001). In the multivariate analysis, Karnofsky performance scale, surgical extent, TMZ, and the methylation status of the MGMT promoter were identified as strong prognostic factors for OS, with an estimated HR of greater than 1.5 (all p<0.001). Additionally, subventricular zone involvement, temporalis muscle thickness, RT regimen, and the mutation status of TERT promoter and TP53 gene were found to be significant prognostic factors for OS, with an estimated HR of less than 1.5. The eGBM-molGPA was established based on these prognostic factors (Table 1) and patients were allocated to three risk groups, which included high risk (total score of 3.0-4.5), intermediate risk (1.5-2.5), and low risk (0.0-1.0). Patients treated with CFRT plus TMZ had significantly improved OS compared to those treated with HFRT plus TMZ or RT alone in the low and intermediate risk groups (p<0.001). However, in the high-risk group, there was no significant difference in OS between treatment options (p = 0.770).

CONCLUSION

CFRT plus TMZ can be a more effective strategy for selected eGBM patients compared to HFRT. For high-risk patients, a protracted treatment schedule might not be beneficial. The novel eGBM-molGPA can be used as a clinical tool for choosing wisely among treatment options. Further prospective studies are warranted to establish optimal RT guidelines for eGBM patients.

Financial Improvements from Short Course Adjuvant Vaginal Cuff Brachytherapy (VCB) in Early Endometrial Cancer Compared to Standard of Care, "SAVE" Trial

PURPOSE/OBJECTIVE(S)

Early-stage endometrial cancer is often managed with hysterectomy followed by adjuvant VCB. Financial toxicity from cancer treatment is a strong driver of adherence. The SAVE trial is a multicenter, prospective randomized trial of standard of care (SoC) VCB doses delivered in 3-5 fractions per physician discretion compared to a 2-fraction course. We report on secondary cost endpoints, quantifying the financial impacts of shorter treatment courses on institutions and participating patients.

MATERIALS/METHODS

Technical (TechCs), professional (PCs), and total charges (TotCs) were collected prospectively and are reported as raw and Medicare-adjusted charges per patient. Geographic variations were standardized with CMS Geographic Practice Cost Indices (GPCI), and inflation was adjusted using the Consumer Price Index (CPI): Medical Care. Distance to treatment center was calculated from the patient's zip code to the corresponding treatment center. Cost of commutes was estimated through round-trip travel distance multiplied by average gas MPG for new vehicles by treatment year and state. Median income for each patient's zip code was estimated using 5-year Household income in 2021 inflation-adjusted dollars from the US Census. Mann-Whitney U, T- and Chi-square tests were used to compare characteristics between the two groups.

RESULTS

One hundred eight patients were analyzed. SoC VCB was delivered in 3, 4 and 5 fractions for 27/54 (50%), 11/54 (20%), and 16/54 (30%), respectively. Median total distance traveled per patient for SoC vs. experimental arms was 213 vs 137 miles (p = .12), and median cost of commute for patients was 36.3 vs 18.0 USD (p = .11). Compared to 2-fraction treatment, 5-fraction treatment resulted in longer travel distances (median 462 vs. 137 miles, p < 0.01) and increased travel costs (median 59.3 v. 18.0 USD, p = < 0.01). Median income by zip code for SoC v. experimental arms was 79,704 vs. 79,671 USD (p = 1.0). For SoC v. experimental arms, 11 (20%) vs 7 (13%) of patients had zip codes with median income in the lowest or second lowest quintiles (p = 0.5). Adjusted raw PCs per patient did not differ between SoC vs. experimental arms (9,159$ vs. 7,532$, p = 0.19). TechCs were significantly higher on the SoC arm (35,734$ vs. 24,696$ p = < 0.01), as were TotCs (44,892$ vs. 32,228$, p < 0.01;). Medicare-adjusted PCs, TechCs, and TotCs were higher for the SoC arm (Table 1).

CONCLUSION

Two-fraction VCB resulted in fewer treatments per patient, reduced cost of travel compared to longer courses, and an adjusted reduction in healthcare expenditures compared to standard of care. Ongoing work will include assessment of patient-reported financial toxicities.

Unplanned Hospitalization and Subsequent Mortality in Lung Cancer Patients Undergoing Concomitant Chemo-/Immuno-Therapy and Radiotherapy: An Analysis of Over 10,000 Patients in a Nationwide Database

PURPOSE/OBJECTIVE(S)

Radiotherapy (RT) and concomitant chemotherapy (CHT) is a major modality for treating many malignancies including lung cancer and is associated with toxicity-related unplanned hospitalization (UPH). Previous investigations of factors associated with UPH have been single institutional retrospective studies and none assessed the role of concurrent immunotherapy (IO). Here, we aimed to identify factors associated with UPH and in-hospital mortality by leveraging a multi-institutional nationwide database.

MATERIALS/METHODS

The Vizient® Clinical Data Base which includes data from 98% of the AAMC hospitals and 110 cancer hospitals, was queried for lung cancer patients (any histology) treated in 2019-2021 with RT+CHT/IO. Endpoints were UPH and mortality during or within 30 days of completion of RT. The variables included age, sex, race, ethnicity, income level (quartile), an education level (quartile), any concomitant CHT or IO drugs, RT technique (3D vs. IMRT vs. SBRT), obesity, prior hospitalization within 3 months, prior oncologic surgery within 3 months, prior CHT and/or IO within 3 months, insurance types, hospital types (Rural vs. Urban, AAMC vs. non-AAMC, NCCN vs. non-NCCN, bed size tertile). Logistic regression was performed to identify variables associated with UPH and in-hospital mortality. Data from the Vizient Clinical Data Base used with permission of Vizient, Inc. All rights reserved.

RESULTS

A total of 10,337 patients were included. The rate of UPH and mortality among UPH was 24.5% and 3.2%, respectively. Factors associated with UPH included other races (vs. White, OR 1.44; 95% CI 1.11-1.88; p<0.001), living in a low income zip code (OR 1.7; 95% CI 1.39-2.09; p = 0.0006), living in a zip code with lower education attainment (OR 0.71; 95% CI 0.58-0.86; p = 0.0007), CHT/IO types (cis-etoposide vs. carbo-Taxol, OR 1.33; 95% CI 1.13-1.57; p<0.0001), obesity (OR 1.71; 95% CI 1.53-1.92; p<0.0001), prior hospitalization (OR 2.0; 95% CI 1.80-2.22; p<0.0001), prior oncologic surgery (OR 0.34; 95% CI 0.22-0.52; p<0.0001), other primary payers (vs. commercial; OR 1.75; 95% CI 1.37-2.23; p<0.0001), rural hospital (OR 1.3; 95% CI 1.07-1.62, p<0.01), small bed size (OR 0.59; 95% CI 0.5-0.71; p<0.0001). Factors associated with in-hospital mortality included CHT/IO type (p<0.0001, but cis-etoposide vs. carbo-taxol no difference), prior hospitalization (OR 0.34; 95% CI 0.2-0.56; p<0.0001), AAMC (OR 2.12; 95% CI 1.23-3.67; p = 0.007), bed size (OR 0.58; 95% CI 0.38-0.88; p<0.01).

CONCLUSION

In the largest study to date regarding UPH and in-hospital mortality related to lung RT, we identified factors contributing to these endpoints. Future prospective studies are warranted to develop strategies to prevent these complications in high-risk populations.

A Photograph-Based Visualization and Prediction Framework for Radiation-Induced Dermatitis

PURPOSE/OBJECTIVE(S)

This study aimed to suggest a photograph-based prediction system for acute radiation-induced dermatitis (RID), which can be applied to notify patients about the risk of the development of skin discomfort during radiotherapy.

MATERIALS/METHODS

The proposed system compared the spatial dose distribution with the RID region using the following methods. Skin photographs of patients were taken using an RGB-depth camera to acquire the shape information of RID. The skin surface data measured from the camera was registered with the shape of the external body contour using an iterative closest point algorithm. Spatial dose distribution of skin was extracted from the external body contour to a depth of 2 mm and projected onto the plane of the skin photograph using a transformation matrix for skin depth data. To compare the spatial distribution of skin dose with the shape of RID, the region of RID in patients' skin was delineated on photographs into three toxicity symptoms referring to the CTCAE criteria grade 1 (skin redness), grade 2 (dry desquamation), and grade 3 (moist desquamation). The degree of overlap between the shape of each RID and skin dose distribution was evaluated using the dice similarity coefficient (DSC). Threshold doses for predicting RID occurrence were estimated by skin isodose lines with the highest DSC. The developed system was validated using data from 19 patients who received volumetric modulated arc therapy for head-neck cancer at a single institution.

RESULTS

Threshold doses for RID grades 1, 2, and 3 were estimated using 18, 18, and 2 individual RID labels delineated on skin photographs, respectively. Isodose lines with the highest DSC for RID grades 1, 2, and 3 were calculated as 26.0 Gy, 36.5 Gy, and 54.0 Gy, respectively. A strong overlap (average DSC > 0.6) was observed between isodose skin lines and the shape of RID labels in all RID grades.

CONCLUSION

Assessing the spatial information of skin dose can be helpful in predicting acute RID. The region of RID shows a strong similarity with the skin dose distribution in head-neck patients. Visualization of skin dose on the patient photograph is potent to patient education for preparing the cosmetic discomfort during radiotherapy, which may lead to the improvement of the patient satisfaction in treatment.

Measurement of the Dependence of the Hadron Production Fraction Ratios f_{s}/f_{u} and f_{d}/f_{u} on B Meson Kinematic Variables in Proton-Proton Collisions at sqrt[s]=13 TeV

The dependence of the ratio between the B_{s}^{0} and B^{+} hadron production fractions, f_{s}/f_{u}, on the transverse momentum (p_{T}) and rapidity of the B mesons is studied using the decay channels B_{s}^{0}→J/ψϕ and B^{+}→J/ψK^{+}. The analysis uses a data sample of proton-proton collisions at a center-of-mass energy of 13 TeV, collected by the CMS experiment in 2018 and corresponding to an integrated luminosity of 61.6  fb^{-1}. The f_{s}/f_{u} ratio is observed to depend on the B p_{T} and to be consistent with becoming asymptotically constant at large p_{T}. No rapidity dependence is observed. The ratio of the B^{0} to B^{+} meson production fractions, f_{d}/f_{u}, is also measured, for the first time in proton-proton collisions, using the B^{0}→J/ψK^{*0} decay channel. The result is found to be within 1 standard deviation of unity and independent of p_{T} and rapidity, as expected from isospin invariance.

Measurement of the Lifetime and Λ Separation Energy of _{Λ}^{3}H

The most precise measurements to date of the _{Λ}^{3}H lifetime τ and Λ separation energy B_{Λ} are obtained using the data sample of Pb-Pb collisions at sqrt[s_{NN}]=5.02  TeV collected by ALICE at the LHC. The _{Λ}^{3}H is reconstructed via its charged two-body mesonic decay channel (_{Λ}^{3}H→^{3}He+π^{-} and the charge-conjugate process). The measured values τ=[253±11(stat)±6(syst)]  ps and B_{Λ}=[102±63(stat)±67(syst)]  keV are compatible with predictions from effective field theories and confirm that the _{Λ}^{3}H structure is consistent with a weakly bound system.

Search for Exotic Higgs Boson Decays H→AA→4γ with Events Containing Two Merged Diphotons in Proton-Proton Collisions at sqrt[s]=13 TeV

We present the first direct search for exotic Higgs boson decays H→AA, A→γγ in events with two photonlike objects. The hypothetical particle A is a low-mass spin-0 particle decaying promptly to a merged diphoton reconstructed as a single photonlike object. We analyze the data collected by the CMS experiment at sqrt[s]=13  TeV corresponding to an integrated luminosity of 136  fb^{-1}. No excess above the estimated background is found. We set upper limits on the branching fraction B(H→AA→4γ) of (0.9-3.3)×10^{-3} at 95% confidence level for masses of A in the range 0.1-1.2 GeV.

Clinical characteristics and outcomes of Clostridioides difficile infection in the intensive care unit: a KASID multi-centre study

BACKGROUND

Despite the growing clinical and economic burden of Clostridioides difficile infection (CDI), data on CDI in the intensive care unit (ICU) in the Asia-Pacific region are lacking.

METHODS

This retrospective study analysed 191 patients who were treated with CDI in the ICUs of three hospitals in South Korea from January 2017 to May 2021. Backward-stepwise multiple logistic regression was used to identify factors influencing the treatment response and mortality.

RESULTS

Fifty-eight patients (30.4%) were considered immunocompromised. The mean Charlson comorbidity index was 5.65 ± 2.39 (10-year survival rate: 21%), the APACHE II score was 20.86 ± 7.78 (mortality rate: 40%), the ATLAS score was 5.45 ± 1.59 (cure rate: 75%), and the SOFA score was 7.97 ± 4.03 (mortality rate: 21.5%). Fifty-eight (30.4%) of the CDI cases were severe and 40 (20.9%) were fulminant. Oral vancomycin or oral metronidazole was the most frequently first-line treatments (N = 57; 32.6%). The 10-day response rate was 59.7% and the eight-week overall mortality rate was 41.4%. Fulminant CDI (OR 0.230; 95% CI 0.085-0.623) and each one-unit increment in the SOFA score (OR 0.848; 95% CI 0.759-0.947) were associated with treatment failure. High APACHE II (OR 0.355; 95% CI 0.143-0.880) and SOFA (OR 0.164; 95% CI 0.061-0.441) scores were associated with higher mortality.

CONCLUSIONS

High-risk patients in the ICU had a higher mortality rate and a lower cure rate of CDI. Further research is required to provide more accurate prediction scoring systems and better clinical outcomes.

Observation of Same-Sign WW Production from Double Parton Scattering in Proton-Proton Collisions at sqrt[s]=13 TeV

The first observation of the production of W^{±}W^{±} bosons from double parton scattering processes using same-sign electron-muon and dimuon events in proton-proton collisions is reported. The data sample corresponds to an integrated luminosity of 138  fb^{-1} recorded at a center-of-mass energy of 13 TeV using the CMS detector at the CERN LHC. Multivariate discriminants are used to distinguish the signal process from the main backgrounds. A binned maximum likelihood fit is performed to extract the signal cross section. The measured cross section for production of same-sign W bosons decaying leptonically is 80.7±11.2(stat) _{-8.6}^{+9.5}(syst)±12.1(model)  fb, whereas the measured fiducial cross section is 6.28±0.81(stat)±0.69(syst)±0.37(model)  fb. The observed significance of the signal is 6.2 standard deviations above the background-only hypothesis.

Observation of the Rare Decay of the η Meson to Four Muons

A search for the rare η→μ^{+}μ^{-}μ^{+}μ^{-} double-Dalitz decay is performed using a sample of proton-proton collisions, collected by the CMS experiment at the CERN LHC with high-rate muon triggers during 2017 and 2018 and corresponding to an integrated luminosity of 101  fb^{-1}. A signal having a statistical significance well in excess of 5 standard deviations is observed. Using the η→μ^{+}μ^{-} decay as normalization, the branching fraction B(η→μ^{+}μ^{-}μ^{+}μ^{-})=[5.0±0.8(stat)±0.7(syst)±0.7(B_{2μ})]×10^{-9} is measured, where the last term is the uncertainty in the normalization channel branching fraction. This work achieves an improved precision of over 5 orders of magnitude compared to previous results, leading to the first measurement of this branching fraction, which is found to agree with theoretical predictions.

Measurements of jet multiplicity and jet transverse momentum in multijet events in proton-proton collisions at s=13TeV

Multijet events at large transverse momentum (p T ) are measured at s = 13 Te V using data recorded with the CMS detector at the LHC, corresponding to an integrated luminosity of 36.3 fb - 1 . The multiplicity of jets with p T > 50 Ge V that are produced in association with a high-p T dijet system is measured in various ranges of the p T of the jet with the highest transverse momentum and as a function of the azimuthal angle difference Δ ϕ 1 , 2 between the two highest p T jets in the dijet system. The differential production cross sections are measured as a function of the transverse momenta of the four highest p T jets. The measurements are compared with leading and next-to-leading order matrix element calculations supplemented with simulations of parton shower, hadronization, and multiparton interactions. In addition, the measurements are compared with next-to-leading order matrix element calculations combined with transverse-momentum dependent parton densities and transverse-momentum dependent parton shower.