Changes in Target Coverage and Dose to the Normal Brain during Fractionated Stereotactic Radiotherapy for Metastatic Brain Tumors

PURPOSE/OBJECTIVE(S)

Fractionated stereotactic radiotherapy (SRT) has been applied to large brain metastases to reduce the risk of radiation necrosis. For fractionated SRT, potential of interfractional tumor changes during the treatment period, such as tumor size, shape, and geometry, must be considered to improve the tumor local control. Our center performs adaptive re-planning for large brain metastases based on repeat MRI verification with a contrast agent in the middle of the treatment period. Purpose of this study is to evaluate the dosimetric impact of the changes in tumor size, shape, and geometry on the doses to the targets and normal brain in patients with brain metastases undergoing fractionated SRT.

MATERIALS/METHODS

Fifteen solitary large intracranial metastatic lesions treated with fractionated SRT were investigated. Standardized planning MRI (MRI-1) and repeat verification MRI (MRI-2) were performed during the middle of the irradiation period. The GTV on the MRI-1 and MRI-2 scans was contoured by the same oncologist. The PTV was created by adding an isotropic margin of 1 mm from the GTV in all directions. Volumetric modulated arc therapy (VMAT) with beam energies of 6 MV (flattening filter-free mode) was used and plans were normalized such that PTV D95% or D98% was equal to the prescribed dose. Beam configuration and intensity on the initial VMAT plan were used to evaluate the dose to the tumor and the normal brain on MRI-2. We evaluated the impact of D98% on the GTV using the plans on the MRI-1 and MRI-2 scans. For the normal brain, the V90%, V80%, and V50% were investigated.

RESULTS

The median GTV changed from 9.8 cc (range of 3.2-33.0 cc) to 9.7 cc (range of 2.8-36.5 cc) (p = 0.482). Three and four tumors exhibited volume shrinkage and enlargement changes of >10%. Five tumors exhibited volume shrinkage and enlargement changes of <10%. Three tumors showed no volume changes. Of the 15 large brain metastases, 12 tumors required treatment plan modification. The dosimetric parameters of the GTV, PTV, and normal brain did not significantly differ between the MRI-1 and MRI-2 scans. Regarding the tumor dose, the D98% to the GTV increased in patients with tumor shrinkage because of dose inhomogeneity and decreased in patients with tumor enlargement. The V90%, V80%, and V50% increase with decreasing tumor volumes and were linearly related to the tumor volume difference, with a coefficient of determination of 0.97, 0.98, and 0.97, respectively.

CONCLUSION

Our study demonstrated the usefulness of repeat verification MRI for adaptive radiotherapy in the middle of the treatment period due to changes in tumor size, shape, and geometry in patients with brain metastases. Repeated MRI should be considered to evaluate the dose to the target and normal brain, which improves tumor local control and reduces brain necrosis, to reduce the magnitude of underdosing to the target or overdosing to the normal brain during the treatment period.

Multicenter Retrospective Study of Stereotactic Body Radiotherapy for Patients with Previously Untreated Initial Small Hepatocellular Carcinoma

PURPOSE/OBJECTIVE(S)

The effectiveness of stereotactic body radiation therapy (SBRT) for hepatocellular carcinoma (HCC) has been shown in many studies and its therapeutic effect is similar to radiofrequency ablation (RFA). However, many of these studies were done in combination with transcatheter chemoembolization (TACE), for recurrent HCC, or on a small scale. To better understand the specific outcomes of SBRT for HCC, we conducted a multicenter retrospective analysis of SBRT for previously untreated initial HCC at Japanese Society of Clinical Oncology (JCOG) member hospitals.

MATERIALS/METHODS

Patientswho underwent SBRT for HCC at JCOG member hospitals between July 2013 and December 2017 and met the following eligibility criteria were included: (1) initial HCC; (2) ≤ 3 nodules, ≤ 5 cm in diameter; (3) a Child-Pugh (CP) score of A or B; and (4) unsuitability for or refusal of standard treatment, such as surgery, transplantation, RFA and TACE. We evaluated the overall survival (OS), recurrence-free survival (RFS) which was defined as the first instance of intra-hepatic recurrence after SBRT, disease-specific survival (DSS) using Kaplan-Meier analysis. Using Grey's test, patients who died of other diseases were analyzed as competing risks to estimate the cumulative incidence of local recurrence (CLR). Adverse events directly related to SBRT also analyzed using Common Terminology Criteria for Adverse Events version 5.0 (CTCAE v5.0).

RESULTS

Seventy-three patients with 79 lesions from 14 hospitals were analyzed. The median age was 77 years (range; 50-89 years), and the median tumor size was 23 mm (range; 6-50 mm). The median radiation dose was 40 Gy (range; 35-60 Gy) in five fractions (range; 4-8). The median follow-up period was 45 months (range; 0-103 months). There were three cases where follow-up was not possible due to unexpected events unrelated to SBRT, while the remaining 70 patients were successfully followed for at least six months. The 2 and 3year OS, RFS, DSS, and CLR rates were 84.3% (95% CI: 75.8-92.8%) and 69.9% (95% CI: 58.7-81%), 67.5% (95% CI: 56.0-79.0%) and 57.9% (95% CI: 45.2-70.5%), 95.1% (95% CI:89.7-100%)/87.6% (95% CI:78.8-96.3%), and 11.4% (95% CI: 5.3-20.0%) and 20.0% (95% CI: 11.2-30.5%), respectively. Four cases (5.5%) of adverse events of grade 3 or higher were reported: one case of grade 3 laboratory toxicities, one case of grade 3 liver failure, one case of grade 3 portal tumor thrombosis, and one case of grade 4 duodenal ulcer. No grade 5 toxicities were observed.

CONCLUSION

The results of our study demonstrate that SBRT for HCC is highly effective in achieving local control and is safe to administer. In addition, survival outcomes are favorable. SBRT is a promising treatment modality, especially for small HCCs for that is not suitable for standard treatment.

Preclinical in vitro evaluation of immune suppression induced by GYM329, Fc-engineered sweeping antibody

Fc-engineering is commonly used to improve the therapeutic potency of antibody (Ab) treatments. Because FcγRIIb is the only inhibitory FcγR that contains an immunoreceptor tyrosine-based inhibition motif (ITIM), Fc-engineered Abs with enhanced binding affinity to FcγRIIb might provide immune suppression in clinical contexts. GYM329 is an anti-latent myostatin Fc-engineered Ab with increased affinity to FcγRIIb which is expected to improve muscle strength in patients with muscular disorders. Cross-linking of FcγRIIb by immune complex (IC) results in phosphorylation of ITIM to inhibit immune activation and apoptosis in B cells. We examined whether the IC of Fc-engineered Abs with enhanced binding affinity to FcγRIIb causes phosphorylation of ITIM or B cell apoptosis using GYM329 and its Fc variant Abs in human and cynomolgus-monkey (cyno) immune cells in vitro. IC of GYM329 with enhanced binding affinity to human FcγRIIb (×5) induced neither ITIM phosphorylation nor B cell apoptosis. As for GYM329, FcγRIIb should work as an endocytic receptor of small IC to sweep latent myostatin, so it is preferable that GYM329 induces neither ITIM phosphorylation nor B cell apoptosis to prevent immune suppression. In contrast, IC of myo-HuCy2b, the Ab with enhanced binding affinity to human FcγRIIb (×4), induced ITIM phosphorylation and B cell apoptosis. The result of the present study demonstrated that Fc-engineered Abs with similar binding affinity to FcγRIIb had different effects. Thus, it is important to also investigate FcγR-mediated immune functions other than binding to fully understand the biological effects of Fc-engineered Abs.

Acute circumflex coronary artery occlusion; dilemma in diagnosis and management

Background

Acute coronary syndrome (ACS) with occlusion of the circumflex coronary artery (LCX) poses diagnostic dilemma that may lead to a delay in reperfusion.

Purpose

We sought to assess the diagnostic significance of initial electrocardiography (ECG) changes in patients with acute LCX occlusion in relation to its clinical characteristics and the management.

Methods

From consecutive 1269 patients with ACS who were admitted to our institution during a 5-year period (2015–2019), 138 patients with ACS due to LCX occlusion were analyzed for clinical, ECG and angiographic presentation, and the door-to-balloon (DTB) time. ECG changes were classified into 4 different patterns: 1) ST-elevation in inferior/lateral leads (ST-E); 2) ST-depression in V1-V4 (ST-D); 3) no significant ST changes (No-ST); and 4) others.

Results

(1) No-ST pattern was found in 47 patients (34%), ST-E in 47 patients (34%), ST-D in 25 patients (18%) and others in 19 patients (14%). (2) Occlusion site: Proximal LCX; 16 patients with No-ST (34%), 6 patients with ST-E (13%), 13 patients with ST-D (52%). Distal LCX; 28 patients with No-ST (60%), 35 patients with ST-E (74%), 11 patients with ST-D (44%) (p=0.007). (Table) (3) Echocardiographic identification of left ventricular asynergy; 31 patients with No-ST (66%), 38 patients with ST-E (81%), 22 patients with ST-D (88%). (4) No-ST group was associated with longer DTB time; 245 min (170–562 min), compared to 93 min (83–121 min) in ST-E group and 97 min (70–129 min) in ST-D group (p&lt;0.0001). DTB time ≤90 min was significantly uncommon in No-ST group (11%), compared to ST-E group (46%) and ST-D group (43%) (p=0.0004). (Figure)

Conclusion

One-third of the patients with LCX-ACS showed no ST changes, resulting in significantly longer DTB time. Improving diagnostic accuracy with anticipation for LCX-ACS and the use of echocardiographic examination and also the possible application of posterior leads (V7-V9) recording is challenging but critical to avoid delayed reperfusion and to improve outcomes in these patients without ECG changes.

Funding Acknowledgement

Type of funding sources: None.

Enhanced therapeutic index of an antimicrobial peptide in mice by increasing safety and activity against multidrug-resistant bacteria

The rising prevalence of antibiotic resistance underscores the urgent need for novel antimicrobial agents. Antimicrobial peptides (AMPs) are potentially effective therapeutics that disrupt bacterial membranes regardless of resistance to traditional antibiotics. We have developed engineered cationic AMPs (eCAPs) with broad activity against multidrug-resistant (MDR) bacteria, but stability remains an important concern. Therefore, we sought to enhance the clinical utility of eCAP WLBU2 in biological matrices relevant to respiratory infection. A designed substitution of d-Val for l-Val resulted in increased resistance to protease enzymatic degradation. We observed multiple gains of functions such as higher activity against bacteria in biofilm mode of growth, significantly lower toxicity to erythrocytes and white blood cells compared to WLBU2, with increased safety in mice. Direct airway delivery revealed a therapeutic index of >140 for the selected enantiomer compared to that of <35 for WLBU2. The data warrant clinical exploration by aerosolized delivery to mitigate MDR-related respiratory infection.

Corrigendum to "High glucose concentration-induced expression of pentraxin-3 in a rat model of continuous peritoneal dialysis"

This correct the article DOI: 10.14670/HH-11-756.

High glucose concentration-induced expression of pentraxin-3 in a rat model of continuous peritoneal dialysis

BACKGROUND

Continuous exposure to peritoneal dialysis fluids (PDFs) is associated with pathological responses such as persistent micro-inflammation, which leads to ultrafiltration failure. Pentraxin-3 (PTX3), a multifunctional soluble pattern recognition receptor, is produced at sites of inflammation by a wide range of cell types. This study investigates the in vivo expression of PTX3 in the peritoneal membrane of a rat continuous peritoneal dialysis (PD) model, as well as the effect of high glucose on the in vitro expression of PTX3.

METHODS

The expression of PTX3 was analyzed using RT-PCR, real-time PCR, immunohistochemistry and western blotting in a PD rat model receiving saline or conventional PDF containing 3.86% glucose for 8 weeks. The effects of high glucose on the expression of PTX3 were examined in cultured rat peritoneal mesothelial cells (RPMCs), mouse macrophage-like cells, and mouse fibroblasts.

RESULTS

In a rat model of PD, eight-week instillation of the conventional PDF produced increased submesothelial thickening, followed by substantially enhanced PTX3 protein levels in the submesothelial layer of peritoneal membrane. PTX3 was detected in peritoneal mesothelial cells, macrophages and fibroblasts in the thickened submesothelial area. Glucose was found to induce PTX3 protein expression in RPMCs as well as macrophage-like cells and fibroblasts.

CONCLUSION

Continuous exposure to conventional PDF induces PTX3 expression in the peritoneal membrane of rats. High glucose may be involved in the mechanism of PDF-induced local micro-inflammation in the peritoneum.

Supertransmission channel for an intrinsic localized mode in a one-dimensional nonlinear physical lattice

It is well known that a moving intrinsic localized mode (ILM) in a nonlinear physical lattice looses energy because of the resonance between it and the underlying small amplitude plane wave spectrum. By exploring the Fourier transform (FT) properties of the nonlinear force of a running ILM in a driven and damped 1D nonlinear lattice, as described by a 2D wavenumber and frequency map, we quantify the magnitude of the resonance where the small amplitude normal mode dispersion curve and the FT amplitude components of the ILM intersect. We show that for a traveling ILM characterized by a specific frequency and wavenumber, either inside or outside the plane wave spectrum, and for situations where both onsite and intersite nonlinearity occur, either of the hard or soft type, the strength of this resonance depends on the specific mix of the two nonlinearities. Examples are presented demonstrating that by engineering this mix the resonance can be greatly reduced. The end result is a supertransmission channel for either a driven or undriven ILM in a nonintegrable, nonlinear yet physical lattice.

Muon reconstruction efficiency and momentum resolution of the ATLAS experiment in proton-proton collisions at [Formula: see text] TeV in 2010

This paper presents a study of the performance of the muon reconstruction in the analysis of proton-proton collisions at [Formula: see text] TeV at the LHC, recorded by the ATLAS detector in 2010. This performance is described in terms of reconstruction and isolation efficiencies and momentum resolutions for different classes of reconstructed muons. The results are obtained from an analysis of [Formula: see text] meson and [Formula: see text] boson decays to dimuons, reconstructed from a data sample corresponding to an integrated luminosity of 40 pb[Formula: see text]. The measured performance is compared to Monte Carlo predictions and deviations from the predicted performance are discussed.

The differential production cross section of the [Formula: see text](1020) meson in [Formula: see text] = 7 TeV [Formula: see text] collisions measured with the ATLAS detector

A measurement is presented of the [Formula: see text] production cross section at [Formula: see text] = 7 TeV using [Formula: see text] collision data corresponding to an integrated luminosity of 383 [Formula: see text], collected with the ATLAS experiment at the LHC. Selection of [Formula: see text](1020) mesons is based on the identification of charged kaons by their energy loss in the pixel detector. The differential cross section is measured as a function of the transverse momentum, [Formula: see text], and rapidity, [Formula: see text], of the [Formula: see text](1020) meson in the fiducial region 500 [Formula: see text] 1200 MeV, [Formula: see text] 0.8, kaon [Formula: see text] 230 MeV and kaon momentum [Formula: see text] 800 MeV. The integrated [Formula: see text]-meson production cross section in this fiducial range is measured to be [Formula: see text] = 570 [Formula: see text] 8 (stat) [Formula: see text] 66 (syst) [Formula: see text] 20 (lumi) [Formula: see text].

Search for dark matter in events with a hadronically decaying W or Z boson and missing transverse momentum in pp collisions at √s=8 TeV with the ATLAS detector

A search is presented for dark matter pair production in association with a W or Z boson in pp collisions representing 20.3  fb(-1) of integrated luminosity at √s=8  TeV using data recorded with the ATLAS detector at the Large Hadron Collider. Events with a hadronic jet with the jet mass consistent with a W or Z boson, and with large missing transverse momentum are analyzed. The data are consistent with the standard model expectations. Limits are set on the mass scale in effective field theories that describe the interaction of dark matter and standard model particles, and on the cross section of Higgs production and decay to invisible particles. In addition, cross section limits on the anomalous production of W or Z bosons with large missing transverse momentum are set in two fiducial regions.

Measurement of jet shapes in top-quark pair events at [Formula: see text] using the ATLAS detector

A measurement of jet shapes in top-quark pair events using 1.8 fb-1 of [Formula: see text]pp collision data recorded by the ATLAS detector at the LHC is presented. Samples of top-quark pair events are selected in both the single-lepton and dilepton final states. The differential and integrated shapes of the jets initiated by bottom-quarks from the top-quark decays are compared with those of the jets originated by light-quarks from the hadronic W-boson decays [Formula: see text] in the single-lepton channel. The light-quark jets are found to have a narrower distribution of the momentum flow inside the jet area than b-quark jets.

Measurement of top quark polarization in top-antitop events from proton-proton collisions at √s=7 TeV using the ATLAS detector

This Letter presents measurements of the polarization of the top quark in top-antitop quark pair events, using 4.7  fb(-1) of proton-proton collision data recorded with the ATLAS detector at the Large Hadron Collider at √s=7  TeV. Final states containing one or two isolated leptons (electrons or muons) and jets are considered. Two measurements of α(ℓ)P, the product of the leptonic spin-analyzing power and the top quark polarization, are performed assuming that the polarization is introduced by either a CP conserving or a maximally CP violating production process. The measurements obtained, α(ℓ)P(CPC)=-0.035±0.014(stat)±0.037(syst) and α(ℓ)P(CPV)=0.020±0.016(stat)(-0.017)(+0.013)(syst), are in good agreement with the standard model prediction of negligible top quark polarization.

Magnesium intake decreases Type 2 diabetes risk through the improvement of insulin resistance and inflammation: the Hisayama Study

AIMS

Early studies have shown that magnesium intake decreases the risk of Type 2 diabetes, but the results are still inconsistent. We prospectively examined the association between magnesium intake and incidence of Type 2 diabetes in a general Japanese population.

METHODS

A total of 1999 subjects without diabetes aged 40-79 years who underwent a 75-g oral glucose tolerance test were followed up prospectively for a mean of 15.6 years.

RESULTS

During the follow-up, 417 subjects developed Type 2 diabetes. The age- and sex-adjusted incidence of Type 2 diabetes significantly decreased with increasing magnesium intake quartile levels (≤ 148.5, 148.6-171.5, 171.6-195.5 and ≥ 195.6 mg/day, P for trend = 0.01). In multivariate analyses, after adjusting for comprehensive risk factors and other dietary factors, the hazard ratio of Type 2 diabetes was 0.67 (95% CI 0.49-0.92; P = 0.01) in the third quartile and 0.63 (95% CI 0.44-0.90; P = 0.01) in the highest quartile compared with the first quartile. In addition, the risk of Type 2 diabetes was 14% lower (P = 0.04) for a 1-sd increment of log-transformed magnesium intake in the multivariate-adjusted model. In stratified analysis, there were statistically significant interactions between magnesium intake and levels of homeostasis model assessment of insulin resistance, high-sensitivity C-reactive protein or alcohol intake on the risk of Type 2 diabetes (all P < 0.05).

CONCLUSIONS

Our findings suggest that increased magnesium intake was a significant protective factor for the incidence of Type 2 diabetes in the general Japanese population, especially among subjects with insulin resistance, low-grade inflammation and a drinking habit.

Measurement of the azimuthal angle dependence of inclusive jet yields in Pb+Pb collisions at √(sNN)=2.76 TeV with the ATLAS detector

Measurements of the variation of inclusive jet suppression as a function of relative azimuthal angle, Δφ, with respect to the elliptic event plane provide insight into the path-length dependence of jet quenching. ATLAS has measured the Δφ dependence of jet yields in 0.14 nb(-1) of √(s(NN))=2.76 TeV Pb+Pb collisions at the LHC for jet transverse momenta p(T)>45 GeV in different collision centrality bins using an underlying event subtraction procedure that accounts for elliptic flow. The variation of the jet yield with Δφ was characterized by the parameter, v(2)(jet), and the ratio of out-of-plane (Δφ~π/2) to in-plane (Δφ~0) yields. Nonzero v(2)(jet) values were measured in all centrality bins for p(T)<160 GeV. The jet yields are observed to vary by as much as 20% between in-plane and out-of-plane directions.

Epidemiology and molecular characterization of bacteremia due to carbapenem-resistant Klebsiella pneumoniae in transplant recipients

We conducted a retrospective study of 17 transplant recipients with carbapenem-resistant Klebsiella pneumoniae bacteremia, and described epidemiology, clinical characteristics and strain genotypes. Eighty-eight percent (15/17) of patients were liver or intestinal transplant recipients. Outcomes were death due to septic shock (18%), cure (24%) and persistent (>7 days) or recurrent bacteremia (29% each). Thirty- and 90-day mortality was 18% and 47%, respectively. Patients who were cured received at least one active antimicrobial agent and underwent source control interventions. Forty-one percent (7/17) of patients had intra-abdominal infections; all except one developed persistent/recurrent bacteremia despite drainage. Two patients tolerated persistent bacteremia for >300 days. All patients except one were infected with sequence type 258 (ST258), K. pneumoniae carbapenemase (KPC)-2-producing strains harboring a mutant ompK35 porin gene; the exception was infected with an ST37, KPC-3-producing strain. Seventy-one percent (12/17) of patients were infected with ST258 ompK36 mutant strains. In two patients, persistent bacteremia was caused by two strains with different ompK36 genotypes. Three ompK36 mutations were associated with significantly higher carbapenem minimum inhibitory concentrations than wild-type ompK36. Pulse-field gel electrophoresis identified a single ST258 lineage; serial strains from individual patients were indistinguishable. In conclusion, KPC-K. pneumoniae bacteremia exhibited highly diverse clinical courses following transplantation, and was caused by clonal ST258 strains with different ompK36 genotypes.

Improved luminosity determination in pp collisions at [Formula: see text] using the ATLAS detector at the LHC

The luminosity calibration for the ATLAS detector at the LHC during pp collisions at [Formula: see text] in 2010 and 2011 is presented. Evaluation of the luminosity scale is performed using several luminosity-sensitive detectors, and comparisons are made of the long-term stability and accuracy of this calibration applied to the pp collisions at [Formula: see text]. A luminosity uncertainty of [Formula: see text] is obtained for the 47 pb-1 of data delivered to ATLAS in 2010, and an uncertainty of [Formula: see text] is obtained for the 5.5 fb-1 delivered in 2011.

Measurement of the inclusive jet cross-section in pp collisions at [Formula: see text] and comparison to the inclusive jet cross-section at [Formula: see text] using the ATLAS detector

The inclusive jet cross-section has been measured in proton-proton collisions at [Formula: see text] in a dataset corresponding to an integrated luminosity of [Formula: see text] collected with the ATLAS detector at the Large Hadron Collider in 2011. Jets are identified using the anti-kt algorithm with two radius parameters of 0.4 and 0.6. The inclusive jet double-differential cross-section is presented as a function of the jet transverse momentum pT and jet rapidity y, covering a range of 20≤pT<430 GeV and |y|<4.4. The ratio of the cross-section to the inclusive jet cross-section measurement at [Formula: see text], published by the ATLAS Collaboration, is calculated as a function of both transverse momentum and the dimensionless quantity [Formula: see text], in bins of jet rapidity. The systematic uncertainties on the ratios are significantly reduced due to the cancellation of correlated uncertainties in the two measurements. Results are compared to the prediction from next-to-leading order perturbative QCD calculations corrected for non-perturbative effects, and next-to-leading order Monte Carlo simulation. Furthermore, the ATLAS jet cross-section measurements at [Formula: see text] and [Formula: see text] are analysed within a framework of next-to-leading order perturbative QCD calculations to determine parton distribution functions of the proton, taking into account the correlations between the measurements.

Search for a light charged Higgs boson in the decay channel [Formula: see text] in [Formula: see text] events using pp collisions at [Formula: see text] with the ATLAS detector

A search for a charged Higgs boson (H+) in [Formula: see text] decays is presented, where one of the top quarks decays via t→H+b, followed by H+→ two jets ([Formula: see text]). The other top quark decays to Wb, where the W boson then decays into a lepton (e/μ) and a neutrino. The data were recorded in pp collisions at [Formula: see text] by the ATLAS detector at the LHC in 2011, and correspond to an integrated luminosity of 4.7 fb-1. With no observation of a signal, 95 % confidence level (CL) upper limits are set on the decay branching ratio of top quarks to charged Higgs bosons varying between 5 % and 1 % for H+ masses between 90 GeV and 150 GeV, assuming [Formula: see text].

A robust route to enzymatically functional, hierarchically self-assembled peptide frameworks

The addition of enzyme biofunctionality to self-assembling peptide nanofibers is challenging since such additions can inhibit functionality or self-assembly. We introduce a method for peptide nanofiber enzyme functionalization, demonstrated by the attachment of a polymerization synthase to peptide nanofibers. The enzyme generates a biocompatible, biodegradable biopolyester coat on the fibers with applicablity in medical engineering. This approach provides a template for generation of functional bionanomaterials.