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Introduction: The aim of this study is to compare patient geometrical uncertainties in the treatment of breast boost three-dimensional conformal radiation therapy (3D-CRT) considering both manual alignment and automatic different registration methods in cone-beam computed tomography (CBCT). Methods: A total of 85 patients were chosen for this study. A total of 254 registrations of CBCT vs planning computed tomography (CT) were retrospectively performed using automatic registration algorithms from Elekta XVI system (Clipbox and Mask) to detect patient setup uncertainties. All CBCTs were also matched manually by three health professionals. Mean shift values obtained with manual registration performed by health professionals were used as reference. Absolute value of difference between automatic algorithm shifts and reference values shifts was collected for each enrolled patient considering the three different spatial directions (x, y ,z), and the magnitude was calculated (δm for Mask and δc for Clipbox). Results: Data analysis showed a significant difference in δm and δc. t-Test statistics showed a high difference between Mask and Clipbox, in particular mean δm = (1.3 ± 0.1) mm and δc = (3.3 ± 1.2) mm (p-value Conclusions: These results suggest that the Mask algorithm may be the optimal choice for patient setup verification in clinical practice for breast boost treatment in 3D-CRT.

This study investigated the radiation dose to surgeon eye lens for single procedure and normalised to exposure parameters for eight selected neuroradiology, cardiovascular and radiology interventional procedures.The procedures investigated were diagnostic study, Arteriovenous Malformations treatment (AVM) and aneurysm embolization for neuroradiology procedures, Coronary Angiography and Percutaneous Transluminal Coronary Angioplasty (CA-PTCA), Pacemaker and Implantable Cardioverter-Defibrillator implantation (PM-ICD), Endovascular Aortic Repair (EVAR) and Fenestrated Endovascular Aortic Repair (FEVAR) for cardiovascular and electrophysiology procedures. CT-guided lung biopsy was also monitored. All procedures were performed with table-mounted and ceiling-suspended shields (0.5 mm lead equivalent thickness), except for FEVAR and PM-ICD where only a table mounted shield was present, and CT-guided lung biopsy where no shield was used. Dose assessment was performed using a dosemeter positioned close to the most exposed eye of the surgeon, outside the protective eyewear.The surgeon most exposed eye lens median HIn interventional procedures, the 20 mSv/year dose limit for surgeon eye lens exposure might be exceeded if shields or protective eyewear are not used. Surgeon eye lens doses, normalised to single procedures and to exposure parameters, are a valuable tool for determining appropriate radiation protection measures and dedicated eye lens dosemeter assignment.

Purpose To perform a multi-centre survey on the eye lens equivalent dose absorbed by primary interventionalist during catheterization procedures, using a personal dosimeter placed close to the eye lens. Methods 15 different cardiologists working in 3 different centers, for a total of 5 operating rooms were enrolled. All of them were provided with a single thermoluminescent dosimeter positioned on the inner side of the temples of eyeglasses. The dose monitoring, performed on a two-months basis, started in 2016 and is still running. All dose measurements were performed by a ISO 17025 standard accredited dosimetry service thus providing certified uncertainties as well. Correlation of eye lens and wrist dose with KAP was also investigated. Results A total number of 101 eye lens measurements were performed. Annual eye lens dose estimation was obtained for all 15 surgeons (mean, mode, range, standard deviation: 10.8, 8, 4.9–27.3, 5.6 mSv, respectively). Uncertainties on annual eye lens dose estimations ranged between 10% and 20%. No significant correlation was found between eye lens dose and KAP. Conclusions Cardiologists involved in catheterization procedures may receive annual eye lens doses close to the ICRP 118 dose limit and thus individual monitoring with a dedicated dosimeter should be carried out. Uncertainty assessment play a relevant role in eye lens equivalent dose estimation to ensure not to exceed dose limit.

RationaleTriage is crucial for patient’s management and estimation of the required Intensive Care Unit (ICU) beds is fundamental for Health Systems during the COVID-19 pandemic.ObjectiveTo assess whether chest Computed Tomography (CT) of COVID-19 pneumonia has an incremental role in predicting patient’s admission to ICU.MethodsWe performed volumetric and texture analysis of the areas of the affected lung in CT of 115 outpatients with COVID-19 infection presenting to the Emergency Room with dyspnea and unresponsive hypoxyemia. Admission blood laboratory including lymphocyte count, serum lactate dehydrogenase, D-dimer and C-Reactive Protein and the ratio between the arterial partial pressure of oxygen and inspired oxygen were collected. By calculating the areas under the receiver-operating characteristic curves (AUC), we compared the performance of blood laboratory-arterial gas analyses features alone and combined with the CT features in two hybrid models (Hybrid radiological and Hybrid radiomics)for predicting ICU admission. Following a machine learning approach, 63 patients were allocated to the training and 52 to the validation set.Measurements and Main ResultsTwenty-nine (25%) of patients were admitted to ICU. The Hybrid radiological model comprising the lung %consolidation performed significantly (p=0.04) better in predicting ICU admission in the validation (AUC=0.82; 95%Confidence Interval 0.68-0.95) set than the blood laboratory-arterial gas analyses features alone (AUC=0.71; 95%Confidence Interval 0.56-0.86). A risk calculator for ICU admission was derived and is available at:https://github.com/cgplab/covidappConclusionsThe volume of the consolidated lung in CT of patients with COVID-19 pneumonia has a mild but significant incremental value in predicting ICU admission.

Radioprotection of the eye lens of medical staff involved in Surgical procedures is a subject of international debates since ICRP recommended, on 2011, a lower equivalent dose limit for the lens of the eye. In this work we address the effectiveness of different models of X-ray protective eyewear by relating actual dosimetry measurements to an ad hoc developed mathematical model, in order to disentangle the contribution of geometrical factors and shield capabilities. Phantom irradiation was carried out in fixed exposure conditions in angiographic room: we found that measured Dose Reduction Factors (DRF) strongly depend on the ergonomics of the investigated eyewear. Actually a very poor DRF was observed in the case of a glass model in spite of its high nominal attenuation, whereas a protective tool with low shielding capabilities such a visor resulted much more effective as a consequence of is shape (i.e. extended geometric protection of the eye lens). Our work highlights the need of the introduction of a specific parameter to quantify the effectiveness of the protection tools and able to predict their DRF by taking into account the geometry of the clinical condition of exposure. Aiming at making steps forward the standardization of the guidelines concerning the features of eye protective tools, we developed a simple mathematical model describing the eye lens irradiation geometry which allows the introduction, for each eyewear, of a comprehensive parameter, the Eye Protection Effectiveness (EPE), that, for any defined clinical irradiation condition and glass shielding capabilities and shape, defines the overall effective X-ray protection of the eyewear.

Pre and post-operative exposure levels of medical staff and people from public in intra-operative Ru-106 ophthalmic brachytherapy are reported, together with attenuation properties of selected shielding materials. In particular radiation exposure of workers during plaque transportation and during medical assistance of implanted plaque patient was measured. Taking into account dose rates and considering standard assistance procedure of hospitalized patients, the exposure of medical staff and people of the public were evaluated for a given workload. In order to provide tools to optimize radiation protection, considering social and economic aspects due to possible hospital discharge or hospital stay, the attenuation properties of common shielding materials (lead, concrete, red brick, PMMA and gypsum) were measured, considering both narrow and broad beam setups. The eye was simulated using a water equivalent phantom and plaque was fixed on it. All measurements were performed with calibrated survey meters. Results were compared with numerical simulation of bremsstrahlung X-ray radiation spectra emitted from patient eye. Exposure levels measured at 1 m distance in front of the implanted eye are 0.05 µSv/h/MBq, at 10 cm from patient head, 0.44 µSv/h/MBq (plaque side), 0.4 µSv/h/MBq (front), 0.25 µSv/h/MBq (lateral, opposed to plaque), 0.2 µSv/h/MBq (back). Average exposure levels, under conservative assumptions, for medical staff is 17 µSv/patient and less than 23 µSv/patient for careers and comforters. TVLs in lead and concrete are about 1.6 cm and 11.5 cm respectively.

Purpose To propose an MRI quality assurance procedure that can be used for routine controls and multi-centre comparison of different MR-scanners for quantitative diffusion-weighted imaging (DWI). Materials and methods 44 MR-scanners with different field strengths (1 T, 1.5 T and 3 T) were included in the study. DWI acquisitions (b-value range 0–1000 s/mm2), with three different orthogonal diffusion gradient directions, were performed for each MR-scanner. All DWI acquisitions were performed by using a standard spherical plastic doped water phantom. Phantom solution ADC value and its dependence with temperature was measured using a DOSY sequence on a 600 MHz NMR spectrometer. Apparent diffusion coefficient (ADC) along each diffusion gradient direction and mean ADC were estimated, both at magnet isocentre and in six different position 50 mm away from isocentre, along positive and negative AP, RL and HF directions. Results A good agreement was found between the nominal and measured mean ADC at isocentre: more than 90% of mean ADC measurements were within 5% from the nominal value, and the highest deviation was 11.3%. Away from isocentre, the effect of the diffusion gradient direction on ADC estimation was larger than 5% in 47% of included scanners and a spatial non uniformity larger than 5% was reported in 13% of centres. Conclusion ADC accuracy and spatial uniformity can vary appreciably depending on MR scanner model, sequence implementation (i.e. gradient diffusion direction) and hardware characteristics. The DWI quality assurance protocol proposed in this study can be employed in order to assess the accuracy and spatial uniformity of estimated ADC values, in single- as well as multi-centre studies.

Aim To investigate the effect of colour scale choice on diagnostic performance in the interpretation of medical images. Materials and methods Twelve clinicians interpreted 210 myocardial computed tomography (CT) perfusion (CTP) examinations, and nine clinicians interpreted 165 magnetic resonance imaging (MRI) apparent diffusion coefficient (ADC) prostate images. In three separate sessions, each participant read the same image set using greyscale, hot-iron, and rainbow scales, respectively. Participants scored their level of confidence for tumour presence in the ADC study, and for ischaemia in the CTP study, from 0 to 100. The area under the receiver operating characteristic (ROC) curve (AUC) was used as the performance metric. For cases that scored >50, CTP readers' agreement on the ischaemic transmural extent was analysed, and ADC map readers' selected values and coordinates for the lowest ADC within the detected tumour were compared across different colour scales. Results For CTP detection, the AUC was up to 0.10 higher with greyscale, 0.67±0.02 (standard error), compared to rainbow, 0.56±0.02, and detection with hot-iron was in between (0.61±0.03). For ischaemic transmural lesion categorisation, observed inter-reader agreement was highest with greyscale for category 25–50%. There is a small tendency for rainbow and greyscale to outperform hot-iron in the detection of prostate tumours. The selected lowest ADC value and pixel localisation was similar with all colour scales. Conclusions The present findings suggest that colour visualisation has a measurable effect on CTP and ADC performance. Further investigation is necessary to determine the magnitude of the effect in diagnostic tasks.

Purpose The aim of this study was to propose and validate across various clinical scanner systems a straightforward multiparametric quality assurance procedure for proton magnetic resonance spectroscopy (MRS). Methods Eighteen clinical 1.5 T and 3 T scanner systems for MRS, from 16 centres and 3 different manufacturers, were enrolled in the study. A standard spherical water phantom was employed by all centres. The acquisition protocol included 3 sets of single (isotropic) voxel (size 20 mm) PRESS acquisitions with unsuppressed water signal and acquisition voxel position at isocenter as well as off-center, repeated 4/5 times within approximately 2 months. Water peak linewidth (LW) and area under the water peak (AP) were estimated. Results LW values [mean (standard deviation)] were 1.4 (1.0) Hz and 0.8 (0.3) Hz for 3 T and 1.5 T scanners, respectively. The mean (standard deviation) (across all scanners) coefficient of variation of LW and AP for different spatial positions of acquisition voxel were 43% (20%) and 11% (11%), respectively. The mean (standard deviation) phantom T2 values were 1145 (50) ms and 1010 (95) ms for 1.5 T and 3 T scanners, respectively. The mean (standard deviation) (across all scanners) coefficients of variation for repeated measurements of LW, AP and T2 were 25% (20%), 10% (14%) and 5% (2%), respectively. Conclusions We proposed a straightforward multiparametric and not time consuming quality control protocol for MRS, which can be included in routine and periodic quality assurance procedures. The protocol has been validated and proven to be feasible in a multicentre comparison study of a fairly large number of clinical 1.5 T and 3 T scanner systems.

Purpose To propose a magnetic resonance imaging (MRI) quality assurance procedure that can be used for multicenter comparison of different MR scanners for quantitative diffusion-weighted imaging (DWI). Materials and Methods Twenty-six centers (35 MR scanners with field strengths: 1T, 1.5T, and 3T) were enrolled in the study. Two different DWI acquisition series (b-value ranges 0–1000 and 0–3000 s/mm2, respectively) were performed for each MR scanner. All DWI acquisitions were performed by using a cylindrical doped water phantom. Mean apparent diffusion coefficient (ADC) values as well as ADC values along each of the three main orthogonal directions of the diffusion gradients (x, y, and z) were calculated. Short-term repeatability of ADC measurement was evaluated for 26 MR scanners. Results A good agreement was found between the nominal and measured mean ADC over all the centers. More than 80% of mean ADC measurements were within 5% from the nominal value, and the highest deviation and overall standard deviation were 9.3% and 3.5%, respectively. Short-term repeatability of ADC measurement was found

This study aimed to test the sensitivity of a transmission detector for online dose monitoring of intensity-modulated radiation therapy (IMRT) for detecting small delivery errors. Furthermore, the correlation of changes in detector output induced by small delivery errors with other metrics commonly employed to quantify the deviations between calculated and delivered dose distributions was investigated.Transmission detector measurements were performed at three institutions. Seven types of errors were induced in nine clinical step-and-shoot (SS) IMRT plans by modifying the number of monitor units (MU) and introducing small deviations in leaf positions. Signal reproducibility was investigated for short- and long-term stability. Calculated dose distributions were compared in terms of γ passing rates and dose-volume histogram (DVH) metrics (e.g., DBoth short- and long-term reproducibility was within 1%. Dose variations down to 1 MU (∆signal 1.1 ± 0.4%) as well as changes in field size and positions down to 1 mm (∆signal 2.6 ± 1.0%) were detected, thus indicating high error-detection sensitivity. A moderate correlation of detector signal was observed with γ passing rates (RThe detector is capable of detecting small delivery errors in MU and leaf positions, and is thus a highly sensitive dose monitoring device for SS IMRT for clinical practice. The results of this study indicate a good correlation of detector signal with DVH metrics; therefore, clinical action levels can be defined based on the presented data.

Purpose The AIFM working group on MR intercomparison has proposed a quality assurance protocol for MRI diffusion weighted imaging (DWI). The aim of this study is to test the accuracy of apparent diffusion coefficient (ADC) evaluation at the isocentre of the scanner. Methods Seventeen centres and twenty-six MRI scanners (20/6; 1.5 T/3.0 T) were enrolled in this study. A custom spherical water phantom (14 cm diameter, filled with doped aqueous solution) specifically designed for DWI QA was provided to all participants. ADC value was certified as in [1] . Phantom was placed at isocentre of scanner. 5 mm thick axial slices at the isocentre were acquired, using three DWI sequences (b-value varying form 0 s/mm2 to 1000 s/mm2 at 200 s/mm2 steps), differing in gradient diffusion direction. For each diffusion direction, ADC image was generated with monoexponential fit and corrected for temperature. Analysis was performed with a custom Matlab software code. Average ADC was calculated for each diffusion direction ( ADC x , ADC y , ADC z ) in a 2 × 2 cm2 ROI at the centre of the phantom. A chi-squared consistency test was performed on the three ADC values. The mean value ( ADC ref ) was compared with the certified ADC C value. Results Differences within ADC x,y,z are less than 1.5%, for 21 scanners. For seven scanners ADC x,y,z were not consistent among themselves. ( ADC ref / ADC C - 1 ) vary from +10% to −7% (mean value −1%). Only in four scanners | ( ADC ref / ADC C - 1 ) | is larger than 5%. Conclusions The proposed protocol and multipurpose phantom provide a simple ADC quality assurance procedure. The measured isocentre ADCs are within 1% with reference to wrt diffusion directions and consistent with certified value within 1%.

Purpose The dependence of ADC (measured in isotropic phantom) on position and ADC phase encoding may be used to test MRI scanner performances and may play relevant effect on quantitative data accuracy in clinical imaging. Quantitative results of AIFM multicentre intercomparison are reported. Methods Twenty-six MR scanners (20/6 1.5 T/3.0 T magnetic field strength) were enrolled in this study. Custom spherical water phantom (14 cm diameter) specifically designed for DWI QA was provided to all participants. ADC value was certified as in [1] . Phantom was placed at isocentre of scanner. Using three DWI sequences (b-value varying form 0 s/mm2 to 1000 s/mm2), differing for the gradient diffusion direction (Gdd), 5 mm thick axial slices were acquired (5 mm gap). Acquisition was repeated exchanging frequency and phase encoding direction. ADC maps were generated for each Gdd. Seven 2 × 2 cm2 ROIs were considered: one at isocentre and six in periphery (left, right, superior, inferior, head and feet). For each acquisition, maximum relative difference between periphery and central ROIs ADC was calculated ( δ ADC % x,y,z ) . Maximum δ ADC % x,y,z with respect to three acquisitions ( δ M%) was also considered. As for phase/frequency encoding direction dependences, ADC x,y,z differences on central ROI were measured. Results Differences Absolute value of δ M is below 5% for 19 scanners, 18 scanners show δ M > 0. Spatial direction of maximal variation is “x” in 23 scanners, “y” in the other. Gdd associated to δ M is x/y/z for 9/12/5 scanners. Differences between −2% and +1% have been observed with respect to phase encoding direction. Conclusions A simple protocol for quantitative evaluation of ADC spatial and phase encoding dependence has been proposed. Difference in ADC between isocentre and periphery should be consider in precision ADC measurements.

Purpose MRI scanner performance temporal stability is fundamental aspect in several multi-parametric exams (like diffusion, functional and spectroscopy) effect of order of few percent may be clinically relevant. Revised version of Friedman protocol (JMRI, 23 -2006) was adopted to check stability of scanners over time on weekly basis. Linewidth of water peak in MR spectroscopy after optimization is considered as well. Results over a long period survey of several clinical scanners are reported. Methods The purpose of the procedure is to measure time stability of the scanners in conditions that are as similar as possible to the clinical settings. The head coil and scanning sequence used clinically were tested. A time series of 200 images of QA vendor phantom is collected. The automated analysis provides information about signal intensity, uniformity, magnitude spectrum, radius of decorrelation (RdC), short term reproducibility, SNR and signal fluctuation to noise ratio. RdC represents the size of ROI for which the main source of signal noise is systematic and not statistic. With same setup, linewidth after B0 homogeneity optimisation is measured. Data were acquired on four 1.5 T MRI clinical scanners, on a 4 years time interval. Results Data fluctuations of considered parameters are of order of few percent (varying between 1% and 9%), significant variations have been observer after component change and software upgrade. Fourier analysis of short term signal doesn’t show periodic noise. Short term reproducibility is below 1% for all considered scanners. RdC is 18 pixels for two scanners and 6 pixels for other. No significant variation have been observed during temporal series. Linewidth is stable within 6%. Conclusions Regular check of parameter stability provides strong feedback regarding scanner performances, and may allow to predict possible malfunctioning. Proposed protocol may be used as basic QA in advanced MRI technique.

Purpose The use of unsealed sources (either in nuclear medicine or in radiochemical bio-laboratories) involves the risk of internal contamination for workers after partial evaporation of the unsealed source during its use. This issue was already addressed in [1] , the aim of this work is to extend that work towards a comprehensive model taking into account also the airborne contamination after radionuclide evaporation from the cumulated surface contamination of the working area. Methods The above mentioned model takes into account the manipulation time (tm, the manipulated activity (A), the frequency of manipulations, the total time the workers spend in the laboratory (on an yearly basis), the air exchange ratio (R) and the half-life of the manipulated radionuclides. According to the actual working conditions, the model evaluates firstly the radionuclide air concentration as a function of time and thereafter the committed effective dose depending on the time spent in the laboratory by the worker. Results During tm the radioisotope manipulation determines both air contamination (AC) and probabilistic surface contamination (SC). After tm AC decreases due to R, whereas surface contamination increases after each manipulation, decreasing only through physical decay, thus leading to an asymptotic SC in the long run. SC is more relevant for long-life radioisotopes. Conclusions Application of the model to an actual bio-laboratory case shows that contribution to inhaled activity from surface contamination may be relevant or even dominant especially for long-life radionuclide (i.e. 3H and 14C). Great care should be used in cleaning the working surfaces after each manipulation to avoid or at last reduce to a reasonable level surface contamination. Smear test looks the test of choice to accurately verify the effective contamination level.

Purpose Quality assurance in advanced and quantitative magnetic resonance techniques is strongly recommended [1] , [2] , [3] . The aim of this study was to propose and validate across various clinical scanner systems a straightforward quality assurance procedure for proton Magnetic Resonance Spectroscopy (MRS). Methods Eighteen clinical 1.5 T and 3 T scanners for MRS were enrolled in the study. The protocol included 3 sets of single voxel PRESS acquisitions without water signal suppression, repeated 4/5 times within approximately 2 months and performed using a standard water phantom supplied to all centres. Water peak linewidth (LW), water peak area (AP) and phantom T2 were estimated. Results LW values ranged from 0.4 Hz to 1.6 Hz, with 3 T and 1.5 T scanner systems showing similar performances. Coefficient of variation (CV) of LW values for repeated measurements were lower than 35% (except for only 3 scanners). AP showed significant (p 0.99 and 0.95 for 1.5 T and 3 T scanner systems, respectively). CV of AP for different spatial positions was less than 25%, and no relevant difference was observed between 3 T and 1.5 T scanners. Mean phantom T2 value and CV for repeated measurements were 1147 ms and 4%, respectively, for 1.5 T scanners, and 1010 ms and 9%, respectively, for 3 T scanners. Conclusions We proposed a straightforward multiparametric and not time consuming quality control protocol for MRS, which can be included in routine quality assurance procedures. The protocol has been validated and proven to be feasible in a multicentre intercomparison study of 18 clinical 1.5 T and 3 T scanner systems.

Purpose Mammographic screening represents one of the most significant medical expose to radiation for women. The method proposed from European Reference Organisation for Quality Assured Breast Screening and Diagnostic Services (EUREF) evaluate average glandular dose (AGD) considering the breast glandularity (BG) a function of breast thickness (BT). VOLPARA software (Volpara Solutions Limited) compute BG from acquired images using a multi-parametric algorithm. The purpose of this study is to evaluate the difference between AGD computed in both method and to assess the applicability of automatic tools for patient dose optimisation and mammographic unit QCs. Methods Mammographic screening exams from last 10 years performed in our institution have been considered. More than 350’000 exams overall (total 1.5 M of expositions), from seven mammographic units (of three different vendors), were included in this study. Exams have been performed using automatic exposure control settings. Data was extracted from DICOM images and processed using VOLPARA software (Volpara Solutions Limited) and analysed with a custom Matlab software. For each exposition difference between Diff = AGD EUREF - AGD VOLPARA was determinated. Exposure data are retrieved to identify patient dose optimisation strategies and to track device performances. Results Average Diff is 0.07 ± 0.13 mGy (min/max −1.7/+1.8 mGy), mean breast thickness is 55 mm (SD 13 mm min/max 10/117 mm). In figure is reported percent distribution of Diff as function of BT. Large part of exams shows Diff > 0 (71% of total), the remains have Diff 0. These results are generally reproducible among seven mammographic units considered. Conclusions Presented results indicate EUREF approach overestimate AGD, the proposed method allow to assess personal dosimetry and could be implemented in order to monitor in live time AGD difference from EUREF evaluation. Use of automatic dose software allow to monitor possibly variation in exposition parameters.

Purpose The use of 106Ru plaque was introduced for choroidal melanomas therapy. The aim of this study is workers and public exposure evaluation, in pre and post-operative phase of the treated patient. In particular attenuation properties of selected shielding materials and exposure levels around patient head and transport/sterilisation safety containers are reported. Methods Exposure was measured around the head of five patients, in multiple positions at various distances from the skin. Dose rates around the transport/sterilisation container were also measured. Attenuation measurements were performed simulating the eye with a 25mm diameter plastic sphere, filled with water and the plaque attached on it. All measurements were performed with a calibrated instrumentations. Selected materials attenuation properties were measured in “narrow” beam mode (IEC 61331-1:2014). A custom code was developed to perform numerical simulation of BS spectrum. Results In Table HVLs and TVLs for selected materials and the average exposure levels (±SD) measured around patients are reported. Five positions around the head, at 10 cm distance from the skin were considered, plus two positions at 1m. Exposure levels around the transport container are nearly constant for any given direction; average values is 1.6 μSv/h/MBq at contact and 0.013 μSv/h/MBq at 1 m. Conclusions Considering typical activity of the implanted plaques, and conservative recovery and assistance times, up to 60 patients may be treated in a year, without exceeding 1mSv/y for post-operative activities. For the same number of patients, even considering a 8 hours/day standing at 1.5 m from the patient bed, the worker received dose is around 0.65 mSv/y. Attenuation properties for selected materials were measured and agree with simulated results. Main contribution to exposure comes from X- γ radiation, BS is almost negligible from radiation protection point of view.

Purpose The aim of this study is to propose a protocol for DWI QA being easy to implement while still providing quantitative information on relevant parameters for the scanner QC as well as for clinical applications. The measured quantity is the apparent diffusion coefficient (ADC) and its dependence from gradient diffusion direction (Gdd) and phase encoding direction (PED). Methods A spherical water phantom (14 cm diameter), designed to allow fast and easy measurement of solution temperature, is proposed. The phantom is filled with doped aqueous solution (ADC value certified) and placed at isocentre of scanner. The protocol consists of five set of acquisition of 19 slices, repeated for three orthogonal Gdd. First and second acquisitions are identical, the others differ for the PED and acquisition plane. Each slice (for each Gdd) is acquired with six different b-values varying from 0 s/mm2 to 1000 s/mm2. From each acquisition and Gdd, ADC map of the phantom is generated with monoexponential fit, corrected for temperature and ADC profile along three orthogonal direction is extracted. From first two acquisitions short term reproducibility and SNR are evaluated; second and third acquisitions are used to detect phase encoding direction effects, lasts three maps are used to detect acquisition plane effects on ADC (details in Table 1 ). Results A preliminary test of the protocol on 1.5T MRI scanner demonstrated its applicability to routine QA. Relative difference between on-centre and periphery ADC values varies from −5% and +3% and phase encoding effect is less than 0.5%. Gdd variations are around +1%. Acquisition plane differences are less than 1% at isocentre and of the order of 5% in periphery. SNR at isocenter is 550 and short term variation is 0.2%. Conclusions The proposed protocol provides a simple QA procedure for DWI application. Selected indexes provide quantitative information on many relevant acquisition parameters.

Purpose The immediate consequence of the new equivalent dose limit for the lens of the eye was a change in the international basic safety standards (BSS) and in the European BSS and the adoption of new limit. For the Catheter Laboratory Procedure, available literature mentions a poor correlation between chest dose measurements and eye lens doses. Aim of the study is to evaluate, if there is any, the correlation between clinical and technical parameters and operator lens dose. Methods Operators, who have used ceiling suspended screen, were monitored throughout thermoluminescence dosimeters (TLDs). The accredited laboratory pass EURADOS intercomparison on Eye Lens in 2016, using TLD calibrated in Hp(0.07), therefore also Hp(0.07) dosimeters are suitable for this application. Chest TLD dosimeter were placed under the lead apron at chest level, hand TLD on the bracelet and the lens TLD was positioned under the shielded glasses. Patient dose values (kerma area product), clinical and technical parameters, as number and type of procedures, were recorded and analyzed. Results The lens dose for main operator in Catheterization Lab of the first 3 centres enrolled are reported. As expected, hands dose depends on the type of procedure performed. Despite this, it is possible to find a weak correlation between the hands dose and the total number of procedures performed by the operator. The chest dose seems to be a completely unrelated parameter with the lens dose. The lens dose does not correlate with the parameters analyzed. Conclusions Lens dose monitor is an extremely complex features. The position of the dosimeter, the type of procedure, the operator experience, and also clinical condition of the patient strongly affect that parameter. Chest and bracelet dosimeters appear not to be adequate for efficient lens dose monitoring.

The objective of this study was to investigate the efficacy of first-line chemotherapy containing irinotecan and/or oxaliplatin in patients with advanced mucinous colorectal cancer. Prognostic factors associated with response rate and survival were identified using univariate and multivariate logistic and/or Cox proportional hazards analyses. The population included 255 patients, of whom 49 (19%) had mucinous and 206 (81%) had non-mucinous colorectal cancer. The overall response rates for mucinous and non-mucinous tumours were 18.4 (95% CI, 7.5-29.2%) and 49% (95% CI, 42.2-55.8%), respectively (P=0.0002). After a median follow-up of 45 months, median overall survival for the mucinous patients was 14.0 months compared with 23.4 months for the non-mucinous group (hazard ratio (HR), 1.74; CI 95%, 1.27-3.31; P=0.0034). After adjustment for significant features by multivariate Cox regression analysis, mucinous histology was associated with poor overall survival (HR, 1.593, 95% CI, 1.05-2.40; P=0.0267), together with performance status ECOG 2, number of metastatic sitesor =2, and peritoneal metastases. This retrospective analysis shows that patients with mucinous colorectal cancer have poor responsiveness to oxaliplatin/irinotecan-based first-line combination chemotherapy and an unfavourable prognosis compared with non-mucinous colorectal cancer patients.

Background: The reinjection of autologous 131I-labelled low-density lipoprotein (LDL) followed by vascular scintigraphy has been used to investigate lipid-containing plaques, but no information is available on the early stages of plaques in hypertensives. Vascular scintigraphy after re-injection of autologous 131I-labelled LDL was used to investigate early atherosclerotic lesions visualized by sonography in the carotid arteries of patients with hypertension. Patients and methods: 10 male patients (4 smokers; mean age 56 ± 8 years;) with early carotid atherosclerosis (mono- or bilateral; intima-media-thickness ranging from 1.5 to 3.5mm) as shown by sonography were studied. All these normolipemic patients suffered from primary hypertension and were treated with diuretics. As controls 6 healthy male subjects (3 smokers; mean age 54 ± 9 years;), with normal blood pressure and lipid pattern were recruited. Results: Hot spots appeared in the areas with early atherosclerosis in 7 patients, while none were seen in controls. Positive kinetic curves were observed in 4 patients. No significant differences emerged in the target/non-target ratios. Conclusions: Vascular lipoprotein uptake in hypertensive patients is apparently late and rather limited; the uptake pattern may depend on plaque composition.

We study di-boson production via both neutral and charged current at the Large Hadron Collider, i.e. subprocesses $q\bar q\to e^+\nu_e \mu^-\bar\nu_\mu$ + ${\rm{c.c.}}$ and $q\bar q'\to l^+\nu_l l^{'+}l^{'-}$ + ${\rm{c.c.}}$, respectively, where $q,q'$ are quarks and $l,l'=e,\mu$, in all possible combinations, in the context of the 4-Dimensional Composite Higgs Model. These modes enable the production in the intermediate steps of several additional -- with respect to the Standard Model -- neutral and charged gauge bosons belonging to the spectrum of this scenario, all of which in resonant topologies. We not only find these channels to be accessible over the background but also show that, after a dedicated cut-based analysis, kinematic reconstruction of most such resonances is always possible. However, since the Electro-Weak precision data generally disfavor neutral and charged gauge boson masses below the TeV range and also their large couplings to light-fermions, these modes turn out to be relevant only for the 14 TeV option with high integrated luminosity.

We investigate the scope of the Large Hadron Collider (LHC) in probing the parameter space of a 4-Site (4S) model supplemented by one composite Higgs state. We concentrate on the yield of `mixed' di-boson production giving three leptons and missing (transverse) energy in the final state, i.e., events induced via the sub-process $q\bar q' -> l^+��_l l^{'+}l^{'-}$ + ${\rm{c.c.}}$, where $q,q'$ are quarks and $l,l'=e,��$ in all possible combinations, signature which enables the production in the intermediate steps of all additional -- with respect to the Standard Model (SM) -- neutral and charged gauge bosons belonging to the spectrum of this scenario, all of which in resonant topologies. We not only find this channel to be accessible over the background but also show that, after a dedicated cut-based analysis, kinematical reconstruction of all such resonances is always possible. We finally compare the yield of the mixed di-boson mode to that of the `charged' di-boson one and find that the former is of lesser scope than the latter at smaller gauge boson masses but it overcomes it at higher values, thereby revealing itself a viable search mode covering new regions of parameter space.

We report the results of long-term cyclical clodronate therapy (200 mg IV infusion every 3 weeks) on 235 women with postmenopausal osteoporosis recruited over 6 years. A retrospective analysis of clinical and instrumental findings in 183 postmenopausal osteoporotic patients was used as control data. Clodronate was well-tolerated and compliance was good. Bone mineral density (BMD) increased significantly and the upward trend persisted for all 6 years of therapy (5.69 +/- 0.184%) vs. controls: -1.47% +/- 0.813%, p

We investigate the scope of the LHC in probing the parameter space of a 4-site model supplemented by one composite Higgs state, assuming all past, current and future energy and luminosity stages of the CERN machine. We concentrate on the yield of charged di-boson production giving two opposite-charge different-flavour leptons and missing (transverse) energy, i.e., events induced via the subprocess $q\bar q\to e^+\nu_e \mu^-\bar\nu_\mu$ + ${\rm{c.c.}}$, which enables the production in the intermediate step of all additional neutral and charged gauge bosons belonging to the spectrum of this model, some of which in resonant topologies. We find this channel accessible over the background at all LHC configurations after a dedicated cut-based analysis. We finally compare the yield of the di-boson mode to that of Drell-Yan processes and establish that they have complementary strengths, one covering regions of parameter space precluded to the others and vice versa.

We present a new complete analysis of the electroweak precision observables within the recently proposed 4-site Higgsless model, which is based on the SU(2)L×SU(2)1×SU(2)2×U(1)Y gauge symmetry and predicts six extra gauge bosons, W1,2± and Z1,2. Within the ?i (i=1, 2, 3, b) parametrization, we compute for the first time the electroweak precision test bounds via a complete numerical algorithm going beyond commonly used approximations. Both ?1,3 impose strong constraints. Hence, it is mandatory to consider them jointly when extracting electroweak precision test bounds and to fully take into account the correlations among the electroweak precision measurements. The phenomenological consequence is that the extra gauge bosons must be heavier than 250 GeV. Their couplings to SM fermions, even if bounded, might be of the same order of magnitude than the SM ones. In contrast to other Higgsless models, the 4-site model is not fermiophobic. The new gauge bosons could thus be discovered in the favored Drell-Yan channel already during the present run of the LHC experiment

Interference effects are widely neglected in searches for new physics. This is the case in recent publications on searches for W'-bosons using leptonic final states. We examine the effects of interference on distributions frequently used to determine mass limits for possible W'-bosons and show that there are important qualitative effects on the behaviour of the new physics signal. There are two main consequences. Firstly, exclusion limits where interferences effects have not been considered are likely to have been overestimated. Secondly, presenting experimental results as a function of a transverse mass cut rather than in terms of the contribution of new physics to the total cross-section would be more informative., Comment: 31 pages, 8 figures. Published version

ARDS is a life-threatening pulmonary disease with a rapidly progressive decline due mainly to multi-organ failure. Death occurs in 50-75% of ARDS cases. The diagnosis and therapy should start in the first six days of this fatal disease when mortality is at its lowest level. The 99mTc-DTPA-measured pulmonary alveolar epithelial permeability (PAEP) is strikingly increased in ARDS even in comparison to heavy smokers. Furthermore, surfactant inhalation has been shown to be of therapeutic value. In five ARDS patients with increased PAEP (T0.5 = 12% pred.) 20 mg/kg of aerosolized surfactant determined a dramatic improvement in blood gases and PAEP (51.8% pred.) No patient remained dependent on ventilatory treatment.

We consider a four site Higgsless model based on the $SU(2)_L\times SU(2)_1\times SU(2)_2\times U(1)_Y$ gauge symmetry, which predicts two neutral and four charged extra gauge bosons, $Z_{1,2}$ and $W^\pm_{1,2}$. We compute the properties of the new particles, and derive indirect and direct limits on their masses and couplings from LEP and Tevatron data. In contrast to other Higgsless models, characterized by fermiophobic extra gauge bosons, here sizeable fermion-boson couplings are allowed by the electroweak precision data. The prospects of detecting the new predicted particles in the favoured Drell-Yan channel at the LHC are thus investigated. The outcome is that all six extra gauge bosons could be discovered in the early stage of the LHC low-luminosity run., Comment: 36 pages, 25 figures, references, figures and content added