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DOE OSTI2014

MAVTgsa: An R Package for Gene Set (Enrichment) Analysis

Gene set analysis methods aim to determine whether an a priori defined set of genes shows statistically significant difference in expression on either categorical or continuous outcomes. Although many methods for gene set analysis have been proposed, a systematic analysis tool for identification of different types of gene set significance modules has not been developed previously. This work presents an R package, called MAVTgsa, which includes three different methods for integrated gene set enrichment analysis. (1) The one-sided OLS (ordinary least squares) test detects coordinated changes of genes in gene set in one direction, either up- or downregulation. (2) The two-sided MANOVA (multivariate analysis variance) detects changes both up- and downregulation for studying two or more experimental conditions. (3) A random forests-based procedure is to identify gene sets that can accurately predict samples from different experimental conditions or are associated with the continuous phenotypes. MAVTgsa computes the P values and FDR (false discovery rate) q -value for all gene sets in the study. Furthermore, MAVTgsa provides several visualization outputs to support and interpret the enrichment results. This package is available online.

Chien, Chih-Yi↗

DOE OSTI2022

Prognostic importance of the preoperative New‐Naples prognostic score for patients with gastric cancer

Abstract Background The wide applicability of the Naples prognostic score (NPS) is still worthy of further study in gastric cancer (GC). This study aimed to construct a New‐NPS based on the differences in immunity and nutrition in patients with upper and lower gastrointestinal tumors to help obtain an individualized prediction of prognosis. Methods This study retrospectively analyzed patients who underwent radical gastrectomy from April 2014 to September 2016. The cutoff values of the preoperative neutrophil‐to‐lymphocyte ratio (NLR), lymphocyte‐to‐monocyte ratio (LMR), serum albumin (Alb), and total cholesterol (TC) were calculated by ROC curve analysis. ROC and t‐ROC were used to evaluate the accuracy of the prognostic markers. The Kaplan–Meier method and log‐rank test were used to analyze the overall survival probability. Univariate and multivariate analyses based on Cox risk regression were used to show the independent predictors. The nomogram was made by R studio. The predictive accuracy of nomogram was assessed using a calibration plot, concordance index (C‐index), and decision curve. Results A total of 737 patients were included in training cohort, 411 patients were included in validation cohort. ROC showed that the New‐NPS was more suitable for predicting the prognosis of GC patients. NPS = 2 indicated a poor prognosis. Multivariate analysis showed that CEA ( P = 0.026), Borrmann type ( P = 0.001), pTNM ( P < 0.001), New‐NPS ( P < 0.001), and nerve infiltration ( P = 0.035) were independent risk factors for prognosis. Conclusion The New‐NPS based on the cutoff values of NLR, LMR, Alb, and TC is not only suitable for predicting prognosis but can also be combined with clinicopathological characteristics to construct a nomogram model for GC patients.

Wang, Hao↗

DOE OSTI2018

Multivariate network traffic analysis using clustered patterns

Traffic analysis is a core element in network operations and management for various purposes including change detection, traffic prediction, and anomaly detection. In this paper, we introduce a new approach to online traffic analysis based on a pattern-based representation for high-level summarization of the traffic measurement data. Unlike the past online analysis techniques limited to a single variable to summarize (e.g., sketch), the focus of this study is on capturing the network state from the multivariate attributes under consideration. To this end, we employ clustering with its benefit of the aggregation of multidimensional variables. The clustered result represents the state of the network with regard to the monitored variables, which can also be compared with the observed patterns from previous time windows enabling intuitive analysis. Finally, we demonstrate the proposed method with two popular use cases, one for estimating state changes and the other for identifying anomalous states, to confirm its feasibility. Our extensive experimental results with public traces and collected monitoring measurements from ESnet traffic traces show that our pattern-based approach is effective for multivariate analysis of online network traffic with visual and quantitative tools.

97 MATHEMATICS AND COMPUTING↗

DOE OSTI2015

Peeking Network States with Clustered Patterns

Network traffic monitoring has long been a core element for effec- tive network management and security. However, it is still a chal- lenging task with a high degree of complexity for comprehensive analysis when considering multiple variables and ever-increasing traffic volumes to monitor. For example, one of the widely con- sidered approaches is to scrutinize probabilistic distributions, but it poses a scalability concern and multivariate analysis is not gen- erally supported due to the exponential increase of the complexity. In this work, we propose a novel method for network traffic moni- toring based on clustering, one of the powerful deep-learning tech- niques. We show that the new approach enables us to recognize clustered results as patterns representing the network states, which can then be utilized to evaluate “similarity” of network states over time. In addition, we define a new quantitative measure for the similarity between two compared network states observed in dif- ferent time windows, as a supportive means for intuitive analysis. Finally, we demonstrate the clustering-based network monitoring with public traffic traces, and show that the proposed approach us- ing the clustering method has a great opportunity for feasible, cost- effective network monitoring.

97 MATHEMATICS AND COMPUTING↗

DOE OSTI2013

SEARCH FOR THE STANDARD MODEL HIGGS BOSON IN ITS ASSOCIATED PRODUCTION WITH A W VECTOR BOSON IN pp COLLISIONS AT p s = 1:96TEV

In this dissertation, results from a search for the Standard Model (SM) Higgs boson is shown. The SM is the theoretical framework which describes particles of matter and force carrier gauge bosons. To solve the mass problem in the SM, the Higgs mechanism was introduced in 1963. The Higgs mechanism causes an electroweak symmetry breaking and a new massive scalar boson was postulated. This particle is the Higgs boson. A search for the Higgs boson has been ongoing at the Tevatron where protons and antiprotons were allowed to collide at a center-of-mass energy of 1:96 TeV. For a low mass Higgs, that is a Higgs with a mass lower than 135 GeV, the dominant decay mode is Higgs to a pair of b-quarks (H ! bb ). This work concentrated on a Higgs whose mass is in the range of 100 150 GeV, with a W vector boson produced with the Higgs boson. The final state chosen is the one which contains a lepton a neutrino and a pair of b-quarks. This study used data provided by the DZERO experiment. Results presented here are the outcome of analyzing 5:3 fb􀀀1 of data from RunII period. The analysis used different techniques to increase the sensitivity of the study. Data were subdivided based on lepton flavor, number of jets in sample, jets identified as b-jets and dates of collected data. A multivariate analysis technique based on boosted decision trees were used to separate signal from background processes, physical and instrumental. A good agreement between data and simulated events was observed. An observed (expected) upper limit of 4:5 (4:8) for a Higgs of mass 115 GeV was set on the ratio of the Higgs production to its decay branching ratio at the 95% confidence level.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

DOE OSTI2015

Relationship Between Radiation Therapy Dose and Outcome in Patients Treated With Neoadjuvant Chemoradiation Therapy and Surgery for Stage IIIA Non-Small Cell Lung Cancer: A Population-Based, Comparative Effectiveness Analysis

Purpose: To compare, using the National Cancer Database, survival, pathologic, and surgical outcomes in patients with stage IIIA non-small cell lung cancer treated with differential doses of neoadjuvant chemoradiation therapy, with the aim to discern whether radiation dose escalation was associated with a comparative effectiveness benefit and/or toxicity risk. Methods and Materials: Patients in the National Cancer Database with stage IIIA non-small cell lung cancer treated with neoadjuvant chemoradiation therapy and surgery between 1998 and 2005 were analyzed. Dose strata were divided between 36 to 45 Gy (low-dose radiation therapy, LD-RT), 45 to 54 Gy (inclusive, standard-dose, SD-RT), and 54 to 74 Gy (high-dose, HD-RT). Outcomes included overall survival, residual nodal disease, positive surgical margin status, hospital length of stay, and adverse surgical outcomes (30-day mortality or readmission). Results: The cohort consisted of 1041 patients: 233 (22%) LD-RT, 584 (56%) SD-RT, and 230 (22%) HD-RT. The median, 3-year, and 5-year overall survival outcomes were 34.9 months, 48%, and 37%, respectively. On univariable analysis, patients treated with SD-RT experienced prolonged overall survival (median 38.3 vs 31.8 vs 29.0 months for SD-RT, LD-RT, and HD-RT, respectively, P=.0089), which was confirmed on multivariable analysis (hazard ratios 0.77 and 0.81 vs LD and HD, respectively). Residual nodal disease was seen less often after HD-RT (25.5% vs 31.8% and 37.5% for HD-RT, LD-RT, and SD-RT, respectively, P=.0038). Patients treated with SD-RT had fewer prolonged hospital stays. There were no differences in positive surgical margin status or adverse surgical outcomes between the cohorts. Conclusions: Neoadjuvant chemoradiation therapy between 45 and 54 Gy was associated with superior survival in comparison with doses above and below this threshold. Although this conclusion is limited by selection bias, clear candidates for trimodality therapy do not seem to achieve additional benefit with dose escalation.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

DOE OSTI2016

The Impact of Radiation Treatment Time on Survival in Patients With Head and Neck Cancer

Purpose: To assess the impact of radiation treatment time (RTT) in head and neck cancers on overall survival (OS) in the era of chemoradiation. Methods and Materials: Patients with diagnoses of tongue, hypopharynx, larynx, oropharynx, or tonsil cancer were identified by use of the National Cancer Database. RTT was defined as date of first radiation treatment to date of last radiation treatment. In the definitive setting, prolonged RTT was defined as >56 days, accelerated RTT was defined as <47 days, and standard RTT was defined as 47 to 56 days. In the postoperative setting, prolonged RTT was defined as >49 days, accelerated RTT was defined as <40 days, and standard RTT was defined as 40 to 49 days. We used χ{sup 2} tests to identify predictors of RTT. The Kaplan-Meier method was used to compare OS among groups. Cox proportional hazards model was used for OS analysis in patients with known comorbidity status. Results: 19,531 patients were included; 12,987 (67%) had a standard RTT, 4,369 (34%) had an accelerated RTT, and 2,165 (11%) had a prolonged RTT. On multivariable analysis, accelerated RTT (hazard ratio [HR] 0.84; 95% confidence interval [CI] 0.73-0.97) was associated with an improved OS, and prolonged RTT (HR 1.25; 95% CI 1.14-1.37) was associated with a worse OS relative to standard RTT. When the 9,200 (47%) patients receiving definitive concurrent chemoradiation were examined, prolonged RTT (HR 1.29; 95% CI 1.11-1.50) was associated with a worse OS relative to standard RTT, whereas there was no significant association between accelerated RTT and OS (HR 0.76; 95% CI 0.57-1.01). Conclusion: Prolonged RTT is associated with worse OS in patients receiving radiation therapy for head and neck cancer, even in the setting of chemoradiation. Expeditious completion of radiation should continue to be a quality metric for the management of head and neck malignancies.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

DOE OSTI2015

Non-Rhabdomyosarcoma Soft Tissue Sarcomas in Children: A Surveillance, Epidemiology, and End Results Analysis Validating COG Risk Stratifications

Purpose: Non-rhabdomyosarcoma soft tissue sarcomas (NRSTS) are a heterogeneous group of sarcomas that encompass over 35 histologies. With an incidence of ∼500 cases per year in the United States in those <20 years of age, NRSTS are rare and therefore difficult to study in pediatric populations. We used the large Surveillance, Epidemiology, and End Results (SEER) database to validate the prognostic ability of the Children's Oncology Group (COG) risk classification system and to define patient, tumor, and treatment characteristics. Methods and Materials: From SEER data from 1988 to 2007, we identified patients ≤18 years of age with NRSTS. Data for age, sex, year of diagnosis, race, registry, histology, grade, primary size, primary site, stage, radiation therapy, and survival outcomes were analyzed. Patients with nonmetastatic grossly resected low-grade tumors of any size or high-grade tumors ≤5 cm were considered low risk. Cases of nonmetastatic tumors that were high grade, >5 cm, or unresectable were considered intermediate risk. Patients with nodal or distant metastases were considered high risk. Results: A total of 941 patients met the review criteria. On univariate analysis, black race, malignant peripheral nerve sheath (MPNST) histology, tumors >5 cm, nonextremity primary, lymph node involvement, radiation therapy, and higher risk group were associated with significantly worse overall survival (OS) and cancer-specific survival (CSS). On multivariate analysis, MPNST histology, chemotherapy-resistant histology, and higher risk group were significantly poor prognostic factors for OS and CSS. Compared to low-risk patients, intermediate patients showed poorer OS (hazard ratio [HR]: 6.08, 95% confidence interval [CI]: 3.53-10.47, P<.001) and CSS (HR: 6.27; 95% CI: 3.44-11.43, P<.001), and high-risk patients had the worst OS (HR: 13.35, 95% CI: 8.18-21.76, P<.001) and CSS (HR: 14.65, 95% CI: 8.49-25.28, P<.001). Conclusions: The current COG risk group stratification for children with NRSTS has been validated with a large number of children in the SEER database.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

DOE OSTI2019

Tumor Volume Is Better Than Diameter for Predicting the Prognosis of Patients with Early-Stage Non-small Cell Lung Cancer

Background: This study aimed to investigate whether tumor volume (TV) is better than diameter for predicting the prognosis of patients with early-stage non-small cell lung cancer (NSCLC) after complete resection. Methods: This study retrospectively reviewed the clinicopathologic characteristics of 274 patients with early-stage NSCLC who had received pretreatment computed tomography (CT) scans and complete resection. TV was semi-automatically measured from CT scans using an imaging software program. The optimal cutoff of TV was determined by X-tile software. Disease-free survival (DFS) and overall survival (OS) were assessed by the Kaplan–Meier method. The prognostic significance of TV and other variables was assessed by Cox proportional hazards regression analysis. Results: Using 3.046 cm{sup 3} and 8.078 cm{sup 3} as optimal cutoff values of TV, the patients were separated into three groups. A larger TV was significantly associated with poor DFS and OS in the multivariable analysis. Kaplan–Meier curves of DFS and OS showed significant differences on the basis of TV among patients with stage 1a disease, greatest tumor diameter (GTD) of 2 cm or smaller, and GTD of 2–3 cm, respectively. Using two TV cutoff points, three categories of TV were created. In 54 cases (19.7%), patients migrated from the GTD categories of 2 cm or smaller, 2–3 cm, and larger than 3 cm into the TV categories of 3.046 cm{sup 3} or smaller, 3.046–8.078 cm{sup 3}, and larger than 8.078 cm{sup 3}. Conclusion: TV is an independent prognostic factor of DFS and OS for early-stage NSCLC. The findings show that TV is better than GTD for predicting the prognosis of patients with early-stage NSCLC.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

DOE OSTI2014

Study of Orbitally Excited $B_{(s)}$ Mesons and Evidence for a New $B\pi$ Resonance with the CDF II Detector

This thesis presents an analysis of excited states of B0, B+ and B0 s mesons, decaying to B mesons while emitting a pion or kaon. They are reconstructed from their decay products and a selection is performed to discard wrongly reconstructed B(s) mesons with the multivariate analysis software NeuroBayes, as described in chapter 5. In the training process, the sPlot method and measured and simulated data are used. Chapter 6 describes how the properties of excited B(s) are determined by an unbinned maximum likelihood t to their mass spectra. The systematic uncertainties determined in this analysis are described in chapter 7. The results of this thesis are presented in chapter 8 and a conclusion is given in chapter 9. The results shown in this thesis have been published before in [1].

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

DOE OSTI2015

Increasing Radiation Therapy Dose Is Associated With Improved Survival in Patients Undergoing Stereotactic Body Radiation Therapy for Stage I Non–Small-Cell Lung Cancer

Purpose: To determine the comparative effectiveness of different stereotactic body radiation therapy (SBRT) dosing regimens for early-stage non–small-cell lung cancer, using a large national database, focusing on the relative impact of dose as a function of tumor stage. Methods and Materials: The study included patients in the National Cancer Database from 2003 to 2006 with T1-T2N0M0 inoperable lung cancer (n=498). The biologically effective dose (BED) was calculated according to the linear quadratic formula using an α/β ratio of 10. High versus lower-dose (HD vs LD) SBRT was defined as a calculated BED above or below 150 Gy. Overall survival was estimated using Kaplan-Meier methods and Cox proportional hazard regression. Results: The 5 most common dose fractionation schemes (percentage of cohort) used were 20 Gy × 3 (34%), 12 Gy × 4 (16%), 18 Gy × 3 (10%), 15 Gy × 3 (10%), and 16 Gy × 3 (4%). The median calculated BED was 150 Gy (interquartile range 106-166 Gy). The 3-year overall survival (OS) for patients who received HD versus LD was 55% versus 46% (log–rank P=.03). On subset analysis of the T1 cohort there was no association between calculated BED and 3-year OS (61% vs 60% with HD vs LD, P=.9). Among the T2 cohort, patients receiving HD experienced superior 3-year OS (37% vs 24%, P=.01). On multivariable analysis, factors independently prognostic for mortality were female gender (hazard ratio [HR] 0.76, P=.01), T2 tumor (HR 1.99, P=.0001), and HD (HR 0.68, P=.001). Conclusions: This comparative effectiveness analysis of SBRT dose for patients with stage I non–small-cell lung cancer suggests that higher doses (>150 Gy BED) are associated with a significant survival benefit in patients with T2 tumors.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

DOE OSTI2016

Static and Dynamical Structural Investigations of Metal-Oxide Nanocrystals by Powder X-ray Diffraction: Colloidal Tungsten Oxide as a Case Study

N/A

Caliandro, Rocco↗

DOE OSTI2011

Chemotherapy response and recurrence-free survival in neoadjuvant breast cancer depends on biomarker profiles: results from the I-SPY 1 TRIAL (CALGB 150007/150012; ACRIN 6657)

Neoadjuvant chemotherapy for breast cancer allows individual tumor response to be assessed depending on molecular subtype, and to judge the impact of response to therapy on recurrence-free survival (RFS). The multicenter I-SPY 1 TRIAL evaluated patients with C3 cm tumors by using early imaging and molecular signatures, with outcomes of pathologic complete response (pCR) and RFS. The current analysis was performed using data from patients who had molecular profiles and did not receive trastuzumab. The various molecular classifiers tested were highly correlated. Categorization of breast cancer by molecular signatures enhanced the ability of pCR to predict improvement in RFS compared to the population as a whole. In multivariate analysis, the molecular signatures that added to the ability of HR and HER2 receptors, clinical stage, and pCR in predicting RFS included 70-gene signature, wound healing signature, p53 mutation signature, and PAM50 risk of recurrence. The low risk signatures were associated with significantly better prognosis, and also identified additional patients with a good prognosis within the no pCR group, primarily in the hormone receptor positive, HER-2 negative subgroup. The I-SPY 1 population is enriched for tumors with a poor prognosis but is still heterogeneous in terms of rates of pCR and RFS. The ability of pCR to predict RFS is better by subset than it is for the whole group. Molecular markers improve prediction of RFS by identifying additional patients with excellent prognosis within the no pCR group.

59 BASIC BIOLOGICAL SCIENCES↗

DOE OSTI2016

Salivary Cytokine Levels and Oral Mucositis in Head and Neck Cancer Patients Treated With Chemotherapy and Radiation Therapy

Purpose: We assessed the presence of salivary cytokines, their modulation during chemoradiation therapy (CTRT), and their association with oral mucositis severity in patients with head and neck cancer (HNC). Methods and Materials: The present prospective observational study enrolled 55 patients with locally advanced HNC requiring CTRT. We also studied 10 healthy volunteers and 10 patients with other cancers. The salivary levels of 13 cytokines were analyzed. We constructed a cytokine predictive score of oral mucositis severity. Results: The baseline salivary cytokine levels were not associated with the severity of treatment-induced oral mucositis. The cytokine levels overall increased during treatment, especially in patients with worse mucositis. In particular, on univariable analysis, an increase of interleukin (IL)-1β (area under the curve [AUC] 0.733; P=.009), IL-6 (AUC 0.746; P=.005), and tumor necrosis factor-α (AUC 0.710; P=.005) at the third week of treatment was significantly associated with the development of severe oral mucositis. On multivariable analysis, the predictive score based on the IL-1β and IL-6 changes from baseline to week 3 was an early strong predictor of higher grade oral mucositis. Conclusions: The treatment of HNC patients with concurrent CTRT induces a significant increase in the salivary levels of IL-1β, IL-6, and tumor necrosis factor-α, all positively associated with the severity of mucosal toxicity. A greater increase of IL-1β and IL-6 3 weeks after treatment initiation is predictive of worse oral mucositis, representing a potential tool for the early identification of patients at risk.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

DOE OSTI2017

Analysis of charcoal blast furnace slags by laser-induced breakdown spectroscopy

Laser-induced breakdown spectroscopy (LIBS) was used for the analysis of charcoal blast furnace slags. Plasma was generated by an application of a 1064 nm wavelength Nd:YAG laser beam to the surface of pellets created from the slags. The presence of Al, Ca, Fe, K, Mg, Mn, and Si was determined by identifying their characteristic spectral signatures. Multivariate analysis was performed for the quantification of these elements. The predicted LIBS results were found in agreement with the inductively coupled plasma optical emission spectrometry analysis. The limit of detection for Al, Ca, Fe, K, Mg, Mn, and Si was calculated to be 0.10%, 0.22%, 0.02%, 0.01%, 0.01%, 0.005%, and 0.18%, respectively.

36 MATERIALS SCIENCE↗

DOE OSTI2014

Integrated Analyses of Multiple Worldwide Aerosol Mass Spectrometer Datasets for Improved Understanding of Aerosol Sources and Processes and for Comparison with Global Models

The AMS is the only current instrument that provides real-time, quantitative, and size-resolved data on submicron non-refractory aerosol species with a time resolution of a few minutes or better. The AMS field data are multidimensional and massive, containing extremely rich information on aerosol chemistry, microphysics and dynamics—basic information that is required to evaluate and quantify the radiative climate forcing of atmospheric aerosols. The high time resolution of the AMS data also reveals details of aerosol dynamic variations that are vital to understanding the physico-chemical processes of atmospheric aerosols that govern aerosol properties relevant to the climate. There are two primary objectives of this 3-year project. Our first objective is to perform highly integrated analysis of dozens of AMS datasets acquired from various urban, forested, coastal, marine, mountain peak, and rural/remote locations around the world and synthesize and inter-compare results with a focus on the sources and the physico-chemical processes that govern aerosol properties relevant to aerosol climate forcing. Our second objective is to support our collaboration with global aerosol modelers, in which we will supply the size-resolved aerosol composition and temporal variation data (via a public web interface) and our analysis results for use in model testing and validation and for translation of the rich AMS database into model constraints that can improve climate forcing simulations. Several prominent global aerosol modelers have expressed enthusiastic support for this collaboration. The specific tasks that we propose to accomplish include 1) to develop, validate, and apply multivariate analysis techniques for improved characterization and source apportionment of organic aerosols; 2) to evaluate aerosol source regions and relative contributions based on back-trajectory integration (PSCF method); 3) to summarize and synthesize submicron aerosol information, including composition, concentration, size distribution and (inferred) shape and mixing state in various environments and their regional and seasonal variations within the context of regional and global modeling; and 4) to quantitatively evaluate important processes in various atmospheric environments and during different seasons, focusing on acid-catalyzed SOA formation, new particle growth, and photochemical processes of atmospheric organic aerosols (i.e., SOA production and POA oxidation). We will also examine the correlations and compile the ratios between important pairs of aerosol and gas phase species using region-specific and season-specific correlations and as a function of photochemical age and compare them with the ratios produced by various models. To enable our collaborations with the modelers, we will supply (via a public web interface) AMS data and our analysis results for use in model testing and validation and facilitate the use of the AMS information to constrain calculations of radiative forcing. Model output and AMS measurements and derived parameters will be compared with a focus on regional variability of model/measurement discrepancies and their causes. Finally we will share results, insights and data mining algorithms through peer-reviewed publications, presentations/tutorials at conferences/workshops, and web dissemination of analysis results and in-house developed software packages.

58 GEOSCIENCES↗

DOE OSTI2016

Correlation Between the Severity of Cetuximab-Induced Skin Rash and Clinical Outcome for Head and Neck Cancer Patients: The RTOG Experience

Purpose: To evaluate the severity of cetuximab-induced skin rash and its correlation with clinical outcome and late skin toxicity in patients with head and neck squamous cell carcinoma treated with chemoradiation therapy and cetuximab. Methods and Materials: Analysis included patients who received loading dose and ≥1 cetuximab dose concurrent with definitive chemoradiation therapy (70 Gy + cisplatin) or postoperative chemoradiation therapy (60-66 Gy + docetaxel or cisplatin). Results: Six hundred two patients were analyzed; 383 (63.6%) developed grade 2 to 4 cetuximab rash. Patients manifesting grade 2 to 4 rash had younger age (P<.001), fewer pack-years smoking history (P<.001), were more likely to be males (P=.04), and had p16-negative (P=.04) oropharyngeal tumors (P=.003). In univariate analysis, grade 2 to 4 rash was associated with better overall survival (hazard ratio [HR] 0.58, P<.001) and progression-free survival (HR 0.75, P=.02), and reduced distant metastasis rate (HR 0.61, P=.03), but not local-regional failure (HR 0.79, P=.16) relative to grade 0 to 1 rash. In multivariable analysis, HRs for overall survival, progression-free survival, distant metastasis, and local-regional failure were, respectively, 0.68 (P=.008), 0.85 (P=.21), 0.64 (P=.06), and 0.89 (P=.48). Grade ≥2 rash was associated with improved survival in p16-negative patients (HR 0.28 [95% confidence interval 0.11-0.74]) but not in p16-positive patients (HR 1.10 [0.42-2.89]) (P=.05 for interaction). Twenty-five percent of patients with grade 2 to 4 acute in-field radiation dermatitis experienced grade 2 to 4 late skin fibrosis, versus 14% of patients with grade 0 to 1 acute in-field radiation dermatitis (P=.002). Conclusion: Grade 2 to 4 cetuximab rash was associated with better survival, possibly due to reduction of distant metastasis. This observation was noted mainly in p16-negative patients. Grade 2 to 4 acute in-field radiation dermatitis was associated with higher rate of late grade 2 to 4 skin fibrosis.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

DOE OSTI2020

Combined Plasmonic Au-nanoparticle and Conducting Metal Oxide High-temperature Optical Sensing with LSTO

<span style="color: rgba(0, 0, 0, 0.79); font-family: "Source Sans Pro", source-sans-pro, museo_sans300, museo-sans, Arial, sans-serif; font-size: 16px; background-color: rgb(255, 255, 255);">Fiber optic sensor technology offers several advantages for harsh-environment applications. However, the development of optical gas sensing layers that are stable under harsh environmental conditions is an ongoing research challenge. In this work, electronically conducting metal oxide lanthanum-doped strontium titanate (LSTO) films embedded with gold nanoparticles are examined as a sensing layer for application in reducing gas flows at high temperature (600–800 °C). A strong localized surface plasmon resonance (LSPR) based response to hydrogen is demonstrated in the visible region of the spectrum, while a Drude free electron-based response is observed in the near-IR. Characteristics of these responses are studied both on planar glass substrates and on silica fibers. Charge transfer between the oxide film and the gold nanoparticles is explored as a possible mechanism governing the Au LSPR response and is considered in terms of the corresponding properties of the conducting metal oxide-based matrix phase. Principal component analysis is applied to the combined plasmonic and free-carrier based response over a range of temperatures and hydrogen concentrations. It is demonstrated that the combined visible and near-IR response of these films provides improved versatility for multiwavelength interrogation, as well as improved discrimination of important process parameters (concentration and temperature) through application of multivariate analysis techniques.</span>

Wuenschell, Jeffrey K.↗