The effect of post-stroke hyperglycaemia on the levels of brain damage and repair-related circulating biomarkers: the Glycaemia in Acute Stroke Study II.

BACKGROUND AND PURPOSE: The aim was to identify whether post-stroke hyperglycaemia (PSH) influences the levels of circulating biomarkers of brain damage and repair, and to explore whether these biomarkers mediate the effect of PSH on the ischaemic stroke (IS) outcome. METHODS: This was a secondary analysis of the Glycaemia in Acute Stroke II study. Biomarkers of inflammation, prothrombotic activity, endothelial dysfunction, blood-brain barrier rupture, cell death and brain repair processes were analysed at 24-48 h (baseline) and 72-96 h (follow-up) after IS. The associations of the biomarkers and stroke outcome (modified Rankin Scale score at 3 months) based on the presence of PSH were compared. RESULTS: A total of 174 patients participated in this sub-study. Brain-derived neurotrophic factor (BDNF) at admission was negatively correlated with glucose levels. PSH was associated with a trend toward higher levels of endothelial progenitor cells (EPCs) at baseline. The EPCs in the PSH group then decreased in the follow-up samples (-8.5 ± 10.3) compared with the non-PSH group (4.7 ± 7.33; P = 0.024). However, neither BDNF nor EPC values had correlation with the 3-month outcome. Higher interleukin-6 at follow-up was associated with poor outcomes (modified Rankin Scale > 2) independently of PSH. CONCLUSION: Post-stroke hyperglycaemia appears to be associated with a negative regulation of BDNF and a different reaction in EPC levels. However, neither BDNF nor EPCs showed significant mediation of the PSH association with IS outcome, and only higher interleukin-6 in the follow-up samples (72-96 h) was related to poor outcomes, independently of PSH status. Further studies are needed to achieve definite conclusions.

Glycemia in Acute Stroke II study: a call to improve post-stroke hyperglycemia management in clinical practice.

BACKGROUND AND PURPOSE: The aim of the study was to analyze the effect of conventional glucose management, which aimed to maintain glucose levels <155 mg/dL (8.5 mmol/L), on glucose control and the outcomes of patients with acute ischaemic stroke (IS) in a clinical practice setting. METHODS: This was a multicenter, prospective cohort study of patients with acute IS. Patients were classified into four groups based on their initial 48-h capillary glucose levels and the administration of and response to corrective treatment: (i) untreated and maximum glucose levels <155 mg/dL (8.5 mmol/L) within the first 48 h; (ii) treated and good responders [glucose levels persistently <155 mg/dL (8.5 mmol/L)]; (iii) treated and non-responders [any glucose values ≥155 mg/dL (8.5 mmol/L) during the 24 h after the start of corrective treatment]; and (iv) untreated with any glucose value ≥155 mg/dL (8.5 mmol/L). The primary outcome was death or dependence at 3 months (blinded rater). RESULTS: A total of 213 patients were included. Ninety-seven (45.5%) patients developed glucose levels ≥155 mg/dL (8.5 mmol/L), 69 (71.1%) underwent corrective treatment and 31 patients underwent no corrective treatment at the physician's discretion [28 of whom had isolated values ≥155 mg/dL (8.5 mmol/L)]. Only 11 (16%) patients responded to conventional treatment, whereas 58 (84%) patients were non-responsive. Non-responders showed a twofold higher risk of death or dependence at 3 months (odds ratio, 2.472; 95% confidence interval, 1.096-5.576; P = 0.029). CONCLUSIONS: Lack of response to conventional treatment for glucose management in acute IS is frequent and associated with poor outcomes.

Stereotactic body radiation therapy for liver metastases in oligometastatic disease.

Oligometastatic cancers designate cancers in which the number of metastases is less than five, corresponding to a particular biological entity whose prognosis is situated between a localized and metastatic disease. The liver is one of the main sites of metastases. When patients are not suitable for surgery, stereotactic body radiotherapy provides high local control rate, although these data come mainly from retrospective studies, with no phase III study results. The need for a high therapeutic dose (biologically effective dose greater than 100Gy) while respecting the constraints on the organs at risk, and the management of respiratory movements require expertise and sufficient technical prerequisites. The emergence of new techniques such as MRI-guided radiotherapy could further increase the effectiveness of stereotactic radiotherapy of liver metastases, and thus improve the prognosis of these oligometastatic cancers.

Radiation therapy of the primary tumour and/or metastases of digestive metastatic cancers.

Metastatic gastrointestinal cancer is not an uncommon situation, especially for pancreatic, gastric, and colorectal cancers. In this setting, few data are available on the impact of the treatment of the primary tumour. Oligometastatic disease is associated with longer survival in comparison with more advanced disease. Metastasis-directed therapy, such as stereotactic body radiotherapy, seems related to better outcomes, but the level of evidence is low. In most tumour locations, prospective data are very scarce and inclusion in ongoing trials is strongly recommended.

Beyond hyperglycemia: glycaemic variability as a prognostic factor after acute ischemic stroke.

INTRODUCTION: Glycaemic variability (GV) refers to variations in blood glucose levels, and may affect stroke outcomes. This study aims to assess the effect of GV on acute ischaemic stroke progression. METHODS: We performed an exploratory analysis of the multicentre, prospective, observational GLIAS-II study. Capillary glucose levels were measured every 4 hours during the first 48 hours after stroke, and GV was defined as the standard deviation of the mean glucose values. The primary outcomes were mortality and death or dependency at 3 months. Secondary outcomes were in-hospital complications, stroke recurrence, and the impact of the route of insulin administration on GV. RESULTS: A total of 213 patients were included. Higher GV values were observed in patients who died (n = 16; 7.8%; 30.9 mg/dL vs 23.3 mg/dL; p = 0.05). In a logistic regression analysis adjusted for age and comorbidity, both GV (OR = 1.03; 95% CI, 1.003-1.06; p = 0.03) and stroke severity (OR = 1.12; 95% CI, 1.04-1.2; p = 0.004) were independently associated with mortality at 3 months. No association was found between GV and the other outcomes. Patients receiving subcutaneous insulin showed higher GV than those treated with intravenous insulin (38.95 mg/dL vs 21.34 mg/dL; p < 0.001). CONCLUSIONS: High GV values during the first 48 hours after ischaemic stroke were independently associated with mortality. Subcutaneous insulin may be associated with higher VG levels than intravenous administration.

[Quality assurance of radiotherapy in clinical research]. / Assurance qualité de la radiothérapie en recherche clinique.

Quality assurance for radiotherapy of a clinical trial is an important step from the design of the clinical trial. A precise definition of quality assurance must be given in detail in the clinical protocol of the clinical trial. By its implementation, quality assurance allows a homogeneity of the clinical trial, which can lead to a reduction of the biases of results interpretation for the clinical trial. The complexity of the radiotherapy to be carried out within the framework of the clinical trial can induce a gradation for the radiotherapy quality assurance program of the trial. However, the following steps are always present and must be described either directly in the clinical protocol or in a specific chapter, radiotherapy quality assurance, of the clinical protocol. The detailed characteristics of the medical imaging required to prepare for the treatment, the delineation of the targets and organs at risk, the requirements related to the planning, the treatment itself, possibly including the positioning repositioning control images, of the patient. For the delineation and planning stages, it is common to set up benchmarking based on test cases (dummy run, dry run). Their validation makes it possible for the center to get credentials for the clinical trial. Some trials can provide for an additional quality assurance point, such End-to-End test for which the investigating center must carry out, according to the clinical protocol, the preparation, the planning, the treatment on an anthropomorphic test object containing models of targets, organs at risk as well as dosimeters. Quality assurance of radiotherapy in clinical research is an essential part to be taken into account from the design of the clinical study. The commitment of the investigating center in terms of human and material resources in compliance with the protocol and in the quality assurance of the trial constitute a guarantee of limitation of the biases for the study and its interpretation, facilitating the answer of the scientific question asked by the trial.

Quality/risk management system in radiotherapy: Changes afoot.

The French sanitary and regulatory context in which radiotherapy centres are comprised is evolving. Risk and quality management systems are currently adapting to these evolutions. The French nuclear safety agency (ASN) decision of July 1st 2008 on quality assurance obligations in radiotherapy has reached 10 years of age, and the French high authority of health (HAS) certification system 20 years now. Mandatory tools needed for the improvement of quality and safety in healthcare are now well known. From now on, the focus of healthcare policies is oriented towards evaluation of efficiency of these new organisations designed following ASN and HAS nationwide guidelines.

External irradiation treatment process.

The purpose of this article is to describe the external irradiation process and updated recommendations of the French society for radiation oncology for patient follow-up.

Specificities of clinical research in radiotherapy.

The aim of this review is to present the specificities of clinical research in radiation oncology. Objectives are similar to all research in oncology: to improve the efficacy and to decrease toxic effects. Phase III trials remain the main methodology to demonstrate an improvement in efficiency, but phase I-II and registers are also important tools to validate an improvement in the therapeutic index with new technologies. In this article we discuss the special features of end-points, selection of population, and design for radiation oncology clinical trials. Quality control of delivered treatments is an important component of these protocols. Financial issues are also discussed, in the particular context of France.

Guidelines for external radiotherapy and brachytherapy procedures: 3rd edition.

The purpose of the first two editions of the guidelines for external radiotherapy procedures, published in 2007 and 2016 respectively, was to issue recommendations aimed at optimising, harmonising and standardising practices. The purpose of this third edition, which includes brachytherapy, is identical while also taking into account recent technological improvements (intensity modulation radiation therapy, stereotactic radiotherapy, and three-dimension brachytherapy) along with findings from literature. Part one describes the daily use of general principles (quality, security, image-guided radiation therapy); part two describes each treatment step for the main types of cancer.

Beyond hyperglycemia: glycaemic variability as a prognostic factor after acute ischemic stroke. / Más allá de la hiperglucemia: la variabilidad glucémica como factor pronóstico en el infarto cerebral agudo.

INTRODUCTION: Glycaemic variability (GV) refers to variations in blood glucose levels, and may affect stroke outcomes. This study aims to assess the effect of GV on acute ischaemic stroke progression. METHODS: We performed an exploratory analysis of the multicentre, prospective, observational GLIAS-II study. Capillary glucose levels were measured every 4 hours during the first 48 hours after stroke, and GV was defined as the standard deviation of the mean glucose values. The primary outcomes were mortality and death or dependency at 3 months. Secondary outcomes were in-hospital complications, stroke recurrence, and the impact of the route of insulin administration on GV. RESULTS: A total of 213 patients were included. Higher GV values were observed in patients who died (n = 16; 7.8%; 30.9 mg/dL vs 23.3 mg/dL; p = 0.05). In a logistic regression analysis adjusted for age and comorbidity, both GV (OR = 1.03; 95% CI, 1.003-1.06; p = 0.03) and stroke severity (OR = 1.12; 95% CI, 1.04-1.2; p = 0.004) were independently associated with mortality at 3 months. No association was found between GV and the other outcomes. Patients receiving subcutaneous insulin showed higher GV than those treated with intravenous insulin (38.95 mg/dL vs 21.34 mg/dL; p < 0.001). CONCLUSIONS: High GV values during the first 48 hours after ischaemic stroke were independently associated with mortality. Subcutaneous insulin may be associated with higher VG levels than intravenous administration.

Evidence of extranuclear cell sensitivity to alpha-particle radiation using a microdosimetric model. I. Presentation and validation of a microdosimetric model.

A microdosimetric model that makes it possible to consider the numerous biological and physical parameters of cellular alpha-particle irradiation by radiolabeled mAbs was developed. It allows for the calculation of single-hit and multi-hit distributions of specific energy within a cell nucleus or a whole cell in any irradiation configuration. Cells are considered either to be isolated or to be packed in a monolayer or a spheroid. The method of calculating energy deposits is analytical and is based on the continuous-slowing-down approximation. A model of cell survival, calculated from the microdosimetric spectra and the microdosimetric radiosensitivity, z(0), was also developed. The algorithm of calculations was validated by comparison with two general Monte Carlo codes: MCNPX and Geant4. Microdosimetric spectra determined by these three codes showed good agreement for numerous geometrical configurations. The analytical method was far more efficient in terms of calculation time: A gain of more than 1000 was observed when using our model compared with Monte Carlo calculations. Good agreements were also observed with previously published results.

Evidence of extranuclear cell sensitivity to alpha-particle radiation using a microdosimetric model. II. Application of the microdosimetric model to experimental results.

A microdosimetric model was used to analyze the results of experimental studies on cells of two lymphoid cell lines (T2 and Ada) irradiated with (213)Bi-radiolabeled antibodies. These antibodies targeted MHC/peptide complexes. The density of target antigen could be modulated by varying the concentration of the peptide loaded onto the cells. This offered the possibility of changing the ratio of specific (from cell-bound antibody) to non-specific (from antibody present in the supernatant) irradiation. For both cell lines, survival plotted as a function of the mean absorbed dose was a decreasing exponential. For the T2 cells, the microdosimetric sensitivity calculated for the whole cell was equal whether the irradiation was non-specific (z(0) = 0.12 +/- 0.02 Gy) or specific (z(0) = 0.12 +/- 0.09 Gy). Similar results were obtained for Ada cells. These results constitute a biological validation of the microdosimetric model. For both cells, the measured cell mortality was greater than the percentage of hit cells calculated with the model at low mean absorbed doses. This observation thus suggests bystander effects. It poses the question of the relevance of the mean absorbed dose to the cell nuclei. A new concept in cellular dosimetry taking into account cytoplasm or membrane irradiation and bystander modeling appears to be needed.

[Overview of adaptive radiotherapy in 2019: From implementation to clinical use]. / État des lieux de la radiothérapie adaptative en 2019 : de la mise en place à l'utilisation clinique.

Intensity modulated radiotherapy combined with image guided radiotherapy has led to increase the precision of external beam radiotherapy. However, intra or inter-fraction anatomical variations are frequent during the treatment course and can cause under-dosing of the target volume and/or over-dosing of the organs at risk. Several adaptive radiotherapy (ART) strategies can be defined to compensate these anatomical variations. The purpose of this article is to provide an overview of available ART strategies: offline, online, hybrid (library of treatment plans) or in real-time, while considering the arrival of MR-Linac devices in radiotherapy departments. The tools required to these ART strategies such as auto-segmentation, deformable image registration, calculation of the daily dose or dose accumulation, are also described. Implementing an ART strategy requires a rigorous quality assurance process, at each stage and on the entire workflow, as well as prior organization and training from of all the trades. A strong multidisciplinary involvement is finally required in order to ensure ART treatments.

[X-ray imaging dose due to the digital imaging devices used in radiation therapy for patient positioning and repositioning: How to take it into account?]. / Les doses dues à l'imagerie numérique pour le contrôle de positionnement du patient en radiothérapie: comment les prendre en compte?

The patient positioning and repositioning control in radiation therapy all along the treatment can be conducted using a variety of X-ray sources and imaging detector devices. The development of image guided radiation therapy techniques leads to more frequent use of this imaging control. In this article we summarize the current methods for measuring the dose delivered by X-ray imaging devices used in radiation therapy, as well as basic proposals to take account of these imaging doses for prescribing, recording and reporting radiation therapy treatment.

[Reference bases of radiotherapy under stereotaxic conditions for bronchopulmonary, hepatic, prostatic, upper aero-digestive, cerebral and bone tumors or metastases]. / Bases référentielles de la radiothérapie en conditions stéréotaxiques pour les tumeurs ou métastases bronchopulmonaires, hépatiques, prostatiques, des voies aérodigestives supérieures, cérébrales et osseuses.

Since decades, stereotactic radiotherapy has spread out worldwide. Published results are very numerous. To clarify obviousness among all the publications, this recommendation review was written. Voluntarily, authors limited analysis of international best evidence literature on malignant tumors of lung, liver, prostate, head and neck, and metastasis of bone and brain. These data could be used to advance standardization and quality improvement of treatments performed in the nationwide radiotherapy departments and can provide useful guidance for centers worldwide.

A voxel-based mouse for internal dose calculations using Monte Carlo simulations (MCNP).

Murine models are useful for targeted radiotherapy pre-clinical experiments. These models can help to assess the potential interest of new radiopharmaceuticals. In this study, we developed a voxel-based mouse for dosimetric estimates. A female nude mouse (30 g) was frozen and cut into slices. High-resolution digital photographs were taken directly on the frozen block after each section. Images were segmented manually. Monoenergetic photon or electron sources were simulated using the MCNP4c2 Monte Carlo code for each source organ, in order to give tables of S-factors (in Gy Bq-1 s-1) for all target organs. Results obtained from monoenergetic particles were then used to generate S-factors for several radionuclides of potential interest in targeted radiotherapy. Thirteen source and 25 target regions were considered in this study. For each source region, 16 photon and 16 electron energies were simulated. Absorbed fractions, specific absorbed fractions and S-factors were calculated for 16 radionuclides of interest for targeted radiotherapy. The results obtained generally agree well with data published previously. For electron energies ranging from 0.1 to 2.5 MeV, the self-absorbed fraction varies from 0.98 to 0.376 for the liver, and from 0.89 to 0.04 for the thyroid. Electrons cannot be considered as 'non-penetrating' radiation for energies above 0.5 MeV for mouse organs. This observation can be generalized to radionuclides: for example, the beta self-absorbed fraction for the thyroid was 0.616 for I-131; absorbed fractions for Y-90 for left kidney-to-left kidney and for left kidney-to-spleen were 0.486 and 0.058, respectively. Our voxel-based mouse allowed us to generate a dosimetric database for use in preclinical targeted radiotherapy experiments.

[Validation of intensity modulated radiation therapy patient plans with portal images]. / Validation des plans de radiothérapie conformationnelle avec modulation d'intensité avec les images portales.

The goal of this study was to show the feasibility of step and shoot intensity-modulated radiation therapy pre-treatment quality control for patients using the electronic portal imaging device (iViewGT) fitted on a Sli+ linac (Elekta Oncology Systems, Crawley, UK) instead of radiographic films. Since the beginning of intensity-modulated radiation therapy treatments, the dosimetric quality control necessary before treating each new patient has been a time-consuming and therefore costly obligation. In order to fully develop this technique, it seems absolutely essential to reduce the cost of these controls, especially the linac time. Up to now, verification of the relative dosimetry field by field has been achieved by acquiring radiographic films in the isocenter plane and comparing them to the results of the XiO planning system (Computerized Medical Systems, Missouri, USA) using RIT113 v4.1 software (Radiological Imaging Technology, Colorado, USA). A qualitative and quantitative evaluation was realised for every field of every patient. A quick and simple procedure was put into place to be able to make the same verifications using portal images. This new technique is not a modification of the overall methodology of analysis. The results achieved by comparing the measurement with the electronic portal imaging device and the calculation with the treatment planning system were in line with those achieved with the films for all indicators we studied (isodoses, horizontal and vertical dose profiles and gamma index).

[Image-guided radiotherapy]. / Radiothérapie guidée par l'image.

Recent advances in radiation oncology are based on improvement in dose distribution thanks to IMRT and improvement in target definition through new diagnostic imaging such as spectroscopic or functional MRI or PET. However, anatomic variations may occur during treatment decreasing the benefit of such optimization. Image-guided radiotherapy reduces geometric uncertainties occurring during treatment and therefore should reduce dose delivered to healthy tissues and enable dose escalation to enhance tumour control. However, IGRT experience is still limited, while a wide panel of IGRT modalities is available. A strong quality control is required for safety and proper evaluation of the clinical benefit of IGRT combined or not with IMRT.

[French national evaluation for helicoidal tomotherapy: description of indications, dose constraints and set-up margins]. / Evaluation nationale de la tomothérapie hélicoïdale: description des indications, des contraintes de dose et des seuils de repositionnement.

After a request for proposal initiated by National Institute against cancer (INCa) in 2005, three French centers in France started tomotherapy in the first semester of 2007. A national policy of evaluation was performed to study the feasibility of this innovative technique and to compare the interest of helicoidal tomotherapy with other modalities of conformal therapy. Common protocols have been designed to facilitate this evaluation. Description of dose, IMRT levels and constraints are achieved according to each selected indication as: sarcoma, head and neck tumors, lung cancer, mesothelioma, bone metastases, anal carcinoma and craniospinal irradiation.