Acute Toxicity and Early Oncological Outcomes After Intraoperative Electron Radiotherapy (IOERT) as Boost Followed by Whole Breast Irradiation in 157 Early Stage Breast Cancer Patients—First Clinical Results From a Single Center

Introduction: Breast conserving surgery (BCS) followed by postoperative whole breast irradiation (WBI) is the current standard of care for early stage breast cancer patients. Boost to the tumor bed is recommended for patients with a higher risk of local recurrence and may be applied with different techniques. Intraoperative electron radiotherapy (IOERT) offers several advantages compared to other techniques, like direct visualization of the tumor bed, better skin sparing, less inter- and intrafractional motion, but also radiobiological effects may be beneficial. Objective of this retrospective analysis of IOERT as boost in breast cancer patients was to assess acute toxicity and early oncological outcomes.Material and Methods: All patients, who have been irradiated between 11/2014 and 01/2018 with IOERT during BCS were analyzed. IOERT was applied using the mobile linear accelerator Mobetron with a total dose of 10 Gy, prescribed to the 90% isodose. After ensured woundhealing, WBI followed with normofractionated or hypofractionated regimens. Patient reports, including diagnostic examinations and toxicity were analyzed after surgery and 6–8 weeks after WBI. Overall survival, distant progression-free survival, in-breast and contralateral breast local progression-free survival were calculated using the Kaplan-Meier method. Furthermore, recurrence patterns were assessed.Results: In total, 157 patients with a median age of 57 years were evaluated. Postoperative adverse events were mild with seroma and hematoma grade 1–2 in 26% and grade 3 in 0.6% of the patients. Wound infections grade 2–3 occurred in 2.2% and wound dehiscence grade 1–2 in 1.9% of the patients. Six to eight weeks after WBI radiotherapy-dependent acute dermatitis grade 1–2 was most common in 90.9% of the patients. Only 4.6% of the patients suffered from dermatitis grade 3. No grade 4 toxicities were documented after surgery or WBI. 2- and 3-year overall survival and distant progression-free survival, were 97.5 and 93.6, and 0.7 and 2.8%, respectively. In-breast recurrence and contralateral breast cancer rates after 3 years were 1.9 and 2.8%, respectively.Conclusion: IOERT boost during BCS is a safe treatment option with low acute toxicity. Short-term recurrence rates are comparable to previously published data and emphasize, that IOERT as boost is an effective treatment

Effects of incidence angles of ions on the mass resolution of an energy compensated 3D atom probe

Abstract We have used a first-order reflectron lens in an optical tomographic atom probe in order to improve the mass resolution. Calculations have been performed to determine the effect of second-order errors in ion energy and incidence angle on the performance of the lens. By applying a correction procedure based on the results of these calculations, we have been able to improve experimental mass resolution by 30%.

Measurements of the Delta(1232) Transition Form Factor and the Ratio sigma_n\sigma_p From Inelastic Electron-Proton and Electron-Deuteron Scattering

Measurements of inclusive electron-scattering cross sections using hydrogen and deuterium targets in the region of the Delta(1232) resonance are reported. A global fit to these new data and previous data in the resonance region is also reported for the proton. Transition form factors have been extracted from the proton cross sections for this experiment over the four-momentum transfer squared range 1.64 < Q^2 < 6.75 (GeV/c)^2 and from previous data over the range 2.41 < Q^2 < 9.82 (GeV/c)^2. The results confirm previous reports that the Delta(1232) transition form factor decreases more rapidly with Q^2 than expected from perturbative QCD. The ratio of sigma _n \sigma_p in the \Delta(1232) resonance region has been extracted from the deuteron data for this experiment in the range 1.64 < Q^2 < 3.75 (GeV/c)^2 and for a previous experiment in the range 2.4 < Q^2 < 7.9 (GeV/c)^2. A study has been made of the model dependence of these results. This ratio sigma_n\sigma_p for \Delta(1232) production is slightly less than unity, while sigma_n\sigma_p for the nonresonant cross sections is approximately 0.5, which is consistent with deep inelastic scattering results.Comment: 10 figures. 42 pages, including figures. submitted to Physical Review

Phase composition and long range order in γ′ phase of a nickel base single crystal superalloy CMSX2: An atom probe study

International audienceA time of flight atom-probe has been used to investigate the partitioning of alloying elements in a two phases (γ and γ′) nickel-base superalloy CMSX2. The experimental conditions required to obtain reliable data are given. The high spatial resolution of the atom-probe has been exploited for the γ-γ′ interface analysis. The γ-γ′ transition takes place within one atomic layer. The study of the long range order existing in the γ′ has been performed. The plane by plane analysis of the ordered precipitates shows the alternation of (001) Al rich planes with (001) Ni rich planes. The probabilities of presence of each element on each kind of site are evaluated from the measured composition of the (001 ) planes. \textcopyright 1984

Fim atom-probe investigation of the interphase boundary of a nickel-base superalloy

International audienceThe matrix-precipitate interface of a nickel-base superalloy has been studied using a time-of-flight atom-probe. A layer-by-layer analysis of (200) planes was performed normally to the interphase boundary. The composition profile obtained shows that the phase change occurs within one atomic layer. In addition, the results indicate that the interface is located on a mixed plane of the ordered precipitate (L12 type structure). ?? 1986

Fim atom-probe investigation of the interphase boundary of a nickel-base superalloy

International audienceThe matrix-precipitate interface of a nickel-base superalloy has been studied using a time-of-flight atom-probe. A layer-by-layer analysis of (200) planes was performed normally to the interphase boundary. The composition profile obtained shows that the phase change occurs within one atomic layer. In addition, the results indicate that the interface is located on a mixed plane of the ordered precipitate (L12 type structure). ?? 1986

Phase composition and long range order in γ′ phase of a nickel base single crystal superalloy CMSX2: An atom probe study

International audienceA time of flight atom-probe has been used to investigate the partitioning of alloying elements in a two phases (γ and γ′) nickel-base superalloy CMSX2. The experimental conditions required to obtain reliable data are given. The high spatial resolution of the atom-probe has been exploited for the γ-γ′ interface analysis. The γ-γ′ transition takes place within one atomic layer. The study of the long range order existing in the γ′ has been performed. The plane by plane analysis of the ordered precipitates shows the alternation of (001) Al rich planes with (001) Ni rich planes. The probabilities of presence of each element on each kind of site are evaluated from the measured composition of the (001 ) planes. \textcopyright 1984

The shape of field emitters and the ion trajectories in three- dimensional atom probes

International audienceThe lateral resolution of three-dimensional atom probes is mainly controlled by the aberrations of the ion trajectories near the specimen surface. For the first time, a simulation program has been developed to reconstruct the ion trajectories near a sharp hemispherical electrode defined at the atomic scale. Surface atoms submitted to the highest field were removed one by one. The consecutive gradual change of the surface topology was taken into account in the calculation of ion trajectories. As the tip was 'field evaporated', the initial spherical shape of the emitter was observed to transform gradually into a polygonal shape. When the tip reached its equilibrium shape, the field distribution at the tip surface was found to be much more uniform compared to the initial distribution. The calculated distribution of ion impacts on the detector exhibits the presence of depleted zones both at the centre of low index poles and along \textless001\textgreater zone axes. These predictions are in excellent agreement with experiments