Reconsidering frailty from a human and social sciences standpoint: towards an interdisciplinary approach to vulnerability.

Although frailty is an important, well-characterized concept in the provision of medical care to older adults, it has not been linked to the concept of vulnerability developed in the humanities and social sciences. Here, we distinguish between the two main dimensions of vulnerability: a fundamental, anthropological dimension in which people are exposed to a risk of injury, and a relational dimension in which people depend on each other and on their environment. The relational notion of vulnerability might provide healthcare professionals with a better understanding of frailty (and its potential interaction with precarity). Precarity situates people in their relationship with a social environment that might threaten their living conditions. Frailty corresponds to individual-level changes in adaptation to a living environment and the loss of ability to evolve or react in that environment. Therefore, we suggest that by considering the geriatric notion of frailty as a particular form of relational vulnerability, healthcare professionals could better understand the specific needs of frail, older people-and thus provide more appropriate care.

Registration methods in radiotherapy.

PURPOSE: The aim of this study is to present a short and comprehensive review of the methods of medical image registration, their conditions and applications in radiotherapy. A particular focus was placed on the methods of deformable image registration. METHODS: To structure and deepen the knowledge on medical image registration in radiotherapy, a medical literature analysis was made using the Google Scholar browser and the medical database of the PubMed library. RESULTS: Chronological review of image registration methods in radiotherapy based on 34 selected articles. A particular attention was given to show: (i) potential regions of the application of different methods of registration, (ii) mathematical basis of the deformable methods and (iii) the methods of quality control for the registration process. CONCLUSIONS: The primary aim of the medical image registration process is to connect the contents of images. What we want to achieve is a complementary or extended knowledge that can be used for more precise localisation of pathogenic lesions and continuous improvement of patient treatment. Therefore, the choice of imaging mode is dependent on the type of clinical study. It is impossible to visualise all anatomical details or functional changes using a single modality machine. Therefore, fusion of various modality images is of great clinical relevance. A natural problem in analysing the fusion of medical images is geographical errors related to displacement. The registered images are performed not at the same time and, very often, at different respiratory phases.

Bitumen Aging-Laboratory Simulation Methods Used in Practice and Selected Directions of Research on New Methods.

Changes in the properties of bitumen binders that occur as a result of aging have a huge impact on the durability of products produced from them. In particular, asphalt pavements, which constitute the most common use of petroleum bitumen, are susceptible to damage resulting from the increasing stiffness of the bitumen during its life cycle. Increased stiffness of asphalt pavements reduces the pavement resistance to low-temperature cracks and fatigue cracks, ultimately leading to the loss of their functional properties and the need for road repair. The rate of changes in bitumen properties is influenced by many factors, the most important of which are environmental conditions, technological parameters of binder processing, and physicochemical properties. The greatest impact on minimizing the adverse effect of aging is the use of bitumen suitably resistant to aging, and changing the technological parameters of its application. This article reviews the literature and standardized test methods of bitumen aging, with a focus on the methods that are most often used in practice, to evaluate the suitability of bitumen for use in road construction. The presented methods are limited to aging simulation. This mini-review presents the most important stages of aging procedures, their advantages and limitations, as identified by the authors of this publication for different types of bitumen. Moreover, the most important directions of developments in the field of new laboratory aging tests are highlighted. The suggestions are based on the industrial practice of the authors of this review, taking into account identified demands for quality control in the industry.

Evaluation of the accuracy of dose delivery in stereotactic radiotherapy using the Velocity commercial software.

PURPOSE: The purpose of this study was to evaluate the accuracy of dose delivery during stereotactic radiotherapy of the lung (SBRT) and brain (SRT) tumours by registered CT (rCT) images obtained from CT used for planning (pCT) and cone-beam CT (CBCT). METHODS: The study is based on two groups of patients (10 patients each) undergoing SBRT and SRT. To assess the correctness of the propagation of the GTV (brain group) and ITV (lung group) contours, the volumes calculated on the pCT and rCT studies were analysed. The Dice-Sørensen similarity coefficient (DSC) was used to check the variability in the position of GTV/ITV observed between pCT and rCT. The dose recalculated on rCT was compared with the dose from pCT. RESULT: GTV and ITV determined on pCT and rCT studies did not differ statistically (p = 0.770 for ITV and p = 0.086 for GTV). DSC obtained for the lung group was statistically smaller than that for the brain group (p < 0.001). Differences between doses obtained for 99% of the ITV/GTV on pCT and rCT studies were within ±10% and did not exceed the clinically acceptable tolerance. CONCLUSION: The observed changes in the volume (ITV/GTV) were within the area of the original PTV volume. The differences between the planned and delivered doses in the ITV/GTV were not clinically significant.

Accuracy of registrations between cone-beam computed tomography and conventional computed tomography images and dose mapping methods in RaySearch software for the bladder during brachytherapy of cervical cancer patients.

PURPOSE: The aim of the study was to assess selected methods of image registration available in the RaySearch software and their impact on the accuracy of mapping of doses deposited in the bladder during brachytherapy (BRT) of cervical cancer in images used during external beam radiotherapy (EBRT). MATERIAL AND METHODS: The study was based on data from ten patients. Cone-beam computed tomography (CBCT) images (BRT) were aligned with CT images (EBRT) using four registration methods: Reg_1 (rigid), Reg_2a, Reg_2b (hybrid), and Reg_3 (biomechanical). Image mapping accuracy was evaluated based on bladder's anatomy. Sørensen-Dice coefficient (DSC) values were analyzed for all the registrations. Discrepancies between triangular mesh points set on the basis of bladder contours were analyzed. Dose distributions from BRT were transformed according to registration results and mapped on CT images. Original BRT doses deposited in 2 cm3 volume of the bladder were compared to those transformed and associated with bladder's volume determined on CT images. RESULTS: Mean DSC values amounted to 0.36 (Reg_1), 0.87 and 0.88 (Reg_2a and Reg_2b), and 0.97 (Reg_3). Significant differences were found between DSC for the following comparisons: Reg_3/Reg_1 (p = 0.001), Reg_2a/Reg_1 (p = 0.011), and Reg_2b/Reg_1 (p = 0.014). The lowest discrepancies between triangular mesh points were for Reg_3 (p < 0.001, Reg_3 vs. Reg_1, and p = 0.039, Reg_3 vs. Reg_2b). Finally, the lowest discrepancies between the original and transformed doses were found for Reg_3. Nevertheless, only 5 out of 10 observations for Reg_3 yielded error of less than 5%. CONCLUSIONS: Biomechanical registration (Reg_3) enabled the most accurate alignment between CBCT and CT images. Satisfactory registration results of anatomical structures do not guarantee a correct mapping of primary BRT doses on the bladder delineated on CT images during EBRT. The results of dose transformation based on biomechanical registration had an error of less than 5% for only 50% of the observations.