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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 901 records · Page 50
All sourcesNASA NTRSDOE OSTI
DOE OSTI2012

Predictive Factors for Radiation Pneumonitis in Hodgkin Lymphoma Patients Receiving Combined-Modality Therapy

Purpose: This study sought to quantify the risk of radiation pneumonitis (RP) in Hodgkin lymphoma (HL) patients receiving mediastinal radiation therapy (RT) and to identify predictive factors for RP. Methods and Materials: We identified 75 patients with newly diagnosed HL treated with mediastinal RT and 17 patients with relapsed/refractory HL treated with mediastinal RT before or after transplant. Lung dose-volumetric parameters including mean lung dose and percentage of lungs receiving 20 Gy were calculated. Factors associated with RP were explored by use of the Fisher exact test. Results: RP developed in 7 patients (10%) who received mediastinal RT as part of initial therapy (Radiation Therapy Oncology Group Grade 1 in 6 cases). A mean lung dose of 13.5 Gy or greater (p = 0.04) and percentage of lungs receiving 20 Gy of 33.5% or greater (p = 0.009) significantly predicted for RP. RP developed in 6 patients (35%) with relapsed/refractory HL treated with peri-transplant mediastinal RT (Grade 3 in 4 cases). Pre-transplant mediastinal RT, compared with post-transplant mediastinal RT, significantly predicted for Grade 3 RP (57% vs. 0%, p = 0.015). Conclusions: We identified threshold lung metrics predicting for RP in HL patients receiving mediastinal RT as part of initial therapy, with the majority of cases being of mild severity. The risk of RP is significantly higher with peri-transplant mediastinal RT, especially among those who receive pre-transplant RT.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2013

Neoadjuvant Chemoradiation for Distal Rectal Cancer: 5-Year Updated Results of a Randomized Phase 2 Study of Neoadjuvant Combined Modality Chemoradiation for Distal Rectal Cancer

Purpose: To assess the efficacy of 2 different approaches to neoadjuvant chemoradiation for distal rectal cancers. Methods and Materials: One hundred six patients with T3/T4 distal rectal cancers were randomized in a phase 2 study. Patients received either continuous venous infusion (CVI) of 5-Fluorouracil (5-FU), 225 mg/m{sup 2} per day, 7 days per week plus pelvic hyperfractionated radiation (HRT), 45.6 Gy at 1.2 Gy twice daily plus a boost of 9.6 to 14.4 Gy for T3 or T4 cancers (Arm 1), or CVI of 5-FU, 225 mg/m{sup 2} per day, Monday to Friday, plus irinotecan, 50 mg/m{sup 2} once weekly × 4, plus pelvic radiation therapy (RT), 45 Gy at 1.8 Gy per day and a boost of 5.4 Gy for T3 and 9 Gy for T4 cancers (Arm 2). Surgery was performed 4 to 10 weeks later. Results: All eligible patients (n=103) are included in this analysis; 2 ineligible patients were excluded, and 1 patient withdrew consent. Ninety-eight of 103 patients (95%) underwent resection. Four patients did not undergo surgery for either disease progression or patient refusal, and 1 patient died during induction chemotherapy. The median time of follow-up was 6.4 years in Arm 1 and 7.0 years in Arm 2. The pathological complete response (pCR) rates were 30% in Arm 1 and 26% in Arm 2. Locoregional recurrence rates were 16% in Arm 1 and 17% in Arm 2. Five-year survival rates were 61% and 75% and Disease-specific survival rates were 78% and 85% for Arm1 and Arm 2, respectively. Five second primaries occurred in patients on Arm 1, and 1 second primary occurred in Arm 2. Conclusions: High rates of disease-specific survival were seen in each arm. Overall survival appears affected by the development of unrelated second cancers. The high pCR rates with 5-FU and higher dose radiation in T4 cancers provide opportunity for increased R0 resections and improved survival.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2014

Hypofractionated Intensity Modulated Radiation Therapy in Combined Modality Treatment for Bladder Preservation in Elderly Patients With Invasive Bladder Cancer

Purpose/Objective(s): To review our experience with bladder-preserving trimodality treatment (TMT) using hypofractionated intensity modulated radiation therapy (IMRT) for the treatment of elderly patients with muscle-invasive bladder cancer. Methods and Materials: Retrospective study of elderly patients treated with TMT using hypofractionated IMRT (50 Gy in 20 fractions) with concomitant weekly radiosensitizing chemotherapy. Eligibility criteria were as follows: age ≥70 years, a proven diagnosis of muscle-invasive transitional cell bladder carcinoma, stage T2-T3N0M0 disease, and receipt of TMT with curative intent. Response rate was assessed by cystoscopic evaluation and bladder biopsy. Results: 24 patients with a median age of 79 years were eligible. A complete response was confirmed in 83% of the patients. Of the remaining patients, 1 of them underwent salvage cystectomy, and no disease was found in the bladder on histopathologic assessment. After a median follow-up time of 28 months, of the patients with a complete response, 2 patients had muscle-invasive recurrence, 1 experienced locoregional failure, and 3 experienced distant metastasis. The overall and cancer-specific survival rates at 3 years were 61% and 71%, respectively. Of the surviving patients, 75% have a disease-free and functioning bladder. All patients completed hypofractionated IMRT, and 19 patients tolerated all 4 cycles of chemotherapy. Acute grade 3 gastrointestinal or genitourinary toxicities occurred in only 4% of the patients, and acute grade 3 or 4 hematologic toxicities, liver toxicities, or both were experienced by 17% of the cohort. No patient experienced grade 4 gastrointestinal or genitourinary toxicity. Conclusions: Hypofractionated IMRT with concurrent radiosensitizing chemotherapy appears to be an effective and well-tolerated curative treatment strategy in the elderly population and should be considered for patients who are not candidates for cystectomy or who wish to avoid cystectomy.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2014

Involved-Node Proton Therapy in Combined Modality Therapy for Hodgkin Lymphoma: Results of a Phase 2 Study

Purpose: This study describes the early clinical outcomes of a prospective phase 2 study of consolidative involved-node proton therapy (INPT) as a component of combined-mode therapy in patients with stages I to III Hodgkin lymphoma (HL) with mediastinal involvement. Methods and Materials: Between September 2009 and June 2013, 15 patients with newly diagnosed HL received INPT after completing chemotherapy in an institutional review board-approved protocol comparing the dosimetric impact of PT with those of three-dimensional conformal radiation therapy (3DCRT) and intensity modulated RT. Based on {sup 18}F-Fluorodeoxyglucose positron emission tomography/computed tomography ({sup 18}F-FDG PET/CT) response, 5 children received 15 to 25.5 cobalt Gy equivalent (CGE) of INPT after receiving 4 cycles of Adriamycin, Bleomycin, Vincristine, Etoposide, Prednisone, Cyclophosphamide or Vincristine, adriamycin, methotrexate, Prednisone chemotherapy, and 10 adults received 30.6 to 39.6 CGE of INPT after 3 to 6 cycles of Adriamycin, Bleomycine, Vinblastine, Dacarbazine. Patients were routinely evaluated for toxicity during and after treatment, using Common Terminology Criteria for Adverse Events, version 3.0, and for relapse by physical examination and routine imaging. Relapse-free survival (RFS) and event-free survival (EFS) rates were calculated using the Kaplan-Meier method from the time of diagnosis. Results: The median follow-up was 37 months (range, 26-55). Two events occurred during follow-up: 1 relapse (inside and outside the targeted field) and 1 transformation into a primary mediastinal large B cell lymphoma. The 3-year RFS rate was 93%, and the 3-year EFS rate was 87%. No acute or late grade 3 nonhematologic toxicities were observed. Conclusions: Although decades of follow-up will be needed to realize the likely benefit of PT in reducing the risk of radiation-induced late effects, PT following chemotherapy in patients with HL is well-tolerated, and disease outcomes were similar to those of conventional photon therapy.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2015

Serum Transforming Growth Factor-β1 Change After Neoadjuvant Chemoradiation Therapy Is Associated With Postoperative Pulmonary Complications in Esophageal Cancer Patients Undergoing Combined Modality Therapy

Purpose: Our aim was to investigate the association of clinical factors, dosimetric parameters, and biomarkers with postoperative pulmonary complications (PPCs) in patients with locally advanced esophageal squamous cell carcinoma (ESCC) treated by neoadjuvant concurrent chemoradiation therapy (CCRT) under strict pulmonary dose constraints and esophagectomy. Methods and Materials: We prospectively enrolled 112 patients undergoing trimodality treatment (including radiation therapy [40 Gy], concurrent taxane-/5-fluorouracil-based regimens, and radical esophagectomy) for ESCC. A PPC was defined as pneumonia or acute respiratory distress syndrome within 30 days after surgery. Serum samples were collected before and within 1 month after CCRT. The association of serum biomarkers with PPCs was detected by proximity ligation assay (PLA) and verified by enzyme-linked immunosorbent assay. Associations of clinical factors, lung dosimetric parameters, and biomarkers with PPC were tested statistically. Results: Thirty-three patients (29.5%) had PPCs. None of the dosimetric parameters was associated with PPCs. Preoperative functional vital capacity (FVC) was significantly associated with PPCs (P=.004). Of the 15 PLA-screened biomarkers, posttreatment transforming growth factor-β1 (TGF-β1) was borderline significantly associated with PPCs (P=.087). Patients with PPCs had significantly larger pre-CCRT to post-CCRT decrease in serum TGF-β1 concentration (−11,310 vs −5332 pg/mL, P=.005) and higher pre-CCRT to post-CCRT percent decline in serum TGF-β1 concentration (−37.4% vs −25.0%, P=.009) than patients without PPCs. On multivariate analysis, preoperative FVC (P=.003) and decrease in TGF-β1 >7040 pg/mL (P=.014) were independent factors associated with PPCs. Conclusions: Preoperative FVC and decrease in serum TGF-β1 level after dose-limited CCRT to the lung are associated with the development of PPCs.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2016

Long-Term Outcomes Among Patients Who Achieve Complete or Near-Complete Responses After the Induction Phase of Bladder-Preserving Combined-Modality Therapy for Muscle-Invasive Bladder Cancer: A Pooled Analysis of NRG Oncology/RTOG 9906 and 0233

Purpose: To investigate the differences in outcomes among patients with muscle-invasive bladder cancer on NRG Oncology Radiation Therapy Oncology Group protocols 9906 and 0233 who achieved complete response and near-complete response after induction chemoradiation and then completed bladder-preserving therapy with chemoradiation therapy (chemo-RT) to full dose (60-64 Gy). Patients and Methods: A pooled analysis was performed on 119 eligible patients with muscle-invasive bladder cancer enrolled on NRG Oncology Radiation Therapy Oncology Group trials 9906 and 0233, who were classified as having a complete (T0) or near-complete (Ta or Tis) response after induction chemo-RT and completed consolidation with a total RT dose of at least 60 Gy. Bladder recurrence, salvage cystectomy rates, and disease-specific survival were estimated by the cumulative incidence method and bladder-intact and overall survivals by the Kaplan-Meier method. Results: Among the 119 eligible patients, 101 (85%) achieved T0, and 18 (15%) achieved Ta or Tis after induction chemo-RT and proceeded to consolidation. After a median follow-up of 5.9 years, 36 of 101 T0 patients (36%) versus 5 of 18 Ta or Tis patients (28%) experienced bladder recurrence (P=.52). Thirteen patients among complete responders eventually required late salvage cystectomy for tumor recurrence, compared with 1 patient among near-complete responders (P=.63). Disease-specific, bladder-intact, and overall survivals were not significantly different between T0 and Ta/Tis cases. Conclusions: The bladder recurrence and salvage cystectomy rates of the complete and the near-complete responders were similar. Therefore it is reasonable to recommend that patients with Ta or Tis after induction chemo-RT continue with bladder-sparing therapy with consolidation chemo-RT to full dose (60-64 Gy).

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2024

Phonon modal analysis of thermal transport in ThO 2 with point defects using equilibrium molecular dynamics

Defects can significantly degrade the thermal conductivity of ThO 2 , an advanced nuclear fuel material as well as a surrogate for other fluorite-structured materials. Here, we investigate how point defects in ThO 2 impact phonon mode-resolved thermal transport. By incorporating phonon modes from lattice dynamics, we decompose the trajectory and heat flux to phonon normal mode space and extract key phonon properties, including phonon relaxation times and their contributions to thermal conductivity. We implement two methods. The first method is based on the Green Kubo formalism to resolve the contribution of each phonon mode to thermal conductivity. The second resolves the lifetime of individual phonon modes and the thermal conductivity is calculated using the Boltzmann transport equation within relaxation time approximation. Notably, a lower contribution of acoustic modes is revealed compared to perturbative approaches considering only three-phonon scattering processes. The effects of four types of point defects are evaluated. The strongest impact on a reduction in thermal conductivity is from Th interstitials, followed by Th vacancies. O interstitials/vacancies have a similar impact, albeit smaller than defects on the thorium sublattice. These observations are consistent with previous studies.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗