Fluoroscopy Dose Area Product Research Articles

Impact of 3-dimensional electroanatomic mapping systems on fluoroscopy reduction in catheter ablation of supraventricular tachycardia - then and now

Abstract Funding Acknowledgements Type of funding sources: None. Background Catheter ablation is an effective first-line treatment for symptomatic and recurrent supraventricular tachycardia (SVT). The advent of 3D electroanatomic mapping (EAM) has led to a reduction in fluoroscopy use and consequently lower radiation exposure for patients and staff during SVT ablation. Purpose The aims of this study are to demonstrate if the use of EAM during SVT ablation reduces fluoroscopy time (FT), and determine if further reductions in FT are observed longitudinally. We hypothesise that over time, with continued use and wider adoption of EAM, greater operator experience, and technological advancements in EAM, there will be further reductions in radiation exposure as estimated by FT. Methods All cases of atrioventricular nodal re-entry tachycardia (AVNRT), atrioventricular re-entry tachycardia (AVRT), and/or atrial tachycardia (AT) ablation between May 2011 to May 2022 at a tertiary centre were prospectively recruited. FT between the groups with and without EAM were compared. Within the EAM subset, the trend of FT across the years was also analysed. Results Over this 11-year period, there were 1758 cases of SVT ablation (565 without EAM; 1193 with EAM). Between the two groups, there were no significant differences (p > 0.05) in age, sex, history of structural heart disease and/or ischaemic heart disease, stereotaxis use, and diagnosis (AVNRT, AVRT, AT). Cases using EAM were more likely to have >1 SVT ablated during the procedure (0.04) and require intracardiac echocardiography (ICE) (p < 0.001). The use of EAM was associated with mean reductions in FT and dose area product (DAP) by 19.6 minutes and 18 581 mGy*cm2 respectively (both p < 0.001). EAM was also associated with a longer procedure time (mean +8.8 minutes, p < 0.001). There was no difference in radiofrequency application time between the two groups (p = 0.143). After controlling for potential confounding factors including age, sex, use of stereotaxis, use of ICE, type and number of SVT, history of prior ablation, and structural heart disease and/or ischaemic heart disease, we found over time (2011-2022), further reduction in FT was observed, with a mean reduction of 0.9 minutes year on year (p < 0.001). EAM was gradually adopted through the years with the number of cases per year plateauing after 2017. Between 2011-2017, there was a significant reduction in FT (mean of -1.1 minute year on year, p = 0.020), which was not observed from 2017 onwards (p = 0.088). The greatest reduction in FT was observed after the first year of adoption, with a mean reduction of 6.9 minutes between 2012-2013. Conclusion This demonstrates that use of EAM in SVT ablation reduces FT and fluoroscopy DAP. There was no incremental benefit observed after 6 years of EAM adoption likely related to operator experience. While there is increased interest in zero fluoroscopy SVT ablation, complementary use of fluoroscopy may still be necessary in select complex cases.

Cone Beam CT with Automatic vessel Detection Software versus Conventional 2D Fluoroscopy with Overlay for Prostate Artery Embolization: A Comparison of Prostatic Artery Catheterization Time and Radiation Exposure

Abstract Purpose To evaluate the effect of cone-beam computed tomography (CT) with automatic vessel detection software on prostate artery catheterization and fluoroscopy time in prostate artery embolization (PAE). Methods Fifty patients undergoing PAE for BPH were enrolled in this prospective study. Twenty-five PAEs were performed using automatic vessel detection software with syngo embolization guidance (study) and were compared with 25 PAEs performed using conventional two-dimensional (2D) fluoroscopy with overlay (control). PAE was performed using 300–500 μm trisacryl gelatin spherical particles. The primary outcome parameters were prostatic artery catheterization time and fluoroscopy time. Results Bilateral PAE was achieved in 24/25 cases in both groups. The median right and left prostatic artery catheterization times were similar between the two groups, (p = 0.473 and p = 0.659, respectively). The median fluoroscopy time (28.0 and 42.0 minutes, p = 0.046) and total procedure time (70.0 and 118.0 minutes, p < 0.001) were shorter in the study group. The median total dose area product (DAP) was not significantly different. However, the median CBCT DAP (11406 vs. 6248, p < 0.001) was higher in the study group, while median fluoroscopy DAP (7371 vs. 8426, p < .049) was higher in the control group. Median digital subtraction angiography (DSA), CBCT, and fluoroscopy DAP accounted for 27%, 45%, and 29% of the total DAP in the study group and 32%, 29%, and 39% in the control group (p < 0.001), respectively. All complications were Clavien–Dindo Grade 1. Conclusion Although CBCT with automatic vessel detection software had no significant effect on time-to-prostatic artery catheterization and total radiation exposure, it reduced the fluoroscopy time and procedure time.

Cone-beam CT and Augmented Fluoroscopy-guided Navigation Bronchoscopy: Radiation Exposure and Diagnostic Accuracy Learning Curves.

The endobronchial diagnosis of peripheral lung lesions suspected of lung cancer remains a challenge from a navigation as well as an adequate tissue sampling perspective. Cone-beam computed tomography (CBCT) guidance is a relatively new technology and allows for 3-dimensional imaging confirmation as well as navigation and biopsy guidance, but, also involves radiation. This study investigates how radiation exposure and diagnostic accuracy in the CBCT-guided navigation bronchoscopy evolves with increasing experience, and, with a specific tailoring of CBCT and fluoroscopic imaging protocols towards the procedure. In this observational clinical trial, all 238 consecutive patients undergoing a CBCT-guided navigation bronchoscopy from the start of our CBCT-guided navigation bronchoscopy program (December 2017) until June 2020 were included. Procedural dose characteristics and diagnostic accuracy are reported as a function of time. Procedural radiation exposure as measured by the dose area product initially was 47.5 Gy·cm2 (effective dose: 14.3 mSv) and gradually reduced to 25.4 Gy·cm2 (5.8 mSv). The reduction in fluoroscopic dose area product was highest, from 19.0 Gy·cm2 (5.2 mSv) to 2.2 Gy·cm2 (0.37 mSv, 88% reduction), despite a significant increase of fluoroscopy time. The diagnostic accuracy of navigation bronchoscopy increased from 72% to 90%. A significant learning effect can be seen in the radiation safety and diagnostic accuracy of a CBCT-guided and augmented fluoroscopy-guided navigation bronchoscopy. With increasing experience and tailoring of imaging protocols to the procedure, the procedural accuracy improved, while the effective dose for patients and staff was reduced.

The Effectiveness and Safety between Monoplane and Biplane Imaging During Coronary Angiographies.

Avoiding unnecessary radiation exposure is the main issue during coronary angiography. Herein, we aimed to investigate whether performing coronary angioplasties with monoplane or biplane imaging most effectively reduces radiation load and shortens the procedure time. We retrospectively enrolled 294 patients who required either coronary angiography or coronary angioplasty. They were divided into groups of only diagnostic angiography, one-, two- or three-vessel diseases. The fluoroscopy dose-area product (DAP), skin dose, fluoroscopy and procedure time were recorded. Among the studied patients, 148 received the procedures with monoplane imaging. Compared with the radiation exposure in the monoplane group, there were significant increases in DAP and skin dose in those who received biplane imaging independently of the number of lesions. This phenomenon was also observed in the patients receiving either diagnostic angiography only or coronary interventions. In addition, there were no significant differences in contrast volume and procedure time between the monoplane and biplane groups. Notably, the average fluoroscopy time in those who received biplane imaging was significantly longer than in those who received monoplane imaging in the one- and two-vessel groups, while there were no significant differences in the diagnostic angiography only and three-vessel diseases groups. Our findings indicated that using monoplane imaging resulted in lesser radiation exposure and similar procedure times in coronary diagnostic and interventional settings compared to using biplane imaging. This observation should be verified in prospective randomized studies.

Is Dual-Axis Rotational Coronary Angiography Radiation Dose Reduction Achievable in a Population with 100% Suspected Coronary Artery Disease? A Randomized Trial

BackgroundPrevious studies have shown a reduction in radiation dose and contrast volume using dual-axis rotational coronary angiography (DARCA), but this has not been replicated in a population with 100% coronary artery disease (CAD). ObjectiveTo find if DARCA dose reduction is achievable in this population, we sought to compare the radiation dose, contrast volume, and procedure time between DARCA and conventional coronary angiography (CCA) techniques in a setting characterized by a prevalence of 100% suspected coronary artery disease. MethodsAn all-comer, prospective, randomized, open-label trial was conducted. Cine acquisition dose–area product (DAP), cumulative air kerma (AK), effective dose (E), fluoroscopic time, contrast volume, AK, cine acquisition DAP (CADAP), fluoroscopic DAP (F-DAP), and total DAP were compared between DARCA and CCA groups. ResultsWe included 503 consecutive patients with suspected CAD. 252 were assigned to DARCA and 251 to CCA. Stable coronary artery disease was reported in 465 cases and non-ST elevation acute coronary syndrome in 38. Mean age: 61.88 ± 11.2 years, male gender 70.2%. DARCA arm patients showed lower total E dose (6.85 [4.55–10.83] vs. 7.91 [5.58–11.94] Sv; P = .0023), and cine E (3.00 [2.00–4.00] vs. 4.00 [3.00–5.00] Sv; P < .0001). Total DAP was also lower (40.3 [26.8–63.7] vs. 46.5 [32.8–70.2] Gycm2; P = .0023), as a consequence of a lower CADAP (16.3 [10.5–22.9] vs. 23.4 [17.4–32.0] Gycm2; P < .0001), with lower AK (367 [248–1497] vs. 497 [381–1827] mGy; P < .0001), with less contrast medium used (90 [60.0–106.0] vs. 100 [75.0–120.0] mL; P = .014). ConclusionIn a population with 100% suspected coronary artery disease, DARCA provides accurate information required in CAD, is safe, and results in a significant decrease in contrast material volume and radiation dose compared with CCA. The required extra projections did not neutralize the DARCA radiation dose and contrast volume reduction achievements.

Assessment of radiation doses received by patients during endoscopic retrograde cholangiopancreatography according to disease location.

patients are exposed to ionizing radiation during endoscopic retrograde cholangiopancreatography (ERCP). Radiation dose depends on multiple factors. The goal of this study was to assess fluoroscopy time (FT), radiation doses and effective dose (ED) during ERCP according to the condition being treated. a descriptive study was performed of 369 consecutive ERCPs from January 2017 to June 2019. Patient demographic and procedure data were collected. FT, cumulative dose area product (DAP), fluoroscopy DAP, DA fluoroscopy, air kerma, and number of radiographs were assessed. ED was estimated using specific conversion factors. the mean age was 73.34 years and 193 subjects were male. Mean FT was 4.56 ± 0.17 min, cumulative DAP was 2,056.73 ± 188.83 cGycm2, fluoroscopy DAP was 1,722.90 ± 82.26 cGycm2 and air kerma was 85.84 ± 4.93 mGy. The number of radiographs was 2.10 ± 0.07 and the mean ED was 5.34 ± 0.49 mSv. FT was significantly longer for choledocholithiasis (CL), proximal malignant biliary stricture (PMBS) and distal malignant biliary stricture (DMBS) versus others (OT). Cumulative DAP was higher for PMBS (p < 0.002). FT, cumulative DAP, fluoroscopy DAP and air kerma values were significantly higher for complicated CL as compared to simple CL. ED was higher for CL, DMBS and PMBS, but only significantly (p < 0.002) for PMBS. FT for ERCP is variable and increases with exploration difficulty. Thus, it is longer in the case of PMBS, as well as with the amount of radiation received by the patients and ED.

What factors affect fluoroscopy use during Bernese periacetabular osteotomy for acetabular dysplasia?

Periacetabular osteotomy (PAO) is the treatment of choice for acetabular dysplasia in the skeletally mature. Little is known about factors affecting fluoroscopy use in PAO. Therefore, we strived to determine patient and surgery factors are associated with the amount of fluoroscopy time and radiation dose during PAO. We performed a retrospective review of 378 patients who underwent PAO between January 2012 and August 2017. The mean age was 21.7 years and 326 (86%) were females. A total of 85 patients underwent concomitant arthroscopy and 60 underwent open arthrotomy. We recorded fluoroscopy time in minutes and radiation dose area product (DAP) in mGy·m2. Multivariate general linear modeling identified independent predictors of fluoroscopy time and radiation dose. Mean fluoroscopy time was 1.21 minutes and mean fluoroscopy DAP was 0.71 mGy·m2. Multivariate predictors of increased fluoroscopy time were male gender (P = 0.001), surgeon (P < 0.001) and whether an arthroscopy was performed (P < 0.001). Multivariate predictors of increased fluoroscopy DAP were increased body mass index (BMI) (P = 0.001), surgeon (P < 0.001) and whether an arthroscopy was performed (P < 0.001). Patients undergoing hip arthroscopy concomitant to PAO are at higher risk of longer fluoroscopy time and higher radiation dose. Other factors affecting fluoroscopy time included male gender and surgeon, while radiation dose was further affected by surgeon and BMI. Our findings can facilitate discussion about the risk of radiation exposure during PAO.

Comparative Outcomes of Transcarotid and Transsubclavian Transcatheter Aortic Valve Replacement

Previous reports described successful use of transcarotid and transsubclavian approaches for the performance of transcatheter aortic valve replacement (TAVR) in patients with severe aortic stenosis who cannot be treated with transfemoral access. The purpose of the present study was to compare these two alternative approaches with respect to safety, efficacy, and procedural efficiency. A retrospective analysis of all TAVR procedures performed through either a transcarotid or a transsubclavian approach at a single tertiary care medical center between January 2016 and October 2018 was performed. Outcomes are reported in accordance with the Valve Academic Research Consortium definitions. During the study period, 33 patients had transcarotid TAVR and 38 patients had transsubclavian TAVR. Transcarotid patients were older (mean age, 82.9 ± 7.2 vs 78.1 ± 8.2 years; P= .012), but otherwise the two groups were not significantly different with respect to preoperative characteristics. Valve deployment was similar between the groups (100% vs 97%; P= .348). Procedure time was shorter with the transcarotid approach (110 ± 32 vs 134 ± 45 minutes; P= .014). There was a lower mean fluoroscopy air kerma in the transcarotid group (682.82 ± 713.48 mGy vs 2141 ± 2055 mGy; P< .001), although fluoroscopy dose-area product did not differ between the groups. There was no difference between the groups with respect to in-hospital or 30-day mortality (0% vs 3%; P= .355), stroke (3% vs 8%; P= .393), or vascular complication (3% vs 4%; P= .840). The transcarotid and the transsubclavian approaches have similar safety and efficacy outcomes. The transcarotid approach had a shorter procedure duration and a trend toward lower fluoroscopy duration and radiation exposure.

Assessing the institutional learning curve for pararenal aortic repair using the fenestrated Anaconda endograft.

Custom-made fenestrated aortic endografts allow exclusion of pararenal aortic aneurysms while maintaining blood flow to aortic branches. Meticulous device planning and precise deployment of the main body are essential to allow successful cannulation of the fenestrations. This study investigates whether a learning curve can be observed with more reliable cannulation and connection of fenestrations over time at a single department of vascular and endovascular surgery with multiple surgeons trained to use the device. A retrospective analysis of data from all patients undergoing primary fenestrated endovascular aneurysm repair during the study period was performed. Outcome measures included case volume and average number of fenestrations over time, average fluoroscopy dose area product per calendar year and primary unconnected fenestration and 30-day mortality rates. Between 1 January 2013 and 31 December 2016, 89 patients with no history of endovascular aneurysm repair underwent fenestrated endovascular aneurysm repair at our institution. The number of fenestrations per case increased over time, averaging 2.6 in 2013 and 3.3 in 2016. Primary unconnected fenestration and 30-day mortality rates were 5.6%. Primary-assisted technical success was 93.3%, secondary-assisted technical success was 94.4%. Fluoroscopy dose area product declined over the study period. Thirty-day mortality and primary unconnected fenestration rates did not significantly change over the study period. Albeit the reduction in lethal complications and primary technical success rates were not statistically significant, a lower percentage of unconnected fenestrations and 30-day mortality per calendar year were observed over time. At the same time, an increasing complexity of performed cases, as reflected by an increasing number of fenestrations per case, was observed. Complications associated with this complex endovascular procedure are potentially lethal and remain an unfortunate reality and may not be entirely dependent on overcoming a learning curve. A higher volume of cases performed over the study period and a reduction in fluoroscopy use can be considered a representation of the institutional development and learning curve for the Anaconda fenestrated endograft at a department with prior complex endovascular aortic repair experience, but due to limitations of the current retrospective observation, deserve further consideration in future trials, ideally designed in a prospective fashion.

A new imaging technology to reduce the radiation dose during uterine fibroid embolization.

Uterine fibroid embolization (UFE) is a minimally invasive imaging-guided treatment using radiation exposure. To compare the patients' radiation exposure during UFE before and after introduction of a new X-ray imaging platform. Forty-one patients were enrolled in a prospective, comparative two-arm project before and after introduction of a new X-ray imaging platform with reduced dose settings, i.e. novel real-time image processing techniques (AlluraClarity). Demographic, pre-interventional imaging, and procedural data, including dose area product (DAP) and estimated organ dose on the ovaries and uterus, were recorded and angiographic quality of overall procedure was assessed. There were no significant differences in demographic characteristics and preoperative fibroid and uterine volumes in the two groups. The new imaging platform led to a significant reduction in mean total DAP (102 vs. 438 Gy.cm2; P < 0.001), mean fluoroscopy DAP (32 vs. 138 Gy.cm2; P < 0.001), mean acquisition DAP (70 vs. 300 Gy.cm2; P < 0.001), and acquisition DAP estimated organ dose in ovaries (42 vs. 118 mGy; P < 0.001) and uterus (40 vs. 118 mGy, P < 0.001), without impairment of the procedure and angiographic image quality. A substantial 77% reduction of DAP values and 64% and 66% reduction in organ dose on ovaries and uterus, respectively, was demonstrated with the new imaging platform, while maintaining optimal imaging quality and efficacy.

Image noise reduction technology allows significant reduction of radiation dosage in cardiac device implantation procedures.

Novel x-ray systems with real-time image noise reduction technology (INRT) to reduce radiation dose during fluoroscopy and cine acquisition have become available. This study evaluated the reduction of radiation dose in device implantation with INRT. Radiation dose data from 132 consecutive new device implantation procedures (102 pacemaker [PM] or implantable cardioverter defibrillator [ICD] and 30 cardiac resynchronization therapy [CRT] devices) performed between January 2015 and December 2015 on an angiography system with INRT (Allura ClarityIQ) were collected. For comparison, radiation dose data from 147 consecutive device implantation procedures (121 PM/ICDs and 26 CRT devices) performed between June 2013 and September 2014 on a C-arm system with continuous and pulsed fluoroscopy option (4 frames/second) were evaluated. Total dose area product (DAP), fluoroscopy DAP, and cine DAP were evaluated. Patient age, gender and body weight, procedure, and fluoroscopy times were similar between systems. In PM/ICD cases, DAP of INRT and C-arm system was similar (423 ± 381 cGycm2 vs 417 ± 517 cGycm) due to pulsed fluoroscopy with the C-arm system (78% of time) and sparse use of cine. In CRT procedures requiring higher image quality (82% use of continuous fluoroscopy with C-arm system), DAP of INRT was significantly lower (1,544 ± 834cGycm vs 7,252 ± 6,431 cGycm, P<0.001) due to less fluoroscopy DAP (1,414 ± 757cGycm vs 5,854 ± 6,767 cGycm) and less cine DAP (130 ± 106cGycm vs 1,399 ± 1,342 cGycm). Considering all procedures, total DAP was reduced by 60% using INRT. Novel INRT results in a substantial lowering of radiation dose in device implantation, in particular, in complex CRT implantation procedures requiring high image quality.

Comprehensive assessment of patient image quality and radiation dose in latest generation cardiac x-ray equipment for percutaneous coronary interventions.

This study aimed to determine whether a reduction in radiation dose was found for percutaneous coronary interventional (PCI) patients using a cardiac interventional x-ray system with state-of-the-art image enhancement and x-ray optimization, compared to the current generation x-ray system, and to determine the corresponding impact on clinical image quality. Patient procedure dose area product (DAP) and fluoroscopy duration of 131 PCI patient cases from each x-ray system were compared using a Wilcoxon test on median values. Significant reductions in patient dose ([Formula: see text]) were found for the new system with no significant change in fluoroscopy duration ([Formula: see text]); procedure DAP reduced by 64%, fluoroscopy DAP by 51%, and "cine" acquisition DAP by 76%. The image quality of 15 patient angiograms from each x-ray system (30 total) was scored by 75 clinical professionals on a continuous scale for the ability to determine the presence and severity of stenotic lesions; image quality scores were analyzed using a two-sample [Formula: see text]-test. Image quality was reduced by 9% ([Formula: see text]) for the new x-ray system. This demonstrates a substantial reduction in patient dose, from acquisition more than fluoroscopy imaging, with slightly reduced image quality, for the new x-ray system compared to the current generation system.

Spot fluoroscopy: a novel innovative approach to reduce radiation dose in neurointerventional procedures.

BackgroundIncreased interest in radiation dose reduction in neurointerventional procedures has led to the development of a method called “spot fluoroscopy” (SF), which enables the operator to collimate a rectangular or square region of interest anywhere within the general field of view. This has potential advantages over conventional collimation, which is limited to symmetric collimation centered over the field of view.PurposeTo evaluate the effect of SF on the radiation dose.Material and MethodsThirty-five patients with intracranial aneurysms were treated with endovascular coiling. SF was used in 16 patients and conventional fluoroscopy in 19. The following parameters were analyzed: the total fluoroscopic time, the total air kerma, the total fluoroscopic dose-area product, and the fluoroscopic dose-area product rate. Statistical differences were determined using the Welch’s t-test.ResultsThe use of SF led to a reduction of 50% of the total fluoroscopic dose-area product (CF = 106.21 Gycm2, SD = 99.06 Gycm2 versus SF = 51.80 Gycm2, SD = 21.03 Gycm2, p = 0.003884) and significant reduction of the total fluoroscopic dose-area product rate (CF = 1.42 Gycm2/min, SD = 0.57 Gycm2/s versus SF = 0.83 Gycm2/min, SD = 0.37 Gycm2/min, p = 0.00106). The use of SF did not lead to an increase in fluoroscopy time or an increase in total fluoroscopic cumulative air kerma, regardless of collimation.ConclusionThe SF function is a new and promising tool for reduction of the radiation dose during neurointerventional procedures.

Comparison of Ultrasound-Guided and Fluoroscopy-Assisted Antegrade Common Femoral Artery Puncture Techniques

To prospectively compare the procedural time and complication rates of ultrasound-guided and fluoroscopy-assisted antegrade common femoral artery (CFA) puncture techniques. Hundred consecutive patients, undergoing a vascular procedure for which an antegrade approach was deemed necessary/desirable, were randomly assigned to undergo either ultrasound-guided or fluoroscopy-assisted CFA puncture. Time taken from administration of local anaesthetic to vascular sheath insertion in the superficial femoral artery (SFA), patients' age, body mass index (BMI), fluoroscopy radiation dose, haemostasis method and immediate complications were recorded. Mean and median values were calculated and statistically analysed with unpaired t tests. Sixty-nine male and 31 female patients underwent antegrade puncture (mean age 66.7 years). The mean BMI was 25.7 for the ultrasound-guided (n = 53) and 25.3 for the fluoroscopy-assisted (n = 47) groups. The mean time taken for the ultrasound-guided puncture was 7 min 46 s and for the fluoroscopy-assisted technique was 9 min 41 s (p = 0.021). Mean fluoroscopy dose area product in the fluoroscopy group was 199 cGy cm(2). Complications included two groin haematomas in the ultrasound-guided group and two retroperitoneal haematomas and one direct SFA puncture in the fluoroscopy-assisted group. Ultrasound-guided technique is faster and safer for antegrade CFA puncture when compared to the fluoroscopic-assisted technique alone.

Long-Term Efficacy of a Mini-Course in Radiation-Reducing Techniques in Invasive Cardiology

To validate the long-term efficacy of a 90-min. educational mini-course in less-irradiating cardiac interventional techniques. Before, two months after, and two years after the mini-course (periods I, II, and III), we analyzed the following radiation dose parameters for ten coronary angiographies (CA), performed by each of 7 cardiologists: total dose-area product (DAP), radiographic and fluoroscopic DAP fractions, number of radiographic frames and runs, and fluoroscopy time. The median patient DAP for periods I, II and III was 31.4, 15.8 and 8.5 Gy × cm2, respectively. The long-term effect was related to shorter median fluoroscopy times (180, 172, and 120 s), shorter (57, 52, and 45) and fewer (12, 12, and 10) radiographic runs, consistent collimation and restriction to an adequate image quality. Both radiographic DAP/frame (28.7, 17.0, and 18.4 mGy × cm2) and fluoroscopic DAP/second (45.7, 24.2, and 10.0 mGy × cm2) decreased significantly. The multivariate linear regression analysis confirmed the increasing efficacy of the mini-course itself (-44.6 and -60.7%), and revealed a decreasing influence of the interventionalist's experience (-8.6% and -4.9% per 1,000 CAs, lifelong performed until the mini-course). The number of CAs performed after the mini-course did not influence the long-term DAP results. The presented educational mini-course allows a significant, long-lasting, and apparently ongoing reduction of patient radiation exposure due to CA. A self-surveillant documentation of relevant radiation parameters is well suited to monitor and improve each operator's individual long-term radiation-reducing efforts.

PF8 Expandable intramedullary nailing: a new method in the treatment of femoral periprosthetic fractures

Introduction: High doses of ionizing radiation are used during surgeries such as interlocking intra-medullary nailing and minimally invasive plate osteosynthesis. So, excessive use of fluoroscopy is seen to be a feared procedure among orthopedic surgeons. DAP (Dose area product) values which shows the total radiation dose with the aid of preinstalled DAPmeters, can bemonitored on the recent fluoroscopic units in mGy·cm2 or mGy·m2. This value is a more reliable indicator than the fluoroscopy time. The aim of the study is to investigate the total fluoroscopic DAP values in interlocking intramedullary nailing operations and comparing the total values with other radiologic procedures. Materials and Methods: Between 2010 and 2012, nine patients underwent femoral locking intramedullary nailing operation in our institute. Total DAP values, fluoroscopy time and number of images were retrieved from the fluoroscopic unit’s HDD. We have also recorded the DAP values of postoperative direct roentgenograms which were taken with portable digital x-ray machine which has on-board DAP meter. While the mean operation time was 3.2 hours (2–4.2 hours), total fluoroscopy use was 1.6 minutes (0.8–3.1 minutes). Results: Total mean DAP value was resulted in 1720mGy·cm2 and total number of fluoroscopic images were 44 (16–82). The mean DAP for postoperative AP and lateral direct femur radiographs were 1790mGy·cm2 and 2100mGy·cm2 respectively. We have found the total fluoroscopic unit DAP values comparable with even AP or lateral direct radiograms. Conclusion: DAP value is more practical than the fluoroscopy time in monitoring the total radiation dose used in the orthopedic procedures. If properly adjusted preoperatively, fluoroscopic units are more reliable and safe than the direct radiographies. We recommend routineuse of fluoroscopy insteadof direct radiographies intraoperatively.

Observations and Considerations on Patient X-ray Exposure in the Electrophysiology Lab.

To assess patient radiation during catheter ablation procedures and operator differences. From 84 patients (51 males, age 63 ± 10 years) undergoing complex catheter ablation by three experienced operators we collected: body mass index (BMI), procedure type and time, fluoroscopy time, dose area product (DAP), air kerma and X-ray system setting (cine, collimation and angiographic imaging angle). A new factor, fluoroscopy DAP-fluoroscopy time ratio, was introduced to compare operator differences. The results show the average procedure time was 179 (± 57) minutes (min), fluoroscopy time was 31 (± 21) min, DAP was 26.4 (± 19.6) Gy.cm(2) and air kerma was 0.26 (± 0.19) Gy. Procedure types were: pulmonary vein isolation (PVI) (52 %), redo PVI (11 %), pulmonary vein ablation catheter (PVAC) (14 %), ventricular tachycardia (VT) (8 %) and others (15 %). Inter-operator difference was observed in fluoroscopy and cine usage. Fluoroscopy DAP-time ratios showed a similar level of patient radiation dose rate by operator A and B (correlation: 0.89), and a significantly higher dose rate by operator C (correlation: 0.20, p<0.001; 0.26, p<0.01, to operator A and B). In conclusion, operators should be aware of patient radiation exposure levels and the influencing factors. Inter- and intra-operator differences can be measured and bench marked for improvement in X-ray efficiency and patient radiation reduction.

Radiation dose in mass screening for gastric cancer with high-concentration barium sulfate compared with moderate-concentration barium sulfate

Recently, high-concentration barium sulfate has been developed and is used in many medical facilities. This study compared radiation dose using high-concentration and moderate-concentration barium sulfate. The dose was evaluated with an experimental method using a gastric phantom and with a clinical examination. In the former, the dose and X-ray tube load were measured on the phantom with two concentrations of barium sulfate. In the latter, the fluoroscopic dose-area product (DAP), the radiographic DAP and their sum, the total DAP, were investigated in 150 subjects (112 males, 38 females) treated with both concentrations of barium sulfate. The effective dose was calculated by the software of PCXMC in every case. The results of the experimental evaluation indicated that the effective dose and X-ray tube load were greater with high-concentration barium sulfate than with moderate-concentration barium sulfate (p < 0.05). The results of the clinical evaluation indicated that the fluoroscopic DAP was greater with moderate-concentration barium sulfate than with high-concentration barium sulfate (p < 0.05), but the radiographic DAP was quite the reverse, so the total DAP and effective dose were almost same with both concentrations of barium sulfate. We conclude that high-concentration barium sulfate does not increase radiation dose in mass screening for gastric cancer.

Impact of intracardiac echocardiography on radiation exposure during adult congenital heart disease catheter-based interventions

Intracardiac echocardiography (ICE) is a widespread approach in many cardiovascular procedures in which it has the potential to reduce the fluoroscopy time and patients radiation exposure. We sought to assess the patient radiation exposure during transcatheter closure of interatrial communications with and without ICE-guidance. In a prospective consecutive series of 25 consecutive patients who underwent transcatheter closure of interatrial communications between May and October 2005 with (15 patients) and without (10 patients) ICE-guidance in a single secondary care referral centre, we measured the dose-area product (DAP), the fluoroscopy dose-area product (FDAP), the total dose-area product (TDAP), and the mean procedural time. In patients underwent ICE-guided transcatheter closure procedure the mean fluoroscopy time, the mean DAP, mean FDAP, and mean TDAP resulted significantly lower than in control patients: 2.0 +/- 0.21 (range 1.6-2.2) versus 5.05 +/- 0.54 (range 4.2-5.8) minutes (P < 0.001) , 13.72 +/- 9.03 (range 11.36-14.63) versus 21.95 +/- 6.93 (range 20.90-23.93) Gycm2 (P < 0.001), 8.25 +/- 1.22 (range 6.60-9.50) versus 20.15 +/- 8.83 (range 18.90-20.93) Gycm2 (P < 0.001), and 29.33 +/- 1.51(range 27.16-31.00) versus 32.61 +/- 2.53 (range 29.20-35.55) Gycm2 (P < 0.01). On the contrary, the mean procedural time, was significantly higher in ICE-guided transcatheter closure patients: 30.2 +/- 2.45 (range 23-40) versus 24.5 +/- 2.45 (range 24-31) minutes (P = 0.03). The radiation exposure during ICE-guided transcatheter closure of interatrial communications in this group of patients was quite lower than that reported in literature for such procedures and compared favourably with radiation exposure of patients in whom the intervention was performed without ICE guidance.

Identification of less-irradiating tube angulations in invasive cardiology

We sought to identify tube angulations in invasive cardiology, which promise minimal radiation exposure to patients and operators. Radiation exposure in invasive cardiology is high. We mapped the fluoroscopic dose-area product per second (DAP/s), applied to an anthropomorphic Alderson-Rando phantom and, in absence of radiation protection devices, the mean personal dose in the operator's position in 10 degrees steps from the 100 degrees right anterior oblique (RAO) to the 100 degrees left anterior oblique (LAO) projection, as well as for all geometrically feasible craniocaudal tube angulations. For our specific setting conditions RAO 20 degrees /0 degrees tube angulation generated the lowest DAP/s and operator's personal dose. The mean patient DAP/s and operator personal dose for all postero-anterior (PA) projections, cranialized and caudalized together, rose significantly: 3.7 and 10.6 times the PA 0 degrees baseline values toward LAO 100 degrees and 3.7 and 2.4 times toward RAO 100 degrees , respectively. Patient and operator values for all PA projections, angulated to the right and left, increased approximately 2.5 times toward 30 degrees craniocaudal angulations. Caudal PA 0 degrees /30 degrees - angulation instead of caudal LAO 60 degrees /20 degrees - angulation for the left coronary main stem and cranial PA 0 degrees /30 degrees + view in place of cranial LAO 60 degrees /20 degrees + view for the left anterior descending coronary artery bifurcation enable 2.6-fold dose reductions to the patient and eight- and five-fold dose reductions to the operator, respectively. The PA views and RAO views >or=40 degrees , heretofore unconventional in clinical routine, should be favored over steep LAO projections >or=40 degrees whenever possible. Tube angulations that are radiation intensive to the patient exponentially increase the operator's radiation risk.