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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 1,009 records · Page 56
All sourcesNASA NTRSDOE OSTI
DOE OSTI2016

PET/MRI of Hepatic 90Y Microsphere Deposition Determines Individual Tumor Response

PurposeThe purpose of our study is to determine if there is a relationship between dose deposition measured by PET/MRI and individual lesion response to yttrium-90 ({sup 90}Y) microsphere radioembolization.Materials and Methods26 patients undergoing lobar treatment with {sup 90}Y microspheres underwent PET/MRI within 66 h of treatment and had follow-up imaging available. Adequate visualization of tumor was available in 24 patients, and contours were drawn on simultaneously acquired PET/MRI data. Dose volume histograms (DVHs) were extracted from dose maps, which were generated using a voxelized dose kernel. Similar contours to capture dimensional and volumetric change of tumors were drawn on follow-up imaging. Response was analyzed using both RECIST and volumetric RECIST (vRECIST) criteria.ResultsA total of 8 hepatocellular carcinoma (HCC), 4 neuroendocrine tumor (NET), 9 colorectal metastases (CRC) patients, and 3 patients with other metastatic disease met inclusion criteria. Average dose was useful in predicting response between responders and non-responders for all lesion types and for CRC lesions alone using both response criteria (p < 0.05). D70 (minimum dose to 70 % of volume) was also useful in predicting response when using vRECIST. No significant trend was seen in the other tumor types. For CRC lesions, an average dose of 29.8 Gy offered 76.9 % sensitivity and 75.9 % specificity for response.ConclusionsPET/MRI of {sup 90}Y microsphere distribution showed significantly higher DVH values for responders than non-responders in patients with CRC. DVH analysis of {sup 90}Y microsphere distribution following treatment may be an important predictor of response and could be used to guide future adaptive therapy trials.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2016

Lung Shunt Fraction prior to Yttrium-90 Radioembolization Predicts Survival in Patients with Neuroendocrine Liver Metastases: Single-Center Prospective Analysis

ObjectiveTo investigate survival outcomes following radioembolization with Yttrium-90 (Y90) for neuroendocrine tumor liver metastases (NETLMs). This study was designed to assess the efficacy of Y90 radioembolization and to evaluate lung shunt fraction (LSF) as a predictor for survival.MethodsA single-center, prospective study of 44 consecutive patients (median age: 58.5 years, 29.5 % male) diagnosed with pancreatic (52.3 %) or carcinoid (47.7 %) NETLMs from 2006 to 2012 who underwent Y90 radioembolization was performed. Patients’ baseline characteristics, including LSF and median overall survival (OS) from first Y90 radioembolization, were recorded and compared between patients with high (≥10 %) and low (<10 %) LSF. Baseline comparisons were performed using Fisher’s exact tests for categorical and Mann–Whitney U test for continuous variables. Survival was calculated using the Kaplan–Meier method. Univariate (Wilcoxon rank-sum test) and multivariate analyses (Cox Proportional Hazard Model) for risk factor analysis were performed.ResultsThere was no statistically significant difference in age, gender, race, tumor properties, or previous treatments between patients with high (n = 15) and low (n = 29) LSF. The median OS was 27.4 months (95 %CI 12.73–55.23), with 4.77 months (95 %CI 2.87–26.73) for high and 42.77 months (95 %CI 18.47–59.73) for low LSF (p = 0.003). Multivariate analysis identified high LSF (p = 0.001), total serum bilirubin >1.2 mg (p = 0.016), and lack of pretreatment with octreotide (p = 0.01) as independent prognostic factors for poorer survival. Tumor type and total radiation dose did not predict survival.ConclusionsLSF ≥10 %, elevated bilirubin levels, and lack of pretreatment with octreotide were found to be independent prognostic factors for poorer survival in patients with NETLMs.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2016

Treatment Outcome Following Transarterial Chemoembolization in Advanced Bone and Soft Tissue Sarcomas

PurposeTransarterial chemoembolization (TACE) is used to treat unresectable bone and soft tissue sarcoma (STS) and as a pre-surgical adjuvant treatment. However, its efficiency for advanced STS is undetermined. This study evaluated TACE’s efficiency in treating advanced STS and prognostic factors for patient survival.Materials and MethodsWe enrolled 39 patients with unresectable STS who underwent TACE as an alternative treatment during 2010–2014, with overall survival (OS) as the primary end point. Cancer pain was evaluated by visual analogue scores (VAS) before and after TACE procedures. Factors that affect survival were evaluated by multivariate analyses (Cox proportional hazard model).ResultsMean OS after TACE was 23.7 ± 2.1 months, with 1-year OS 71.5 %, 2-year OS 45.8 %, and 3-year OS 32.5 %. Lesion number and tumor stage were key predictors of survival. TACE was found to decrease cancer pain VAS and increase relapse interval. Size of polyvinyl alcohol (PVA) particle diameter (P = 0.03) and imaging response (P = 0.044) were also found to affect relapse interval.ConclusionTACE was an effective treatment for advanced STS, with a 32.5 % 3-year OS rate, and led to lower cancer pain VAS and longer relapse intervals than chemoinfusion only. Smaller PVA particles are preferable during the TACE procedure.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2016

Percutaneous Radiofrequency Ablation Versus Robotic-Assisted Partial Nephrectomy for the Treatment of Small Renal Cell Carcinoma

IntroductionThe authors compared the oncologic outcomes of radiofrequency ablation (RFA) with robotic-assisted partial nephrectomy (RPN) for the treatment of T1 stage renal cell carcinoma (RCC).Materials and methodsThis was a retrospective data analysis of a high-volume single tertiary centre. Patients were treated with RFA or RPN following multidisciplinary decision making. Only histologically proven RCCs were included. Baseline demographics were collected, and PADUA scores of tumour features were calculated to standardize baseline anatomy. Peri-operative complications, kidney function and oncological outcomes were compared.ResultsSixty-three cases were included in each group. Baseline renal function was poorer in RFA, and 16/63 RFA patients had tumours in single kidneys compared to 1/63 RPN cases (p < 0.001). Length of stay was shorter in RFA (1 vs. 3 days, p < 0.0001). Post-procedure renal function decline at 30 days was significantly less in RFA [(−0.8) ± 9.6 vs. (−16.1) ± 19.5 mls/min/1.73 m{sup 2}; p < 0.0001]. More minor complications were recorded in RPN (10/63 vs. 4/63, p = 0.15), but local recurrence was numerically higher in RFA (6/63 vs. 1/63, p = 0.11). Disease-free survival (DFS) was not significantly different (adjusted HR = 0.6, 95 % Cl 0.1–3.7; p = 0.60). Increasing tumour size was an independent predictor of local recurrence (adjusted HR = 1.7; 95 % Cl 1.1–2.6 per cm; p = 0.02).ConclusionsBoth RPN and RFA offer very good oncological outcomes for the treatment of T1 RCC with low peri-operative morbidity and similar oncologic outcomes. RFA demonstrated fewer peri-operative complications and better preservation of renal function, whereas RPN had an insignificantly lower local recurrence rate. RFA should be offered alongside RPN for selected cases.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2017

Low Cerebral Blood Volume Identifies Poor Outcome in Stent Retriever Thrombectomy

BackgroundMechanical thrombectomy (MT) is an efficient treatment of acute stroke caused by large-vessel occlusion. We evaluated the factors predicting poor clinical outcome (3-month modified Rankin Scale, mRS >2) although MT performed with modern stent retrievers.MethodsWe prospectively collected the clinical and imaging data of 105 consecutive anterior circulation stroke patients who underwent MT after multimodal CT imaging. Patients with occlusion of the internal carotid artery and/or middle cerebral artery up to the M2 segment were included. We recorded baseline clinical, procedural and imaging variables, technical outcome, 24-h imaging outcome and the clinical outcome. Differences between the groups were studied with appropriate statistical tests and binary logistic regression analysis.ResultsLow cerebral blood volume Alberta stroke program early CT score (CBV-ASPECTS) was associated with poor clinical outcome (median 7 vs. 9, p = 0.01). Lower collateral score (CS) significantly predicted poor outcome in regression modelling with CS = 0 increasing the odds of poor outcome 4.4-fold compared to CS = 3 (95% CI 1.27–15.5, p = 0.02). Lower CBV-ASPECTS significantly predicted poor clinical outcome among those with moderate or severe stroke (OR 0.82, 95% CI 0.68–1, p = 0.05) or poor collateral circulation (CS 0–1, OR 0.66, 95% CI 0.48–0.90, p = 0.009) but not among those with mild strokes or good collaterals.ConclusionsCBV-ASPECTS estimating infarct core is a significant predictor of poor clinical outcome among anterior circulation stroke patients treated with MT, especially in the setting of poor collateral circulation and/or moderate or severe stroke.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2017

Yttrium-90 Radioembolization for Unresectable Combined Hepatocellular-Cholangiocarcinoma

PurposeCombined hepatocellular-cholangiocarcinoma (cHCC-CC) is a rare mixed cell type primary liver cancer with limited data to guide management. Transarterial radioembolization with yttrium-90 microspheres (RE) is an emerging treatment option for both hepatocellular carcinoma and intrahepatic cholangiocarcinoma. This study explored the safety and efficacy of RE for unresectable cHCC-CC.MethodsPatients with histopathologically confirmed cHCC-CC treated with RE were retrospectively evaluated. Clinical and biochemical toxicities were assessed using the Common Toxicity Criteria for Adverse Events v4.03. Radiological response was analyzed using the Response Criteria in Solid Tumors (RECIST) v1.1 and modified RECIST criteria. Survival times were calculated and prognostic variables identified.ResultsTen patients (median age 59 years; six men, four women) with unresectable cHCC-CC underwent 14 RE treatments with resin (n = 6 patients) or glass (n = 4 patients) microspheres. Clinical toxicities were limited to grade 1–2 fatigue, anorexia, nausea, or abdominal pain. No significant biochemical toxicities were observed. Median overall survivals from the first RE treatment and from initial diagnosis were 10.2 and 17.7 months, respectively. Six of seven patients with elevated tumor biomarker levels before RE showed decreased levels after treatment (median decrease of 72%, range 13–80%). Best hepatic radiological response was 60% partial response and 40% stable disease by modified RECIST, and 100% stable disease by RECIST v1.1. Poor performance status and the presence of macrovascular invasion were identified as predictors of reduced survival after RE.ConclusionRE appears to be a safe and promising treatment option for patients with unresectable cHCC-CC. Level of Evidence: Level 4.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2018

Which Criteria Applied in Multi-Phasic CT Can Predict Early Tumor Response in Patients with Hepatocellular Carcinoma Treated Using Conventional TACE: RECIST, mRECIST, EASL or qEASL?

PurposeOur study aimed to evaluate quantitative tumor response assessment (quantitative EASL-[qEASL]) on computed tomography (CT) images in patients with hepatocellular carcinoma (HCC) treated using conventional transarterial chemoembolization (cTACE), compared to existing 1-dimensional and 2-dimensional methods (RECIST, mRECIST, EASL).Materials and MethodsIn this IRB-approved, single-institution retrospective cohort study, 52 consecutive patients with intermediate-stage HCC were consecutively included. All patients underwent contrast-enhanced CT scan at baseline and 4 weeks after cTACE.ResultsMedian follow-up period was 13.5 months (range 1.2–54.1). RECIST, mRECIST and EASL identified progression in 2 (4%), 1 (2%) and 1 (2%) patients, respectively, whereas qEASL identified 10 (19%) patients. qEASL was the only tumor response method able to predict survival among different tumor response groups (P < 0.05), whereas RECIST, mRECIST and EASL did not (P > 0.05). Both EASL and qEASL were able to identify responders and non-responders and were predictive of survival (P < 0.05). Multivariate analysis showed that progression was an independent predictor of overall survival with hazard ratio of 1.9 (P = 0.025). Patients who demonstrated progression with qEASL had significantly shorter survival than those with non-progression (7.6 vs. 20.4 months, P = 0.012). Similar multivariate analysis using RECIST, mRECIST and EASL could not be performed because too few patients were categorized as progressive disease.ConclusionqEASL could be applied on CT images to assess tumor response following cTACE and is a more sensitive biomarker to predict survival and identify tumor progression than RECIST, mRECIST and EASL at an early time point.Level of EvidenceLevel 2a, retrospective cohort study.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2019

Outcomes After Transarterial Embolization of Neuroendocrine Tumor Liver Metastases Using Spherical Particles of Different Sizes

Purpose: To evaluate initial response and overall survival of neuroendocrine tumor (NET) liver metastases initially treated with transarterial embolization (TAE) using spherical particles of different sizes. Methods: A single-institution retrospective review was performed of 160 patients with NET liver metastases initially treated with TAE using < 100 µm (n = 77) or only ≥ 100 µm (n = 83) spherical particles. For each patient, we evaluated: initial response by mRECIST, time to progression, overall survival, complications, primary site, tumor grade and degree of differentiation, volume of liver disease, extrahepatic disease, NET-related symptoms, comorbidities, Child–Pugh score, performance status, lobar versus selective embolization, and arteriovenous shunting. Results: Initial response was higher for TAE using particles < 100 versus TAE using only particles ≥ 100 μm (64 vs 42%, p = 0.007). Multivariate logistic regression showed that use of particles < 100 μm and liver < 50% replaced with tumor were independent predictors of a better initial response rate. There was no difference in major or minor complications between the two particle size groups. Median overall survival after TAE was 55 months for well- to moderately differentiated NET and 13 months for poorly differentiated or undifferentiated NET. There was no significant difference in survival between TAE patients treated with < 100 versus only ≥ 100-μm particles. Conclusion: NET patients treated with TAE using particles < 100 μm had better initial response, but the same overall survival, compared to TAE using only particles ≥ 100 μm.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2018

Radioembolization Super Survivors: Extended Survival in Non-operative Hepatocellular Carcinoma

PurposeTo identify baseline characteristics and long-term prognostic factors in non-transplant patients with unresectable hepatocellular carcinoma (HCC) who had prolonged survival after treatment with yttrium-90 radioembolization (Y90).Materials and MethodsSixty-seven “Super Survivors” (defined as ≥ 3-year survival after Y90) were identified within our 1000-patient Y90 database (2003–2017). Baseline imaging and follow-up occurred at 1 month and every 3 months thereafter. Overall survival (OS) was calculated with Kaplan–Meier estimates with log-rank test in subgroups: Child–Pugh (CP) score, distribution of disease, portal vein thrombus (PVT), and technique (segmental vs lobar Y90).Results Median age 69.5 years (range 45–94 years); 69% male; 60% solitary HCC; 79% unilobar disease; 12% PVT; 10% ascites; Barcelona Clinic Liver Cancer Stage A—54%/B—28%/C—16%/D—2%; CP A—70%/B—28%/C—2%. Longest baseline tumor diameter was 5.4 ± 4.0 cm (mean ± SD). All patients had an imaging response (either partial or complete response). Median OS was 67.5 months (95% CI 55.2–82.5). CP score and main PVT stratified median OS (p = 0.0007 and p = 0.0187, respectively). Beyond 3 years, segmental versus lobar Y90 was associated with improved OS with a median OS of 80.2 versus 46.7 months, respectively (p = 0.0024). Dosing > 200 Gy was not a significant predictor of improved OS.ConclusionsSuper Survivors spanning the BCLC staging system maintained durable OS after radioembolization that was stratified by the extent of underlying liver disease. The common variable among all patients was an imaging response. Segmental versus lobar Y90 may have a long-term associated OS benefit.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2019

Factors Associated with Secondary Functional Patency After Percutaneous Transluminal Angioplasty of the Early Failing or Immature Hemodialysis Arteriovenous Fistula

Purpose: To evaluate the efficacy of percutaneous transluminal angioplasty for early failing hemodialysis arteriovenous fistulas (AVFs) and predictors of secondary functional patency (FP). Methods: A review of our endovascular registry database showed that 61 patients with early failure after a surgically created AVF underwent endovascular intervention between 2011 and 2016. Median time from AVF creation to first intervention was 5.6 weeks. Median duration of follow-up was 14 months. Items related to the technical success rate and primary and secondary FP, and factors associated with secondary FP were analyzed. Results: Technical success was achieved in 55 (90%) of 61 patients. The primary and secondary FP rates were 42% and 65% at 12 months, respectively. Multivariate analysis showed that lesion length (HR; 1.15, P = 0.001) and lesions including juxta-AVF (the portion of fistula vein within 2 cm of the arteriovenous anastomosis, HR; 6.23, P = 0.008) were factors associated with reduced secondary FP. ROC curve analysis indicated lesion length with cutoff value ≥ 9 cm as a risk factor for reduced secondary FP. Secondary FP at 12 months for patients with no risk factors, with 1, and with 2 was 86%, 65%, and 0%, respectively. There was a significant difference in secondary FP rates among these groups (P = 0.001). Conclusions: A lesion length and juxta-AVF lesion are the risk factors for reduced secondary FP. The secondary FP rate at 12 months is acceptable in patients without risk factors.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2019

Reason of Discontinuation After Transarterial Chemoembolization Influences Survival in Patients with Hepatocellular Carcinoma

Background: Transarterial chemoembolization (TACE) for intermediate-stage hepatocellular carcinoma (HCC) is often repeated until unTACEable progression (UTP) occurs. There is little data on the various reasons for stopping TACE and its consequences for subsequent treatment and survival. Aim: To assess the impact of the various reasons of UTP on survival and consequences for subsequent treatments. Methods: Consecutive HCC patients who underwent TACE between 2003 and 2016 were analyzed retrospectively for the reason of TACE discontinuation. UTP was defined according to the EASL guidelines, considering radiological pattern of progression, liver function and performance status (PS). Overall and post-progression survival (OS, PPS) for different reasons of TACE discontinuation were compared. The correlation between time to untreatable progression by chemoembolization (TTUPc) and OS was analyzed. Results: One hundred and sixty-six patients (BCLC-A 40%, BCLC-B 54%, BCLC-C: 7%) were included, undergoing a median of 2 TACE procedures with a median OS of 22.1 months (95% CI 17.4–26.7). UTP occurred in 116 patients (70%) after a median TTUPc of 11.6 months (95% CI 7.8–15.4). There was a strong positive correlation (ρ = 0.816, p < 0.001) between TTUPc and OS. The main reason of UTP was radiological progression (61%), which was mostly intrahepatic (75%). Hepatic decompensation and worsening of PS were independent predictors of OS and PPS. Conclusion: The majority of HCC patients treated with TACE have UTP due to intrahepatic tumor progression with preserved liver function and PS, making them potential candidates for subsequent liver-directed or systemic treatment. TTUPc may be a valuable surrogate endpoint for OS in patients treated with TACE. Level of Evidence: Level II, prognosis study.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2019

Safety of Percutaneous Hepatic Perfusion with Melphalan in Patients with Unresectable Liver Metastases from Ocular Melanoma Using the Delcath Systems’ Second-Generation Hemofiltration System: A Prospective Non-randomized Phase II Trial

Purpose: To investigate the safety and toxicity of percutaneous hepatic perfusion with melphalan (M-PHP) with the Delcath Systems’ second-generation (GEN 2) filter and compare the outcomes with historical data from studies using the first-generation filter. Materials and Methods: A prospective, single-arm, single-center phase II study was carried out including 35 patients with unresectable, histologically confirmed liver metastases from ocular melanoma between February 2014 and June 2017. Main exclusion criteria were extrahepatic disease and age > 75 years. M-PHP was performed with melphalan 3 mg/kg (maximum dose 220 mg). Safety and toxicity were assessed according to the Common Terminology Criteria for Adverse Events version 4.03. Results: A total of 67 M-PHPs were performed in 35 patients (median 2 procedures). Although hematologic grade 3/4 events were seen in the majority of patients (thrombocytopenia 54.5%, leukopenia 75.6%, neutropenia 66.7%, anemia (only grade 3) 18.1%), these were all well manageable or self-limiting. Of the non-hematologic grade 3 events (n = 14), febrile neutropenia (n = 3), pulmonary emboli (n = 2) and post-procedural hemorrhage (n = 2) were most common. A case of sepsis with bacterial pharyngitis was the only non-hematologic grade 4 event. Prior therapy for liver metastases was found to be a predictor of late grade 3/4 neutropenia with an odds ratio of 5.5 (95% CI 1.4–21.7). Conclusions: M-PHP using the GEN 2 filter has an acceptable safety and toxicity profile, and seems to reduce hematologic toxicity when compared to M-PHP with a first-generation filter. Prior therapy of liver metastases is a possible predictive factor in developing grade 3/4 hematologic toxicity.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2019

Prognosticating Survival in Hepatocellular Carcinoma with Elevated Baseline Alpha-fetoprotein Treated with Radioembolization Using a Novel Laboratory Scoring System: Initial Development and Validation

Aims: To investigate laboratory parameters as predictors of overall survival (OS) for hepatocellular carcinoma (HCC) treated with radioembolization and develop/validate a scoring system. Methods: With IRB approval, we included all patients with baseline alpha-fetoprotein (AFP) > 100 ng/dL from our prospectively acquired HCC radioembolization database. Neutrophil–lymphocyte ratio, albumin–bilirubin (ALBI), and AFP were measured at baseline and at 1-, 3-, and 6-month post-radioembolization Landmarks. OS was assessed from these Landmarks. Univariate/multivariate analyses were performed to evaluate OS predictability of these parameters. Baseline Imaging, Laboratory, and Combination scoring systems were developed. Developing/validating groups were created to investigate/validate the score’s OS predictability. Time-dependent receiver operating characteristics (ROC) were evaluated. Patients were stratified into groups I, II, and III by using 25th and 75th percentile cutoffs according to change in Laboratory Score from baseline. Results: 345/401 (86%), 238/401 (59%), and 167/401 (42%) patients had laboratory parameters available at the 1-, 3-, and 6-month Landmarks, respectively. ALBI and AFP were significant OS prognosticators at all Landmarks. The Laboratory Score [ALBI + (0.3 × LnAFP)] was developed/internally validated to predict OS from these Landmarks. Areas under the curve of time-dependent ROCs of the Baseline Imaging vs. Laboratory scores in predicting patient OS post 3 and 6 months Landmarks were 0.56 versus 0.82 and 0.57 versus 0.77, respectively. OS differences in groups I, II, and III according to change in Laboratory Score from baseline were significant (p < 0.001). Conclusions: Post-radioembolization AFP and ALBI scores were significant OS prognosticators. A decrease in post-therapeutic Laboratory Score, which combines AFP and ALBI, correlates with an improved OS.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2019

Propofol Compared to Midazolam Sedation and to General Anesthesia for Percutaneous Microwave Ablation in Patients with Hepatic Malignancies: A Single-Center Comparative Analysis of Three Historical Cohorts

Purpose: In percutaneous ablation procedures, periprocedural pain, unrest and respiratory concerns can be detrimental to achieve a safe and efficacious ablation and impair treatment outcome. This study aimed to compare the association between anesthetic technique and local disease control in patients undergoing percutaneous microwave ablation (MWA) of colorectal liver metastases (CRLM) and hepatocellular carcinoma (HCC). Materials and Methods: This IRB-exempted single-center comparative, retrospective analysis of three cohorts analyzed 90 patients treated for hepatic malignancies from January 2013 until September 2018. The local tumor progression-free survival (LTPFS), safety and periprocedural pain perception were assessed using univariate and multivariate Cox proportional hazard regression analyses to correct for potential confounders. Results: In 114 procedures (22 general anesthesia; 32 midazolam; 60 propofol), 171 liver tumors (136 CRLM; 35 HCC) were treated with percutaneous MWA. Propofol and general anesthesia were superior to midazolam/fentanyl sedation regarding LTPFS (4/94 [4.3%] vs. 19/42 [45.2%] vs. 2/35 [5.7%]; P < 0.001, respectively). Local tumor progression rate was 14.6% (25/171). Eighteen tumors (72.0%) were retreated by ablation. Of them, 14 (78%) were previously treated with midazolam. Propofol versus midazolam (P < 0.001), general anesthesia versus midazolam (P = 0.016), direct postprocedural visual analog pain score above 5 (P = 0.050) and more than one tumor per procedure (P = 0.045) were predictors for LTPFS. Multivariate analysis revealed that propofol versus midazolam (HR 7.94 [95% CI 0.04–0.39; P < 0.001]) and general anesthesia versus midazolam (HR 6.33 [95% CI 0.04–0.69; P = 0.014]) were associated with LTPFS. Pain during and directly after treatment was significantly worse in patients who received midazolam sedation (P < 0.001). Conclusions: Compared to propofol and general anesthesia, midazolam/fentanyl sedation was associated with an increased periprocedural perception of pain and lower local tumor progression-free survival. To reduce the number of repeat procedures required to eradicate hepatic malignancies, general anesthesia and propofol sedation should be favored over midazolam.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2019

Maximizing ENSO as a source of western US hydroclimate predictability

Abstract Until recently, the El Niño–Southern Oscillation (ENSO) was considered a reliable source of winter precipitation predictability in the western US, with a historically strong link between extreme El Niño events and extremely wet seasons. However, the 2015–2016 El Niño challenged our understanding of the ENSO-precipitation relationship. California precipitation was near-average during the 2015–2016 El Niño, which was characterized by warm sea surface temperature (SST) anomalies of similar magnitude compared to the extreme 1997–1998 and 1982–1983 El Niño events. We demonstrate that this precipitation response can be explained by El Niño’s spatial pattern, rather than internal atmospheric variability. In addition, observations and large-ensembles of regional and global climate model simulations indicate that extremes in seasonal and daily precipitation during strong El Niño events are better explained using the ENSO Longitude Index (ELI), which captures the diversity of ENSO’s spatial patterns in a single metric, compared to the traditional Niño3.4 index, which measures SST anomalies in a fixed region and therefore fails to capture ENSO diversity. The physically-based ELI better explains western US precipitation variability because it tracks the zonal shifts in tropical Pacific deep convection that drive teleconnections through the response in the extratropical wave-train, integrated vapor transport, and atmospheric rivers. This research provides evidence that ELI improves the value of ENSO as a predictor of California’s seasonal hydroclimate extremes compared to traditional ENSO indices, especially during strong El Niño events.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2020

Projected changes in the terrestrial and oceanic regulators of climate variability across sub-Saharan Africa

Future changes in the sign and intensity of ocean–land–atmosphere interactions have been insufficiently studied, despite implications for regional climate change projections, extreme event statistics, and seasonal climate predictability. In response to this deficiency, the present study focuses on projected responses to the enhanced greenhouse effect in: (1) the mean state of the atmosphere and land surface; (2) oceanic and terrestrial drivers of sub-Saharan climate variability; and (3) total seasonal climate predictability of sub-Saharan Africa, a region known for its pronounced land–atmosphere coupling. Analysis focuses on output from 23 Earth System Models in the Coupled Model Intercomparison Project Phase Five for the late twentieth and twenty-first centuries. It is projected that the greatest warming across sub-Saharan Africa will occur over the Sahel, the monsoon season will become more persistent into late summer and autumn, short rains in the Horn of Africa (HOA) will intensify, and leaf area index will increase across the HOA. Stepwise Generalized Equilibrium Feedback Assessment, i.e. a multivariate statistical approach, is applied to the model output over sub-Saharan Africa in order to explore the oceanic and terrestrial drivers of regional climate. The models indicate that the study region’s climate variability is dominated by oceanic drivers, with secondary contributions from soil moisture and very modest impacts from vegetation. Overall, the general model consensus of future projections indicates a concerning diminished seasonal predictability of sub-Saharan African regional climate based on key oceanic and terrestrial predictors and an elevated role of the land surface (associated with soil moisture anomalies) compared to oceanic drivers in regulating regional climate variability.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2023

Towards understanding the robust strengthening of ENSO and more frequent extreme El Niño events in CMIP6 global warming simulations

The El Niño Southern Oscillation (ENSO) has profound impacts on weather patterns across the globe, yet there is no consensus on its response to global warming. Several modelling studies find a stronger ENSO in global warming scenarios, while other studies suggest ENSO weakening. Using a broad range of models from the Coupled Model Intercomparison Project phase 6 (CMIP6) and four types of warming experiments, here we show that the majority of the models predict a stronger ENSO by century-end in Shared Social Pathway (SSP) experiments, and in idealized 1pctCO 2 and abrupt 4xCO 2 experiments. Several models, however, do predict no change or ENSO weakening, especially in the idealized experiments. Critically, the strongest forcing (abrupt-4xCO 2 ) does not induce the strongest ENSO response, while differences between the models are much greater than those between warming scenarios. For the long-term response (over 1000 years) the models disagree even on the sign of change. Furthermore, changes in ENSO sea surface temperature (SST) variability are only modestly correlated with the tropical Pacific mean state change. The highest correlation for ENSO SST amplitude is found with the mean zonal SST gradient in the SSP5-8.5 experiment (R = –0.58). In contrast, changes in ENSO rainfall variability correlate well with changes in the mean state, as well as with changes in ENSO SST variability. When evaluating the Bjerknes Stability Index for a subset of models, we find that it is not a reliable predictor of ENSO strengthening, as this index tends to predict greater stability with warming. We argue that the enhanced ENSO stability is offset by increases in atmospheric noise or/and potential nonlinear effects. However, a robust inter-model mechanism that can explain a stronger ENSO simulated with global warming is still lacking. Therefore, caution should be exercised when considering ENSO changes based on a single model or warming scenario.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2025

Climate models project increasing precipitation in the US Southwest in 2024–2100

We analyzed the measured precipitation in the southwestern US and found that, from 1900 to 2024, precipitation decreased at an average rate of − 1.2 cm per year per 100 years. The most significant precipitation decreases occurred in the three-month period from February to April. At the same time, precipitation during the southwestern monsoon season (July, August, and September) remained relatively stable. The ensemble mean of all CMIP6 (Coupled Model Intercomparison Project phase 6) climate models, along with the regression model incorporating anthropogenic aerosol (AER) and Pacific Decadal Oscillation (PDO) as predictors, projects precipitation to increase from 2024 to 2100. This projected precipitation increase relies on the anticipated decrease in emissions of anthropogenic aerosols, which is associated with the transition from fossil fuel burning to renewable and nuclear energy sources.

54 ENVIRONMENTAL SCIENCES↗