Abstract
Background
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F-fluciclovine is a synthetic amino acid positron emission tomography (PET) radiotracer that is approved for use in prostate cancer. In this clinical study, we characterised ...the kinetic model best describing the uptake of
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F-fluciclovine in breast cancer and assessed differences in tracer kinetics and static parameters for different breast cancer receptor subtypes and tumour grades.
Methods
Thirty-nine patients with pathologically proven breast cancer underwent 20-min dynamic PET/computed tomography imaging following the administration of
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F-fluciclovine. Uptake into primary breast tumours was evaluated using one- and two-tissue reversible compartmental kinetic models and static parameters.
Results
A reversible one-tissue compartment model was shown to best describe tracer uptake in breast cancer. No significant differences were seen in kinetic or static parameters for different tumour receptor subtypes or grades. Kinetic and static parameters showed a good correlation.
Conclusions
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F-fluciclovine has potential in the imaging of primary breast cancer, but kinetic analysis may not have additional value over static measures of tracer uptake.
Clinical Trial Registration
NCT03036943.
CHICO2 (Compact Heavy Ion COunter), is a large solid-angle, charged-particle detector array developed to provide both θ and ϕ angle resolutions matching those of GRETINA (Gamma-Ray Energy Tracking ...In-beam Nuclear Array). CHICO2 was successfully tested at the Argonne National Laboratory where it was fielded as an auxiliary detector with GRETINA for γ-ray spectroscopic studies of nuclei using a 252Cf spontaneous fission source, stable beams, and radioactive beams from CARIBU. In field tests of the 72,76Ge beams on a 0.5mg/cm2208Pb target at the sub-barrier energy, CHICO2 provided charged-particle angle resolutions (FWHM) of 1.55° in θ and 2.47° in ϕ. This achieves the design goal for both coordinates assuming a beam-spot size (>3mm) and the target thickness (>0.5mg/cm2). The combined angular resolution of GRETINA/CHICO2 resulted in a Doppler-shift corrected energy resolution of 0.60% for 1MeV coincident de-excitation γ-rays. This is nearly a factor of two improvements in resolution and sensitivity compared to Gammasphere/CHICO. Kinematically-coincident detection of scattered ions by CHICO2 still maintains the mass resolution (ΔM/M) of ~5% that enhanced isolation of scattered weak beams of interest from scattered contaminant beams.
During early November 2013, the magnetosphere experienced concurrent driving by a coronal mass ejection (CME) during an ongoing high‐speed stream (HSS) event. The relativistic electron response to ...these two kinds of drivers, i.e., HSS and CME, is typically different, with the former often leading to a slower buildup of electrons at larger radial distances, while the latter energizing electrons rapidly with flux enhancements occurring closer to the Earth. We present a detailed analysis of the relativistic electron response including radial profiles of phase space density as observed by both Magnetic Electron and Ion Sensor (MagEIS) and Relativistic Electron Proton Telescope instruments on the Van Allen Probes mission. Data from the MagEIS instrument establish the behavior of lower energy (<1 MeV) electrons which span both intermediary and seed populations during electron energization. Measurements characterizing the plasma waves and magnetospheric electric and magnetic fields during this period are obtained by the Electric and Magnetic Field Instrument Suite and Integrated Science instrument on board Van Allen Probes, Search Coil Magnetometer and Flux Gate Magnetometer instruments on board Time History of Events and Macroscale Interactions during Substorms, and the low‐altitude Polar‐orbiting Operational Environmental Satellites. These observations suggest that during this time period, both radial transport and local in situ processes are involved in the energization of electrons. The energization attributable to radial diffusion is most clearly evident for the lower energy (<1 MeV) electrons, while the effects of in situ energization by interaction of chorus waves are prominent in the higher‐energy electrons.
Key Points
Electrons are energized by concurrent radial transport and in situ processes
Energization is driven by CME overlapping with HSS
Strong chorus and ULF wave activity are observed during energization
F-fluciclovine is a synthetic amino acid positron emission tomography (PET) radiotracer that is approved for use in prostate cancer. In this clinical study, we characterised the kinetic model best ...describing the uptake of
F-fluciclovine in breast cancer and assessed differences in tracer kinetics and static parameters for different breast cancer receptor subtypes and tumour grades.
Thirty-nine patients with pathologically proven breast cancer underwent 20-min dynamic PET/computed tomography imaging following the administration of
F-fluciclovine. Uptake into primary breast tumours was evaluated using one- and two-tissue reversible compartmental kinetic models and static parameters.
A reversible one-tissue compartment model was shown to best describe tracer uptake in breast cancer. No significant differences were seen in kinetic or static parameters for different tumour receptor subtypes or grades. Kinetic and static parameters showed a good correlation.
F-fluciclovine has potential in the imaging of primary breast cancer, but kinetic analysis may not have additional value over static measures of tracer uptake.
NCT03036943.
Gamma-ray line (GRL) and solar energetic proton (SEP) events observed from February 1980 through January 1985 are compared in order to substantiate and better characterize the lack of correlation ...between GRL fluences and SEP event peak fluxes. The scatter plot of SEP event peak flux vs. GRL fluence is presented, and the ratio of 'solar' to 'interplanetary', about 10 MeV protons, is presented. It is shown that, while even large SEP events can originate in flares lacking detectable GRL emission, the converse case of flares with a significant GRL line fluence by lacking protons in space is rare. The ratio R of the number of about 10 MeV protons that produce GRL emission at the flare site to the number of about 10 MeV protons detected in space can vary from event to event by four orders of magnitude. There is a clear tendency for impulsive flares to have larger values of R than long-duration flares, where the flare time scale is given by the e-folding decay time of the associated soft X-ray emission.
Linearized, absolutely calibrated VUV images of the LMC with a resolution of about 50 arcsec are presented. The images were made by a sounding rocket payload in two bandpasses with effective ...wavelengths for hot stars near 1500 A and 1930 A. The flux in each bandpass is measured for the associations in the list of Lucke and Hodge (1970). The results are discussed and their relationship to the overall characteristics of star formation in the LMC are discussed. A simple model for propagating star formation in the LMC is presented whose results closely resemble the distribution of associations revealed by the VUV images.
The present investigation is concerned with an exceptionally well observed flare showing good evidence of magnetic change occurring in the impulse peak of the energy release. The presented ...observations confirm that a flare can produce observable, sudden, permanent changes in the photospheric magnetic field. The considered flare occurred on April 10, 1980, in Hale Region 16747 (NOAA Region 2372). The observations indicate that the flare was triggered by a small emerging magnetic bipole. The main energy release occurred in the eruption of a filament.
Images obtained by a rocket-borne UV imaging telescope are used here to determine near-UV fluxes for 17 sources in M31 that are optical globular-cluster candidates and for the bright open cluster ...vdB0 in M31. Far-UV fluxes or flux limits are determined for the same clusters. The m(NUV)-V colors for M31 clusters are similar to those of Galactic clusters, except for the high-metallicity M31 cluster Bo 171. Four of the detected clusters have optical, m(NUV) - V, and m(FUV) - V colors indicating ages of about 100 million years. These four clusters are probably similar to the so-called 'blue globular' clusters of the LMC. The existence of young LMC-type blue globulars and the possible existence of middle-aged metal-rich globulars may indicate that M31 has continued to form globular clusters throughout its life.
Results of near-simultaneous IUE and Voyager ultraviolet spectrometer (UVS) observations of 3C 273, obtained during the period of 1985 late July-early August are reported. The UVS data show a ...significant drop in flux for observed wavelengths below 1060 A. This may be due to Lyman continuum absorption in the rest frame of 3C 273. If so, then the lack of associated Lyman-alpha absorption severely constrains the properties of the absorbing medium. The most plausible explanation may therefore be that the edge is due to absorption in an accretion disk within the nucleus of 3C 273. Alternatively, models in which the drop in flux is due to a turnover in the underlying continuum cannot be excluded; this interpretation raises serious questions concerning the total energy budget in the broad-line regions. In either case, there can be no reddening of the source of continuum emission other than that due to the Galaxy.
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