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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 1,711 records · Page 95
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DOE OSTI2014

Glioblastoma Recurrence Patterns After Radiation Therapy With Regard to the Subventricular Zone

Purpose: We evaluated the influence of tumor location and tumor spread in primary glioblastoma (GBM), with respect to the subventricular zone (SVZ), on recurrence behavior, progression-free survival (PFS), and overall survival (OS). Methods and Materials: 607 patients (376 male and 231 female) with a median age of 61.3 years (range, 3.0-87.9 years) and primary GBM treated with radiation therapy (RT) from 2004 to 2012 at a single institution were included in this retrospective study. Preoperative images and follow-up examination results were assessed to evaluate tumor location. Tumors were classified according to the tumor location in relation to the SVZ. Results: The median PFS of the study population was 5.2 months (range, 1-91 months), and the median OS was 13.8 months (range, 1-102 months). Kaplan-Meier analysis showed that tumor location in close proximity to the SVZ was associated with a significant decline in PFS and OS (4.8 and 12.3 months, respectively; each P<.001). Furthermore, in cases where tumors were involved with the SVZ, distant cerebral progression (43.8%; P=.005) and multifocal progression (39.8%; P=.008) were more common. Interestingly, opening of the ventricle during the previous surgery showed no impact on PFS and OS. Conclusion: GBM in close proximity to the SVZ was associated with decreased survival and had a higher risk of multifocal or distant progression. Ventricle opening during surgery had no effect on survival rates.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2015

Hemithoracic Intensity Modulated Radiation Therapy After Pleurectomy/Decortication for Malignant Pleural Mesothelioma: Toxicity, Patterns of Failure, and a Matched Survival Analysis

Purpose: To investigate safety, efficacy, and recurrence after hemithoracic intensity modulated radiation therapy after pleurectomy/decortication (PD-IMRT) and after extrapleural pneumonectomy (EPP-IMRT). Methods and Materials: In 2009-2013, 24 patients with mesothelioma underwent PD-IMRT to the involved hemithorax to a dose of 45 Gy, with an optional integrated boost; 22 also received chemotherapy. Toxicity was scored with the Common Terminology Criteria for Adverse Events v4.0. Pulmonary function was compared at baseline, after surgery, and after IMRT. Kaplan-Meier analysis was used to calculate overall survival (OS), progression-free survival (PFS), time to locoregional failure, and time to distant metastasis. Failures were in-field, marginal, or out of field. Outcomes were compared with those of 24 patients, matched for age, nodal status, performance status, and chemotherapy, who had received EPP-IMRT. Results: Median follow-up time was 12.2 months. Grade 3 toxicity rates were 8% skin and 8% pulmonary. Pulmonary function declined from baseline to after surgery (by 21% for forced vital capacity, 16% for forced expiratory volume in 1 second, and 19% for lung diffusion of carbon monoxide [P for all = .01]) and declined still further after IMRT (by 31% for forced vital capacity [P=.02], 25% for forced expiratory volume in 1 second [P=.01], and 30% for lung diffusion of carbon monoxide [P=.01]). The OS and PFS rates were 76% and 67%, respectively, at 1 year and 56% and 34% at 2 years. Median OS (28.4 vs 14.2 months, P=.04) and median PFS (16.4 vs 8.2 months, P=.01) favored PD-IMRT versus EPP-IMRT. No differences were found in grade 4-5 toxicity (0 of 24 vs 3 of 24, P=.23), median time to locoregional failure (18.7 months vs not reached, P not calculable), or median time to distant metastasis (18.8 vs 11.8 months, P=.12). Conclusions: Hemithoracic intensity modulated radiation therapy after pleurectomy/decortication produced little high-grade toxicity but led to progressive declines in pulmonary function; OS and PFS were better in PD-IMRT compared with EPP-IMRT.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2014

Choosing Wisely? Patterns and Correlates of the Use of Hypofractionated Whole-Breast Radiation Therapy in the State of Michigan

Purpose: Given evidence from randomized trials that have established the non-inferiority of more convenient and less costly courses of hypofractionated radiotherapy to the whole breast in selected breast cancer patients who receive lumpectomy, we sought to investigate the use of hypofractionated radiation therapy and factors associated with its use in a consortium of radiation oncology practices in Michigan. We sought to determine the extent to which variation in use occurs at the physician or practice level versus the extent to which use reflects individualization based on potentially relevant patient characteristics (such as habitus, age, chemotherapy receipt, or laterality). Methods and Materials: We evaluated associations between receipt of hypofractionated radiation therapy and various patient, provider, and practice characteristics in a multilevel model. Results: Of 1477 patients who received lumpectomy and whole-breast radiation therapy and were registered by the Michigan Radiation Oncology Quality Consortium (MROQC) from October 2011 to December 2013, 913 had T1-2, N0 breast cancer. Of these 913, 283 (31%) received hypofractionated radiation therapy. Among the 13 practices, hypofractionated radiation therapy use ranged from 2% to 80%. On multilevel analysis, 51% of the variation in the rate of hypofractionation was attributable to the practice level, 21% to the provider level, and 28% to the patient level. On multivariable analysis, hypofractionation was more likely in patients who were older (odds ratio [OR] 2.16 for age ≥50 years, P=.007), less likely in those with larger body habitus (OR 0.52 if separation between tangent entry and exit ≥25 cm, P=.002), and more likely without chemotherapy receipt (OR 3.82, P<.001). Hypofractionation use was not higher in the last 6 months analyzed: 79 of 252 (31%) from June 2013 to December 2013 and 204 of 661 (31%) from October 2011 to May 2013 (P=.9). Conclusions: Hypofractionated regimens of whole-breast radiation therapy have been variably administered in the adjuvant setting in Michigan after the publication of long-term trial results and consensus guidelines. Most of this variability is explained at the practice and provider level rather than by patient-level features, although care is being individualized to some degree.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2015

Time Interval From Breast-Conserving Surgery to Breast Irradiation in Early Stage Node-Negative Breast Cancer: 17-Year Follow-Up Results and Patterns of Recurrence

Purpose: A retrospectivechart review was conducted to determine whether the time interval from breast-conserving surgery to breast irradiation (surgery-radiation therapy interval) in early stage node-negative breast cancer had any detrimental effects on recurrence rates. Methods and Materials: There were 566 patients with T1 to T3, N0 breast cancer treated with breast-conserving surgery and breast irradiation and without adjuvant systemic treatment between 1985 and 1992. The surgery-to-radiation therapy intervals used for analysis were 0 to 8 weeks (201 patients), >8 to 12 weeks (233 patients), >12 to 16 weeks (91 patients), and >16 weeks (41 patients). Kaplan-Meier estimates of time to local recurrence, disease-free survival, distant disease-free survival, cause-specific survival, and overall survival rates were calculated. Results: Median follow-up was 17.4 years. Patients in all 4 time intervals were similar in terms of characteristics and pathologic features. There were no statistically significant differences among the 4 time groups in local recurrence (P=.67) or disease-free survival (P=.82). The local recurrence rates at 5, 10, and 15 years were 4.9%, 11.5%, and 15.0%, respectively. The distant disease relapse rates at 5, 10, and 15 years were 10.6%, 15.4%, and 18.5%, respectively. The disease-free failure rates at 5, 10, and 15 years were 20%, 32.3%, and 39.8%, respectively. Cause-specific survival rates at 5, 10, and 15 years were 92%, 84.6%, and 79.8%, respectively. The overall survival rates at 5, 10, and 15 years were 89.3%, 79.2%, and 66.9%, respectively. Conclusions: Surgery-radiation therapy intervals up to 16 weeks from breast-conserving surgery are not associated with any increased risk of recurrence in early stage node-negative breast cancer. There is a steady local recurrence rate of 1% per year with adjuvant radiation alone.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2015

Nodal Stage of Surgically Resected Non-Small Cell Lung Cancer and Its Effect on Recurrence Patterns and Overall Survival

Purpose: Current National Comprehensive Cancer Network guidelines recommend postoperative radiation therapy (PORT) for patients with resected non-small cell lung cancer (NSCLC) with N2 involvement. We investigated the relationship between nodal stage and local-regional recurrence (LR), distant recurrence (DR) and overall survival (OS) for patients having an R0 resection. Methods and Materials: A multi-institutional database of consecutive patients undergoing R0 resection for stage I-IIIA NSCLC from 1995 to 2008 was used. Patients receiving any radiation therapy before relapse were excluded. A total of 1241, 202, and 125 patients were identified with N0, N1, and N2 involvement, respectively; 161 patients received chemotherapy. Cumulative incidence rates were calculated for LR and DR as first sites of failure, and Kaplan-Meier estimates were made for OS. Competing risk analysis and proportional hazards models were used to examine LR, DR, and OS. Independent variables included age, sex, surgical procedure, extent of lymph node sampling, histology, lymphatic or vascular invasion, tumor size, tumor grade, chemotherapy, nodal stage, and visceral pleural invasion. Results: The median follow-up time was 28.7 months. Patients with N1 or N2 nodal stage had rates of LR similar to those of patients with N0 disease, but were at significantly increased risk for both DR (N1, hazard ratio [HR] = 1.84, 95% confidence interval [CI]: 1.30-2.59; P=.001; N2, HR = 2.32, 95% CI: 1.55-3.48; P<.001) and death (N1, HR = 1.46, 95% CI: 1.18-1.81; P<.001; N2, HR = 2.33, 95% CI: 1.78-3.04; P<.001). LR was associated with squamous histology, visceral pleural involvement, tumor size, age, wedge resection, and segmentectomy. The most frequent site of LR was the mediastinum. Conclusions: Our investigation demonstrated that nodal stage is directly associated with DR and OS but not with LR. Thus, even some patients with, N0-N1 disease are at relatively high risk of local recurrence. Prospective identification of risk factors for local recurrence may aid in selecting an appropriate population for further study of postoperative radiation therapy.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2015

Assessment of Parametrial Response by Growth Pattern in Patients With International Federation of Gynecology and Obstetrics Stage IIB and IIIB Cervical Cancer: Analysis of Patients From a Prospective, Multicenter Trial (EMBRACE)

Purpose: To assess disease response along the parametrial space according to tumor morphology in patients with International Federation of Gynecology and Obstetrics (FIGO) stage IIB and IIIB cervical cancer at the time of image-guided adaptive brachytherapy. Methods and Materials: Patients with FIGO stage IIB and IIIB cervical cancer registered as of November 2013 in the EMBRACE study were evaluated. Tumors were stratified according to morphologic subtype on magnetic resonance imaging (expansive and infiltrative), and the characteristics of those subtypes were analyzed. Parametrial involvement at diagnosis and at brachytherapy was evaluated, and the response to chemo-radiotherapy was classified as good, moderate, or poor. The response grade was compared between the 2 groups and analyzed with regard to tumor volumes, and dosimetric parameters. Results: A total of 452 patients were evaluated, of whom 186 had expansive growth type and 266 had infiltrative morphology. Patients with infiltrative tumors had more extensive disease, as indicated by a higher rate of FIGO stage IIIB disease, as well as radiologic evidence of extension into the distal parametrial space and to the pelvic side wall on magnetic resonance imaging. Cervical necrosis was more common in the infiltrative group. Good response was more common in the expansive group (34% vs 24%; P=.02), and poor response was more common in the infiltrative group (11% and 19%; P=.02). Mean gross tumor volume at diagnosis was equal in both groups (51.7 cm{sup 3}). The high-risk clinical target volume was larger in infiltrative tumors (37.9 cm{sup 3} vs 33.3 cm{sup 3}, P=.005). The mean high-risk clinical target volume D{sub 90} was slightly higher in expansive tumors (92.7 Gy and 89.4 Gy, P<.001). Conclusion: Infiltrative tumors are more advanced at presentation and respond less favorably to chemo-radiotherapy when compared with expansive tumors that are more or less equivalent in size. The use of image-guided adaptive brachytherapy allows achieving reasonably high doses in both groups.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2015

Mapping Patterns of Ipsilateral Supraclavicular Nodal Metastases in Breast Cancer: Rethinking the Clinical Target Volume for High-risk Patients

Purpose: To map the location of metastatic supraclavicular (SCV) lymph nodes (LNMs) in breast cancer patients with SCV node involvement and determine whether and where the radiation therapy clinical target volume (CTV) of this region could be modified in high-risk subsets. Methods and Materials: Fifty-five patients with metastatic SCV LNMs were eligible for geographic mapping and atlas coverage analysis. All LNMs and their epicenters were registered proportionally by referencing the surrounding landmarks onto simulation computed tomography images of a standard patient. CTVs based on selected SCV atlases, including the one by the Radiation Therapy Oncology Group (RTOG) were contoured. A modified SCV CTV was tried and shown to have better involved-node coverage and thus theoretically improved prophylaxis in this setting. Results: A total of 50 (91%) and 45 (81.8%) patients had LNMs in the medial and lateral SCV subregions, respectively. Also, 36 patients (65.5%) had LNMs located at the junction of the jugular-subclavian veins. All nodes were covered in only 25.5% to 41.8% of patients by different atlases. The RTOG atlas covered all nodes in 25.5% of patients. Stratified by the nodes in all the patients as a whole, 49.2% to 81.3% were covered, and the RTOG atlas covered 62.6%. The lateral and posterior borders were the most overlooked locations. Modification by extending the borders to natural anatomic barriers allowed the new CTV to cover all the nodes in 81.8% of patients and encompass 96.1% of all the nodes. Conclusions: According to the distribution of SCV LNMs, the extent of existing atlases might not be adequate for potential metastatic sites in certain groups of patients. The extension of the lateral and posterior CTV borders in high-risk or recurrent patients might be a reasonable approach for increasing coverage. However, additional data in more homogeneous populations with localized disease are needed before routine application.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2016

Global Pattern of Nasopharyngeal Cancer: Correlation of Outcome With Access to Radiation Therapy

Purpose: This study aimed to estimate the treatment outcome of nasopharyngeal cancer (NPC) across the world and its correlation with access to radiation therapy (RT). Methods and Materials: The age-standardized mortality (ASM) and age-standardized incidence (ASI) rates of NPC from GLOBOCAN (2012) were summarized, and [1−(ASM/ASI)] was computed to give the proxy relative survival (RS). Data from the International Atomic Energy Agency (IAEA) and the World Bank were used to assess the availability of RT in surrogate terms: the number of RT equipment units and radiation oncologists per million population. Results: A total of 112 countries with complete valid data were analyzed, and the proxy RS varied widely from 0% to 83% (median, 50%). Countries were categorized into Good, Median, and Poor outcome groups on the basis of their proxy RS (<45%, 45%-55%, and >55%). Eighty percent of new cases occurred in the Poor outcome group. Univariable linear regression showed a significant correlation between outcome and the availability of RT: proxy RS increased at 3.4% (P<.001) and 1.5% (P=.001) per unit increase in RT equipment and oncologist per million population, respectively. The median number of RT equipment units per million population increased significantly from 0.5 in the Poor, to 1.5 in the Median, to 4.6 in the Good outcome groups, and the corresponding number of oncologists increased from 1.1 to 3.3 to 7.1 (P<.001). Conclusions: Nasopharyngeal cancer is a highly treatable disease, but the outcome varies widely across the world. The current study shows a significant correlation between survival and access to RT based on available surrogate indicators. However, the possible reasons for poor outcome are likely to be multifactorial and complex. Concerted international efforts are needed not only to address the fundamental requirement for adequate RT access but also to obtain more comprehensive and accurate data for research to improve cancer outcome.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2016

Practice Patterns Analysis of Ocular Proton Therapy Centers: The International OPTIC Survey

Purpose: To assess the planning, treatment, and follow-up strategies worldwide in dedicated proton therapy ocular programs. Methods and Materials: Ten centers from 7 countries completed a questionnaire survey with 109 queries on the eye treatment planning system (TPS), hardware/software equipment, image acquisition/registration, patient positioning, eye surveillance, beam delivery, quality assurance (QA), clinical management, and workflow. Results: Worldwide, 28,891 eye patients were treated with protons at the 10 centers as of the end of 2014. Most centers treated a vast number of ocular patients (1729 to 6369). Three centers treated fewer than 200 ocular patients. Most commonly, the centers treated uveal melanoma (UM) and other primary ocular malignancies, benign ocular tumors, conjunctival lesions, choroidal metastases, and retinoblastomas. The UM dose fractionation was generally within a standard range, whereas dosing for other ocular conditions was not standardized. The majority (80%) of centers used in common a specific ocular TPS. Variability existed in imaging registration, with magnetic resonance imaging (MRI) rarely being used in routine planning (20%). Increased patient to full-time equivalent ratios were observed by higher accruing centers (P=.0161). Generally, ophthalmologists followed up the post–radiation therapy patients, though in 40% of centers radiation oncologists also followed up the patients. Seven centers had a prospective outcomes database. All centers used a cyclotron to accelerate protons with dedicated horizontal beam lines only. QA checks (range, modulation) varied substantially across centers. Conclusions: The first worldwide multi-institutional ophthalmic proton therapy survey of the clinical and technical approach shows areas of substantial overlap and areas of progress needed to achieve sustainable and systematic management. Future international efforts include research and development for imaging and planning software upgrades, increased use of MRI, development of clinical protocols, systematic patient-centered data acquisition, and publishing guidelines on QA, staffing, treatment, and follow-up parameters by dedicated ocular programs to ensure the highest level of care for ocular patients.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2016

The Pattern of Use of Hypofractionated Radiation Therapy for Early-Stage Breast Cancer in New South Wales, Australia, 2008 to 2012

Purpose: Increasing phase 3 evidence has been published about the safety and efficacy of hypofractionated radiation therapy, in comparison with standard fractionation, in early-stage, node-negative breast cancer. However, uptake of hypofractionation has not been universal. The aim of this study was to investigate the hypofractionation regimen variations in practice across public radiation oncology facilities in New South Wales (NSW). Methods and Materials: Patients with early breast cancer registered in the NSW Clinical Cancer Registry who received radiation therapy for early-stage breast cancer in a publicly funded radiation therapy department between 2008 and 2012 were identified. Data extracted and analyzed included dose and fractionation type, patient age at first fraction, address (for geocoding), year of diagnosis, year of treatment, laterality, and department of treatment. A logistic regression model was used to identify factors associated with fractionation type. Results: Of the 5880 patients fulfilling the study criteria, 3209 patients (55%) received standard fractionation and 2671 patients (45%) received hypofractionation. Overall, the use of hypofractionation increased from 37% in 2008 to 48% in 2012 (range, 7%-94% across departments). Treatment facility and the radiation oncologist prescribing the treatment were the strongest independent predictors of hypofractionation. Weaker associations were also found for age, tumor site laterality, year of treatment, and distance to facility. Conclusions: Hypofractionated regimens of whole breast radiation therapy have been variably administered in the adjuvant setting in NSW despite the publication of long-term trial results and consensus guidelines. Some factors that predict the use of hypofractionation are not based on guideline recommendations, including lower rates of left-sided treatment and increasing distance from a treatment facility.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2017

{sup 18}F-Fluorodeoxyglucose/Positron Emission Tomography Predicts Patterns of Failure After Definitive Chemoradiation Therapy for Locally Advanced Non-Small Cell Lung Cancer

Background: We previously reported that pretreatment positron emission tomography (PET) identifies lesions at high risk for progression after concurrent chemoradiation therapy (CRT) for locally advanced non-small cell lung cancer (NSCLC). Here we validate those findings and generate tumor control probability (TCP) models. Methods: We identified patients treated with definitive, concurrent CRT for locally advanced NSCLC who underwent staging {sup 18}F-fluorodeoxyglucose/PET/computed tomography. Visible hypermetabolic lesions (primary tumors and lymph nodes) were delineated on each patient's pretreatment PET scan. Posttreatment imaging was reviewed to identify locations of disease progression. Competing risks analyses were performed to examine metabolic tumor volume (MTV) and radiation therapy dose as predictors of local disease progression. TCP modeling was performed to describe the likelihood of local disease control as a function of lesion size. Results: Eighty-nine patients with 259 hypermetabolic lesions (83 primary tumors and 176 regional lymph nodes) met the inclusion criteria. Twenty-eight patients were included in our previous report, and the remaining 61 constituted our validation cohort. The median follow-up time was 22.7 months for living patients. In 20 patients, the first site of progression was a primary tumor or lymph node treated with radiation therapy. The median time to progression for those patients was 11.5 months. Data from our validation cohort confirmed that lesion MTV predicts local progression, with a 30-month cumulative incidence rate of 23% for lesions above 25 cc compared with 4% for lesions below 25 cc (P=.008). We found no evidence that radiation therapy dose was associated with local progression risk. TCP modeling yielded predicted 30-month local control rates of 98% for a 1-cc lesion, 94% for a 10-cc lesion, and 74% for a 50-cc lesion. Conclusion: Pretreatment FDG-PET identifies lesions at risk for progression after CRT for locally advanced NSCLC. Strategies to improve local control should be tested on high-risk lesions, and treatment deintensification for low-risk lesions should be explored.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2018

Patterns of Involved-Field Radiation Therapy Protocol Deviations in Pediatric Versus Adolescent and Young Adults With Hodgkin Lymphoma: A Report From the Children's Oncology Group AHOD0031

The presented protocol for pediatric intermediate-risk Hodgkin lymphoma evaluated the use of a dose-intensive chemotherapy regimen (ABVE-PC [doxorubicin, bleomycin, vincristine, etoposide, cyclophosphamide, prednisone]) with response-based therapy augmentation (addition of DECA [dexamethasone, etoposide, cisplatin, cytarabine]) or therapy reduction (elimination of radiation).

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2018

Contemporary Statewide Practice Pattern Assessment of the Palliative Treatment of Bone Metastasis

Palliative radiation therapy for bone metastases is often viewed as a single entity, despite national guidelines providing input principally only for painful uncomplicated bone metastases. Data surrounding the treatment of bone metastases are often gleaned from questionnaires of what providers would theoretically do in practice or from population-based data lacking critical granular information. We investigated the real-world treatment of bone metastases with radiation therapy.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2021

Review of Palliative Radiation Therapy Patterns of Practice for Adrenal Metastases in British Columbia

The adrenal gland is a common site of metastasis in patients with advanced cancer, but it is rarely symptomatic. A subset of patients develop a complex pain syndrome with anorexia, nausea, and poorly localized visceral pain in the back, flank, or epigastric region. These symptoms can affect quality of life and are occasionally challenging to palliate. The role of palliative radiation therapy (PRT) in these patients is unclear. This population-based retrospective study evaluates PRT practices for patients with adrenal metastases and aims to describe treatment response and acute toxicity.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2022

Patterns of Care, Tolerability, and Safety of the First Cohort of Patients Treated on a Novel High-Field MR-Linac Within the MOMENTUM Study: Initial Results From a Prospective Multi-Institutional Registry

High-field magnetic resonance-linear accelerators (MR-Linacs), linear accelerators combined with a diagnostic magnetic resonance imaging (MRI) scanner and online adaptive workflow, potentially give rise to novel online anatomic and response adaptive radiation therapy paradigms. The first high-field (1.5T) MR-Linac received regulatory approval in late 2018, and little is known about clinical use, patient tolerability of daily high-field MRI, and toxicity of treatments. Herein we report the initial experience within the MOMENTUM Study (NCT04075305), a prospective international registry of the MR-Linac Consortium.

62 RADIOLOGY AND NUCLEAR MEDICINE↗