Typical values for pediatric interventional cardiology catheterizations: A standardized approach towards Diagnostic Reference Level establishment

PurposeTo define weight-stratified Diagnostic Reference Levels (DRL) typical values for pediatric interventional cardiology (IC) procedures adopting standardized methodologies proposed by ICRP135 and RP185.MethodsProcedures performed at the pediatric catheterization room of the University-Hospital of Padua were analysed. Patients were stratified into body weight (BW) classes and DRL quantities were analysed for the most performed procedures. Typical values are defined as median P_KA and K_a,r. For database consistency, sampling and exclusion methods were precisely defined. The DRL-curve methodology by means of quantile regression median curves was investigated to assess the relationship between P_KA and weight. A like-to-like comparison with literature was made.Results385 procedures were analysed. A large P_KA variability was observed in each weight group. P_KA differences across BW groups were not always statistically significant. When stratifying by procedure, P_KA variability decreased while correlations of P_KA and P_KA/FT with weight increased. The established typical values are generally lower than DRLs published data, whatever stratification method adopted. The highest P_KA median values were observed for Angioplasty (4.9 and 11.6 Gycm² for 5-<15 kg and 15-<30 kg, respectively). The DRL-curve approach shows promising results for Valvuloplasty and Angioplasty.ConclusionsTypical values for pediatric IC DRL quantities were determined according to ICRP135 and RP185 methodologies. Stratification by BW classification does not reduce the variability of the P_KA values, unlike what happens when stratifying by procedure type. Results seem to corroborate that variability and exposure are more affected by procedure type and complexity than by patient weight. DRL-curve is a feasible approach.     

Updating national diagnostic reference levels for interventional cardiology and methodological aspects

The aim of this study is to propose national diagnostic reference levels (DRL) for updating in the field of interventional cardiology and to include technical details to help plan optimization.Medical physics experts and interventional cardiologists from 14 hospitals provided patient dose indicators from coronary angiography and percutaneous coronary interventions. Information about X-ray system dose settings and image quality was also provided.The dose values from 30,024 procedures and 26 interventional laboratories were recorded. The national DRLs proposed for coronary angiography and percutaneous coronary interventions were respectively 39 and 78 Gy·cm² for air kerma area product (P_KA), 530 and 1300 mGy for air kerma at reference point (K_a,r), 6.7 and 15 min of fluoroscopy time and 760 and 1300 cine images. 36% of the KAP meters required correction factors from 10 to 35%. The dose management systems should allow these corrections to be included automatically. The dose per image in cine in reference conditions differed in a factor of 5.5.Including X-ray system dose settings in the methodology provides an insight into the differences between hospitals. The DRLs proposed for Spain in this work were similar to those proposed in the last European survey. The poor correlation between X-ray systems dose settings and patient dose indicators highlights that other factors such as operation protocols and complexity may have more impact in patient dose indicators, which allows a wide margin for optimization. Dose reduction technology together with appropriate training programs will be determinant in the future reduction of patient dose indicators.     

Institutional Diagnostic Reference Levels and Peak Skin Doses in selected diagnostic and therapeutic interventional radiology procedures

PurposeInstitutional (local) Diagnostic Reference Levels for Cerebral Angiography (CA), Percutaneous Transhepatic Cholangiography (PTC), Transarterial Chemoembolization (TACE) and Percutaneous Transhepatic Biliary Drainage (PTBD) are reported in this study.Materials and methodsData for air kerma-area product (P_KA), air kerma at the patient entrance reference point (K_a,r), fluoroscopy time (FT) and number of images (NI) as well as estimates of Peak Skin Dose (PSD) were collected for 142 patients. Therapeutic procedure complexity was also evaluated, in an attempt to incorporate it into the DRL analysis.ResultsLocal P_KA DRL values were 70, 34, 189 and 54 Gy.cm² for CA, PTC, TACE and PTBD respectively. The corresponding DRL values for K_a,r were 494, 194, 1186 and 400 mGy, for FT they were 9.2, 14.2, 27.5 and 22.9 min, for the NI they were 844, 32, 602 and 13 and for PSD they were 254, 256, 1598 and 540 mGy respectively. P_KA for medium complexity PTBD procedures was 2.5 times higher than for simple procedures. For TACE, the corresponding ratio was 1.6. PSD was estimated to be roughly 50% of recorded K_a,r for procedures in the head/neck region and 10% higher than recorded K_a,r for procedures in the body region. In only 5 cases the 2 Gy dose alarm threshold for skin deterministic effects was exceeded.ConclusionProcedure complexity can differentiate DRLs in Interventional Radiology procedures. PSD could be deduced with reasonable accuracy from values of K_a,r that are reported in every angiography system.     

Diagnostic reference levels during fluoroscopically guided interventions using mobile C-arms in operating rooms: A national multicentric survey

PurposeTo establish diagnostic reference levels (DRLs) and achievable levels (ALs) for the most common fluoroscopically guided interventions (FGIs) performed in operating rooms using mobile C-arm equipment.MethodsA national survey was performed in 57 centers in France. Anonymous data from 6817 patients undergoing FGIs were prospectively collected over a period of 7 months. DRLs (third quartile of the distribution) and ALs (median of the distribution) were determined for each type of intervention in terms of kerma area product (KAP) and fluoroscopy time (FT).ResultsDRLs and ALs were proposed for 31 procedure types related to seven surgical specialties: orthopedics (n = 9), urology (n = 3), vascular (n = 6), cardiology (n = 5), neurosurgery (n = 3), gastrointestinal (n = 3), and multi-specialty (n = 2). DRLs in terms of KAP ranged from 0.1 Gy·cm² for hallux valgus to 78 Gy·cm² for abdominal aortic aneurysm endovascular repair. A factor of 155 was obtained between the FTs for a herniated lumbar disk (0.2 min) and an abdominal aortic aneurysm endovascular repair (31 min). The highest variations were obtained within orthopedic procedures in terms of KAP (ratio 122) and within gastrointestinal procedures in terms of FT (ratio 9). Overall, the FGIs associated with the highest radiation exposure (KAP > 10 Gy·cm²) were found in the cardiology, vascular, and gastrointestinal specialties.ConclusionsDRLs and ALs are suggested for a wide range of FGIs performed in operating rooms using a mobile C-arm. We aim at providing a practical optimization tool for medical physicists and surgeons.     

Patient exposure data and operator dose in coronary interventional procedures: Impact of body-mass index and procedure complexity

PurposeThe aim of this study was to assess patient exposure data and operator dose in coronary interventional procedures, when considering patient body-mass index and procedure complexity.MethodsTotal air kerma area product (P_KA), Air-Kerma (AK), Fluoroscopy time (FT), operator dose and patient body-mass index (BMI) from 97 patients’ procedures (62 coronary angiography (CA) and 35 Percutaneous Coronary Intervention (PCI) were collected for one year. For PCI procedures, also the complexity index-CI was collected. Continuous variables for each of the 2 groups procedures (CA and PCI) were compared as medians with interquartile range and using Mann-Whitney U test. Multiple group data were compared using Kruskal-Wallis test (significance: p < 0.05).ResultsMedian P_KA was 63 and 125 Gy cm² for CA and PCI respectively (p < 0.001); FT was 3 and 14 min, respectively (p < 0.001). P_KA and FT significantly increased (p < 0.05) with BMI class for CA procedures. P_KA and FT also increased in function of CI class for PCI, thought significantly only for FT (p < 0.001), possibly because of the low number of PCI procedures included; cine mode contributed most to P_KA. Significant dose variability was observed among cardiologists for CA procedures (p < 0.001).ConclusionsDose references levels for P_KA and FT in interventional cardiology should be defined - on a sufficient number of procedures- in function of CI and BMI classes. These could provide an additional tool for refining a facility’s quality assurance and optimization processes. Dose variability associated with cardiologists underlines the importance of continuous training.     

Towards the definition of Institutional diagnostic reference levels in paediatric interventional cardiology procedures in Greece

This study aimed to evaluate paediatric radiation doses in a dedicated cardiology hospital, with the objective of characterising patterns in dose variation. The ultimate purpose was to define Local (Institutional) Diagnostic Reference Levels (LDRLs) for different types of paediatric cardiac interventional procedures (IC), according to patient age. From a total of 710 cases performed during three consecutive years, by operators with more than 15 years of experience, the age was noted in only 477 IC procedures. The median values obtained for Fluoroscopy Time (FT), Number of Frames (N) and Kerma Area Product (P_KA) by age range were 5.8 min, 1322 and 2.0 Gy.cm² for <1 y; 6.5 min, 1403 and 3.0 Gy.cm² for 1 to <5 y; 5.9 min, 950 and 7.0 Gy.cm² for 5 to <10 y; 5.7 min, 940 and 14.0 Gy.cm² for 10 to <16 y, respectively. A large range of patient dose data is observed, depending greatly on procedure type and patient age. In all age groups the range of median FT, N and P_KA values was 3.1–15.8 min, 579–1779 and 1.0–20.8 Gy.cm² respectively. Consequently, the definition of LDRLs presents challenges mainly due to the multiple clinical and technical factors affecting the outcome. On the other hand the lack of paediatric IC DRLs makes the identification of good practices more difficult. A consensus is needed on IC procedures nomenclature and grouping in order to allow a common assessment and comparison of doses.     

Eye lens dose correlations with personal dose equivalent and patient exposure in paediatric interventional cardiology performed with a fluoroscopic biplane system

PurposeTo analyse the correlations between the eye lens dose estimates performed with dosimeters placed next to the eyes of paediatric interventional cardiologists working with a biplane system, the personal dose equivalent measured on the thorax and the patient dose.MethodsThe eye lens dose was estimated in terms of H_p(0.07) on a monthly basis, placing optically stimulated luminescence dosimeters (OSLDs) on goggles. The H_p(0.07) personal dose equivalent was measured over aprons with whole-body OSLDs. Data on patient dose as recorded by the kerma-area product (P_KA) were collected using an automatic dose management system. The 2 paediatric cardiologists working in the facility were involved in the study, and 222 interventions in a 1-year period were evaluated. The ceiling-suspended screen was often disregarded during interventions.ResultsThe annual eye lens doses estimated on goggles were 4.13 ± 0.93 and 4.98 ± 1.28 mSv. Over the aprons, the doses obtained were 10.83 ± 0.99 and 11.97 ± 1.44 mSv. The correlation between the goggles and the apron dose was R² = 0.89, with a ratio of 0.38. The correlation with the patient dose was R² = 0.40, with a ratio of 1.79 μSv Gy⁻¹ cm⁻². The dose per procedure obtained over the aprons was 102 ± 16 μSv, and on goggles 40 ± 9 μSv. The eye lens dose normalized to P_KA was 2.21 ± 0.58 μSv Gy⁻¹ cm⁻².ConclusionsMeasurements of personal dose equivalent over the paediatric cardiologist’s apron are useful to estimate eye lens dose levels if no radiation protection devices are typically used.     

Proposed local diagnostic reference levels in angiography and interventional neuroradiology and a preliminary analysis according to the complexity of the procedures

The aim of this study was to propose local diagnostic reference levels (DRL) for exposure to radiation during diagnostic procedures and neuroradiological interventions such as cerebral angiography and embolisation of cerebral aneurysms (intra-cranial aneurysms and arteriovenous malformations). Hospitals should adopt the national DRLs for use locally or establish their own DRLs based on local practice, if sufficient local data are available.For this purpose we studied a sample of 113 cerebral angiography procedures and 82 embolisations of cerebral aneurysms. The data recorded included the kerma-area product (KAP), the fluoroscopy time and the number of frames for each procedure: third quartiles from the total dosimetric databank were calculated and proposed as provisional local DRL. Since the complexity of a procedure must be taken into account when evaluating the radiation dose, in the case of embolisation of aneurysms (intra-cranial), in this initial phase we assessed whether the complexity of the embolisation procedure is related to the size of the aneurysm and/or its site. We, therefore, re-calculated the DRL for only intra-cranial aneurysms, leaving aside the arteriovenous malformations. Considering that the DRL calculated for all the therapeutic procedures are similar to those calculated considering only intra-cranial aneurysms, at the moment we propose, besides the DRL for cerebral angiography, a single DRL for all interventional procedures, even when the clinical pictures are very different. Local preliminary DRLs were proposed as follows: 180 Gy cm², 12 min and 317 frames for cerebral angiography and 487 Gy cm², 46 min and 717 frames for interventional procedures (intra-cranial aneurysms and arteriovenous malformations).     

Preliminary diagnostic reference levels for endoscopic retrograde cholangio-pancreatography in Greece

The main objective of this study was to determine the preliminary Diagnostic Reference Levels (DRLs) in terms of Kerma Area Product (KAP) and fluoroscopy time (Tf) during Endoscopic Retrograde Cholangio-Pancreatography (ERCP) procedures. Additionally, an investigation was conducted to explore the statistical relation between KAP and Tf.Data from a set of 200 randomly selected patients treated in 4 large hospitals in Greece (50 patients per hospital) were analyzed in order to obtain preliminary DRLs for KAP and Tf during therapeutic ERCP procedures. Non-parametric statistic tests were performed in order to determine a statistically significant relation between KAP and Tf.The resulting third quartiles for KAP and Tf for hospitals (A, B, C and D) were found as followed: KAP_A = 10.7 Gy cm², Tf_A = 4.9 min; KAP_B = 7.5 Gy cm², Tf_B = 5.0 min; KAP_C = 19.0 Gy cm², Tf_C = 7.3 min; KAP_D = 52.4 Gy cm², Tf_D = 15.8 min. The third quartiles, calculated for the total 200 cases sample, are: KAP = 18.8 Gy cm² and Tf = 8.2 min. For 3 out of 4 hospitals and for the total sample, p-values of statistical indices (correlation of KAP and Tf) are less than 0.001, while for the Hospital A p-values are ranging from 0.07 to 0.08. Using curve fitting, we finally determine that the relation of Tf and KAP is deriving from a power equation (KAP = Tf^1.282) with R² = 0.85.The suggested Preliminary DRLs (deriving from the third quartiles of the total sample) for Greece are: KAP = 19 Gy cm² and Tf = 8 min, while the relation between KAP and Tf is efficiently described by a power equation.     

Uptake kinetics and storage capacity of dissolved inorganic phosphorus and corresponding dissolved inorganic nitrate uptake in Saccharina latissima and Laminaria digitata (Phaeophyceae)

Uptake rates of dissolved inorganic phosphorus and dissolved inorganic nitrogen under unsaturated and saturated conditions were studied in young sporophytes of the seaweeds Saccharina latissima and Laminaria digitata (Phaeophyceae) using a “pulse‐and‐chase” assay under fully controlled laboratory conditions. In a subsequent second “pulse‐and‐chase” assay, internal storage capacity (ISC) was calculated based on V_M and the parameter for photosynthetic efficiency F_v/F_m. Sporophytes of S. latissima showed a V_S of 0.80 ± 0.03 μmol · cm^?2 · d^?1 and a V_M of 0.30 ± 0.09 μmol · cm^?2 · d^?1 for dissolved inorganic phosphate (DIP), whereas V_S for DIN was 11.26 ± 0.56 μmol · cm^?2 · d^?1 and V_M was 3.94 ± 0.67 μmol · cm^?2 · d^?1. In L. digitata, uptake kinetics for DIP and DIN were substantially lower: V_S for DIP did not exceed 0.38 ± 0.03 μmol · cm^?2 · d^?1 while V_M for DIP was 0.22 ± 0.01 μmol · cm^?2 · d^?1. V_S for DIN was 3.92 ± 0.08 μmol · cm^?2 · d^?1 and the V_M for DIN was 1.81 ± 0.38 μmol · cm^?2 · d^?1. Accordingly, S. latissima exhibited a larger ISC for DIP (27 μmol · cm^?2) than L. digitata (10 μmol · cm^?2), and was able to maintain high growth rates for a longer period under limiting DIP conditions. Our standardized data add to the physiological understanding of S. latissima and L. digitata, thus helping to identify potential locations for their cultivation. This could further contribute to the development and modification of applications in a bio‐based economy, for example, in evaluating the potential for bioremediation in integrated multitrophic aquacultures that produce biomass simultaneously for use in the food, feed, and energy industries.     

Evaluation of electrocoagulation,flocculation, and sedimentation harvesting methods on microalgae consortium grown in anaerobically digested abattoir effluent

Microalgae dewatering is a major bottleneck for biomass production in a large-scale microalgal production system which accounts for 20–60% of production cost. In this study, three dewatering systems of electrocoagulation, flocculation, and pH-induced flocculation were evaluated for microalgal consortium grown in anaerobically digested abattoir effluent at pH 6.5 and 9.5. At the shortest time (15 min) and the highest current density (0.08 A cm^?2), the highest microalgae recoveries of 78 and 84% were obtained with the corresponding power consumptions of 1.25 and 1.07 kWh kg^?1 for cultures at pH 6.5 and 9.5. For microalgae suspension at pH 6.5, the highest biomass recovery of 77% was obtained when 100 mg L^?1 of FeCl₃·6H₂O (after 15 min) or 100 mg L^?1 of Al₂(SO₄)₃·18H₂O (after 30 min) was added. However, microalgal recoveries significantly increased when FeCl₃·6H₂O or Al₂(SO₄)₃·18H₂O was used with the culture at pH 9.5. pH-Induced experiments showed that cultures adjusted at pH 10.5 had 36% higher biomass recovery compared to that in cultures at pH 8.5 after 2 h. The results of this study showed that cultures at higher pH (9.5) had a better microalgae recovery in all dewatering systems than cultures at lower pH (6.5).

     

Local diagnostic reference levels for intraoral dental radiography in the public hospitals of Cyprus

PurposeThe purpose of this study was to determine local DRLs for children and adults undergoing intraoral dental examinations at the intraoral radiology units of the public hospitals in Cyprus.MethodsMeasurements were made on all the twenty intraoral X-ray units of the public hospitals in Cyprus with the intention to establish the local DRLs for all the possible intraoral X-ray examinations for children and adults. All units are film based. The measurements were made by a Dose Area Product (DAP) meter (GAMMEX RMI 841-RD) placed at the surface of the dental unit’s X-ray shaping cone (FSD 20 cm). A diagnostic radiology dosimeter (Dosimax Plus A) was also placed at an FSD of 100 cm to compare the dose reading between the two dosimeters.ResultsDRLs were established at the 3rd quartile for 7 exposure settings corresponding to 12 types of teeth (Adult and children mandibular and maxillary incisor, premolar and molar) with values of 197, 163, 128, 102, 81, 65 and 49 mGycm⁻² and 7.23, 5.94, 4.75, 3.68, 3.10, 2.41 and 1.88 mGy for benchmark nominal exposure times of 1000, 800, 640, 500, 400, 320 and 250 ms respectively, at a nominal exposure voltage of 70 kVp.ConclusionsThe local DRLs of the present study compare well with other similar published DRLs.     

Cold induced vasodilatation and cardiovascular responses in humans during cold water immersion of various upper limb areas

To study the physiological responses induced by immersing in cold water various areas of the upper limb, 20 subjects immersed either the index finger (T1), hand (T2) or forearm and hand (T3) for 30 min in 5°C water followed by a 15-min recovery period. Skin temperature of the index finger, skin blood flow (Q_sk) measured by laser Doppler flowmetry, as well as heart rate (HR) and mean arterial blood pressure (ˉBP_a) were all monitored during the test. Cutaneous vascular conductance (CVC) was calculated as Q_sk / ˉBP_a. Cold induced vasodilatation (CIVD) indices were calculated from index finger skin temperature and CVC time courses. The results showed that no differences in temperature, CVC or cardiovascular changes were observed between T2 and T3. During T1, CIVD appeared earlier compared to T2 and T3 [5.90 (SEM 0.32) min in T1 vs 7.95 (SEM 0.86) min in T2 and 9.26 (SEM 0.78) min in T3, P < 0.01]. The HR was unchanged in T1 whereas it increased significantly at the beginning of T2 and T3 [+13 (SEM 2) beats · min⁻¹ in T2 and +15 (SEM 3) beats · min⁻¹ in T3, P < 0.01] and then decreased at the end of the immersion [−12 (SEM 3) beats · min⁻¹ in T2, and −15 (SEM 3) beats · min⁻¹ in T3, P < 0.01]. Moreover, ˉBP_aincreased at the beginning of T1 but was lower than in T2 and T3 [+9.3 (SEM 2.5) mmHg in T1, P < 0.05;  +20.6 (SEM 2.6) mmHg and 26.5 (SEM 2.8) mmHg in T2 and T3, respectively, P < 0.01]. The rewarming during recovery was faster and higher in T1 compared to T2 and T3. These results showed that general and local physiological responses observed during an upper limb cold water test differed according to the area immersed. Index finger cooling led to earlier and faster CIVD without significant cardiovascular changes, whereas hand or forearm immersion led to a delayed and slower CIVD with a bradycardia at the end of the test. Accepted: 26 November 1996     

Signal-to-noise ratio improvements using anti-scatter grids with different object thicknesses and tube voltages

PurposeThe appropriate object thickness to start using anti-scatter grids (grids) has not sufficiently investigated in previous studies, and thus we rigorously investigated the effectiveness of two generally used grids with grid ratios of 6 and 10 (G6 and G10) for different 50–200 mm thicknesses at tube voltages of 60–100 kV.MethodsAcrylic phantoms with 30 × 30 cm² and different thicknesses were used to measure the signal-to-noise ratio improvement factors (SIFs) of grids. To evaluate the infants’ conditions, field sizes of 225, 400, and 625 cm² were also evaluated at 60–80 kV. In addition, the signal difference-to-noise ratio (SDNR) was used to evaluate tube voltage dependencies of grids for each thickness.ResultsSIF values exceeded 1.0 for ≥70 mm thicknesses and mostly exceeded 1.07 for the 100 mm thickness with 400 cm² field size corresponding to a 1-year-old infant abdomen. The estimated dose reduction capabilities for a 1-year-old infant were approximately 15% using G10 at 70 and 80 kV. The tube voltage dependencies for grid use was almost not prominent for all conditions tested, except for some conditions that are not clinically realistic.ConclusionsG6 and G10 can improve SNR for  ≥100 mm thickness. The results from this work demonstrate approximately 15% dose reduction or image quality improvements at the same dose level for the use of G6 and G10 grids for 100 mm thickness, traditionally excluded from the recommended grid use conditions.     

Characteristics of activated carbon remove sulfur particles against smog

Sulfur particles, which could cause diseases, were the main powder of smog. And activated carbon had the very adsorption characteristics. Therefore, five sulfur particles were adsorbed by activated carbon and were analyzed by FT-IR. The optimal adsorption time were 120 min of Na₂SO₃, 120 min of Na₂S₂O₈, 120 min of Na₂SO₄, 120 min of Fe₂(SO₄)₃ and 120 min of S. FT-IR spectra showed that activated carbon had the eight characteristic absorption of SS stretch, H₂O stretch, OH stretch, CH stretch, conjugated CO stretch or CC stretch, CH₂ bend, CO stretch and acetylenic CH bend vibrations at 3850 cm^–1, 3740 cm^–1, 3430 cm^–1, 2920 cm^–1, 1630 cm^–1, 1390 cm^–1, 1110 cm^–1 and 600 cm^–1, respectively. For Na₂SO₃, the peaks at 2920 cm^–1, 1630 cm^–1, 1390 cm^–1 and 1110 cm^–1 achieved the maximum at 20 min. For Na₂S₂O₈, the peaks at 3850 cm^–1, 3740 cm^–1 and 2920 cm^–1 achieved the maximum at 60 min. The peaks at 1390 cm^–1, 1110 cm^–1 and 600 cm^–1 achieved the maximum at 40 min. For Na₂SO₄, the peaks at 3430 cm^–1, 2920 cm^–1, 1630 cm^–1, 1390 cm^–1, 1110 cm^–1 and 600 cm^–1 achieved the maximum at 60 min. For Fe₂(SO₄)₃, the peaks at 1390 cm^–1, 1110 cm^–1 and 600 cm^–1 achieved the maximum at 20 min. For S, the peaks at 1630 cm^–1, 1390 cm^–1 and 600 cm^–1 achieved the maximum at 120 min. It provided that activated carbon could remove sulfur particles from smog air to restrain many anaphylactic diseases.     

Establishing national diagnostic reference levels (DRLs) for computed tomography in Egypt

ObjectivesTo establish national diagnostic reference levels (DRLs) in Egypt for computed tomography (CT) examinations of adults and identify the potential for optimization.MethodsData from 3762 individual patient’s undergoing CT scans of head, chest (high resolution), abdomen, abdomen-pelvis, chest-abdomen-pelvis and CT angiography (aorta and both lower limbs) examinations in 50 CT facilities were collected. This represents 20% of facilities in the country and all of the 27 Governorates. Results were compared with DRLs of UK, USA, Canada, Japan, Australia and France.ResultsThe Egyptian DRLs for CTDI_vol in mGy are for head: 30, chest (high resolution): 22, abdomen (liver metastasis): 31, abdomen-pelvis: 31, chest-abdomen–pelvis: 33 and CT angiography (aorta and lower limbs): 37. The corresponding DRLs for DLP in mGy.cm are 1360, 420, 1425, 1325, 1320 and 1320. For head CT, the Egyptian DRL for CTDI_vol is 2–3 times lower than the DRLs from other countries. However, the DRL in terms of DLP is in the same range or higher as compared to others. The Egyptian DRL for chest CT (high resolution) is similar to others for DLP but higher for CTDI_vol. For abdomen and abdomen-pelvis DRLs for CTDI_vol are higher than others. For DLP, the DRLs for abdomen are higher than DRL in UK and lower than those in Japan, while for abdomen-pelvis they are higher than other countries.ConclusionDespite lower DRLs for CTDI_vol, an important consistent problem appears to be higher scan range as DRLs for DLP are higher.     

Postoperative endometrial carcinoma treated with external beam irradiation plus vaginal-cuff brachytherapy. Is there a dose relationship with G2 vaginal complications?

AimTo analyse the possible relationship between the EQD2_(α/β=3Gy) at 2 cm³ of the vagina and late toxicity in vaginal-cuff-brachytherapy (VBT) after external-beam-irradiation (EBRT) for postoperative endometrial carcinoma (EC).Materials and methodsFrom 2014 to 2016, 62 postoperative EC patients were treated with EBRT + VBT. The median EBRT dose was 45 Gy (44 Gy–50.4 Gy). VBT involved a single 7 Gy dose. Toxicity was prospectively evaluated using the RTOG score for the rectum and bladder and the objective LENT-SOMA criteria for the vagina. EQD2_{(α/β = 3Gy)} at 2 cm³ of the most exposed part of the vagina was calculated by the sum of the EBRT + VBT dose. Statistics: Boxplot, Student’s t and Chi-square tests and ROC curves.ResultsMean follow-up: 39.2 months (15–68). Late toxicity: bladder:0 patient; rectum:2 patients-G1; Vagina: 26 patients-17G1, 9G2; median EQD2_(α/β=3Gy) at 2 cm³ in G0-G1 patients was 70.4 Gy(SD2.36), being 72.5 Gy(SD2.94) for G2p. The boxplot suggested a cut-point identifying the absence of G2: 100 % of G2p received >68 Gy, ROC curves showed an area under the curve of 0.72 (sensitivity of 1 and specificity of 0.15).ConclusionsDoses >68 Gy EQD2_(α/β=3Gy) at 2 cm³ to the most exposed area of the vagina were associated with late G2 vaginal toxicity in postoperative EC patients treated with EBRT + VBT suggesting a very good dose limit to eliminate the risk of G2 late toxicity. The specificity obtained indicates the need for prospective analyses.     

Influence of mixed antibiotics on Microcystis aeruginosa during the application of glyphosate and hydrogen peroxide algaecides

Antibiotics regulate various physiological functions in cyanobacteria and may interfere with the control of cyanobacterial blooms during the application of algaecides. In this study, Microcystis aeruginosa was exposed to H₂O₂ and glyphosate for 7 d in the presence of coexisting mixed antibiotics (amoxicillin, spiramycin, tetracycline, ciprofloxacin, and sulfamethoxazole) at an environmentally relevant concentration of 100 ng · L^?1. The mixed antibiotics significantly (P < 0.05) alleviated the growth inhibition effect of 15–45 μM H₂O₂ and 40–60 mg · L^?1 glyphosate. According to the increased contents of chlorophyll a and protein, decreased content of malondialdehyde, and decreased activities of superoxide dismutase and glutathione S‐transferase, antibiotics may reduce the toxicity of the two algaecides through the stimulation of photosynthesis and the reduction in oxidative stress. The presence of coexisting antibiotics stimulated the production and release of microcystins in the M. aeruginosa exposed to low concentrations of algaecides and posed an increased threat to aquatic environments. To eliminate the secondary pollution caused by microcystins, high algaecide doses that are ≥45 μM for H₂O₂ and ≥60 mg · L^?1 for glyphosate are recommended. This study provides insights into the ecological hazards of antibiotic contaminants and the best management practices for cyanobacterial removal under combined antibiotic pollution conditions.     

Patient doses and occupational exposure in a hybrid operating room

PurposeThis study aimed to characterize the radiation exposure to patients and workers in a new vascular hybrid operating room during X-ray-guided procedures.MethodsDuring one year, data from 260 interventions performed in a hybrid operating room equipped with a Siemens Artis Zeego angiography system were monitored. The patient doses were analysed using the following parameters: radiation time, kerma-area product, patient entrance reference point dose and peak skin dose. Staff radiation exposure and ambient dose equivalent were also measured using direct reading dosimeters and thermoluminescent dosimeters.ResultsThe radiation time, kerma-area product, patient entrance reference point dose and peak skin dose were, on average, 19:15 min, 67 Gy·cm², 0.41 Gy and 0.23 Gy, respectively. Although the contribution of the acquisition mode was smaller than 5% in terms of the radiation time, this mode accounted for more than 60% of the effective dose per patient. All of the worker dose measurements remained below the limits established by law.ConclusionsThe working conditions in the hybrid operating room HOR are safe in terms of patient and staff radiation protection. Nevertheless, doses are highly dependent on the workload; thus, further research is necessary to evaluate any possible radiological deviation of the daily working conditions in the HOR.     

Efficacy and Safety of Insulin Lispro in Obese Patients with Type 2 Diabetes: A Retrospective Meta-Analysis of 7 Randomized Controlled Trials

ObjectiveTo evaluate the efficacy and safety of insulin lispro in the treatment of patients with type 2 diabetes (T2DM) who had a body mass index (BMI) ≥ 30 kg/m² (obese) compared with patients with BMIs < 30 kg/m² (nonobese).MethodsA retrospective analysis of predefined endpoints from 7 randomized clinical trials of T2DM patients treated with insulin lispro was performed. The primary efficacy measure was to assess the noninferiority of insulin lispro in obese patients versus nonobese patients as measured by the change in hemoglobin A1C (HbA_1c) from baseline to Month 3 (n = 1,518), using a noninferiority margin of 0.4%. The secondary measures included overall hypoglycemia incidence and event rates and relative change in body weight.ResultsMean changes in HbA_1c from baseline (9.06% for obese and 8.92% for nonobese) to Month 3 were similar for obese patients (–1.03%) and nonobese (–1.02%), with a least squares (LS) mean difference (95% confidence interval [CI]) of –0.05% (–0.17%, 0.07%; P = .384). The overall incidence of hypoglycemia (53% vs. 63%; P < .001) and rate of hypoglycemia (0.93 vs. 1.76 events per 30 days; P < .001) was significantly lower in obese patients compared with nonobese patients. The 2 BMI cohorts did not demonstrate a significant difference in mean percent changes in body weights (LS mean difference = 0.4% [–0.2%, 0.9%]; P = .202).ConclusionObese patients with T2DM treated with insulin lispro were able to achieve the same level of glycemic control as their nonobese counterparts, with some evidence supporting a reduced risk of hypoglycemia. (Endocr Pract. 2014;20:389-398)