Trends in Adjuvant External Beam Radiation Therapy for Nonanaplastic Thyroid Cancer in California, 2003-2017

BackgroundExternal beam radiation therapy (EBRT) is rarely used to treat patients with differentiated or medullary thyroid cancer. Although EBRT is generally administered to patients with high-risk or unresectable diseases, neither its indications for the use nor the associated outcomes are well-defined. We used a statewide cohort to assess the trends in EBRT use and postradiation outcomes in California.MethodsA population-based study of patients within the California Cancer Registry who underwent EBRT after surgery for nonanaplastic thyroid cancer (2003-2017) was conducted. The primary outcome was the annual utilization rate of EBRT. The secondary outcomes included Kaplan-Meier analysis for cause-specific survival and identifying factors associated with improved survival after EBRT.ResultsAmong the 57 607 patients with nonanaplastic thyroid cancer from 2003 to 2017, 344 (0.6%) patients received EBRT. EBRT was utilized in 0.4% of papillary, 1.1% of follicular, and 7.7% of medullary thyroid cancers in California. Overall, 99 (28.8%) patients treated with EBRT died of thyroid cancer. The 10-year cause-specific survival of all patients with thyroid cancer after EBRT was 61.5% (95% CI: 54.8%-69.1%) and that of patients without distant disease was 80.3% (95% CI: 73.5%-87.8%). The survival outcomes varied by tumor size, histology, disease stage, patient age at diagnosis, and the presence of extrathyroidal extension (P < .05).ConclusionsThe use of adjuvant EBRT for nonanaplastic thyroid cancer remained stable and low in California from 2003 to 2017. The comparative efficacy of EBRT was not discernible in this study, but disease control appeared durable in select patients. Well-controlled observational studies and/or prospective studies are needed to better define which patients benefit from EBRT.     

Ectoine disperses keratin and alters hydration kinetics in stratum corneum

Moisturizing compounds are commonly applied topically to human stratum corneum (SC). Many types of molecular species are employed, most commonly including humectants and occlusives. We find new evidence of keratin dispersion caused by the moisturizing compound ectoine (1,4,5,6-tetrahydro-2-methyl-4-pyrimidinecarboxylic acid), and provide the first characterization of its impacts on the hydration kinetics and biomechanics of SC. A second compound, 2-(2-hydroxyethoxy)ethylguanidine succinate (HEG) was investigated for comparison. A suite of biomechanical and biochemical assays including FTIR, drying stress, and cellular cohesion were used. Studies were conducted on normal, lipid-extracted, and lipid plus natural moisturizing factor extracted SC. Ectoine was found to improve the dispersity and hydration of keratin bundles in corneocytes. It also decreased rates of stress development in lipid extracted SC when exposed to a dry environment by ～30% while improving stress reduction during rehydration by ～20%. Peak stresses were increased in harsh drying environments of <5% RH, but SC swelling measurements suggest that water retention was improved in ambient conditions. Further, changes up to ～4 J/m² were seen in cohesion after ectoine treatments, suggesting corneodesmosome interactions. HEG was tested and found to disperse keratin without impacting corneodesmosomes. These results indicate that keratin dispersants produce beneficial effects on SC hydration kinetics, ultimately resulting in higher SC hydration under ambient conditions.     

Ohmic Contact Fabrication Using a Focused-ion Beam Technique and Electrical Characterization for Layer Semiconductor Nanostructures

Layer semiconductors with easily processed two-dimensional (2D) structures exhibit indirect-to-direct bandgap transitions and superior transistor performance, which suggest a new direction for the development of next-generation ultrathin and flexible photonic and electronic devices. Enhanced luminescence quantum efficiency has been widely observed in these atomically thin 2D crystals. However, dimension effects beyond quantum confinement thicknesses or even at the micrometer scale are not expected and have rarely been observed. In this study, molybdenum diselenide (MoSe₂) layer crystals with a thickness range of 6-2,700 nm were fabricated as two- or four-terminal devices. Ohmic contact formation was successfully achieved by the focused-ion beam (FIB) deposition method using platinum (Pt) as a contact metal. Layer crystals with various thicknesses were prepared through simple mechanical exfoliation by using dicing tape. Current-voltage curve measurements were performed to determine the conductivity value of the layer nanocrystals. In addition, high-resolution transmission electron microscopy, selected-area electron diffractometry, and energy-dispersive X-ray spectroscopy were used to characterize the interface of the metal–semiconductor contact of the FIB-fabricated MoSe₂ devices. After applying the approaches, the substantial thickness-dependent electrical conductivity in a wide thickness range for the MoSe₂-layer semiconductor was observed. The conductivity increased by over two orders of magnitude from 4.6 to 1,500 Ω⁻¹ cm⁻¹, with a decrease in the thickness from 2,700 to 6 nm. In addition, the temperature-dependent conductivity indicated that the thin MoSe₂ multilayers exhibited considerably weak semiconducting behavior with activation energies of 3.5-8.5 meV, which are considerably smaller than those (36-38 meV) of the bulk. Probable surface-dominant transport properties and the presence of a high surface electron concentration in MoSe₂ are proposed. Similar results can be obtained for other layer semiconductor materials such as MoS₂ and WS₂.     

A new strategy for craniospinal axis localization and adaptive dosimetric evaluation using cone beam CT

Background and AimComputational complexities encountered in craniospinal irradiation (CSI) have been widely investigated with different planning strategies. However, localization of the entire craniospinal axis (CSA) and evaluation of adaptive treatment plans have traditionally been ignored in CSI treatment. In this study, a new strategy for CSI with comprehensive CSA localization and adaptive plan evaluation has been demonstrated using cone beam CT with extended longitudinal field-of-view (CBCT_eLFOV).Materials and MethodsMulti-scan CBCT images were acquired with fixed longitudinal table translations (with 1 cm cone-beam overlap) and then fused into a single DICOM-set using the custom software coded in MatLab™. A novel approach for validation of CBCT_eLFOV was demonstrated by combined geometry of Catphan-504 and Catphan-604 phantoms. To simulate actual treatment scenarios, at first, the end-to-end workflow of CSI with VMAT was investigated using an anthropomorphic phantom and then applied for two patients (based on random selection).ResultsThe fused CBCT_eLFOV images were in excellent agreement with planning CT (pCT). The custom developed software effectively manages spatial misalignments arising out of the uncertainties in treatment/setup geometry. Although the structures mapped from pCT to CBCT_eLFOV showed minimal variations, a maximum spatial displacement of up to 1.2 cm (and the mean of 0.8 ± 0.3 cm) was recorded in phantom study. Adaptive plan evaluation of patient paradigms showed the likelihood of under-dosing the craniospinal target.ConclusionOur protocol serves as a guide for precise localization of entire CSA and to ensure adequate dose to the large and complex targets. It can also be adapted for other complex treatment techniques such as total-marrow-irradiation and total-lymphoid-irradiation.     

Multicenter evaluation of a synthetic single-crystal diamond detector for CyberKnife small field size output factors

PurposeThe aim of the present work was to evaluate small field size output factors (OFs) using the latest diamond detector commercially available, PTW-60019 microDiamond, over different CyberKnife systems. OFs were measured also by silicon detectors routinely used by each center, considered as reference.MethodsFive Italian CyberKnife centers performed OFs measurements for field sizes ranging from 5 to 60 mm, defined by fixed circular collimators (5 centers) and by Iris^™ variable aperture collimator (4 centers). Setup conditions were: 80 cm source to detector distance, and 1.5 cm depth in water. To speed up measurements two diamond detectors were used and their equivalence was evaluated. MonteCarlo (MC) correction factors for silicon detectors were used for comparing the OF measurements.ResultsConsidering OFs values averaged over all centers, diamond data resulted lower than uncorrected silicon diode ones. The agreement between diamond and MC corrected silicon values was within 0.6% for all fixed circular collimators. Relative differences between microDiamond and MC corrected silicon diodes data for Iris^™ collimator were lower than 1.0% for all apertures in the totality of centers. The two microDiamond detectors showed similar characteristics, in agreement with the technical specifications.ConclusionsExcellent agreement between microDiamond and MC corrected silicon diode detectors OFs was obtained for both collimation systems fixed cones and Iris^™, demonstrating the microDiamond could be a suitable detector for CyberKnife commissioning and routine checks. These results obtained in five centers suggest that for CyberKnife systems microDiamond can be used without corrections even at the smallest field size.     

LCA of Danish Fish Products. New methods and insights (9 pp)

Goal, Scope and Background This article presents the main results from a PhD dissertation about environmental impacts from Danish fish products. The focus is on LCA results for flatfish, but the article also gives an overview of screenings of other fish species. Furthermore, it includes an analysis of the energy consumption in the fishing stage – as a function of fish species and fishing methods. Alternative impact categories that have not been included in the quantitative LCA and policy perspectives are elaborated in the discussion part of the paper. Methods The study represents a consequential LCA approach (opposed to attributional) and the functional unit is one kg consumed flatfish filet in units of 300 gram (cardboard boxes). Data are obtained from statistics, interviews, literature, and databases – mainly ETH-ESU 96 and the Danish LCA food database. The EDIP 97 method has been applied for life cycle impact assessment (LCIA) and the results have been verified by Ecoindicator 99. Results The results of the flatfish LCA show that the fishing stage has the largest impact potential for the investigated impact categories. This is mainly due to a relatively high fuel consumption and significant emissions of biocides from anti-fouling agents (contributing to ecological toxicity). But large reductions in fuel intensity (fuel consumption per kg caught fish) can be obtained by changing the type of fishing gear – particularly in flatfish fisheries. The consumption and retail stages represent significant impact potentials as well, while processing is insignificant. LCA screenings of other fish species show the same picture, but there are cases (herring, mackerel and mussels) where the fishing stage is less important, while the opposite is the case for processing – mainly due to energy intensive packaging materials. Discussion A limited number of impact categories have been investigated, but a 'qualitative' LCA, focusing on other fishery specific impacts, emphasises that the fishing stage is indeed the overall most important. In this regard, it is argued that fuel requirements in many cases are proportional to environmental impacts related to 'discard' and 'seafloor damage'. Hence, it is worth focusing on energy for many reasons. In a policy context, it is a paradox that mainly the fish processing industry has been subjected to environmental regulations. Recommendation and Perspective Future scenarios indicate that energy consumption will remain one of the most important environmental aspects in the fishing stage – partly due to regulations of anti-fouling biocides (e.g. TBT) and partly because of the continued depletion of fish stocks. From an environmental policy perspective, it is therefore recommended to broaden the perspective of existing fishery regulations and increase the focus on fishing gear and energy in the primary production (fishing stage).     

Evaluation of a variable angle scanning method to estimate relative abundance and distribution of fish using a single-beam echosounder in shallow lakes

The validity of a hydroacoustic procedure was assessed using a combination of horizontal and vertical scanning to map the distribution of targets and to estimate target density in a shallow lake. Three distribution patterns were created using 37–50 artificial targets (metal hex nuts) anchored at known positions. Real and acoustic maps were qualitatively similar. Aggregation indices estimated by hydroacoustics were within 15% of the real values. Target density ranged from 1 to 8 targets per 100 m⁻³. Estimated target densities were within one target of the real values for 88% of our observations. The variable angle approach was used also to monitor daily and seasonal variations in fish distribution and relative abundance outside the littoral zone. Dace Phoxinus eos × P. neogaeus appeared to use the littoral as a refuge during the day and to migrate to the pelagic zone at dusk. The movements of dace outside the littoral zone were limited to the months of June-August. The variable angle acoustic approach can be useful to estimate fish distribution and relative abundance in shallow lakes.     

Tensile Stress in Nanometre Thick MBE Grown CaF2 on (111) Si

CaF₂ epitaxial layers were prepared by MBE and investigated by RBS and ion channeling measurements. Films of about 30 nm thickness were found to be strained by tensile stress causing a rhombohedral symmetry of the layers. These results are interpreted in terms of the different thermal expansion coefficients of substrate and deposit, respectively.