Combination of dual-energy computed tomography and iterative metal artefact reduction to increase general quality of imaging for radiotherapy patients with high dense materials. Phantom study

PurposeTo evaluate the use of pseudo-monoenergetic reconstructions (PMR) from dual-energy computed tomography, combined with the iterative metal artefact reduction (iMAR) method.MethodsPseudo-monoenergetic CT images were obtained using the dual-energy mode on the Siemens Somatom Definition AS scanner. A range of PMR combinations (70–130 keV) were used with and without iMAR. A Virtual Water™ phantom was used for quantitative assessment of error in the presence of high density materials: titanium, alloys 330 and 600. The absolute values of CT number differences (AD) and normalised standard deviations (NSD) were calculated for different phantom positions. Image quality was assessed using an anthropomorphic pelvic phantom with an embedded hip prosthesis. Image quality was scored blindly by five observers.ResultsAD and NSD values revealed differences in CT number errors between tested sets. AD and NSD were reduced in the vicinity of metal for images with iMAR (p < 0.001 for AD/NSD). For ROIs away from metal, with and without iMAR, 70 keV PMR and pCT AD values were lower than for the other reconstructions (p = 0.039). Similarly, iMAR NSD values measured away from metal were lower for 130 keV and 70 keV PMR (p = 0.002). Image quality scores were higher for 70 keV and 130 keV PMR with iMAR (p = 0.034).ConclusionThe use of 70 keV PMR with iMAR allows for significant metal artefact reduction and low CT number errors observed in the vicinity of dense materials. It is therefore an attractive alternative to high keV imaging when imaging patients with metallic implants, especially in the context of radiotherapy planning.     

External beam radiation therapy with kilovoltage x-rays

Kilovoltage (kV) x-rays are most commonly used for diagnostic imaging due to their sensitivity to tissue composition. In radiation therapy (RT), due to their fast attenuation, kV x-rays are typically only used for superficial irradiation of skin cancer and for intra-operative RT (IORT). Recently, however, a number of kV RT techniques have emerged. In this review article, we provide a brief overview of the use of kV x-rays for RT.Various kV x-ray source technologies suitable for RT, such as conventional x-ray tubes as well as novel x-ray sources, are first described. This x-ray source section is then followed by a section on their implementation in terms of clinical, veterinary and preclinical applications. Specifically, IORT, superficial RT and dose enhancement with iodine and gold nanoparticles, as well as microbeam RT and FLASH RT are discussed in this context. Then, a number of kV x-ray RT applications in modeling and proof-of-principle stages, such as breast external beam RT with rotational sources, kilovoltage arc therapy and the BriXS Compton pulsed x-ray sources, are reviewed. Finally, some clinical and economic considerations for the development of kV RT techniques are discussed.     

Glibenclamide modulates glucantime activity and disposition in Leishmania major

A source of chemotherapeutic failure in anti-infective therapies is the active movement of drugs across membranes, through ATP-binding cassette (ABC) transporters. In fact, simultaneous administration of therapeutic drugs with ABC transporter blockers has been invoked to be the way to actively prevent the emergence of drug resistance. Herein, we demonstrate that glucantime’s efficacy in decreasing the infection rate of Leishmania-infected macrophages is strongly enhanced when used in combination with glibenclamide, a specific blocker of ABC transporters. Intracellular ABC transporters mediate glucantime sequestration in intracellular organelles. Their selective inhibition may effectively increase the cytoplasmic concentration of glucantime and its leishmanicidal activity. Our results reveal for the first time that glibenclamide targets in Leishmania major a compartment associated with a multivesicular system that is simultaneously labeled by the acidic marker LysoTracker-red and may represent the organelle where antimonials are sequestered. These results constitute a proof of concept that conclusively demonstrates the potential value that combination therapy with an ABC transporter blocker may have for leishmaniasis therapy.     

Obesity in Older Adults: Technical Review and Position Statement of the American Society for Nutrition and NAASO,The Obesity Society

Obesity causes serious medical complications and impairs quality of life. Moreover, in older persons, obesity can exacerbate the age‐related decline in physical function and lead to frailty. However, appropriate treatment for obesity in older persons is controversial because of the reduction in relative health risks associated with increasing body mass index and the concern that weight loss could have potential harmful effects in the older population. This joint position statement from the American Society for Nutrition and NAASO, The Obesity Society reviews the clinical issues related to obesity in older persons and provides health professionals with appropriate weight‐management guidelines for obese older patients. The current data show that weight‐loss therapy improves physical function, quality of life, and the medical complications associated with obesity in older persons. Therefore, weight‐loss therapy that minimizes muscle and bone losses is recommended for older persons who are obese and who have functional impairments or medical complications that can benefit from weight loss.     

The Effect of Dolphin-Assisted Therapy on the Cognitive and Social Development of Children with Down Syndrome

Cognitive and speech development are delayed in children with Down syndrome (DS). We investigated the effect of dolphin-assisted therapy (DAT), a form of animal-assisted intervention, on the development of speech/language and social behavior in children with DS. We hypothesized that DAT would improve the social and cognitive functions with respect to verbalization and thereby promote task performance. A semi-crossover design was used to study 45 children with DS: 18 received a weekly one-hour session of DAT for 6 weeks (group A), 12 children (group B) started with swimming pool sessions (control period of 6 weeks) and thereafter received DAT, and 17 children (group C) were put on a waiting list (control period of 6 weeks) before receiving DAT. The parameters “verbalization,” “impulsiveness,” “proper understanding of rules,” “recognition of persons,” and “establishing contacts” were measured using the Matson Evaluation of Social Skills for Individuals with Severe Retardation (MESSIER) before and after DAT, as well as before and after each of the control periods. Repeated measures ANOVA revealed no significant changes for any of the variables during the control periods (swimming pool, waiting list). Following the period of DAT there was a significant improvement in “verbalization” and “recognition of persons,” while “impulsiveness” decreased. No significant changes were found for the other parameters. “Verbalization” continued to increase during the follow-up period of 6 months, while “recognition of persons” slightly decreased. The results of this study provide support for our hypothesis. Through improvements in verbalization and the recognition of persons, the execution of tasks among children with DS receiving DAT improved. Additional studies are needed to determine if these positive effects of DAT are long-term.