bluuebunny/crossref_metadata_2025_split huggingface dataset:
Decompression and Dynamic Transpedicular Stabilization Using Polyetheretherketone Rods and Pedicle Screws vs. Decompression Alone for Single-Level Spinal Canal Stenosis with Listhesis: A Retrospective Case-Control Study
Authors: Tosic Lazar , Baschera Dominik , Oberle Joachim , Alex Alfieri 
Published: August 2019

Abstract
Background Spinal stenosis is frequently caused by spondylolisthesis, and surgical treatment may be indicated. However, whether decompression alone or decompression with dynamic stabilization offers better surgical outcomes remains unclear. We compared the clinical and radiologic results of patients with single-level lumbar spinal stenosis and grade 1 spondylolisthesis undergoing microsurgical decompression alone or decompression with transpedicular dorsal dynamic stabilization.
Methods We retrospectively analyzed 20 patients undergoing microsurgical decompression and dorsal dynamic transpedicular stabilization using polyetheretherketone (PEEK) rods in one center from 2011 to 2017. Twenty patients with the same diagnosis undergoing microsurgical decompression alone were used as controls. Reoperation of the index and neighboring segments, back/leg pain, neurologic deficits, and the use of pain medication were assessed. For stabilization patients, radiographic progression of degeneration in the neighboring segments, listhesis degree in the index segment, and implant failure were assessed.
Results All patients had good clinical outcomes at 3 and 12 months postoperatively. In stabilization patients, the visual analog scale (VAS) score for leg pain decreased from 5 points (median) to 1.6 at 3 months and 0.6 at 1 year postoperatively. In controls, the VAS score improved from 4.8 points to 1.1 at 3 months and 0.3 at 1 year postoperatively. The VAS score for back pain in stabilization patients decreased from 7.6 points (median) to 1.7 at 3 months and 0.1 at 1 year postoperatively. In controls, it decreased from 7.7 points to 1.1 at 3 months and 0.2 at 1 year postoperatively. In patients with additional dynamic stabilization, a longer hospital stay (stabilization group: 8.7 ± 4.1; control: 6.2 ± 1.6 days), longer operative time (stabilization group: 132.7 ± 41.3; control: 83.2 ± 31.7 minutes), and higher complication rates (revision surgery performed in two stabilization patients) were found.
Conclusion No indications in our study showed that additional dynamic stabilization with PEEK rods offers any advantage over decompression alone.
Evaluation of a clinical dose accumulation algorithm using deformable gel dosimetry
Authors: Matrosic Charles K , Holmes Shannon , Bednarz Bryan , Culberson Wesley 
Published: August 2019

Abstract
Deformable 3D dosimetry represents a robust method of verifying the accuracy of clinical deformable dose accumulation algorithms used to monitor interfraction anatomical changes during radiotherapy treatments. For this study, a deformable abdominal phantom was developed incorporating a deformable nPAG gel dosimeter for the dose verification of Adaptivo™, a commercial software program with a deformable dose accumulation algorithm. A comparison was made for three single fraction irradiations of gel dosimeters, each with a different deformation state. Additionally, a comparison was made for the cumulative dose over a three-fraction treatment of a single gel dosimeter with individual fraction deformations matching those of the single fraction measurements. The single fraction irradiations resulted in target contour dose volume histograms (DVH) created by Adaptivo™ that were in close agreement with those determined by gel dosimeter measurements for doses similar to and higher than the planned target dose, with two of the three cases matching to within 5%. Discrepancies are attributed to a deformed contour compression during analysis in the cases where the phantom was deformed. The three-fraction treatment resulted in very close agreement between the DVHs determined through the gel dosimeter measurements and Adaptivo™ calculations across the full range of doses, with an average absolute discrepancy of 2.0% and a maximum absolute discrepancy of 6.3%.
Feasibility of radiosurgery dosimetry using NIPAM 3D dosimeters and x-ray CT
Authors: Adamson Justus , Carroll Jaclyn , Trager Michael , Yoon Paul , Kodra Jacob , Yin Fang-Fang , Maynard Evan , Hilts Michelle , Oldham Mark , Jirasik Andrew 
Published: August 2019

Abstract
We investigated the feasibility of using N-isopropylacrylamide (NIPAM) dosimeters with x-ray CT to verify radiosurgery dose. Dosimeters were prepared at one facility and shipped to a second facility for irradiation. A simulation CT was acquired and plans prepared for a 4 field box, and a 4 arc VMAT radiosurgery plan to 6 targets with 1cm diameter. Each dosimeter was aligned via CBCT and irradiated, followed by 5 diagnostic CTs acquired after >24 hours, which were averaged for analysis. Absolute dose calibration was applied and dose evaluated for both plans. Hounsfield Units were proportional to dose above 10-12Gy. For the 4-field box, mean difference between measured and predicted dose >10Gy was -0.13Gy ±1.69Gy and gamma index was <1 for 72% and 65% of voxels using a 5% / 1mm and 3% / 2mm criteria, respectively (threshold = 15Gy, global dose criteria). For the multifocal SRS case, mean dose within each target was within -0.14Gy± 0.55Gy of the expected value, and gamma index was < 1 for 94.0% and 99.5% of voxels, respectively (threshold = 15Gy). NIPAM based 3D dosimetry with x-ray CT is well suited for validating radiosurgery spatial alignment, as well as dose distributions when dose is above 10-12Gy.
Evaluation of a lung-equivalent gel dosimeter for MR image-guided radiation therapy
Authors: McDonald BA , Lee HJ , Ibbott GS 
Published: August 2019

Abstract
With recent advances in magnetic resonance image-guided radiation therapy (MR-IGRT), Fricke gel dosimetry has demonstrated value for its ability to measure three-dimensional dose distributions in the presence of a strong magnetic field. This strong magnetic field causes hot and cold spots in dose distributions at the interfaces of lung and normal tissue due to a phenomenon known as the electron return effect (ERE). In this paper, we report the development of lung-equivalent gel dosimeters to better measure dose to lung tissue caused by the ERE. Small polystyrene beads of variable sizes were mixed into Fricke xylenol orange gelatin (FXG) and ferrous oxide xylenol orange (FOX) gels. Lung-equivalence was confirmed by measuring the average CT number of each gel. The effects of gel type, bead size, and voxel size on uniformity and signal intensity were investigated. The smallest beads ( < 1 mm) exhibited the best uniformity, with values comparable to conventional gel with 2 mm voxels. Signal intensity followed an inverse relationship with uniformity, but FXG low-density dosimeters generated enough signal to produce acceptable quality images. The spin-lattice relaxation rate (R1 = 1/T1) increased with dose, which enabled us to measure dose to both soft tissue and lung due to the ERE using a phantom simulating the soft tissue-lung interface.
Pre-clinical and small field dosimetry
Authors: Wuu Cheng-Shie , Wang Yi-Fang , Xu Andy Y. , Adamovics John 
Published: August 2019

Abstract
Preclinical in vivo studies have drastically improved over the past decade with the development of cone beam computed tomography (CBCT) image-guided small animal irradiation systems. Such systems produce 220 or 225 kV x-rays with square and circular field sizes ranging from 0.5 to 10 mm. The dosimetry of such equipment involving kilovoltage small-field dosimetry has not received as much attention as the megavoltage small-field dosimetry. The dosimetry of megavoltage small fields can be challenging due to lateral charged particle disequilibrium, detector volume averaging effect, and high dose gradients. Clinically there has been a rapid increase in the use of small fields in modern radiotherapy techniques such as stereotactic radiosurgery (SRS) and stereotactic radiotherapy (SBRT). This study presents dosimetric properties of image-guided small animal irradiation systems. Both EBT Gafchromic films and 3-D PRESAGE measured beam data were presented and compared with the calculated dose distribution from a commissioned planning system. For megavoltage small-field dosimetry, EBT3 films and PRESAGE dosimeters were used to measure the dose distributions for MLC-delimited 6 x 6 to 20 x 20 mm2 square fields, and for selected IMRT and VMAT plans with small field sizes or segments of 1-4 cm. A single-beam optical CT scanner was used as the readout mechanism of the radiation-induced 3-D information in the PRESAGE phantoms. Measured data sets were compared with calculated results from Eclipse Acuros XB. The results for kilovoltage small animal irradiator showed that PDD data measured from EBT films and PRESAGE dosimeters are in agreement within 3%; profiles and 2-D dose distributions measured from PRESAGE present a larger penumbra compared with those from EBT films. Discrepancies between measured beam data and treatment planning data were identified. For megavoltage small fields, the measured data percent depth dose, beam profiles, and dose distributions were found to agree within experimental uncertainties for EBT films and PRESAGE dosimeters. Beam profiles for MLC-delimited field sizes less than 10 mm reveal some discrepancies in the penumbra region between measured data and calculated results. Dose distributions from EBT film and PRESAGE measurements demonstrate that 3-D dosimetry measurement for small-field IMRT and VMAT QA may be necessary to ensure a complete verification of dose delivery and accuracy.
Optimization for stability of the deformable FlexyDos3D radiation dosimeter and curing effects
Authors: Wheatley M J , Balatinac A S , Booth J T , De Deene Y 
Published: August 2019

Abstract
Previous formulations of the FlexyDos3D dosimeter have shown significant changes in the dose-response over time. In this study, various formulations of the dosimeter were created and tested to see if this stability could be improved. A dosimeter that was stable over a three-day period was found. Rapid manufacture of this dosimeter for patient-specific validation of radiotherapy treatments is desirable. The use of 3D printing manufacturing techniques for thermosetting polymers require high temperatures to cure the polymer within a reasonable time. The effect of different curing temperatures and times were investigated for the FlexyDos3D radiation dosimeter for its effect on stability. No significant difference in the dose-response was found for dosimeters cured for different curing times beyond an hour. A significant dose-response offset was found between dosimeters cured at different temperatures, but the dose-response sensitivity was the same.
Development of fast Monte Carlo code for high dose rate brachytherapy
Authors: Hu Ankang , Qiu Rui , Wu Zhen , Li Chunyan , Zhang Hui , Li Junli 
Published: August 2019

Abstract
Brachytherapy plays an important role in the treatment of various cancers. The TG-43 formalism is widely used in dose calculation for brachytherapy, but it is not accurate as it assumes the patient as homogeneously constituted of water. Monte Carlo simulation can obtain accurate result, but computing time using traditional code is too long to be accepted in clinical application. This work developed a fast Monte Carlo code THUBrachy for high dose rate brachytherapy dose calculation. THUBrachy can simulate photon with energy up to 3MeV for heterogeneous materials and obtain dose, fluence and dose distribution. It applies several accelerators such as Graphics Processing Unit (GPU), Intel Xeon Phi to perform dose calculation with good accuracy and high speed. THUBrachy adopts several parallel programming models to transplant the code onto different hardware accelerators. Voxel geometry based on CT images is used to describe the tissues of patient. A linear track-length estimator is used for dose calculation. In the preliminary accuracy test, a cuboid water model and a heterogeneous-material model were selected as the phantoms. Dose and fluence distributions were calculated by both THUBrachy and FLUKA which is a well-benchmarked Monte Carlo code. A total of 5×108 photons were simulated to make the uncertainty in all area less than 5%. The maxium difference of the results in low dose area is less than 3% and in high dose area is less than 1%, indicating a good agreement. In the performance test, a phantom consisted by 24 types of human tissue materials was chosen to estimate the performance in practical application. Dose distributions with an uncertainty of 2% or less for the target volume were obtained in less than 1 min by simulating 5×107 photons with a GTX 1080Ti, while FLUKA taking several hours to simulate the same number of particles. There is great potential for clinical application in brachytherapy dose planning using this fast Monte Carlo code.
How important is the dose rate sensitivity of 2D and 3D radiation dosimeters?
Authors: De Deene Yves 
Published: August 2019

Abstract
Several kinds of chemical 3D radiation dosimeters have been fabricated to acquire the dose distribution in clinical radiotherapy. A legitimate concern with every new dosimeter is its dose rate dependent response because, the dose rate in each point of the phantom during a clinical treatment is unknown. Unfortunately, many 3D dosimeters have shown some degree of dose rate dependence. In practice, radiation dosimeters are mostly calibrated using a calibration curve that is obtained by irradiating calibration vials with different doses but using a fixed dose rate. Therefore, when applying a dose calibration to an experimentally obtained dose distribution, a deviation between the measured dose distribution and the actual dose distribution can be expected. In this computational study, the effect of a dose rate dependent dosimeter response on a theoretical dose distribution has been investigated. In order to compare the effect of dose rate, a gamma evaluation is performed between the predefined dose distribution and the dose distribution that is affected by a dose rate dependent radiation response. It is found that a dose rate difference of -10%, results in a gamma pass rate of 100% in the 3D dose distribution.
Multi-scale dosimetry with multi-scale Chinese reference phantoms
Authors: Qiu Rui , Wu Zhen , Li Chunyan , Ren Li , Wang Wenjing , Ma Ruiyao , Hu An kang , Zhu Hongyu , Li Junli 
Published: August 2019

Abstract
Recent studies on the development and applications of Chinese reference phantoms are reported in this paper. The Chinese adult reference male (CRAM) and female (CRAF) phantoms had been developed in previous work. A Chinese male phantom library was constructed with 7 different heights ranging from 155 cm to 185 cm and 12 phantoms with different total body masses in each height. Chinese paediatric reference phantoms were constructed for 3 months, 1 year, 5 years, 10 years, and 15 years male and female respectively. Detailed organ models were developed, including a set of microscopic skeletal models, a set of detailed breast models, a detailed human respiratory tract model and a detailed eye model. The phantoms were applied in radiation protection, including dose estimation from external exposure and internal exposure, in normal situations and in accidental situations, and detailed dose distributions in radiation-sensitive organs. The phantoms were also applied in medical imaging field such as dose estimation in mammography, CT and X-ray radiology, and could be potentially used in the secondary cancer estimation induced by radiation therapy.
A benchtop UV irradiator for 3D dosimetry laboratories with dose considerations in a spinning NMR test tube
Authors: De Deene Yves 
Published: August 2019

Abstract
Many different chemical radiation dosimeters have been fabricated over the last 20 years. In the search for new dosimeters, next to being sensitive to clinical radiation doses, several other physicochemical characteristics need to be satisfied, such as stability of the dose response, spatial integrity, temperature independence, dose rate independence and tissue equivalence. The development of new dosimeters is often hindered by a limited access to radiation facilities to irradiate hundreds of test tubes or cuvettes to study these physicochemical properties. To facilitate this basic experimental research, we propose the use of an inexpensive UVC irradiator. While care is required in extrapolating the results obtained with UV radiation to high energetic X-rays, for several studies, a UV irradiator is a handy tool for first line investigation of new dosimeters. In this study, we calculated the dose distribution in a cylindrical test tube when being rotated during UV exposure. A quantitative analysis allows the optimization of the set-up to obtain dose rates in the sample in similar order of magnitude that are delivered at a clinical Linac. Regardless the usefulness of a UVC irradiator in the laboratory for preliminary testing, it should not be a complete replacement for measurements with high energetic X-rays.
Survivalism and Other Class Fantasies
Authors: Shonkwiler Alison 
Published: August 2019

Abstract
The subjective demands of crisis capitalism are addressed by three books on the literature and culture of the late twentieth and early twenty-first centuries. These texts shed light on the possibilities and limits of materialist critique in holding various forms of ruthless, abstracted, and injurious capitalism to account. Measuring the uneven development of neoliberal subjectivities across different groups and conditions invites readers to theorize the class dimensions embedded in aesthetic narratives. An analysis of the “microeconomic mode” of contemporary subjectivity, which redefines the traditional liberal political subject to a narrowly survivalist subject of “life-interest,” offers a way of understanding how populations become increasingly sortable into more- and less-disposable groups. A study of deindustrialization literature, focused on the working-class experience, considers the cultural persistence of the blue-collar figure in a service and knowledge economy. A study of finance fictions argues that contemporary capitalism fits a new, psychotic paradigm and requires theorizing a new financial ontology of the present.
Dual nationality revisited: a modern approach to dual nationals in non-ICSID arbitrations
Authors: Michalopoulos Stavros , Hicks Edward 
Published: August 2019

Abstract
The authors revisit the vexed question of the standing of investors to bring a claim against one of their states of origin. Contrary to Article 25 of the Convention on the Settlement of Investment Disputes between States and Nationals of Other States (ICSID Convention), which forbids natural persons in possession of the nationality of the host state to initiate proceedings against it, the majority of other arbitration rules do not provide for such a prohibition. Consequently, unlike the realm of diplomatic protection, where the question seems settled, there is little guidance in the treaty-based field of investment arbitration on the probable scenario of a dual national suing one of its states of nationality in a non-ICSID arbitration context. Some tribunals have resorted to traditional principles to deny investment protection to dual nationals, whereas recent awards have been considerably more lenient. This article will demonstrate that, given the fundamental differences between investment treaty arbitration and diplomatic protection, the application by analogy of doctrinal formulations of the former to the latter is not warranted. Instead, a holistic interpretation in accordance with Article 31 of the Vienna Convention on the Law of Treaties should be the primary point of focus of international tribunals, taking into account the object and purpose of the treaty and comparable treaty practice.
A-03 Ethnic/Racial Differences in Longitudinal Neurocognitive Change among People Living with HIV
Authors: Watson C , Kamalyan L , Hussain M , Tang B , Collier A , Clifford D , Gelman B , Sacktor N , Morgello S , McCutchan J A , Ellis R , Grant I , Heaton R , Marquine M 
Published: August 2019

Abstract
HIV disproportionately affects Black and Latino people in the United States, but data on longitudinal neurocognitive patterns for these groups are scarce. This study evaluated the incidence and predictors of neurocognitive decline by ethnicity/race in a cohort of Black, Latino, and White people living with HIV (PLWH). Participants included 499 PLWH (43.5% White, 42.7% Black, 13.8% Latino; mean age at baseline = 43.5) from the six-site CNS HIV Anti-Retroviral Therapy Effects Research (CHARTER) study. Participants completed comprehensive neurocognitive and neuromedical evaluations over 3-7 study visits for an average of 2.8 years (SD = 1.1). Interpertation of neurocognitive change was based on published methods using regression-based norms that correct for baseline performance and practice effects. Survival analyses investigated the relationship between ethnicity/race and neurocognitive change, and predictors of neurocognitive decline. In follow-up, 108 participants (21.6%) declined, 311 (62.3%) remained stable, and 80 (16.0%) improved. In Cox proportional hazard models, hazard ratios for neurocognitive decline were increased for Latinos compared to Whites (HR = 2.19, 95%CI = 1.32-3.63, p = .002) and Blacks (HR = 1.87, 95%CI = 1.14-3.04, p = .01). Including significant covariates (baseline nadir CD4, hepatitis C Virus, and VACS Index: a composite marker of physical health among PLWH)did not significantly decrease the elevated risk for decline among Latinos. We found that Latino PLWH appear to have higher risk of neurocognitive decline compared to White and Black PLWH. Traditional markers of HIV disease and physical health at baseline did not explain this elevated risk of neurocognitive decline. Future research examining economic, socio-environmental, and culturally-relevant biomedical factors may help to explain this observed ethnic/racial disparity in longitudinal neurocognitive function in HIV.