Radiation Dose

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Radiation Dose-Enhancement Is a Potent Radiotherapeutic Effect of Rare-Earth Composite Nanoscintillators in Preclinical Models of Glioblastoma

Radiation Dose-Enhancement Is a Potent Radiotherapeutic Effect of Rare-Earth Composite Nanoscintillators in Preclinical Models of Glioblastoma

www.advancedsciencenews.com www.advancedscience.com Figure 7. Radiation dose-enhancement by LaF 3 :Ce leads to a full recovery of 15% of the animals bearing a F98-brain tumor. A) Survival curve obtained after treatment when LaF 3 :Ce nanoparticles are delivered by CED (20 µL of 50 mg mL −1 ). B) Growth curve of the animals, presented as a percentage of change compared to the mass of the animal on the day of tumor implantation. The two long-term survivors were euthanized on day 129 (115 days after treatment), although they were showing no clinical signs of pathology. C) Correlation between the survival and the volume of tumor not overlapped by the distribution of nanoparticles. The two long-term survivors do not appear on this graph as they were euthanized without clinical signs. D–G) Hematoxylin and eosin (H&E) staining of brain slices collected after euthanasia of a representative animal from the control group (D), the group receiving a CED injection only (E), the group receiving only the irradiation (F) and the group receiving the CED injection and the irradiation (G). For this last group, we chose an animal that died early (34 days post tumor inoculation). Scale bar = 1 mm. H) H&E staining of a slice of the brain of one of the two long-term survivors. Scale bar = 1 mm. I) LIBS image of a consecutive slice of the brain of a long-term survivor. LaF 3 :Ce nanoparticles are still visible in the brain
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Reduced Radiation Dose with Model-based Iterative Reconstruction versus Standard Dose with Adaptive Statistical Iterative Reconstruction in Abdominal CT for Diagnosis of Acute Renal Colic

Reduced Radiation Dose with Model-based Iterative Reconstruction versus Standard Dose with Adaptive Statistical Iterative Reconstruction in Abdominal CT for Diagnosis of Acute Renal Colic

Materials and Methods: This institutional review board–approved prospective study included 118 patients with symptoms of acute re- nal colic who underwent the following two successive CT examinations: standard-dose ASIR 50% and reduced-dose MBIR. Two radiologists independently reviewed both CT examinations for presence or absence of renal calculi, dif- ferential diagnoses, and associated abnormalities. The im- aging findings, radiation dose estimates, and image quality of the two CT reconstruction methods were compared. Concordance was evaluated by k coefficient, and descrip- tive statistics and t test were used for statistical analysis.
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Key clinical beam parameters for nanoparticle-mediated radiation dose amplification

Key clinical beam parameters for nanoparticle-mediated radiation dose amplification

radiosensitization 9 . A full understanding of all of the relevent biophysical factors will be important for designing a nanoparticle strategy that maximizes the therapeutic benefit. We have shown that key clinical beam parameters can be exploited to increase the efficacy of nanoparticles in external beam radiation therapy. In general, delivering more low energy photons (a softer beam) will result in greater biological effect. The flattening filter free (FFF) delivery mode is a recent clinical innovation mainly used to increase the dose rate and thus decrease the radiation delivery time. This is particularly important in the context of stereotactic treatments in which large amounts of radiation are delivered in a single treatment. That the FFF mode includes a larger proportion of low energy photons is a collatoral advantage for nanoparticle-mediated radiation dose amplification. In the presence of GdNP, FFF beams lead to greater DNA damage and improved survival compared to standard 6 MV beams. Similarly, other technologies such as the modification of the linear accelerator target, as suggested by Berbeco et al. could also provide a greater benefit 4 . In that study, it was shown
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Comparing radiation dose rates in soils and riverine sediment to track the dispersion of radioactive contamination in Fukushima coastal rivers

Comparing radiation dose rates in soils and riverine sediment to track the dispersion of radioactive contamination in Fukushima coastal rivers

Comparing radiation dose rates in soils and riverine sediment to track the dispersion of radioactive contamination in Fukushima coastal rivers Olivier Evrard (1), Yuichi Onda (2), Hugo Lepage (1), Caroline Chartin (1), Irène Lefèvre (1), Olivier Cerdan (3), Philippe Bonté (1), and Sophie Ayrault (1)

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Is mean heart dose a relevant surrogate parameter of left ventricle and coronary arteries exposure during breast cancer radiotherapy A dosimetric evaluation based on individually-determined radiation dose (BACCARAT study)

Is mean heart dose a relevant surrogate parameter of left ventricle and coronary arteries exposure during breast cancer radiotherapy A dosimetric evaluation based on individually-determined radiation dose (BACCARAT study)

Radiotherapy (RT) for breast cancer is an essential part of adjuvant cancer treatment. RT reduces the risk of local recurrence and the risk of breast cancer mortality [ 1 ]. However, left-sided RT, especially, has been shown to induce excess cardiovascular mortality and morbidity [ 2 – 6 ]. The study by Darby et al. [ 5 ] found a linear rela- tionship between the mean heart dose (MHD) and the rate of major coronary event, which increased of 7.4% per Gy of the MHD. These results on radiation-induced ischemic heart disease were confirmed in a more recent study of BC patients treated with three dimensional con- formal radiation therapy (3D-CRT) [ 7 ]. The predomin- ance of ischemic heart disease observed in these studies indicates that the coronary arteries may be the critical structures for the development of radiation induced heart morbidity. Among the three major coronary arter- ies (left anterior descending, circumflex, and right), the left anterior descending (LAD) supplies a major part of the myocardium. Therefore, occlusion of the LAD, may cause a large area of myocardial necrosis and lead to severe left ventricle impairment and congestive heart failure.
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Risk adaptive treatment in Hodgkin's lympoma: reduction of radiation dose and irradiated volume

Risk adaptive treatment in Hodgkin's lympoma: reduction of radiation dose and irradiated volume

been designed to investigate this option. Already in the era of exclusive RT there has been a debate on the optimal dose to be given to cure HL. 10 A compilation of dose control data issued from trials conducted in the 60s to 90s shows that in-field con- trol rates of 98% can be reached with doses in the range of 36Gy instead of what has been thought to be required, i.e. 44Gy. A re-analysis of those data fails to demonstrate any dose-response relationship at doses higher than 32,5Gy. Moreover, the total elapsed treatment time is not of major importance, at least up till seven weeks, which is in contrast to the time-effect observed for other solid tumours. 11
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Evolution for the collective radiation dose for the nuclear reactors from the 2nd through to the 4th generation

Evolution for the collective radiation dose for the nuclear reactors from the 2nd through to the 4th generation

After 2005, the values seem to indicate a downward trend, with a collective dose of 0.48 man.Sv/year in 2013 [22] (see FIG.8.). It should be noted that the doses recorded between 2000 and 2003 do not seem to fit those of the reference [21]. Therefore these data need to be checked and consolidated. Even if the last decade has seen improvements in certain practices which have enabled results closer to those of other reactors, the values reported for BN 600 remain considerably higher than those of other facilities of the same type. The reasons for these differences have not yet been analyzed.
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Radiation dose reduction with dictionary learning based processing for head CT.

Radiation dose reduction with dictionary learning based processing for head CT.

significant deterioration of image quality and may render CT studies clinically unacceptable [5-6]. In the past ten years, some iterative reconstruction (IR) algorithms were introduced to CT to reduce image noise and artifacts, therefore allowing significant dose reduction [7-18]. IR approaches solve the problem via maximizing a prior-regularized cost function using iterative optimizations [7-12]. Clinical potential of IR algorithms has been well demonstrated by the prior image constrained compressed sensing (PICCS) algorithm [12], the adaptive statistical iterative reconstruction (ASIR) algorithm [13-16] and the iDose algorithm [17]. For head CT, around 20%-45% dose reduction without compromising diagnostic accuracy was reported for IR algorithms in several studies [14-17], which is rather modest when compared to abdominal and thoracic applications (50%-75%) [18-19].
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Significant dose reduction using synchrotron radiation computed tomography: first clinical case and application to high resolution CT exams

Significant dose reduction using synchrotron radiation computed tomography: first clinical case and application to high resolution CT exams

of gadolinium may lead to additional DNA double strand breaks 17 . Developing new types of diagnostic imaging modalities like SRCT that do not always require the use of contrast agents and operate at a lower radiation dose appears thus as an option to be seriously considered in diagnostic radiology. The aims of this study were to evaluate the performance and the potential of synchrotron radiation CT using tunable monochromatic low divergence X-rays. This study was performed on a quality assurance phantom as well on a patient involved in an ongoing radiotherapy program clinical trial at the ESRF.
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en fr Dose-effect relationship and dosimetry optimization for selective internal radiation therapy Relation dose-effet et optimisation de la dosimétrie en radiothérapie interne sélective du carcinome hépatocellulaire

Two methods are recommended with RE using resin mi- crospheres to calculate the activity to be injected (5) : body surface area (BSA) method and partition model method. The former is semiempiric and considers only tumor and liver volumes (extrapolated from BSA), whereas the latter is based on medical internal radiation dose principles (6) and differ- entiates 3 discrete vascular compartments—lungs, tumor, and nontumoral liver parenchyma—and takes into account the avidity of each for albumin macroaggregates. However, the partition model method assumes that radiation is homo- geneously distributed in each compartment, which actually is not the case. More recently, treatment planning systems (TPSs) have been applied to RE procedures. This approach, which has been used for many years in EBRT, allows three- dimensional (3D) dosimetry at the voxel level. A TPS can provide dose-volume histograms (DVHs) that show and measure the heterogeneity in the distribution of yttrium-90 ( 90 Y) microspheres in the different compartments. This type of dosimetric analysis could be helpful in the field of RE. The aim of this study was to evaluate 3D voxel-based dosimetry using TPS to identify the predictive factors of tumor control, survival, and toxicity in patients with HCC treated by 90 Y resin microspheres.
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Biological equivalent dose studies for dose escalation in the stereotactic synchrotron radiation therapy clinical trials.

Biological equivalent dose studies for dose escalation in the stereotactic synchrotron radiation therapy clinical trials.

Synchrotron radiation is an innovative tool for the treatment of brain tumors. In the stereotactic synchrotron radiation therapy 共SSRT兲 technique a radiation dose enhancement specific to the tumor is obtained. The tumor is loaded with a high atomic number 共Z兲 element and it is irradiated in stereotactic conditions from several entrance angles. The aim of this work was to assess dosimetric properties of the SSRT for preparing clinical trials at the European Synchrotron Radiation Facility 共ESRF兲. To estimate the possible risks, the doses received by the tumor and healthy tissues in the future clinical conditions have been calculated by using Monte Carlo simulations 共 PENELOPE code 兲. The dose enhancement factors have been determined for different iodine concentrations in the tumor, several tumor positions, tumor sizes, and different beam sizes. A scheme for the dose escalation in the various phases of the clinical trials has been proposed. The biological equivalent doses and the normalized total doses received by the skull have been calculated in order to assure that the tolerance values are not reached. © 2009 American Association of Physicists in Medicine.
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Radiation Hardening of Digital Color CMOS Camera-on-a-Chip Building Blocks for Multi-MGy Total Ionizing Dose Environments

Radiation Hardening of Digital Color CMOS Camera-on-a-Chip Building Blocks for Multi-MGy Total Ionizing Dose Environments

In this work the feasibility of a MGy rad-hard CMOS color digital camera-on-a-chip has been demonstrated. It will serve as a basis for the development of a full size camera including a rad-hard optics and a rad-hard illumination system (which are also currently developed in the frame of the same project). Several significant CIS radiation hardness improvements were presented by investigating some of the mitigation techniques proposed previously: a factor of 5 reduction in readout chain voltage shift, between 5 and 10 times dark current lowering after irradiation (up to 6 MGy(SiO 2 )) and the complete
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P47. Proteomic analysis of the Radiation-Induced Bystander Effects between low-dose irradiated Chondrosarcoma cells and Bystander Chondrocytes

P47. Proteomic analysis of the Radiation-Induced Bystander Effects between low-dose irradiated Chondrosarcoma cells and Bystander Chondrocytes

1 LARIA, CEA-DRF-iRCM, François JACOB Institute, Caen, France ; 2 CIMAP UMR6252, Normandie Univ, ENSICAEN, UNICAEN, CEA, CNRS, Caen, France 3 BPMP, Mass Spectrometry Proteomics Platform, Montpellier, France ; 4 Innovative technologies for Detection and Diagnostics, CEA-DRF-Li2D, Marcoule, France * chevalier@ganil.fr Experimental evidences show that, in addition to direct and targeted effects of radiations, another effect is observed within the surrounding un- irradiated area; irradiated cells relay a stress signal in this close proximity, the bystander effect. Neighbouring un-irradiated cells react to this bystander effect with a specific response, characteristic of a biological context, but with a close relationship to the biological response typically associated with direct radiation exposure. Bystander responses and bystander factors secreted by irradiated cells were observed and studied in many physical and biological conditions, in vitro and in vivo [1].
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Multi-MGy Radiation Hard CMOS Image Sensor: Design, Characterization and X/Gamma Rays Total Ionizing Dose Tests

Multi-MGy Radiation Hard CMOS Image Sensor: Design, Characterization and X/Gamma Rays Total Ionizing Dose Tests

B. Photodiode RHBD Strategy The two main types of photodetectors used in CIS today are the conventional photodiode that can be found in 3-Transistor (3T) active pixels [19] and the buried photodiode, called the Pinned Photodiode (PPD) [20], [21]. The main radiation in- duced degradation mechanism in conventional photodiodes and in PPD at high TID is the effect of the radiation induced posi- tive charge trapping in the STI, the TG spacer and the pre-metal dielectric (PMD) (see Fig. 2) that leads to the depletion and the inversion of the P-doped layers. In PPD pixels, the PMD and TG spacer trapped charges induce important image lag that can be followed by a disappearance of the pinning layer [22]. To date, there is no RHBD technique validated experimentally in literature that can mitigate this radiation effect [9]. In 3T pixels, the STI positive trapped charge leads to a short circuit between the photodiode and the surrounding N regions and to a drop of Charge-to-Voltage conversion Factor (CVF) [10]. Both radia- tion effects can be mitigated by using RHBD techniques. For these reasons, PPDs were excluded for this study (including hole channel PPDs [23], [24] that are also likely to suffer from impor- tant image lag at high TID because of the PMD/spacer trapped charge) and conventional photodiodes hardened-by-design were selected.
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Radiation Hardening of Digital Color CMOS Camera-on-a-Chip Building Blocks for Grad Total Ionizing Dose Environments

Radiation Hardening of Digital Color CMOS Camera-on-a-Chip Building Blocks for Grad Total Ionizing Dose Environments

[et al.] Radiation Hardening of Digital Color CMOS Camera-on-a-Chip Building Blocks for Grad Total Ionizing Dose Environments.. (2016) In: Radiation Effects on Optoelectronic Detectors ([r]

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Optimal KI Prophylactic Dose Determination for Thyroid Radiation Protection After a Single Administration in Adult Rats

Optimal KI Prophylactic Dose Determination for Thyroid Radiation Protection After a Single Administration in Adult Rats

In conclusion, the results of this dose-response study show that KI doses around 0.5 to 0.7 mg/kg provide at least 75% of thyroid protection in these experimental conditions. It was also developed in this work a new method based on ICP-MS mea- surement as an alternative to previous analytical methods or techniques requiring radiotracers to quantify stable iodine in complex biological matrix such as thyroid samples. The distri­ bution of stable iodine in the thyroid 24 hours after KI admin­ istration was decreased for doses higher than 1 mg/kg. This observation could be correlated with the change in the urinary excretion profile of stable iodine, which suggests a possible saturation of the organism by KI doses higher than 1 mg/kg. The dose of 1 mg/kg could then be selected as an optimal dose in terms of saturation and protection of the thyroid. As perspec­ tives, the pharmacokinetics of stable iodine after oral adminis­ tration of this dose of 1 mg/kg KI should be determined in order to model adequate dose regimens for a protracted prophylaxis. In addition, the innocuousness of this dose of KI after repeated administrations should be assessed in different groups of rats representing the different groups of age of the population prior to considering the extension of the indication of KI in case of prolonged exposure to radioactive isotopes of iodine.
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Dose dumping : problématiques et solutions innovantes

Dose dumping : problématiques et solutions innovantes

~ 69 ~ min avant administration de la solution ou du médicament à libération modifiée, et il doit se terminer également 30 min après l’administration. En Europe, la ligne directrice CPMP/EWP/560/95/Rev. 1 du 21 Juin 2012 du CHMP (Committee for Human Medicinal Products) décrit dans ses annexe I et II la procédure standard pour les études de l’interaction avec la nourriture. Il s’agit d’abord d’une étude en administration unique du médicament test avec 240ml d’eau après une période de jeun de 10h et 30 min après le début du repas. En dehors du repas prescrit, les sujets doivent s’abstenir de repas pendant au moins 4heures, et tout prise de nourriture dans les 12h suivant la prise doit être suivie et normalisée. Dans les cas où l’étude en dose unique ne peut être réalisée sur sujets sains ou sur des patients, une étude à dose multiple, une étude de stabilité avec administration du médicament dans des conditions respectivement de jeun et de repas riches pourront être considérées. La composition du repas gras et modérément gras juste avant administration du médicament est décrite précisément. Le repas riche standard contient 800 à 1000 kcal décomposé en 500 à 600 kcal de lipides et 250 kcal d’hydrates carbonés. Le menu standard peut ainsi être donc composé par exemple de deux œufs frits dans du beurre, deux tranches de bacon, deux tranches de pain grillé beurré, 120 ml de gâteau de pommes de terre râpées et 240 ml de lait entier. Des modifications de menus dans ce repas de test standard peuvent être faites tant que le repas fournit les montants semblables de calories, et de protides, de glucides et de lipides avec un volume de repas et une viscosité comparable. [85]
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DoSE: Deobfuscation based on Semantic Equivalence

DoSE: Deobfuscation based on Semantic Equivalence

5 Tigress refers to two-way opaque predicates as question opaque predicates (i.e. P ? ). (EncL) and finally code virtualization (Virt). These combinations allow us to measure the efficiency as well as the limitations of DoSE for two-way opaque predicates detection. Table 3 groups our evaluations of the four code samples listed above, in a way to present results according to the obfuscation techniques that they use. For example, "Case 1" represents the application of ten opaque predicates P ? to our samples A, B, C, and D with the corresponding evaluation; "Case 2" represents the application of four P ? combined with four P T or P F in all samples, etc. The column "(#OP, #FP, #FN)" represents a tuple in which "#OP" is the number of detected two-way predicates, "#FP" is the number of false positive results and "#FN" the number of false negatives. As we can see, we are able to detect all two-way opaque predicates with no false positives and no false negatives in the majority of the cases. The reasons for the few false positive and negative results are the block-centric approach of DoSE and the insertion of infeasible paths. We present these limitations in the following paragraph.
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STATDOSE for 3D dose distributions

STATDOSE for 3D dose distributions

1 Introduction STATDOSE is an interactive computer program for 3-dimensional dose analysis and plotting 1-dimensional dose distributions using the xvgr/xmgr plotting package. 3D dose data such as that generated using the EGS4 user-code DOSXYZ [1], developed at NRCC for the OMEGA project, are examples of typical dose data. STATDOSE functions include normalization, re- binning, plotting and analysis of the dose distributions. Distributions can also be compared both statistically and graphically. Graphs to aid in statistical analysis of the distributions, as well as both cross-plots and depth-doses, are provided by STATDOSE.
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IIU versus FIV : le choix de la dose ?

IIU versus FIV : le choix de la dose ?

Mots-clés : IIU, FIV, grossesse, stimulation ovarienne Introduction: In France, 10% of the couples are infertile and they can benefit from the medically assisted reproduction in order to procreate. According to the biomedicine agency, in 2016, such medical assistance provided positive results for 22% of the IVF-ICSI, 20% of the conventional IVF, 14% of the fresh embryo transfers and 10% of the IUI. Multiple attempts that can be necessary for the obtention of a viable embryo are a source of stress and often generate feelings of failure for couples. This is why the medical team has the desire to decrease the number of attempts. The main purpose of our study is to compare the initial prescribed dose of gonadotrophins for a first attempt at IVF (TA IVF), for an identical estimated ovarian reserve, between naive patients an those who previously had three IUI.
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