Improvement of Radiation-Mediated Immunosuppression of Human NSCLC Tumour Xenografts in a Nude Rat Model

Human tumour xenografts in a nude rat model have consistently been used as an essential part of preclinical studies for anticancer drugs activity in human. Commonly, these animals receive whole body irradiation to assure immunosuppression. But whole body dose delivery might be inhomogeneous and the resulting incomplete bone marrow depletion may modify tumour behaviour. To improve irradiation-mediated immunosuppression of human non-small cell lung cancer (NSCLC) xenografts in a nude rat model irradiation (2 + 2 Gy) from opposite sides of animals has been performed using a conventional X-ray tube. The described modification of whole body irradiation improves growth properties of human NSCLC xenografts in a nude rat model. The design of the whole body irradiation mediated immunosuppression described here for NSCLC xenografts may be useful for research applications involving other types of human tumours

Neue Verfahren der Präzisions-Strahlentherapie

Das Ziel strahlentherapeutischer Behandlung ist es, Tumoren zu vernichten und dabei das gesunde Gewebe weitgehend zu schonen. Eine Präzisions-Radiotherapie erfordert eine möglichst konforme Bestrahlung des Tumors mit der für die Heilung notwendigen Dosis. Für die heute gebräuchlichsten therapeutischen Strahlenquellen – Elektronen-Linearbeschleuniger, welche Elektronen- und harte Röntgenstrahlen bereitstellen – wurden dafür die Methoden der intensitätsmodulierten und bildgeführten Radiotherapie entwickelt. Der nächste Schritt zur Verbesserung der Tumorkonformität ist die klinische Anwendung von Partikelstrahlen (Protonen, leichte Ionen). Entsprechende Anlagen erfordern einen hohen Investitionsaufwand. Eine Reduktion dieses Aufwandes könnte der Einsatz außerordentlich kompakter Beschleunigungsstrukturen eröffnen, welche auf der Wechselwirkung hochintensiver Laserstrahlen mit Materie beruhen.The goal of radiotherapeutic treatment is complete tumour destruction, while sparing the healthy tissue as far as possible. Precision radiotherapy requires tumour-conform irradiation with a curative dose. For electron linear accelerators, the most common therapeutic radiation source at present, delivering beams of electrons and hard X-rays, the methods of intensity-modulated and imageguided radiotherapy have been developed. The next level in improving tumour conformity is the clinical application of particle beams (protons and light ions). Such facilities require substantial investments. The outlay could be reduced, however, by using very compact accelerating structures based upon the interaction of highly intensive laser beams with matter

Range assessment in particle therapy based on prompt gamma-ray timing measurements

Proton and ion beams open up new vistas for the curative treatment of tumors, but adequate technologies for monitoring the compliance of dose delivery with treatment plans in real time are still missing. Range assessment, meaning the monitoring of therapy-particle ranges in tissue during dose delivery (treatment), is a continuous challenge considered a key for tapping the full potential of particle therapies. In this context the paper introduces an unconventional concept of range assessment by prompt-gamma timing (PGT), which is based on an elementary physical effect not considered so far: therapy particles penetrating tissue move very fast, but still need a finite transit time-about 1-2 ns in case of protons with a 5-20 cm range-from entering the patient's body until stopping in the target volume. The transit time increases with the particle range. This causes measurable effects in PGT spectra, usable for range verification. The concept was verified by proton irradiation experiments at the AGOR cyclotron, KVI-CART, University of Groningen. Based on the presented kinematical relations, we describe model calculations that very precisely reproduce the experimental results. As the clinical treatment conditions entail measurement constraints (e.g. limited treatment time), we propose a setup, based on clinical irradiation conditions, capable of determining proton range deviations within a few seconds of irradiation, thus allowing for a fast safety survey. Range variations of 2 mm are expected to be clearly detectable

Comparison of two dedicated 'in beam' PET systems via simultaneous imaging of (12)C-induced beta(+)-activity.

The selective energy deposition of hadrontherapy has led to a growing interest in quality assurance techniques such as 'in-beam' PET. Due to the current lack of commercial solutions, dedicated detectors need to be developed. In this paper, we compare the performances of two different 'in-beam' PET systems which were simultaneously operated during and after low energy carbon ion irradiation of PMMA phantoms at GSI Darmstadt. The results highlight advantages and drawbacks of a novel in-beam PET prototype against a long-term clinically operated tomograph for ion therapy monitoring

Machbarkeitstudie für einen industriellen supraleitenden Table Top Elektronenbeschleuniger

At the Forschungszentrum Rossendorf the build-up of the superconducting 1.3 GHz accelerator ELBE is still in progress. Furthermore a new sc photo injector (SRF gun) is under development, which should accelerate electrons up to 10 MeV at 1.3 GHz frequency. The use of electron accelerators is also more and more interesting for applications where the destructive potential of the electrons are used like sterilization of medical waste and medical products, food irradiation or decontamination of sewage. For these processes a high power is required to achieve a high product throughput in a plant. The aim is therefore to use beam powers of around 100 kW or more. Since the applications of electron accelerators in industrial environments are steadily increasing one can speculate about transferring the above named state of the arte technology to industrial electron accelerators. At the FZR a feasibility study of such a table top electron accelerator (TTE) has been performed to investigate its technical limits and marketabilitys

Children’s and adolescents’ rising animal-source food intakes in 1990–2018 were impacted by age, region, parental education and urbanicity

Animal-source foods (ASF) provide nutrition for children and adolescents’ physical and cognitive development. Here, we use data from the Global Dietary Database and Bayesian hierarchical models to quantify global, regional and national ASF intakes between 1990 and 2018 by age group across 185 countries, representing 93% of the world’s child population. Mean ASF intake was 1.9 servings per day, representing 16% of children consuming at least three daily servings. Intake was similar between boys and girls, but higher among urban children with educated parents. Consumption varied by age from 0.6 at <1 year to 2.5 servings per day at 15–19 years. Between 1990 and 2018, mean ASF intake increased by 0.5 servings per week, with increases in all regions except sub-Saharan Africa. In 2018, total ASF consumption was highest in Russia, Brazil, Mexico and Turkey, and lowest in Uganda, India, Kenya and Bangladesh. These findings can inform policy to address malnutrition through targeted ASF consumption programmes.publishedVersio