Radioactive nuclei for β + γ PET and theranostics: selected candidates

Positron emission tomography (PET) is an established medical diagnostic imaging method. Continuous improvements are aimed at refining image reconstruction, reducing the amount of radioactive tracer and combining with targeted therapy. Time-of-flight (TOF)-PET provides the localization of the tracer through improved time resolution, nuclear physics may contribute to this goal via selection of radioactive nuclei emitting additional γ-rays. This additional radiation, when properly detected, localizes the decay of the tracer at the line of response (LoR) determined by two detected 511 keV quanta. Selected candidates are presented. Some are particularly interesting, as they are strong candidates for theranostic applications.

Telerobotic interventions from a distance: an initial experience in 3D phantom mapping

Introduction The current COVID-19 pandemic has fostered several accelerations in “remote” patient care such as video and telephone clinics, as well as multidisciplinary collaborations using online platforms with experts consulting the local teams from a distance. The next logical step would be to also offer remote-controlled interventions which the expert operator not on site, but in support of the local team. This is especially valuable for complex interventions when either patient or expert operator can not be present at the same place. Purpose We aimed to demonstrate that an expert operator located at far distance (Austria) could directly interact with the remote magnetic navigation system in London (UK) whilst mapping a 3D phantom using an electroanatomical mapping system. Method Two experienced operators of the magnetic navigation system were tasked with creating fast anatomic maps (FAM) of the atrial and ventricular chambers of a 3D phantom using remote magnetic navigation in combination with 3D electroanatomical mapping. One was located in the control room of the magnetic catheter lab (UK) and the second one was in Tirol, Austria and connected through a secure remote desktop connection (via high speed fibre optic cable). Using a solid tip magnetic catheter connected to a mechanical drive, all interactions with the system were carried out via the Odyssey platform. Acquisitions for right and left atrium, as well as right and left ventricles plus aorta was compared with regards to mapping duration, map completeness (as judged by the average distance of surface points from 3D CT scan reconstruction), total 3D map volume and need for additional radiation exposure during the mapping process. Results Mapping time and map completeness when performed by the distant operator was not inferior to the local operator and both did not require any additional radiation exposure during the mapping process. Table 1 demonstrates the mean parameters for each chamber, respectively. Figure 1 depicts the matched data for chamber completeness as compared for the LA (green= local operator, pink= distant operator) using a contrast CT scan as the gold standard. Conclusion Telerobotic 3D mapping of a 3D phantom from a distance was equally fast delivered from the control room as compared to an operator located 1200 km away without compromising on map completeness. This demonstrates the feasibility of telerobotic interventions and stress the need for remote collaboration which is especially valuable when travel of patients and/or physician experts is restricted. Funding Acknowledgement Type of funding sources: None. Matched data for aorta

Eucalyptus Obliqua Tall Forest in Cool, Temperate Tasmania Becomes a Carbon Source during a Protracted Warm Spell in November 2017

Tasmania, which has a cool temperate climate, experienced a protracted warm spell in November 2017. In absolute terms, temperatures during the warm spell were lower than those usually characterising heatwaves. Nonetheless the November 2017 warm spell represented an extreme anomaly based on the local historical climate. Eddy covariance measurements of fluxes made in a Eucalyptus obliqua tall forest at Warra, southern Tasmania, recorded a 39% reduction in gross primary productivity (GPP) during the warm spell. A coincident increase in ecosystem respiration during the warm spell resulted in the forest switching from a carbon sink to a source. Net radiation was significantly higher during the warm spell than in the same period in the preceding two years. This additional radiation drove an increase in latent heat but not sensible heat. Stomatal regulation to limit water loss was unlikely based on soil moisture and vapour pressure deficits. Temperatures during the warm spell were supra-optimal for GPP at that site for 75% of the daylight hours. The decline in GPP during the warm spell was therefore most likely due to temperatures exceeding the site optimum for GPP. These forests will be weaker carbon sinks if, as predicted, heatwave events become more common.

Radiocaesium in the environment of Fukushima

It has been 10 years since the accident at Fukushima Daiichi nuclear power plant in 2011. Large quantities of 131I, 134Cs, and 137Cs were released into the environment, and 80% of 137Cs still remains. In addition to the decrease by attenuation, the transfer of 137Cs to plants, animals, and humans is decreasing due to movement and changing fractions with elapsed time. The activity concentration of 137Cs in the atmosphere has decreased drastically, and the internal radiation dose due to inhalation is negligible. The activity concentration of 137Cs in agricultural plants is decreasing due to decontamination of soil, application of potassium, and lower levels in irrigation water. The activity concentration of 137Cs in wild animals is decreasing, and shows seasonal variation in wild boars. The activity concentration of 137Cs in offshore seawater has decreased to 0.01 Bq l−1. Therefore, the radiation dose is <1 mSv of the additional radiation dose.

Computer-assisted contralateral side comparison of the ankle joint using flat panel technology

Purpose Reduction and osteosynthesis of ankle fractures is a challenging surgical procedure when it comes to the verification of the reduction result. Evaluation is conducted using intra-operative imaging of the injured ankle and depends on the expertise of the surgeon. Studies suggest that intra-individual variance of the ankle bone shape and pose is considerably lower than the inter-individual variance. It stands to reason that the information gain from the healthy contralateral side can help to improve the evaluation. Method In this paper, an assistance system is proposed that provides a side-to-side view of the two ankle joints for visual comparison and instant evaluation using only one 3D C-arm image. Two convolutional neural networks (CNN) are employed to extract the relevant image regions and pose information of each ankle so that they can be aligned with each other. A first U-Net uses a sliding window to predict the location of each ankle. The standard plane estimation is formulated as segmentation problem so that a second U-Net predicts the three viewing planes for alignment. Results Experiments were conducted to assess the accuracy of the individual steps on 218 unilateral ankle datasets as well as the overall performance on 7 bilateral ankle datasets. The experiments on unilateral ankles yield a median position-to-plane error of $$0.73\pm 1.36$$ 0.73 ± 1.36 mm and a median angular error between 2.98$$^\circ $$ ∘ and 3.71$$^\circ $$ ∘ for the plane normals. Conclusion Standard plane estimation via segmentation outperforms direct pose regression. Furthermore, the complete pipeline was evaluated including ankle detection and subsequent plane estimation on bilateral datasets. The proposed pipeline enables a direct contralateral side comparison without additional radiation. This has the potential to ease and improve the intra-operative evaluation for the surgeons in the future and reduce the need for revision surgery.

Precise predictions for photon pair production matched to parton showers in GENEVA

We present a new calculation for the production of isolated photon pairs at the LHC with $$ {\mathrm{NNLL}}_{{\mathcal{T}}_0}^{\prime } $$ NNLL T 0 ′ +NNLO accuracy. This is the first implementation within the Geneva Monte Carlo framework of a process with a nontrivial Born-level definition which suffers from QED singularities. Throughout the computation we use a smooth-cone isolation algorithm to remove such divergences. The higher-order resummation of the 0-jettiness resolution variable $$ {\mathcal{T}}_0 $$ T 0 is based on a factorisation formula derived within Soft-Collinear Effective Theory which predicts all of the singular, virtual and real NNLO corrections. Starting from this precise parton-level prediction and by employing the Geneva method, we provide fully showered and hadronised events using Pythia8, while retaining the NNLO QCD accuracy for observables which are inclusive over the additional radiation. We compare our final predictions to LHC data at 7 TeV and find good agreement.

ESTIMATION OF RADIOLOGICAL EXPOSURE LEVELS IN A MINING AREA BASED ON 238U, 226Ra, 232Th and 40K ACTIVITY MEASUREMENTS: A CASE STUDY FOR BEYLIKOVA-SIVRIHISAR COMPLEX ORE SITE IN TURKEY

The study estimated the radiological exposure levels in a mining area for miners in the Beylikova-Sivrihisar (Turkey) complex ore site containing 238U, 226Ra and 232Th. Sixty samples were collected from the study area based on a geologic map. The radionuclide activities were measured using a 78.5% efficient n-type HPGe detector. The measured mean activities were 1871 ± 38 Bq kg−1 for 238U, 1749 ± 5 Bq kg−1 for 226Ra, 3467 ± 9 Bq kg−1 for 232Th and 309 ± 2 Bq kg−1 for 40K. From the measured results, the external effective dose was calculated to be max. 3.80 ± 0.03 mSv y−1 (mean: 2.04 ± 0.03 mSv y−1) for inside gallery and max. 7.59 ± 0.05 mSv y−1 (mean: 4.08 ± 0.05 mSv y−1) for outdoor. Additionally, the external exposure index was calculated to be Hex = 33.5 ± 0.2(mean: 18.2 ± 0.3) and internal exposure index to be Hin = 45.9 ± 0.3 (mean: 22.9 ± 0.4). The results indicate that additional radiation protection measures should be taken during the mining process if an opencast mining is implemented in Beylikova complex ore deposit.