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639 records · Page 36
All sourcesNASA NTRSDOE OSTI
DOE OSTI2019

Inpatient Opioid Use After Pancreatectomy: Opportunities for Reducing Initial Opioid Exposure in Cancer Surgery Patients

Background: Despite advances in enhanced surgical recovery programs, strategies limiting postoperative inpatient opioid exposure have not been optimized for pancreatic surgery. The primary aims of this study were to analyze the magnitude and variations in post-pancreatectomy opioid administration and to characterize predictors of low and high inpatient use. Methods: Clinical characteristics and inpatient oral morphine equivalents (OMEs) were downloaded from electronic records for consecutive pancreatectomy patients at a high-volume institution between March 2016 and August 2017. Regression analyses identified predictors of total OMEs as well as highest and lowest quartiles. Results: Pancreatectomy was performed for 158 patients (73% pancreaticoduodenectomy). Transversus abdominus plane (TAP) block was performed for 80% (n = 127) of these patients, almost always paired with intravenous patient-controlled analgesia (IV-PCA), whereas 15% received epidural alone. All the patients received scheduled non-opioid analgesics (median, 2). The median total OME administered was 423 mg (range 0–4362 mg). Higher total OME was associated with preoperative opioid prescriptions (p < 0.001), longer hospital length of stay (LOS; p < 0.001), and no epidural (p = 0.006). The lowest and best quartile cutoff was 180 mg of OME or less, whereas the highest and worst quartile cutoff began at 892.5 mg. After adjustment for inpatient team, only epidural use [odds ratio (OR) 0.3; p = 0.04] predicted lowest-quartile OME. Preoperative opioid prescriptions (OR 8.1; p < 0.001), longer operative time (OR 3.4; p = 0.05), and longer LOS (OR 1.1; p = 0.007) predicted highest-quartile OME. Conclusions: Preoperative opioid prescriptions and longer LOS were associated with increased inpatient OME, whereas epidural use reduced inpatient OME. Understanding the predictors of inpatient opioid use and the variables predicting the lowest and highest quartiles can inform decision-making regarding preoperative counseling, regional anesthetic block choice, and novel inpatient opioid weaning strategies to reduce initial postoperative opioid exposure.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2019

Better Defining the Role of Total Neoadjuvant Radiation: Changing Paradigms in Locally Advanced Pancreatic Cancer

Background: This study was designed to better define the role of radiation (Neo-Rad) in addition to neoadjuvant multiagent chemotherapy (NAT) for the treatment of locally advanced pancreatic cancer. Methods: Retrospective cohort study using the NCDB. Individuals with AJCC clinical T3/T4 pancreatic carcinoma who underwent resection and multiagent chemotherapy were included. Kaplan–Meier, logistic-regression, and Cox proportional-hazard models were used for analysis. Results: A total of 2703 patients were included; 2039 had T3 and 664 had T4 tumors, and 1092 (40.4%) received Neo-Rad. Median follow-up was 22.5 months. During the study period, there was increased use of NAT and a decline in the use of Neo-Rad. Addition of Neo-Rad did not affect 30-day (2.51% vs. 3.24%, p = 0.272) or 90-day mortality (5.23% vs. 6.38%, p = 0.216). Neo-Rad was not associated with improved overall survival on univariable (25.95 vs. 24.7 months, p = 0.202), or multivariable analyses (hazard ratio [HR] 0.94; 95% confidence interval [CI] 0.85–1.05). Time from diagnosis to definitive surgery was increased by Neo-Rad (204 vs. 115 days, p < 0.001). Neo-Rad was associated with increased pathologic downstaging in T3 (32.8% vs. 14.4%) (odds ratio [OR] 2.90; 95% CI 2.30–3.66) and T4 tumors (88.9% vs. 77.8%) (OR 2.29; 95% CI 1.44–3.67); complete pathologic response (5.3% vs. 1.6%) (OR 2.89; 95% CI 1.73–4.83), and increased R0 resection rates (85.7% vs. 76.8%) (OR 1.79; 95% CI 1.44–2.23). Conclusions: The use of neoadjuvant therapy is increasing for the treatment of locally advanced pancreatic cancer. The addition of radiation to neoadjuvant chemotherapy is associated with improved antineoplastic effectiveness (downstaging, complete pathologic response), surgical resection (R0 rates), but has no effect on overall survival.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2019

Perioperative Gemcitabine + Erlotinib Plus Pancreaticoduodenectomy for Resectable Pancreatic Adenocarcinoma: ACOSOG Z5041 (Alliance) Phase II Trial

Background: There is considerable interest in a neoadjuvant approach for resectable pancreatic ductal adenocarcinoma (PDAC). This study evaluated perioperative gemcitabine + erlotinib (G+E) for resectable PDAC. Methods: A multicenter, cooperative group, single-arm, phase II trial was conducted between April 2009 and November 2013 (ACOSOG Z5041). Patients with biopsy-confirmed PDAC in the pancreatic head without evidence of involvement of major mesenteric vessels (resectable) were eligible. Patients (n = 123) received an 8-week cycle of G+E before and after surgery. The primary endpoint was 2-year overall survival (OS), and secondary endpoints included toxicity, response, resection rate, and time to progression. Resectability was assessed retrospectively by central review. The study closed early due to slow accrual, and no formal hypothesis testing was performed. Results: Overall, 114 patients were eligible, consented, and initiated protocol treatment. By central radiologic review, 97 (85%) of the 114 patients met the protocol-defined resectability criteria. Grade 3+ toxicity was reported in 60% and 79% of patients during the neoadjuvant phase and overall, respectively. Twenty-two of 114 (19%) patients did not proceed to surgery; 83 patients (73%) were successfully resected. R0 and R1 margins were obtained in 67 (81%) and 16 (19%) resected patients, respectively, and 54 patients completed postoperative G+E (65%). The 2-year OS rate for the entire cohort (n = 114) was 40% (95% confidence interval [CI] 31–50), with a median OS of 21.3 months (95% CI 17.2–25.9). The 2-year OS rate for resected patients (n = 83) was 52% (95% CI 41–63), with a median OS of 25.4 months (95% CI 21.8–29.6). Conclusions: For resectable PDAC, perioperative G+E is feasible. Further evaluation of neoadjuvant strategies in resectable PDAC is warranted with more active systemic regimens.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2019

A Prospective, Open-Label, Multicenter Phase 2 Trial of Neoadjuvant Therapy Using Full-Dose Gemcitabine and S-1 Concurrent with Radiation for Resectable Pancreatic Ductal Adenocarcinoma

Background: Neoadjuvant therapy reportedly shows only marginal clinical benefit in pancreatic ductal adenocarcinoma (PDAC), especially in resectable cases. However, with more effective regimens, neoadjuvant therapy may become a standard of care for resectable cases. A prospective, open-label, multicenter phases 1 and 2 trial of neoadjuvant therapy was conducted using full-dose gemcitabine and S-1 concurrently with 50.4 Gy of radiation therapy (GSRT) for resectable PDAC. This report describes the phase 2 results. Methods: The phase 2 part of this study enrolled 57 patients with cytologically or histologically proven PDAC deemed resectable based on imaging before neoadjuvant therapy. These patients received GSRT. After reevaluation by computed tomography scan, surgical exploration was performed, followed by adjuvant therapy. According to the prescribed protocol of the clinical trial, statistical analyses included 57 phase 2 patients and 6 phase 1 patients who received the same dosage as in phase 2. Results: This trial enrolled 63 patients (42 men and 21 women) with a median age of 70 years. Leukopenia or neutropenia of grade 3 or higher occurred for 79% of the patients, but no other severe adverse events were observed. Among the 63 patients, 54 underwent surgical resection. Intention-to-treat analysis of the 63 patients showed an excellent median survival time lasting as long as 55.3 months. The patients who completed neoadjuvant therapy, surgery, and adjuvant therapy had a 5-year survival rate of 56.6%. Conclusions: This regimen showed outstanding clinical efficacy with acceptable tolerability for patients with resectable PDAC.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2019

Accuracy of Fukuoka and American Gastroenterological Association Guidelines for Predicting Advanced Neoplasia in Pancreatic Cyst Neoplasm: A Meta-Analysis

Background: A differential diagnosis of advanced pancreatic cystic neoplasms (PCNs) is critical to determine optimal treatment. The Fukuoka and American Gastroenterological Association (AGA) guidelines are the most widely accepted criteria for the management of PCNs. Objective: This study aimed to evaluate the diagnostic value of these guidelines in predicting advanced neoplasia (AN). Methods: A comprehensive electronic search of the PubMed, EMBASE, Web of Science, Cochrane Library, and Scopus databases was conducted to identify all relevant studies evaluating the Fukuoka and AGA guidelines in surgically resected and histologically confirmed PCNs. Pooled sensitivity, specificity, and diagnostic odds ratios (DORs) were calculated as compound measures of diagnostic accuracy using the random-effects model. Summary of receiver operating characteristic (SROC) curves and the area under the curve (AUC) were also performed. Results: A total of 21 studies with 3723 patients were included in this meta-analysis. Of these studies, 15, 4, and 2 evaluated the Fukuoka guidelines, the AGA guidelines, and both guidelines, respectively. For AN prediction, the Fukuoka guidelines had a pooled sensitivity of 0.67 (95% confidence interval [CI] 0.64–0.70), pooled specificity of 0.64 (95% CI 0.62–0.66), and pooled DOR of 6.28 (95% CI 4.38–9.01), with an AUC of the SROC of 0.78. AGA guidelines showed a pooled sensitivity of 0.59 (95% CI 0.52–0.65), pooled specificity of 0.77 (95% CI 0.74–0.80), and pooled DOR of 5.84 (95% CI 2.60–13.15), with an AUC of 0.79 (95% CI 0.70–0.88). Conclusion: When used alone, the Fukuoka and AGA guidelines showed similar but unsatisfactory diagnostic accuracy in the risk stratification of malignant potential of PCN. Thus, we recommend that they be applied only as a broad framework in clinical practice.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2013

Is Dynamic Autocrine Insulin Signaling Possible? A Mathematical Model Predicts Picomolar Concentrations of Extracellular Monomeric Insulin within Human Pancreatic Islets

Insulin signaling is essential for β-cell survival and proliferation in vivo. Insulin also has potent mitogenic and anti-apoptotic actions on cultured β-cells, with maximum effect in the high picomolar range and diminishing effect at high nanomolar doses. In order to understand whether these effects of insulin are constitutive or can be subjected to physiological modulation, it is essential to estimate the extracellular concentration of monomeric insulin within an intact islet. Unfortunately, the in vivo concentration of insulin monomers within the islet cannot be measured directly with current technology. Here, we present the first mathematical model designed to estimate the levels of monomeric insulin within the islet extracellular space. Insulin is released as insoluble crystals that exhibit a delayed dissociation into hexamers, dimers, and eventually monomers, which only then can act as signaling ligands. The rates at which different forms of insulin dissolve in vivo have been estimated from studies of peripheral insulin injection sites. We used this and other information to formulate a mathematical model to estimate the local insulin concentration within a single islet as a function of glucose. Model parameters were estimated from existing literature. Components of the model were validated using experimental data, if available. Model analysis predicted that the majority of monomeric insulin in the islet is that which has been returned from the periphery, and the concentration of intra-islet monomeric insulin varies from β50–300 pM when glucose is in the physiological range. Thus, our results suggest that the local concentration of monomeric insulin within the islet is in the picomolar ‘sweet spot’ range of insulin doses that activate the insulin receptor and have the most potent effects on β-cells in vitro. Together with experimental data, these estimations support the concept that autocrine/paracrine insulin signalling within the islet is dynamic, rather than constitutive and saturated.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2011

Dosimetric Comparison of 6 MV and 15 MV Single Arc Rapidarc to Helical TomoTherapy for the Treatment of Pancreatic Cancer

We conducted a planning study to compare Varian's RapidArc (RA) and helical TomoTherapy (HT) for the treatment of pancreatic cancer. Three intensity-modulated radiotherapy (IMRT) plans were generated for 8 patients with pancreatic cancer: one using HT with 6-MV beam (Plan{sub HT6}), one using single-arc RA with 6-MV beam (Plan{sub RA6}), and one using single-arc RA with 15-MV beam (Plan{sub RA15}). Dosimetric indices including high/low conformality index (CI{sub 100%}/CI{sub 50%}), heterogeneity index (HI), monitor units (MUs), and doses to organs at risk (OARs) were compared. The mean CI{sub 100%} was statistically equivalent with respect to the 2 treatment techniques, as well as beam energy (0.99, 1.01, and 1.02 for Plan{sub HT6}, Plan{sub RA6}, and Plan{sub RA156,} respectively). The CI{sub 50%} and HI were improved in both RA plans over the HT plan. The RA plans significantly reduced MU (MU{sub RA6} = 697, MU{sub RA15} = 548) compared with HT (MU{sub HT6} = 6177, p = 0.008 in both cases). The mean maximum cord dose was decreased from 29.6 Gy in Plan{sub HT6} to 21.6 Gy (p = 0.05) in Plan{sub RA6} and 21.7 Gy (p = 0.04) in Plan{sub RA15}. The mean bowel dose decreased from 17.2 Gy in Plan{sub HT6} to 15.2 Gy (p = 0.03) in Plan{sub RA6} and 15.0 Gy (p = 0.03) Plan{sub RA15}. The mean liver dose decreased from 8.4 Gy in Plan{sub HT6} to 6.3 Gy (p = 0.04) in Plan{sub RA6} and 6.2 Gy in Plan{sub RA15}. Variations of the mean dose to the duodenum, kidneys, and stomach were statistically insignificant. RA and HT can both deliver conformal dose distributions to target volumes while limiting the dose to surrounding OARs in the treatment of pancreatic cancer. Dosimetric advantages might be gained by using RA over HT by reducing the dose to OARs and total MUs used for treatment.

61 RADIATION PROTECTION AND DOSIMETRY↗
DOE OSTI2015

Results from the commissioning of a multi-modal endoscope for ultrasound and time of flight PET

The EndoTOFPET-US collaboration has developed a multi-modal imaging system combining Ultrasound with Time-of-Flight Positron Emission Tomography into an endoscopic imaging device. The objective of the project is to obtain a coincidence time resolution of about 200 ps FWHM and to achieve about 1 mm spatial resolution of the PET system, while integrating all the components in a very compact detector suitable for endoscopic use. This scanner aims to be exploited for diagnostic and surgical oncology, as well as being instrumental in the clinical test of new biomarkers especially targeted for prostate and pancreatic cancer. (authors)

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