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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 1,207 records · Page 67
All sourcesNASA NTRSDOE OSTI
DOE OSTI2018

Air pollution and the fetal origin of disease: A systematic review of the molecular signatures of air pollution exposure in human placenta

Fetal development is a crucial window of susceptibility in which exposure-related alterations can be induced on the molecular level, leading to potential changes in metabolism and development. The placenta serves as a gatekeeper between mother and fetus, and is in contact with environmental stressors throughout pregnancy. This makes the placenta as a temporary organ an informative non-invasive matrix suitable to investigate omics-related aberrations in association with in utero exposures such as ambient air pollution.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2012

Prone Whole-Breast Irradiation Using Three-Dimensional Conformal Radiotherapy in Women Undergoing Breast Conservation for Early Disease Yields High Rates of Excellent to Good Cosmetic Outcomes in Patients With Large and/or Pendulous Breasts

Purpose: To report our institution's experience using prone positioning for three-dimensional conformal radiotherapy (3D-CRT) to deliver post-lumpectomy whole breast irradiation (WBI) in a cohort of women with large and/or pendulous breasts, to determine the rate of acute and late toxicities and, more specifically, cosmetic outcomes. We hypothesized that using 3D-CRT for WBI in the prone position would reduce or eliminate patient and breast size as negative prognostic indicators for toxicities associated with WBI. Methods and Materials: From 1998 to 2006, 110 cases were treated with prone WBI using 3D-CRT. The lumpectomy, breast target volumes, heart, and lung were contoured on all computed tomography scans. A dose of 45-50 Gy was prescribed to the breast volume using standard fractionation schemes. The planning goals were {>=}95% of prescription to 95% of the breast volume, and 100% of boost dose to 95% of lumpectomy planning target volume. Toxicities and cosmesis were prospectively scored using the Common Terminology Criteria for Adverse Effects Version 3.0 and the Harvard Scale. The median follow-up was 40 months. Results: The median body mass index (BMI) was 33.6 kg/m{sup 2}, and median breast volume was 1396 cm{sup 3}. The worst toxicity encountered during radiation was Grade 3 dermatitis in 5% of our patient population. Moist desquamation occurred in 16% of patients, with only 2% of patients with moist desquamation outside the inframammary/axillary folds. Eleven percent of patients had Grade {>=}2 late toxicities, including Grade 3 induration/fibrosis in 2%. Excellent to good cosmesis was achieved in 89%. Higher BMI was associated with moist desquamation and breast pain, but BMI and breast volume did not impact fibrosis or excellent to good cosmesis. Conclusion: In patients with higher BMI and/or large-pendulous breasts, delivering prone WBI using 3D-CRT results in favorable toxicity profiles and high excellent to good cosmesis rates. Higher BMI was associated with moist desquamation, but prone positioning removed BMI and breast size as factors for poorer cosmetic outcomes. This series adds to the growing literature demonstrating that prone WBI may be advantageous in select patients.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2013

A Reanalysis of Curvature in the Dose Response for Cancer and Modifications by Age at Exposure Following Radiation Therapy for Benign Disease

Purpose: To assess the shape of the dose response for various cancer endpoints and modifiers by age and time. Methods and Materials: Reanalysis of the US peptic ulcer data testing for heterogeneity of radiogenic risk by cancer endpoint (stomach, pancreas, lung, leukemia, all other). Results: There are statistically significant (P<.05) excess risks for all cancer and for lung cancer and borderline statistically significant risks for stomach cancer (P=.07), and leukemia (P=.06), with excess relative risks Gy{sup -1} of 0.024 (95% confidence interval [CI] 0.011, 0.039), 0.559 (95% CI 0.221, 1.021), 0.042 (95% CI -0.002, 0.119), and 1.087 (95% CI -0.018, 4.925), respectively. There is statistically significant (P=.007) excess risk of pancreatic cancer when adjusted for dose-response curvature. General downward curvature is apparent in the dose response, statistically significant (P<.05) for all cancers, pancreatic cancer, and all other cancers (ie, other than stomach, pancreas, lung, leukemia). There are indications of reduction in relative risk with increasing age at exposure (for all cancers, pancreatic cancer), but no evidence for quadratic variations in relative risk with age at exposure. If a linear-exponential dose response is used, there is no significant heterogeneity in the dose response among the 5 endpoints considered or in the speed of variation of relative risk with age at exposure. The risks are generally consistent with those observed in the Japanese atomic bomb survivors and in groups of nuclear workers. Conclusions: There are excess risks for various malignancies in this data set. Generally there is a marked downward curvature in the dose response and significant reduction in relative risk with increasing age at exposure. The consistency of risks with those observed in the Japanese atomic bomb survivors and in groups of nuclear workers implies that there may be little sparing effect of fractionation of dose or low-dose-rate exposure.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2014

{sup 32}P Brachytherapy Conformal Source Model RIC-100 for High-Dose-Rate Treatment of Superficial Disease: Monte Carlo Calculations, Diode Measurements, and Clinical Implementation

Purpose: A novel {sup 32}P brachytherapy source has been in use at our institution intraoperatively for temporary radiation therapy of the spinal dura and other localized tumors. We describe the dosimetry and clinical implementation of the source. Methods and Materials: Dosimetric evaluation for the source was done with a complete set of MCNP5 Monte Carlo calculations preceding clinical implementation. In addition, the depth dose curve and dose rate were measured by use of an electron field diode to verify the Monte Carlo calculations. Calibration procedures using the diode in a custom-designed phantom to provide an absolute dose calibration and to check dose uniformity across the source area for each source before treatment were established. Results: Good agreement was established between the Monte Carlo calculations and diode measurements. Quality assurance measurements results are provided for about 100 sources used to date. Clinical source calibrations were usually within 10% of manufacturer specifications. Procedures for safe handling of the source are described. Discussion: Clinical considerations for using the source are discussed.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2014

Performance of a Nomogram Predicting Disease-Specific Survival After an R0 Resection for Gastric Cancer in Patients Receiving Postoperative Chemoradiation Therapy

Purpose: The internationally validated Memorial Sloan-Kettering Cancer Center (MSKCC) gastric carcinoma nomogram was based on patients who underwent curative (R0) gastrectomy, without any other therapy. The purpose of the current study was to assess the performance of this gastric cancer nomogram in patients who received chemoradiation therapy after an R0 resection for gastric cancer. Methods and Materials: In a combined dataset of 76 patients from the Netherlands Cancer Institute (NKI), and 63 patients from MSKCC, who received postoperative chemoradiation therapy (CRT) after an R0 gastrectomy, the nomogram was validated by means of the concordance index (CI) and a calibration plot. Results: The concordance index for the nomogram was 0.64, which was lower than the CI of the nomogram for patients who received no adjuvant therapy (0.80). In the calibration plot, observed survival was approximately 20% higher than the nomogram-predicted survival for patients receiving postoperative CRT. Conclusions: The MSKCC gastric carcinoma nomogram significantly underpredicted survival for patients in the current study, suggesting an impact of postoperative CRT on survival in patients who underwent an R0 resection for gastric cancer, which has been demonstrated by randomized controlled trials. This analysis stresses the need for updating nomograms with the incorporation of multimodal strategies.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2014

Uveal Melanoma Treated With Iodine-125 Episcleral Plaque: An Analysis of Dose on Disease Control and Visual Outcomes

Purpose: To investigate, in the treatment of uveal melanomas, how tumor control, radiation toxicity, and visual outcomes are affected by the radiation dose at the tumor apex. Methods and Materials: A retrospective review was performed to evaluate patients treated for uveal melanoma with {sup 125}I plaques between 1988 and 2010. Radiation dose is reported as dose to tumor apex and dose to 5 mm. Primary endpoints included time to local failure, distant failure, and death. Secondary endpoints included eye preservation, visual acuity, and radiation-related complications. Univariate and multivariate analyses were performed to determine associations between radiation dose and the endpoint variables. Results: One hundred ninety patients with sufficient data to evaluate the endpoints were included. The 5-year local control rate was 91%. The 5-year distant metastases rate was 10%. The 5-year overall survival rate was 84%. There were no differences in outcome (local control, distant metastases, overall survival) when dose was stratified by apex dose quartile (<69 Gy, 69-81 Gy, 81-89 Gy, >89 Gy). However, increasing apex dose and dose to 5-mm depth were correlated with greater visual acuity loss (P=.02, P=.0006), worse final visual acuity (P=.02, P<.0001), and radiation complications (P<.0001, P=.0009). In addition, enucleation rates were worse with increasing quartiles of dose to 5 mm (P=.0001). Conclusions: Doses at least as low as 69 Gy prescribed to the tumor apex achieve rates of local control, distant metastasis–free survival, and overall survival that are similar to radiation doses of 85 Gy to the tumor apex, but with improved visual outcomes.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2017

Cerebrovascular Diseases in Childhood Cancer Survivors: Role of the Radiation Dose to Willis Circle Arteries

Background and Purpose: The aim of this study was to investigate the role of radiation dose received to the circle of Willis (WC) during radiation therapy (RT) and of potential dose-response modifiers on the risk of stroke after treatment of childhood cancer. Methods: We evaluated the risk factors for stroke in a cohort of 3172 5-year survivors of childhood cancer who were followed up for a median time of 26 years. Radiation doses to the WC and brain structures were estimated for each of the 2202 children who received RT. Results: Fifty-four patients experienced a confirmed stroke; 39 were ischemic. Patients not receiving RT had a stroke risk similar to that of the general population, whereas those who received RT had an 8.5-fold increased risk (95% confidence interval [CI]: 6.3-11.0). The excess of incidence of stroke increased yearly. The dose of radiation to the WC, rather than to other brain structures, was found to be the best predictor of stroke. The relative risk was 15.7 (95% CI: 4.9-50.2) for doses of 40 Gy or more. At 45 years of age, the cumulative stroke incidence was 11.3% (95% CI: 7.1%-17.7%) in patients who received 10 Gy or more to the WC, compared with 1% expected from general population data. Radiation doses received to the heart and neck also increased the risk. Surgery for childhood brain cancer was linked to hemorrhagic strokes in these patients. Conclusion: The WC should be considered as a major organ at risk during RT for childhood brain cancers. The incidence of radiation-induced ischemic stroke strongly increases with long-term follow-up.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2018

Improved Overall Survival and Locoregional Disease Control With Concurrent PD-1 Pathway Inhibitors and Stereotactic Radiosurgery for Lung Cancer Patients With Brain Metastases

Despite the emerging role of programmed cell death-1 (PD-1) pathway inhibitors for patients with advanced lung cancer, a paucity of data are available on the activity of these agents among patients with brain metastases. We investigated the outcomes of PD-1 pathway inhibitors and stereotactic radiosurgery (SRS) for the treatment of patients with brain metastases from lung cancer.

62 RADIOLOGY AND NUCLEAR MEDICINE↗