Typical values of z-resolution for different Digital Breast Tomosynthesis systems evaluated in a multicenter study.

PURPOSE: The aim of the present study, conducted by a working group of the Italian Association of Medical Physics (AIFM), was to define typical z-resolution values for different digital breast tomosynthesis (DBT) models to be used as a reference for quality control (QC). Currently, there are no typical values published in internationally agreed QC protocols. METHODS: To characterize the z-resolution of the DBT models, the full width at half maximum (FWHM) of the artifact spread function (ASF), a technical parameter that quantifies the signal intensity of a detail along reconstructed planes, was analyzed. Five different commercial phantoms, CIRS Model 011, CIRS Model 015, Modular DBT phantom, Pixmam 3-D, and Tomophan, were evaluated on reconstructed DBT images and 82 DBT systems (6 vendors, 9 models) in use at 39 centers in Italy were involved. RESULTS: The ASF was found to be dependent on the detail size, the DBT angular acquisition range, the reconstruction algorithm and applied image processing. In particular, a progressively greater signal spread was observed as the detail size increased and the acquisition angle decreased. However, a clear correlation between signal spread and angular range width was not observed due to the different signal reconstruction and image processing strategies implemented in the algorithms developed by the vendors studied. CONCLUSIONS: The analysis led to the identification of typical z-resolution values for different DBT model-phantom configurations that could be used as a reference during a QC program.

Effects of insulin therapy optimization with sensor augmented pumps on glycemic control and body composition in people with cystic fibrosis-related diabetes.

Objective: Cystic fibrosis (CF)-related diabetes (CFRD) resulting from partial-to-complete insulin deficiency occurs in 40-50% of adults with CF. In people with CFRD, poor glycemic control leads to a catabolic state that may aggravate CF-induced nutritional impairment and loss of muscle mass. Sensor augmented pump (SAP) therapy may improve glycemic control as compared to multiple daily injection (MDI) therapy. Research design and methods: This non-randomized clinical trial was aimed at evaluating the effects of insulin therapy optimization with SAP therapy, combined with a structured educational program, on glycemic control and body composition in individuals with insulin-requiring CFRD. Of 46 participants who were offered to switch from MDI to SAP therapy, 20 accepted and 26 continued the MDI therapy. Baseline demographic and clinical characteristics were balanced between groups using a propensity score-based overlap weighting procedure and weighted mixed-effects regression models were used to estimate changes in study outcomes. Results: After 24 months changes in HbA1c were: -1.1% (-12.1 mmol/mol) (95% CI: -1.5; -0.8) and -0.1% (-1 mmol/mol) (95% CI: -0.5; 0.3) in the SAP and MDI therapy group, respectively, with a between-group difference of -1.0 (-10 mmol/mol) (-1.5; -0.5). SAP therapy was also associated with a decrease in mean glucose (between group difference: -32 mg/dL; 95% CI: -44; -20) and an increase in TIR (between group difference: 19.3%; 95% CI 13.9; 24.7) and in fat-free mass (between group difference: +5.5 Kg, 95% CI: 3.2; 7.8). Conclusion: Therapy optimization with SAP led to a significant improvement in glycemic control, which was associated with an increase in fat-free mass.

Effects of bilateral lung transplantation on cardiac autonomic modulation and cardiorespiratory coupling: a prospective study.

BACKGROUND: Although cardiac autonomic modulation has been studied in several respiratory diseases, the evidence is limited on lung transplantation, particularly on its acute and chronic effects. Thus, we aimed to evaluate cardiac autonomic modulation before and after bilateral lung transplantation (BLT) through a prospective study on patients enrolled while awaiting transplant. METHODS: Twenty-two patients on the waiting list for lung transplantation (11 women, age 33 [24-51] years) were enrolled in a prospective study at Ospedale Maggiore Policlinico Hospital in Milan, Italy. To evaluate cardiac autonomic modulation, ten minutes ECG and respiration were recorded at different time points before (T0) and 15 days (T1) and 6 months (T2) after bilateral lung transplantation. As to the analysis of cardiac autonomic modulation, heart rate variability (HRV) was assessed using spectral and symbolic analysis. Entropy-derived measures were used to evaluate complexity of cardiac autonomic modulation. Comparisons of autonomic indices at different time points were performed. RESULTS: BLT reduced HRV total power, HRV complexity and vagal modulation, while it increased sympathetic modulation in the acute phase (T1) compared to baseline (T0). The HRV alterations remained stable after 6 months (T2). CONCLUSION: BLT reduced global variability and complexity of cardiac autonomic modulation in acute phases, and these alterations remain stable after 6 months from surgery. After BLT, a sympathetic predominance and a vagal withdrawal could be a characteristic autonomic pattern in this population.

Clinical value of negative 68Ga-PSMA PET/CT in the management of biochemical recurrent prostate cancer patients.

PURPOSE: To evaluate the clinical value of 68Ga-PSMA PET/CT negativity in patients with biochemical recurrent prostate cancer (BCR). METHODS: One hundred three BCR patients (median age, 70 years; median PSA, 0.47 ng/mL) with negative 68Ga-PSMA PET/CT, followed up for at least 1 year, were retrospectively identified in a database of 1003 consecutive patients undergoing 68Ga-PSMA PET/CT for BCR. Clinical recurrence (CR) was determined or excluded on follow-up imaging selected as per clinical practice. Clinical recurrence-free survival (CRFS) was computed from the date of negative 68Ga-PSMA PET/CT to the date of evident disease; frequencies of CRFS were described as per ISUP patient subset (subset 1: ISUP grades 1 and 2; subset 2: ISUP grade 3; subset 3: ISUP grades 4 and 5) and other conventional variables. RESULTS: In 57 patients out of 103 (55.3%), CR was detected in the prostatic fossa (45.6%), nodes (38.6%), and bone (15.8%). The median CRFS was 15.4 months (range, 12.1-20.5), with a CRFS at 12 months in 61.4% of cases (range, 50.9-70.4) whereas the 24-month CRFS was 34.8% (range, 24-45.8). ISUP subset 1 benefited from significantly longer CRFS compared to subset 2 and subset 3 (median CRFS, 20.5 months, 12.6 months, and 12.1 months, respectively). ISUP subset 3 had significantly poorer 24-month CRFS (9.3%) compared to subset 1 (47.8%) and subset 2 (33.5%). At the univariate and multivariate analyses, the ISUP subset was the only significant risk factor for clinical relapse; ISUP subset 3 and subset 2 patients held a higher risk of CR compared to subset 1 patients (HR of 2.75 [1.35-5.57] for subset 3 versus subset 1; HR of 2.08 [1.11-3.88] for subset 2 versus subset 1). CONCLUSION: 68Ga-PSMA PET/CT negativity in early BCR patients (PSA < 0.5 ng/mL) with low-grade primary prostate cancer (ISUP1 and 2) may support the exploration of a clinical surveillance approach in future prospective studies.

Vestibular drop attack: A potential origin from perilymphatic fistula?

Vestibular drop attacks are defined as a sudden fall to the ground without an obvious loss of consciousness lasting a few minutes or seconds. They are usually associated with Meniere's Disease during Tumarkin's phase. This hypothesis was produced in consideration of the case of a young girl affected by perilymphatic fistula and her Drop attacks. Is possible to consider perilymphatic fistulas a drop attack cause? Drop attack could be related with a vestibular sympathetic reflex alteration because it is involved in blood pressure control. Probably drop attack aetiopathogenesis may be due to a sudden change in the otolith function of the utriculus and/or sacculus. At the same time flow mechanisms of cerebrospinal fluid (CSF) have a recognized impact on the origin of vestibular drop attack. According to this, the common origin of the perilymph and of the CSF may be an important argument in favour of the potential role of the fistula in the development of drop attacks.

Bone involvement in young adults with cystic fibrosis awaiting lung transplantation for end-stage respiratory failure.

Patients with cystic fibrosis awaiting lung transplantation for end-stage respiratory failure have high prevalence of reduced bone mineral density and fragility fracture. Suboptimal 25-hydroxyvitamin D levels could significantly contribute to the development of cystic fibrosis-related bone disease. INTRODUCTION: The assessment of the prevalence of cystic fibrosis-related bone disease (CFBD) and its associated risk factors in young adults with cystic fibrosis (CF) awaiting lung transplantation for end-stage respiratory failure. METHODS: Clinical characteristics, bone mineral density (BMD), the parameters of calcium metabolism, including vitamin D (25OHVitD) levels, and the presence of fragility fractures were evaluated in 42 CF patients (24 females, age 34.0 ± 8.4 years) consecutively referred as lung transplant candidates. RESULTS: Mean 25OHVitD levels (54.9 ± 26.2 nmol/L) were below the reference range and hypovitaminosis D (25OHVitD < 75 nmol/L) was found in 34 patients (81%) and daily calcium intakes (median 550 mg/day) were lower than recommended. A BMD below the expected range for age (Z-score of - 2.0 or lower) and at least one prevalent fragility fracture were found in 22 patients (52.4%) and 18 patients (45.2%), respectively. The coexistence of low BMD and the presence of fracture was observed in 13 patients (31.0%). In these patients, the prevalence of nephrolithiasis was higher than in the remaining ones (p = 0.046). The presence of kidney stones was associated with a worse bone status and with severe vitamin D deficiency. In the whole sample, femoral BMD Z-scores were directly correlated with albumin-adjusted calcium (p < 0.05) and 25OHVitD levels (p < 0.01). CONCLUSIONS: Despite the improvement of CF care, CFBD is still highly prevalent in young adults awaiting lung transplantation for end-stage CF. Suboptimal 25OHVitD levels could significantly contribute to the development of CFBD. The presence of nephrolithiasis could be an additional warning about the need for a careful evaluation of bone health in CF patients.

Surveillance Transbronchial Biopsy Program to Evaluate Acute Rejection After Lung Transplantation: A Single Institution Experience.

BACKGROUND: There is no unanimity in the literature regarding the value of transbronchial biopsies (TBBs) performed at a scheduled time after lung transplantation (surveillance TBBs [SBs]), compared to biopsies performed for suspected clinical acute rejection (clinically indicated TBBs [CIBs]). This study exposes an assessment of our experience over the last 4 years through a retrospective analysis of the data collected. METHODS: In our center, SBs are performed at 3, 6, and 12 months after a transplant. Data from 110 patients who underwent a TBB were collected from January 2013 to November 2017. Clinical and functional data along with the histologic results and complications were collected. RESULTS: Overall 251 procedures were performed: 223 for surveillance purposes and 28 for clinical indications. The SBs diagnostic rate was 84%. A grade 2 acute rejection (AR) was detected in 9 asymptomatic patients, all of whom were medically treated, with downgrading of AR documented in all cases. The rate of medical intervention in the SB group was 8%. The CIBs diagnostic rate was 96%. The rate of AR detected by CIBs was significantly higher than by SBs (36% versus 4%; P < .0001). Overall the major complication rate was 4%; no patients required transfusions and no mortality occurred in the patient cohort. CONCLUSIONS: The surveillance protocol did not eliminate the necessity of CIBs, but in 8% of patients early rejection was histologically assessed. The correlation between histologic and clinical data allows a more careful approach to transplanted patients.

Lung Transplantation as Successful Treatment of End-stage Idiopathic Pleuroparenchymal Fibroelastosis: A Case Report.

Pleuroparenchymal fibroelastosis (PPFE) is a rare condition, characterized by predominantly upper-lobe pleural and subjacent parenchymal fibrosis, the latter being intra-alveolar with accompanying elastosis of the alveolar walls that leads a clinical progression to respiratory failure. This condition may not be as rare as it seems to be, because nowadays the increasing awareness among specialists is raising the number of new diagnoses. Limited data are available about the prognosis, both for secondary and idiopathic forms. Nevertheless, the idiopathic form seems to be rapidly progressive and no treatment can control the disease, which is why management is challenging. Since the disease was characterized, PPFE cases have been reported in the literature, but most have been secondary rather than idiopathic. Of these, few have successfully undergone lung transplantation as a treatment of end-stage respiratory failure. We here report a successful case of a 38-year-old man affected by idiopathic PPFE who underwent bilateral lung transplantation after extracorporeal membrane oxygenation bridging for an abrupt transition to critical clinical conditions. After a complex postoperative course and a first year characterized by acute rejection, the patient is alive at 5 years with a good quality of life. Our experience confirms that lung transplantation would be a valuable treatment option in case of end-stage idiopathic PPFE cases.

Lung Allocation Score: A Single-Center Simulation.

BACKGROUND: The lung allocation score (LAS) was introduced in the United States in May 2005 with the main goal of reducing the waiting list mortality of patients with end-stage lung diseases, but also to enhance the lung transplant benefit and improve the management of urgent candidates. Several papers have reported that LAS resulted in a reduction of the waiting list mortality but no significant survival benefit was noted. METHODS: We evaluate the usefulness of LAS as a predictor for lung transplantation outcome in 123 patients listed for lung transplantation in an Italian center. Primary endpoints were waiting list mortality and posttransplant mortality at 1 year; secondary endpoints included perioperative circulatory support, cardiopulmonary bypass, primary graft dysfunction, and long-term survival after transplantation. RESULTS: We observed the absence of correlation between LAS and waiting list mortality. The LAS did not affect the long-term survival in our population. CONCLUSIONS: High LAS was predictive of primary graft dysfunction of grade 3 in the first 72 hours after transplantation.

Radiochromic films for dental CT dosimetry: a feasibility study.

Dental CT dose evaluations are commonly performed using thermoluminescent dosimeters (TLD) inside anthropomorphic phantoms. Radiochromic films with good sensitivity in the X-ray diagnostic field have recently been developed and are commercially available as GAFCHROMIC XR-QA. There are potential advantages in the use of radiochromic films such as a more comprehensive dosimetry thanks to the adjustable size of the film samples. The purpose of this study was to investigate the feasibility of using radiochromic films for dental CT dose evaluations. Film samples were cut with a width of 5mm and a length of 25 mm (strips), the same size as the Alderson Rando anthropomorphic phantom holes used in this study. Dental CT dose measurements were performed using simultaneously both TLD and radiochromic strips in the same phantom sites. Two equipment types were considered for dental CT examinations: a 16 slice CT and a cone beam CT. Organ equivalent doses were then obtained averaging the measurements from the sites of the same organ and effective doses were calculated using ICRP 103 weighting factors. The entire procedure was repeated four times for each CT in order to compare also the repeatability of the two dosimeter types. A linear correlation was found between the absorbed dose evaluated with radiochromic films and with TLD, with slopes of 0.930 and 0.944 (correlation r>0.99). The maximum difference between the two dosimeter's measurements was 25%, whereas the average difference was 7%. The measurement repeatability was comparable for the two dosimeters at cumulative doses above 15 mGy (estimated uncertainty at 1 sigma level of about 5%), whereas below this threshold radiochromic films show a greater dispersion of data, of about 10% at 1 sigma level. We obtained, using respectively Gafchromic and TLD measurements, effective dose values of 107 µSv and 117 µSv (i.e. difference of 8.6%) for the cone beam CT and of 523 µSv and 562 µSv (i.e. difference of 7%) for the multislice CT. This study demonstrates the feasibility of radiochromic films for dental CT dosimetry, pointing out a good agreement with the results obtained using TLD, with potential advantages and the chance of a more extensive dose investigation.

Assessment of the leaching of metallic elements in the technology of solidification in aqueous solution.

Results are presented of experiments performed to optimize the solidification/stabilization system for metallic elements in aqueous solution. This system involves mixing cement and a solution of metallic elements in a conventional mixer: the paste thus obtained is transferred drop by drop into a recipient filled with an aqueous solution of NaOH at 20% by weight, in which it solidifies immediately. The separate use of chloride solutions of Li+, Cr3+, Pb2+ and Zn2+ makes it possible to obtain granules displaying various levels of compressive strength. Three different inertization matrices were used in the experiments, the first consisting solely of Portland cement, the second of Portland cement and a superplasticizer additive, and the third of Portland cement partially replaced with silica-fume and superplasticizer. The results of the tests performed showed a very low level of leaching into the alkaline solidification solution for Cr3+, the quantity leached being under 2% as against higher levels for the other metallic elements. For all the considered elements, the best results were obtained by using silica-fume in the inertization matrix.

[Characterization of a diode system for in vivo dosimetry with electron beams]. / Caratterizzazione di un sistema a diodi per la dosimetria in vivo con fasci di elettroni.

PURPOSE: Current quality assurance regulation stresses the basic role of in vivo dosimetry. Our study evaluates the usefulness and reliability of semiconductor diodes in determining the electron absorbed dose. MATERIAL AND METHODS: P-type EDE semiconductor detectors were irradiated with electron beams of different energies produced by a CGR Saturn Therac 20. The diode and ionization chamber response were compared, and effect of energy value, collimator opening, source skin distance and gantry angle on diode response was studied. RESULTS: Measurements show a maximum increment of about 20% in diode response increasing the beam energy (6-20 MeV). The response also increases with: collimator opening, reaching 5% with field sizes larger than 10x10 cm2 (with the exception of 20 MeV energy); SSD increase (with a maximum of 8% for 20 MeV); transversal gantry incidence, compared with the diode longitudinal axis; it does not affect the response in the interval of +/- 45 degrees. Absorbed dose attenuation at dmax, due to the presence of diode on the axis of the beam as a function of electron energy was also determined : the maximum attenuation value is 15% in 6 MeV electron beams. A dose calculation algorithm, taking into account diode response dependence was outlined. In vivo dosimetry was performed in 92 fields for 80 patients, with an agreement of +/-4 % (1 SD) between prescribed and measured dose. DISCUSSION AND CONCLUSIONS: It is possible to use the EDE semiconductor detectors on a quality control program of dose delivery for electron beam therapy, but particular attention should be paid to the beam incidence angle and diode dose attenuation.

Studies on the in vitro inversion of flurbiprofen.

This paper reports in vitro studies on the metabolic inversion of flurbiprofen (FL), an arylpropionic acid antiinflammatory agent (2-APA). The inversion was studied with both rac-FL and R-FL, by incubation with rat hepatic microsomes, in the presence of either CoASH and ATP or NADPH. The two isomers of the drug were separated as their (+)-(R)-1-phenylethylamides by direct phase high-performance liquid chromatography on a silica gel column with an achiral mobile phase. The inversion was more pronounced in the presence of CoASH and ATP for both the racemate and the R-isomer, which supports the key role of CoA thioesters in the metabolic inversion of profens. The inversion observed in the presence of NADPH suggests that, when the incubation is run with hepatic microsomes, a CYP450-mediated pathway is also active. In order to get more insight into the CYP450-mediated inversion pathway, we studied the effect of irradiating microsomes with a low dose of He-Ne laser radiation (0.2 J). Such irradiation caused a significant increase in inversion at all times studied and normalized the anomalous value of inversion observed at 15 min in this pathway.

Short communication: staff dose reduction during coronary angiography using low framing speed.

Radiation exposure of cardiac catheterization laboratory staff is a known occupational hazard, and efforts are made to obtain dose levels which are "as low as reasonably achievable". This study assessed the reduction in staff radiation exposure using cine framing at 12.5 f s-1 during coronary cineangiography, instead of 25 f s-1. Thermoluminescent dosemeters were used to measure equivalent dose at several sites for the operator, nurse assistant, and X-ray technician during 15 procedures at both frame rates. Patient-related and procedure-related variables were similar in the two groups of examinations. Mean equivalent dose absorbed (microSv) at the left side of the forehead was reduced by 61%, 60% and 36%, for the operator, nurse assistant and X-ray technician, respectively. With use of the lower frame rate similar reductions by 42%, 62% and 62% were measured at the thyroid level, and by 51%, 40% and 61% at the mid-thorax level. Cinefilming at low frame rates during coronary arteriography allows a substantial X-ray dose reduction at all body sites for all staff. Use of lower frame rates wherever possible is of special interest since it may also reduce patient radiation exposure.

Determination of glutamate decarboxylase by high-performance liquid chromatography.

An improved method for the determination of glutamate decarboxylase (GAD) activity is described. The enzyme was evaluated by incubation with glutamic acid (L-Glu) in the presence of pyridoxal 5'-phosphate (PLP): the gamma-aminobutyric acid (GABA) formed was derivatized to PTC-GABA; the latter was subsequently separated and assayed by isocratic HPLC (LiChrospher RP-18 column; isocratic elution with pH 5.8 acetate buffer in acetonitrile-water) with UV absorbance detection at 254 nm. The method described is a sensitive, reproducible and specific assay useful for following variations of GAD activity in vitro; this assay was subsequently used for the evaluation of GAD activity variations after irradiation with low doses of He-Ne laser radiation.

[Radiologic practice and radioprotection in Italian hemodynamic laboratories]. / Pratica radiologica e radioprotezione nei laboratori di emodinamica italiani.

Increasing numbers of diagnostic and therapeutic cardiac catheterization procedures are performed in Italy each year. Radiation exposure of the cardiac catheterization laboratory staff is a known hazard, and there is growing public and professional concern over the risks of low-energy medical ionizing radiation for the patients. The aim of this study was to outline the range of current radiological and radiation protection practice in large-volume cardiac catheterization laboratories in Italy. In August 1994 a questionnaire was submitted to the chief invasive cardiologist of the 32 cardiac catheterization laboratories nation-wide having performed at least 1000 procedures in 1993. All laboratories responded. There were variations in both the radiologic technique (cine framing speed, mean film lengths and fluoroscopy times) and the radiation protection practice (use of shields, leaded collars and glasses, and sites where dosimeters are worn). In 22 of 32 laboratories the cardiologists were not aware of radiation exposure data, and only 6 laboratories could quote the exposure provided by their X-ray system or estimates of the dose absorbed by patients during diagnostic or therapeutic procedures. The results of this survey indicate that radiological practice, and techniques for measuring and reducing exposure of the personnel vary widely in cardiac catheterization laboratories in Italy. These data suggest also that reducing patients' radiation exposure is not, in general, considered to be a quality assurance priority by interventional cardiologists.

A European quality assurance network for radiotherapy: dose measurement procedure.

In the frame of the experimental implementation of a European quality assurance network for external radiotherapy, the methodology in the European Measuring Centre (MC) is presented. Mailed TL dosimeters are used for the check of the beam output and of the beam quality of photon beams. The thermoluminescent material is PTL 717 LiF powder. The readings were first performed on a manual, and then on an automatic reader, with standard deviations of the mean of 0.7% for one dosimeter. Corrections for supralinearity and for the energy dependence of the dosimeter response are applied. An original method has been developed to correct for the variation of the LiF response as a function of time. It is shown that the sensitivity of the powder changes during storage, leading to a kind of 'inverse fading'. The global uncertainty of the TL postal measurement procedure is estimated to be about 1.5% for the 60Co beams and 2% for the x-ray beams. Intercomparisons with the IAEA and with the EORTC have shown an agreement better than 2% for all energies. It can be concluded that the results of the MC are suitable for the requirements of a European quality assurance network.

Effect of in vivo He-Ne laser irradiation on biogenic amine levels in rat brain.

In order to elucidate the metabolic modifications induced in rat brain by low power He-Ne laser irradiation in vivo, the variations in the biogenic amine levels in cortex, striatum and hippocampus were studied. Noradrenaline (NA), dopamine (DA) and serotonin (5-HT) were evaluated by HPLC-EC on irradiated rats, untreated rats (controls) and rats which had undergone restraint stress (stressed). The results obtained on groups of four to eight rats assayed individually showed that irradiation caused a strong increase in 5-HT in striatum and hippocampus, a small but significant decrease in NA in cortex, and DA levels were not significantly affected. Restraint stress per se led to a considerable decrease in 5-HT and DA in striatum and hippocampus, but did not significantly alter the NA levels.