Search

Computational design of therapeutic peptides that enables fast exploration of a combinatorial number of amino acid possibilities has emerged as a popular strategy in antibiotics discovery but identifying peptide inhibitors targeting specific protein-protein interactions (PPIs) still faces significant challenges. Here, we present a new approach for de novo design of target-specific peptides, which combines a Gated Recurrent Unit (GRU) based variational autoencoder (VAE) with Rosetta FlexPepDock for peptide sequence generation and potency assessment, followed by the refinement with all-atom molecular dynamics (MD) simulations. We have utilized the computational protocol to design eight peptide inhibitors specifically disrupting the interaction of β-catenin with TCF/LEF family transcription factors. Four of these peptide inhibitor candidates were synthesized and experimentally tested, of which two displayed enhanced binding affinities for β-catenin compared to the best-known peptide made of all natural amino acids. We also constructed a random peptide library of 710,000 unique peptides, and none of these peptides showed a higher binding affinity than our computationally designed peptides. Our study exemplifies the success of combining deep learning and structure-based modeling and simulation for target-specific peptide design. Besides the development of therapeutic peptides targeting β-catenin/TCF, our approach should be transferable to other PPIs, such as p53/MDM2, Bcl-2/Bax, and CD40/CD40L.

Background The present study attempted to demonstrate how the configuration of hydrogel-coated coils is influenced by different temperature exposures. Thirty detachable hydrogel-coated coils were evaluated in an in vitro water immersion test under five different temperature ranges (22.6 °C, 37 °C, 40–50 °C, 50–60 °C, and 60–70 °C). The configuration changes were classified (configuration I, configuration II, and configuration III) according to the curling that occurred during 30 min of immersion. Configuration stability of five Hydrogel-coated coils was also evaluated in a two-step temperature immersion test. Results All hydrogel-coated coils showed some configuration changes during water immersion. However, a logarithmic transformation of the time and temperature data showed a significant (p R = 0.97, configuration II: R = 0.98, configuration III: R = 0.97). The time needed to reach configuration III (complete coiling) was 160.4 ± 41.9 s at 37.5 °C (range: 100–205 s), 45.7 ± 22.2 s at 47.5 °C (range: 23–70 s), 20.2 ± 7.2 s at 57.5 °C (range: 14–32 s), and 10.3 ± 2.4 s at 67.5 °C (range: 7–13 s). Conclusions Temperatures above 55 °C induced immediate configurational changes in the hydro-coated coils, achieving complete curling within less than 30 s. Temperatures near 36 °C (normal body temperature) require more time to reach optimal coil curling (configuration III). The optimization of HydroCoil preparation can reduce interventional procedural time and improve clinical results.

The aim of this study was to test the nano-hydroxyapatite powder decontamination method on intraorally contaminated titanium discs and to compare this method with current decontamination methods in the treatment of peri-implantitis. Contaminated discs were assigned to six treatment groups (n = 10 each): titanium hand curette; ultrasonic scaler with a plastic tip (appropriate for titanium); ultrasonic scaler with a plastic tip (appropriate for titanium) + H2O2; short-term airflow system (nano-hydroxyapatite airborne-particle abrasion for 30 seconds); long-term airflow system (nano-hydroxyapatite airborne-particle abrasion for 120 seconds); Er:YAG laser (120 mJ/pulse at 10 Hz). There were also two control groups (n = 10 each): contaminated disc (negative control) and sterile disc (positive control). Scanning electron microscopy, energy-dispersive x-ray spectroscopy, and dynamic contact angle analysis were used to determine the most effective surface-treatment method. The highest percentage of carbon (C) atoms was observed in the negative control group, and the lowest percentage of C atoms was found in the long-term airflow group, followed by the short-term airflow, laser, ultrasonic + H2O2, ultrasonic, and mechanical groups. When the groups were examined for wettability, the lowest contact angle degree was observed in the long-term airflow, short-term airflow, and laser groups. Nano-hydroxyapatite and laser treatments for detoxifying and improving infected titanium surfaces may show the most suitable results for reosseointegration.

Background The aim of this study was to present a percutaneous transhepatic biliary puncture simulator that can be used without radiation exposure and that reflects the conventional anatomy of the biliary ducts and its vicinity structures. Methods An anatomically based model of the biliary tree was developed using a cord network fixed to a wooden frame. The skin, ribs, intercostal muscles, and right lower lobe pleura were simulated using foam sponge, plastic tubes, a polystyrene foam panel, and an air pad, respectively. For the puncture, we used a 20-G Chiba needle and a wire with distal double arches; these were used to troll a cord, simulating the successful puncture of a bile duct. A camera was also placed above the model to allow the trainees to train eye-hand coordination while viewing the image on a monitor in real time. The simulator was tested with 60 radiology residents to evaluate the confidence and skills transferability of the training model. Results After receiving an introduction of the system and 5 min of training under tutor surveillance, all participants were able to troll a cord of the biliary simulator by themselves in less than 4 min. Only one participant punctured the simulated pleura. The participants’ evaluations showed positive results, with increased user confidence and skills transferability after the training session. Conclusions This proposed simulator can be an effective tool to improve a trainee’s confidence and competence while achieving procedural and non-procedural interventional radiology skills related to the liver. Trial registration Retrospectively registered

Bu çalışmada farklı taban malzeme bias gerilimleri uygulanarak üretilen CrN kaplamalarının morfolojik, yapısal, kimyasal ve aşınma dayanımı özellikleri incelenmiştir. Sanayide yaygın bir şekilde kullanılan AISI 52100 çeliği taban malzeme olarak seçilmiştir. Kaplama yöntemi olarak fiziksel buhar biriktirme yöntemi kullanılmıştır. Kaplamaların morfolojik özellikleri taramalı elektron mikroskobu kullanılarak incelenmiştir. Kaplamaların kristolografik yapıları X ışını difraksiyonu yöntemi kullanılarak analiz edilmiştir. Kaplamaların kimyasal bileşenleri EDS analizi ile incelenmiştir. Kaplamaların aşınma dayanımı özellikleri 5x10-3 mbar vakum ve normal atmosfer ortamlarında sabit hız, süre ve yük deney parametrelerinde disk üzeri bilye deney düzeneği kullanılarak incelenmiştir. Aşınma hacimleri temassız optik profilometre ile ölçülmüştür. Aşınma mekanizmaları aşınma izlerinden alınan SEM ve EDS analizleri ile karakterize edilmiştir. Yapılan aşınma deneylerinden atmosfer şartlarında CrN kaplanmış bütün numuneler, kaplanmamış numunelere göre daha düşük aşınma miktarına sahip olduğu gözlenmiştir. Atmosfer koşullarında en düşük aşınma miktarı, taban malzemelere 200 Volt bias uygulanan numunelerden elde edilirken, vakum ortamında en düşük aşınma miktarı taban malzemelere 100 Volt bias gerilimi uygulanan numunelerden elde edilmiştir. Atmosfer ortamında aşınma mekanizması bütün numunelerde oksidatif ve abrazif olarak gözlemlenirken, vakum ortamında aşınma mekanizması adhezif olarak gözlenmiştir.

In this study, pure TiN coatings were applied on AISI 52100 steel surfaces with a magnetron sputterer at different direct current (DC) powers and N2 flows to develop a wear-resistant coating for sl...

BackgroundPlacental implantation abnormalities remain among the major causes of massive postpartum hemorrhage and maternal mortality worldwide. To avoid a hysterectomy, prophylactic management with perioperative internal iliac artery balloon occlusion (IIABO) could minimize blood loss and facilitate surgical performance through reductions in the rate of uterine perfusion. We aimed to evaluate the safety and efficacy of IIABO in patients with placental implantation abnormalities.ResultsThe study group consisted of 13 patients, including three patients with placenta previa totalis, seven patients with placenta increta, and three patients with placenta percreta. Prophylactic IIABO was performed in all patients. The median estimated blood loss was 700 ml ± 598.8 ml, the median number of red blood cell transfusion units was 0 ± 0.75, and only two patients required uterine artery embolization. The uterus was preserved in eight patients (61.5%), with an average intra-hospitalary stay of 6 ± 3.2 days. The average fetal radiation dose was 4.67 mGy. No complications were attributed to IIABO placement.ConclusionsThe prophylactic use of IIABO in placental implantation abnormalities is an effective and safe method of controlling perioperative bleeding during cesarean section and hysterectomy. Indications should be strictly controlled, and interdisciplinary planning and management are mandatory.

WOS: 000372307800037, In this study, the applicability of friction stir welding to cast NAB alloy (i.e., C95800) with a thickness of 9 mm has been investigated. The joint performance was determined by conducting optical microscopy, microhardness measurements, and mechanical testing (e.g., tensile and Charpy impact tests). The effect of stir intensity on joint performance was also determined. A grain refinement (equiaxed fine grain structure) as well as evolution of a Widmanstatten structure was achieved within the stir zone of all the joints produced. Thus, all of the joints produced exhibited higher proof stress (i.e., between 512 and 616 MPa) than that of the base material, i.e., 397 MPa. On the other hand, only half of the specimens exhibited higher tensile strength values than that of the base plate (i.e., 794 MPa), whereas the other specimens displayed lower tensile strength than the base plate due to the existence of weld defects, namely cold bonding and/or tunnel defect.

Introduction Post-mortem cardiac MR exams present with different contraction appearances of the left ventricle in cardiac short axis images. It was hypothesized that the grade of post-mortem contraction may be related to the post-mortem interval (PMI) or cause of death and a phenomenon caused by internal rigor mortis that may give further insights in the circumstances of death. Method and materials The cardiac contraction grade was investigated in 71 post-mortem cardiac MR exams (mean age at death 52 y, range 12–89 y; 48 males, 23 females). In cardiac short axis images the left ventricular lumen volume as well as the left ventricular myocardial volume were assessed by manual segmentation. The quotient of both (LVQ) represents the grade of myocardial contraction. LVQ was correlated to the PMI, sex, age, cardiac weight, body mass and height, cause of death and pericardial tamponade when present. In cardiac causes of death a separate correlation was investigated for acute myocardial infarction cases and arrhythmic deaths. Results LVQ values ranged from 1.99 (maximum dilatation) to 42.91 (maximum contraction) with a mean of 15.13. LVQ decreased slightly with increasing PMI, however without significant correlation. Pericardial tamponade positively correlated with higher LVQ values. Variables such as sex, age, body mass and height, cardiac weight and cause of death did not correlate with LVQ values. There was no difference in LVQ values for myocardial infarction without tamponade and arrhythmic deaths. Conclusion Based on the observation in our investigated cases, the phenomenon of post-mortem myocardial contraction cannot be explained by the influence of the investigated variables, except for pericardial tamponade cases. Further research addressing post-mortem myocardial contraction has to focus on other, less obvious factors, which may influence the early post-mortem phase too.

In this study, ~ 3.5 µm thick multilayer titanium alumina nitride (TiAlN), alumina titanium nitride (AlTiN), and alumina chromium nitride (AlCrN) coatings were deposited on the H13 steel surface by cathodic arc physical vapor deposition (CAPVD) method. The tribological performance of the coatings was evaluated by a tribometer at boundary lubrication condition. Then, coating surfaces were observed by optical microscope, optical profilometer, and atomic force microscope to evaluate the morphological changes, wear volumes, and tribofilm thickness. Also, scanning electron microscopy (energy dispersive X-ray) and X-ray photoelectron spectrometry analyses were applied to coating surfaces for the tribochemical evolution of the tribofilm. Results showed that AlCrN coating performed the best tribological behavior at boundary lubricated condition, when compared to TiAlN and AlTiN coatings and it can be used as a wear resistant cam tappet coating in internal combustion engines.

The present paper reports the influence of working pressure and nitrogen flow rate on the mechanical and wear properties of TiN thin films deposited by DC reactive magnetron sputtering with RF bias voltage. The process of PVD coating is conducted in a nitrogen-argon gaseous mixture at a temperature of 150°C and a DC power of 200W for 90 min. The micro hardness and the wear resistance of the TiN are determined prior to and after the PVD coating. The wear volumes of samples were evaluated using optical profilometre. Worn surfaces wereobserved using scanning electron microscopy. It was observed that coated samples showed considerable higher mechanical properties and wear resistance compare to uncoated samples. Abrasive wear mechanism was observed on the surface of worn surfaces., The present paper reportsthe influence of working pressure and nitrogen flow rate on the mechanical andwear properties of TiN thin films deposited by DC reactive magnetron sputteringwith RF bias voltage. The process of PVD coating is conducted in a nitrogen-argongaseous mixture at a temperature of 150°C and a DC power of 200W for 90 min.The micro hardness and the wear resistance of the TiN are determined prior toand after the PVD coating. The wear volumes of samples were evaluated usingoptical profilometre. Worn surfaces were observed using scanning electronmicroscopy. It was observed that coated samples showed considerable highermechanical properties and wear resistance compare to uncoated samples. Abrasivewear mechanism was observed on the surface of worn surfaces.

Diamond-like-carbon (DLC) coatings with high hardness and low friction coefficient exhibit excellent tribological performance under air and vacuum conditions. However, adhesion and cold welding problems in vacuum conditions lead to increase friction coefficient values. These negative effects can be eliminated by different methods such as forming interlayers between coating and substrate or ion treatment of the substrate. In this work, DLC coatings were deposited on untreated and plasma nitrided (at 400 degrees C, 500 degrees C and 600 degrees C for 1 h and 4 h) AISI 4140 steel substrates by magnetron sputtering technique. The effects of plasma nitriding treatment on the friction and wear properties of DLC coatings under air and vacuum conditions were investigated. The structural and mechanical properties of DLC films were examined by XRD, SEM, and microhardness tester, respectively. The friction and wear properties were determined by a tribotester under air and vacuum conditions. The microhardness of samples increased after surface treatments and the highest value was obtained from the sample plasma nitrided at 600 degrees C for 4 h plus DLC coated sample. The wear resistance of samples increased with increasing plasma nitriding time and temperature. Also, it was observed that the samples tested under vacuum condition showed better wear resistance than the samples tested under ambient air. Furthermore, increasing plasma nitriding time and temperature improved the wear performance of the material regardless of the test environment.

To assess whether dose monitoring software can be successfully implemented in fluoroscopically guided interventions and to provide dose data based on levels of complexity.After launching the software (DoseWatch; GE Healthcare Systems, Buc, France), data were collected for 6 months and analyzed by means of kerma-area product (KAP; Gy/cm(2)), cumulative air kerma (KA,R; Gy), and fluoroscopic time (minutes). Data analysis was executed by level of complexity as graded by the operators. Complexity grading was based on factors such as tortuosity and calcification of vessel, variant anatomy, and patient cooperation.The software successfully transferred dose data of 357 fluoroscopically guided procedures. KAP was 0.238-400 Gy/cm(2) with mean, median, and 75th percentile values of 46.0 Gy/cm(2), 163.2 Gy/cm(2), and 541.1 Gy/cm(2) (KA,R, 0.013-4.1 Gy; mean, median, 75th percentile, 0.48 Gy, 0.97 Gy, 3.98 Gy). Highest dose values were seen in transarterial chemoembolization (KAP mean, median, 75th percentile, 229.5 Gy/cm(2), 216.4 Gy/cm(2), 299.9 Gy/cm(2); KA,R mean, median, 75th percentile, 1.9 Gy, 1.2 Gy, 1.7 Gy). Analysis revealed that the level of complexity strongly correlated with KAP (r = 0.88; P.001) whereas there was no direct correlation of KAP and fluoroscopy time. During the same intervention, KA,R and fluoroscopy time increased with level of complexity, but the correlation was not statistically significant.Implementation of dose monitoring software in fluoroscopically guided interventions can be successfully accomplished, and it facilitates data comparison.

MoS 2 coatings are effectively used in vacuum and in water vapor-free environments because of increased friction coefficient and decreased service life under atmospheric conditions. A lot of different alloy elements (e.g., Ti, Nb, Cr) and compounds (e.g., TiN, TiB 2 ) are used to enhance the friction and wear properties of MoS 2 coatings. In this study Ti/TiB 2 /MoS 2 graded-composite coatings (GCC) were deposited by closed-field unbalanced magnetron sputtering (CFUBMS). The structural properties of the coatings were analyzed by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). The hardness of the coatings was measured with the use a microhardness tester. The tribological properties of the coatings were determined under air and vacuum conditions. Ti/TiB 2 /MoS 2 (GCC) have MoS 2 (002) and TiB 2 (100) reflections. The coatings exhibited a dense and non-columnar structure. Tribological properties of the coatings under air and vacuum conditions significantly affected the hardness, thickness and stoichiometric ratio of elements in the structure.

Copper alloys are commonly used in bearings under ambient conditions, but their potential use in aerospace applications with reduced surrounding pressures has not been as extensively investigated. In this study, the sliding friction and wear behaviour of copper alloy CuZn39Pb3 were investigated under both atmospheric and vacuum conditions, with the use of an environmentally controlled pin-on-disk apparatus. Experiments were conducted under pressures of 5×10 −3 mbar, 8×10 −6 mbar and normal atmospheric conditions (1013 mbar) with contact pressures of 0.3, 1.0 and 2.0 MPa and a 1 m/s constant sliding speed. Scanning electron microscopy was used to characterise the features of the wear surfaces, subsurface regions and debris particles. The wear mechanism of the CuZn39Pb3 alloy was mainly adhesive under both under atmospheric and vacuum conditions; however, some indications of abrasion were observed under atmospheric conditions. The wear rate of the CuZn39Pb3 was lower under vacuum conditions. Furthermore, increasing the applied pressure noticeably increased the wear of the alloy under atmospheric conditions but only slightly increased it under an 8×10 −6 mbar vacuum. Extensive subsurface deformation was observed for the alloy tested in air.

TiN, TiAlN, CrAlN and TiAlN/TiSiN films were deposited on AISI H13 hot work steel substrate by cathodic arc evaporation method. Each coating was optimized in laboratory conditions and the highest hardness and wear resistance coatings were taken into consideration for this study. Morphological properties, chemical compositions, crystallographic structure, nano hardness and adhesion strength of coatings were analyzed with SEM, AFM, EDS, XRD, nano indentation and scratch resistance tester. Wear experiments were performed using ball-on-disk tribometer against Al2O3 ball of 6[Formula: see text]mm diameter and wear volume of coatings were measured using optical profilometer. Wear experimental results revealed that all coated samples showed higher wear resistance and hardness than uncoated AISI H13 steel substrate. The highest wear and scratch resistances as well as nano hardness were attained for CrAlN coating. TiAlN coating has the lowest scratch resistance and wear resistance. Adhesive wear mechanism was the dominant wear mechanism for CrAlN coatings which is the highest wear resistant coating. Abrasive wear mechanism was the dominant wear mechanism for TiAlN coatings which is the lowest wear resistant coating.

Both mechanical and chemical methods can be used to clean and decontaminate implant surfaces. Incomplete debridement of infected tissue and failure to clear endotoxins can result in graft failure and a return of the defect. Recently, lasers have gained popularity for sterilizing and cleaning implant surfaces. We determined the effects of laser treatment on the surface characteristics of titanium discs with a Laser-Lok surface. The discs were irradiated with an erbium, chromium: yttrium, scandium, gallium, garnet (Er,Cr:YSGG) laser under various conditions (R1-9). Scanning electron microscopy was used to evaluate the surface. Considerable surface alterations such as melting and flattening were seen at R6 (2 W, 20 Hz, 4 mm, 45 s) and R8 (3 W, 25 Hz, 2 mm, 45 s). In addition, cracking was seen at R8. The laser parameters should be optimized to conserve surface characteristics during the irradiation of implant surfaces.

Purpose To obtain local diagnostic reference levels (DRLs) in diagnostic and therapeutic IR procedures with dose management software to improve radiation protection. Materials and Methods Dose data of various vascular and nonvascular IR procedures performed within 18 months were collected and analyzed with dose management software. To account for different levels of complexity, procedures were subdivided into simple, standard, and difficult procedures as graded by interventional radiologists. Based on these analyses, local DRLs (given as kerma-area product [KAP]) were proposed. Comparison with dose data of others was conducted, and Spearman correlation coefficients were calculated to evaluate relationships between dose metrics. Results Analysis included 1,403 IR procedures (simple/standard/difficult, n=346/702/355). Within the same procedure, KAP tended to increase with level of complexity. Overall, very strong correlation between KAP (Gy ∙ cm 2 ) and cumulative air kerma (K A,R ; Gy) was observed, and moderate to strong correlation between KAP and time and K A,R and time was observed. For simple procedures, strong correlation was seen between KAP and time and K A,R and time; for standard and difficult procedures, only moderate correlation was seen. Correlation between KAP and time and K A,R and time was strong in nonvascular procedures but only moderate in vascular procedures. Conclusions Dose management software can be used to derive local DRLs for various IR procedures, taking into consideration different levels of complexity. Proposed local DRLs can contribute to obtaining detailed national DRLs as part of efforts to improve patients' radiation protection further.

Portal vein embolization (PVE) may be performed before hemihepatectomy to increase the volume of future liver remnant (FLR) and to reduce the risk of postoperative liver insufficiency. We report the case of a 71-year-old patient with hilar cholangiocarcinoma undergoing PVE with access from the right portal vein using a mixture of n-butyl-2-cyanoacrylate and ethiodized oil. During the procedure, nontarget embolization of the left portal vein occurred. An aspiration maneuver of the polymerized plug failed; however, the embolus obstructing portal venous flow in the FLR was successfully relocated into the right portal vein while carefully bypassing the plug with a balloon catheter, inflating the balloon, and pulling the plug into the main right portal vein.

To determine the effect on patient radiation exposure of the combined use of a patient dose monitoring system and real-time occupational dose monitoring during fluoroscopically guided interventions (FGIs).Patient radiation exposure, in terms of the kerma area product (KAP; Gy ∙ cm(2)), was measured in period 1 with a patient dose monitoring system, and a real-time occupational dose monitoring system was additionally applied in period 2. Mean/median KAP in 19 different types of FGIs was analyzed in both periods for two experienced interventional radiologists combined as well as individually. Patient dose and occupational dose were correlated, applying Pearson and Spearman correlation coefficients.Although FGIs were similar in numbers and types over both periods, a substantial decrease was found for period 2 in total mean ± SD/median KAP for both operators together (period 1, 47 Gy ∙ cm(2) ± 67/41 Gy ∙ cm(2); period 2, 37 Gy ∙ cm(2) ± 69/34 Gy ∙ cm(2)) as well as for each individual operator (for all, P.05). Overall, KAP declined considerably in 15 of 19 types of FGIs in period 2. Mean accumulated dose per intervention was 4.6 µSv, and mean dose rate was 0.24 mSv/h. There was a strong positive correlation between patient and occupational dose (r = 0.88).Combined use of a patient dose monitoring system and a real-time occupational dose monitoring system in FGIs significantly lessens patient and operator doses.

In hemodialysis patients, radiographic imaging with iodinated contrast medium (ICM) application plays a central role in the diagnosis and/or follow-up of disease-related conditions. Therefore, safety aspects concerning ICM administration and radiation exposure have a great impact on this group of patients. Current hardware and software improvements including the design and synthesis of modern contrast compounds allow the use of very small amounts of ICM in concert with low radiation exposure. Undesirable ICM side effects are divided into type A (predictable reactions such as heat feeling, headache, and contrast-induced acute kidney injury, for example) and type B (nonpredictable or hypersensitivity) reactions; this chapter deals with the latter. The first onset cannot be prevented. To prevent hypersensitivity upon reexposure of ICM, an allergological workup is recommended. If this is not possible and ICM is necessary, the patient should receive a premedication (H1 antihistamine with or without corticosteroids). Current imaging hardware and software improvements (e.g. such as additional filtration of the X-ray beam) allow the use of very small amount of ICM and small X-ray doses. Proper communication among the team involved in the treatment of a patient may allow to apply imaging protocols and efficient imaging strategies limiting radiation exposure to a minimum. Practical recommendations will guide the reader how to use radiation and ICM efficiently to improve both patient and staff safety.

In hemodialysis patients, radiographic imaging with iodinated contrast medium (ICM) application plays a central role in the diagnosis and/or follow-up of disease-related conditions. Therefore, safety aspects concerning ICM administration and radiation exposure have a great impact on this group of patients. Current hardware and software improvements including the design and synthesis of modern contrast compounds allow the use of very small amounts of ICM in concert with low radiation exposure. Undesirable ICM side effects are divided into type A (predictable reactions such as heat feeling, headache, and contrast-induced acute kidney injury, for example) and type B (nonpredictable or hypersensitivity) reactions; this chapter deals with the latter. The first onset cannot be prevented. To prevent hypersensitivity upon reexposure of ICM, an allergological workup is recommended. If this is not possible and ICM is necessary, the patient should receive a premedication (H1 antihistamine with or without corticosteroids). Current imaging hardware and software improvements (e.g. such as additional filtration of the X-ray beam) allow the use of very small amount of ICM and small X-ray doses. Proper communication among the team involved in the treatment of a patient may allow to apply imaging protocols and efficient imaging strategies limiting radiation exposure to a minimum. Practical recommendations will guide the reader how to use radiation and ICM efficiently to improve both patient and staff safety.

We herein present a patient undergoing selective internal radiation therapy with an almost normal lung shunt fraction of 11.5 %, developing histologically proven radiation pneumonitis. Due to a predominance of pulmonary consolidations in the right lower lung and its proximity to a large liver metastases located in the dome of the right liver lobe a Monte Carlo simulation was performed to estimate the effect of direct irradiation of the lung parenchyma. According to our calculations direct irradiation seems negligible and RP is almost exclusively due to ectopic draining of radioactive spheres.

To test the feasibility of a robotic needle-guidance platform during CT-guided puncture ex vivo.Thin copper wires inserted into a torso phantom served as targets. The phantom was placed on a carbon plate and the robot-positioning unit (RPU) of the guidance platform (iSYS Medizintechnik GmbH, Kitzbuehel, Austria) was attached. Following CT imaging and automatic registration a double oblique trajectory was planned and the RPU was remotely moved into appropriate position and angulation. A 17G-puncture needle was then manually inserted until the preplanned depth, permanently guided by the RPU. The CT scan was repeated and the distance between the actual needle tip and the target was evaluated.Automatic registration was successful in ten experiments and the median duration of an experiment was 9.6 (6.4-46.0) minutes. The angulation of the needle path in x-y and z-axis was within 15.6° to 32.6°, and -32.8° to 3.2°, respectively and the needle insertion depth was 92.8 ± 14.4 mm. The Euclidean distance between the actual needle tip and the target was 2.3 ± 0.8 (range, 0.9-3.7) mm.Automatic registration and accurate needle placement close to small targets was demonstrated. Study settings and torso phantom were very close to the clinical reality.