Cumulative Dose Area Product Research Articles

Radiation exposure and estimated risk of radiation-induced cancer from thoracic and abdominal radiographs in 1307 neonates.

This study examined radiation exposure and the possible risk of radiation-induced cancer in a large sample of newborn and premature patients. In this retrospective study, we included all hospitalised neonates treated at our university hospital who received at least one X-ray examination from 1 January 2013 to 31 December 2018. We evaluated the dose area product (DAP), effective dose (ED), and estimated risk. The International Commission on Radiological Protection Publication 60 defines values (2.8-13 × 10-2 Sv-1) to calculate the estimated risk in relation to the ED. Of the 3843 patients (aged 241.1 ± 35.45 days) treated in the neonatal care unit, 1307 (34%) received at least one X-ray. The mean number of X-ray examinations per patient was 3.19 and correlated negatively with birth weight. The mean cumulative DAP was 5.9 mGy*cm2, and the cumulative ED was 23.7 µSv per hospital stay. Patients with a birth weight of < 1000 g showed the highest cumulative ED and DAP (p < 0.001). Patients with a birth weight of < 2500 g had the highest ED and DAP per image (p < 0.001). The highest radiation exposure (ED/DAP) occurred for thoracic/abdominal examinations, especially for neonates < 500 g (p < 0.001). There is a strong correlation between immaturity, the number of X-ray examinations, and radiation exposure. The total exposure was minimal, and the number of X-rays per patient has been decreasing in recent years. Possible risks to newborns and premature infants caused by ionising X-rays are often the subject of scientific and clinical discussion. Nevertheless, conventional X-ray imaging remains a frequently used tool, and total exposure remains at a very low level. The number of X-rays per patient has been decreasing in a large university hospital. Half of all patients received only one X-ray; most had a birth weight over 1500 g. This radiation risk can be classified as 'minimal' for patients with a birth weight of < 500 g and as 'negligible' for others.

Radiation dose during transarterial chemoembolization and associated factors.

To provide detailed reports on radiation doses during transarterial chemoembolization (TACE) in the cone-beam computed tomography (CBCT) era and to identify the associated factors. This retrospective study included 385 consecutive patients who underwent initial conventional TACE for hepatocellular carcinoma (HCC) between January 2016 and December 2017. In most cases, CBCT was performed at the common hepatic artery or celiac axis to confirm the location of the tumor and the three-dimensional hepatic artery anatomy. Superselective TACE was performed for all technically feasible cases. Information on total dose area product (DAP), total cumulative air kerma (CAK), fluoroscopy time, and DAP and CAK of each digital subtraction angiography (DSA) and CBCT scan was recorded. Multiple linear regression analysis was performed to identify the factors associated with increased DAP during TACE. The mean values of total DAP and CAK were 165.2 ± 81.2 (Gy·cm²) and 837.1 ± 571.0 (mGy), respectively. The mean fluoroscopy time was 19.1 ± 10.3min. The mean DAP caused by fluoroscopy, DSA, and CBCT was 51.8 ± 43.9, 28.0 ± 24.1, and 83.9 ± 42.1Gy·cm², respectively. Male sex, a high body mass index, largest tumor size > 3cm, presence of aberrant right and left hepatic arteries, and superselective TACE were identified as independent predictors of increased total DAP during TACE. We were able to provide detailed reports on radiation doses during TACE and associated factors.

Determinants of radiation exposure during mobile cone-beam CT-guided robotic-assisted bronchoscopy.

Robotic-assisted bronchoscopy (RAB) is an emerging modality to sample pulmonary lesions. Cone-beam computed tomography (CBCT) can be incorporated into RAB. We investigated the magnitude and predictors of patient and staff radiation exposure during mobile CBCT-guided shape-sensing RAB. Patient radiation dose was estimated by cumulative dose area product (cDAP) and cumulative reference air kerma (cRAK). Staff equivalent dose was calculated based on isokerma maps and a phantom simulation. Patient, lesion and procedure-related factors associated with higher radiation doses were identified by logistic regression models. A total of 198 RAB cases were included in the analysis. The median patient cDAP and cRAK were 10.86 Gy cm2 (IQR: 4.62-20.84) and 76.20 mGy (IQR: 38.96-148.38), respectively. Among staff members, the bronchoscopist was exposed to the highest median equivalent dose of 1.48 μSv (IQR: 0.85-2.69). Both patient and staff radiation doses increased with the number of CBCT spins and targeted lesions (p < 0.001 for all comparisons). Patient obesity, negative bronchus sign, lesion size <2.0 cm and inadequate sampling by on-site evaluation were associated with a higher patient dose, while patient obesity and inadequate sampling by on-site evaluation were associated with a higher bronchoscopist equivalent dose. The magnitude of patient and staff radiation exposure during CBCT-RAB is aligned with safety thresholds recommended by regulatory authorities. Factors associated with a higher radiation exposure during CBCT-RAB can be identified pre-operatively and solicit procedural optimization by reinforcing radiation protective measures. Future studies are needed to confirm these findings across multiple institutions and practices.

Technical note: A comparison of physician doses in C-Arm and CT fluoroscopy procedures.

We address the misconception that the typical physician dose is higher for CT fluoroscopy (CTF) procedures compared to C-Arm procedures. We compare physician scatter doses using two methods: a literature review of reported doses and a model based on a modified form of the dose area product (DAP). We define thismodified form of DAP, "cumulative absorbed DAP," as the product of the area of the x-ray beam striking the patient, the dose rate per unit area, and the exposure time. The patient entrance dose rate for C-Arm fluoroscopy (0.2mGy/s) was found to be 15 times lower than for CT fluoroscopy (3mGy/s). A typical beam entrance area for C-Arm fluoroscopy reported in the literature was found to be 10.6×10.6cm (112cm2), whereas for CTF was 0.75×32cm (24cm2). The absorbed DAP rate for C-Arm fluoroscopy (22mGy*cm2/s) was found to be 3.3 times lower than for CTF (72mGy*cm2/s). The mean fluoroscopy time for C-Arm procedures (710s) was found to be 21 times higher than for CT fluoroscopy procedures (23s). The cumulative absorbed DAP for C-Arm procedures was found to be 9.4 times higher when compared to CT procedures (1.59 mGy*m2 vs. 0.17 mGy*m2). The higher fluoroscopy time in C-Arm procedures leads to a much lower cumulative DAP (i.e., physician scatter dose) in CTF procedures. This result can inform interventional physicians deciding on whether to perform inter-procedural imaging inside the room as opposed to retreating from the room.

Radiation dose of cone beam CT combined with shape sensing robotic assisted bronchoscopy for the evaluation of pulmonary lesions: an observational single center study.

Shape sensing robotic-assisted bronchoscopy (ssRAB) combined with radial endobronchial ultrasound (r-EBUS) and cone beam computed tomography (CBCT) is a newer diagnostic modality for the evaluation of pulmonary lesions. There is limited data describing the radiation dose of CBCT combined with ssRAB. The purpose of this study was to describe the technical factors associated with the use of CBCT combined with ssRAB to biopsy pulmonary lesions. We conducted a single center, prospective observational study of patients undergoing ssRAB combined with fixed CBCT for the pulmonary lesion biopsy. We report our patient demographics, and pulmonary lesion and procedure characteristics. A total of 241 ssRAB procedures were performed to biopsy 269 pulmonary lesions. The mean lesion size was measured in the following dimensions: anteroposterior (18.0±8.8 mm), transverse (17.2±10.5 mm), and craniocaudal (17.7±10.2 mm). A mean of 1.5±0.7 (median: 1, range: 1-4) CBCT spins were performed. The mean total fluoroscopy time (FT) was 5.6±2.9 minutes. The mean radiation dose of cumulative air kerma (CAK) was 63.5±46.7 mGy and the mean cumulative dose area product (DAP) was 22.6±16.0 Gy·cm2. Diagnostic yield calculated based on results at index bronchoscopy was 85.9%. There was a low rate of complications with 8 pneumothoraces (3.3%), 5 (2.1%) of which required chest tube placement. We describe the use of ssRAB combined with CBCT to biopsy pulmonary lesions as a safe diagnostic modality with relatively low radiation dose that is potentially comparable to other image guided sampling modalities. Bronchoscopists should be cognizant of the radiation use during the procedure for both patient and staff safety.

Effectiveness of a radiation protective device of interventional echocardiographers during structural heart disease interventions

Interventional echocardiographers (IE) have a crucial role in growing structural heart interventional procedures. Previous studies showed a 5 times higher exposure of IE than that of the invasive cardiologist. No dedicated and adapted radiation protection device currently exists for IE. It is from this observation that the interventional cardiology team of the Nantes University Hospital, together with the company “LemerPax”, have designed a radiation protection cabin (EchoSafe) dedicated to the protection of the IE in the operative room. The objective of this study is to evaluate the radioprotective performances of this cabin in real life. We included during 6 months all procedures that required transesophageal echocardiography. These procedures were divided into two groups (the first on which the usual protection device were used, i.e. a leaded glass door – the second on which the “Echosafe” device was used). We matched the procedures to obtain a total amount of irradiation estimated by the DAP (dose area product) close between the two groups. Irradiation measurements of the IE were performed with 10 TLD (thermoluminescent detectors) distributed over the whole body. We included a total of 64 procedures: 24 procedures in the control group, and 40 in the “echosafe” group. The cumulative DAP for each group was 75,206.9 Cgy/cm2 in the control group, and 70,042 mGy.cm2 in the echosafe group. Patient characteristics were identical between the two groups. The results show that in the “echosafe” group, irradiation was below the dose limit for the left lens, shoulders, thorax, and neck, a 49% reduction in irradiation of the right lens, 76% of the right wrist, 12% of the left wrist, 49% of the pubis, and 36% of the right ankle. The “echosafe” device offers a clear reduction in the irradiation of the IE during structural heart intervention. Irradiation measurment of the sonographer (Fig. 1).

720 Dynamic Hip Screw vs Short Intra Medullary Nail - Which Is Safer for the Surgeon: A Retrospective Comparison of Radiation Exposure

Abstract Aim Dynamic hip screws (DHS) and short intra medullary (IM) nails are fixation methods used for neck of femur (NOF) fractures. Both require fluoroscopic assistance within the operating theatre, therefore exposing the surgeon and patient to ionising radiation. There is minimal literature investigating radiation exposure. Aims of this study are to compare the radiation doses in each procedure and to estimate a normalised dose. Method Retrospective data analysis was carried out for patients who underwent fluoroscopically assisted surgical management of NOF fractures using DHS and short IM nail over a 3-year-period. Data was sourced using electronic operative records and Sectra PACS imaging software. Radiation dose parameters collected were the cumulative dose in milligrays (mGy), cumulative dose area product (DAP) (Gy.cm2) and time of exposure in minutes and seconds. Statistical analysis was performed using SPSS statistical software. Results A total of 56 patients were treated with a DHS, and 46 with short IM nails (Short TFNA - Synthes). 79% of DHS cases were for extra capsular neck of femur fractures versus 100% of short IM nails. Cumulative radiation dose for the DHS group demonstrated a mean of 6.007mGy, compared to 1.153mGy for the short IM nail. Mean exposure times were 1:39 for the DHS group compared to 1:32 for the IM nail. Conclusions Our study showed the difference in cumulative radiation exposure was significantly less when using the short IM nail compared to the DHS. Additional radiation should be considered a safety hazard for the surgeon, theatre staff and patients.

723 Should Radiation Exposure and Surgeon Safety Be Considered in Decision Making? a Single Centre Retrospective Analysis of Radiation Exposure During Intra Medullary Nailing of Proximal Femur Fractures

Abstract Aim Short intra medullary (IM) and long intra medullary nails are fixation methods used for proximal femur fractures. Both require fluoroscopic assistance within the operating theatre, therefore exposing the surgeon and patient to ionising radiation. There is minimal literature investigating radiation exposure. Aims of this study are to compare the radiation doses in each procedure and to estimate a normalised dose. Method Retrospective data analysis was carried out for patients who underwent surgical management of proximal femur fractures with IM nail fixation over a 3-year-period. Data was sourced using electronic operative records and Sectra PACS imaging software. Radiation dose parameters collected were the cumulative dose in milligrays (mGy), cumulative dose area product (DAP) (Gy.cm2) and time of exposure in minutes and seconds. Statistical analysis was performed using SPSS statistical software. Results A total of 108 patients were included in analysis. 42% were treated with a short IM nail (TFNA - Synthes), while 58% had a long IM nail (RAFN, LFNA or TFNA - Synthes). Mean cumulative radiation dose for the short IM nail group was 7.350mGy versus 10.915mGy for the long IM nail (P=0.012). Mean exposure time was 01:32 for short IM nail compared to 02:32 for long IM nail. Conclusions The results confirmed a significant difference in radiation dose and exposure time between both procedures. As the radiation exposure in long nails is almost two-fold, we recommend the use of the short IM nail when the fracture pattern and clinical scenario allow.

Radiation dose reduction during adrenal vein sampling using a new angiographic imaging technology

To compare the patient radiation doses during angiographic selective adrenal vein sampling (AVS) before and after an imaging technology upgrade. In this retrospective single-center-study, cumulative air kerma (AK), cumulative dose area product (DAP), fluoroscopy time and contrast agent dosage were recorded from 70 patients during AVS. 35 procedures were performed before and 35 after an imaging processing technology upgrade. Mean values were calculated and compared using an unpaired student’s t-test. DSA image quality was assessed independently by two blinded readers using a four-point Likert scale (1 = poor; 4 = excellent) and compared using Wilcoxon signed-rank test. After the technology upgrade we observed a significant reduction of 35% in AK (1.7 ± 0.7 vs. 1.1 ± 0.7 Gy, p = 0.01) and a significant reduction of 28% in DAP (235.1 ± 113 vs. 170.1 ± 94 Gy*cm2, p = 0.01) in comparison to procedures before the upgrade. There were no significant differences between the number of exposure frames (143 ± 86 vs. 132 ± 61 frames, p = 0.53), fluoroscopy time (42 ± 23 vs. 36 ± 18 min, p = 0.22), or the amount of contrast medium used (179.5 ± 84 vs. 198.1 ± 109 ml, p = 0.41). There was also no significant difference regarding image quality (3 (2–4) vs. 3 (2–4), p = 0.67). The angiographic imaging technology upgrade significantly decreases the radiation dose during adrenal vein sampling without increasing time of fluoroscopy or contrast volume and without compromising image quality.

Image Mosaic Algorithm-Based Analysis of Effects of Low-Dose X-Rays on Blood Immune Cells

This work aimed to explore the effects of image mosaic algorithm- (IMA-) based low-dose X-rays on deoxyribonucleic acid (DNA) damage of peripheral blood lymphocytes in cardiovascular patients. 84 patients with interventional cardiovascular surgeries were selected as the research objects and divided into coronary intervention surgery (A) group, coronary angiography (B) group, radiofrequency ablation (C) group, and permanent cardiac pacemaker implantation (D) group. They were treated with IMA-based low-dose X-rays, DNA damage indicators of lymphocytes were detected, and the relationship was analyzed between those indicators and radiation dose. Results showed that the cumulative dose (CD) and dose area product (DAP) of group A were the lowest, and those of group D were obviously higher than those of the other three groups ( P &lt; 0.01 ). Besides, the results also showed that the values of CD and DAP of patients from group A and group D were 0.38 ± 0.08 (Gy) and 0.38 ± 0.08 (Gy/cm2) and 1.37 ± 0.21 (Gy) and 1.37 ± 0.21(Gy/cm2), respectively. The comet tail DNA content (TDNA) and tail moment (TM) of each group after surgery increased dramatically compared with before surgery ( P &lt; 0.01 ), and the TDNA and TM of group D were greatly higher than those of the other three groups ( P &lt; 0.01 ). Therefore, TDNA and TM were markedly positively correlated with DAP and CD ( P &lt; 0.01 ). IMA-based X-ray radiotherapy caused reliable DNA damage to peripheral blood lymphocytes of cardiovascular patients, and the greater the radiation dose, the more serious the DNA damage.

Evaluation of the accuracy of the Sureshot® electromagnetic targeting system in distal locking of long-nailed humeral diaphyseal fractures

IntroductionOsteosynthesis of humeral diaphyseal fractures by long intramedullary nailing is a widespread practice. Distal interlocking is a delicate and uncertain step in the procedure, and the free-hand method is adopted by most surgeons. We evaluated the accuracy of a magnetic field-guided system for distal interlocking of long intramedullary nailed humeral diaphyseal fractures. HypothesisThe field magnetic method to interlock distal screws procured satisfying success rates at first attempt in each hole. Study designSingle center, retrospective, descriptive and continuous. Material and methodsWe used the Sureshot® Distal Targeting System (DTS) and the Trigen® (Smith & Nephew) nail. All patients who presented to our center for osteosynthesis of a fracture of the humeral diaphysis by long intramedullary nailing between April 1, 2016 and June 30, 2018 were retrospectively included. ResultsThe analyses included 32 of the 34 patients who presented during this period (mean age, 64 years). There were 51 attempts to install distal interlocking screws. The screws were interlocked successfully in 40 cases (78.4%), and there were 11 failures (21.6%). There was an average of 29 fluoroscopic views and an average cumulative dose area product of 36.90 cGcm2. DiscussionWe found a lower success rate than that found in the literature for the accuracy of Sureshot® DTS in long humeral nailing. We found also a lower success rate than for tibial and femoral centromedullary nailing with this system. Our study showed a success rate of only 78.4% at the first attempt for distal interlocking of Trigen® humeral long nails. Level of evidenceIV; retrospective study without control group.

Radiation dose reduction capabilities of a new C-arm system with optimized hard- and software

PurposeTo assess the radiation dose reduction capabilities and the image quality of a new C-arm system in comparison to a standard C-arm system. MethodProspective, randomized, IRB approved two-arm trial design. 49 consecutive patients with primary or secondary liver cancer were treated with transarterial chemoembolization (TACE) on two different angiography units. 28 patients were treated on a conventional angiography unit B, 21 patients on unit A which provides improved hardware and optimized image processing algorithms. Dose area product (DAP) and fluoroscopy time were recorded. DSA image quality of all procedures was assessed on a four-rank-scale by two independent and blinded readers. ResultsBoth cohorts showed no significant differences with regard to patient characteristics, tumor burden and fluoroscopy time. The new system resulted in a statistically significant reduction of cumulative DAP of 72% compared to the old platform (median 76 vs. 269 Gy*cm2). Individually, Fluoro-DAP and DSA-DAP decreased by 48% and 77% (p = 0.012 and p < 0.01), respectively. No statistically significant differences in DSA image quality were found between the two imaging platforms. ConclusionsThe new C-arm system significantly reduced radiation exposure for TACE procedures without increased radiation time or negative impact on DSA image quality.The combination of optimized hardware and software yields the highest radiation dose reduction and is of utmost importance for patients and interventionalists.

Combining Optimized Image Processing With Dual Axis Rotational Angiography: Toward Low-Dose Invasive Coronary Angiography.

BackgroundDual axis rotational coronary angiography (DARCA) reduces radiation exposure during coronary angiography on older x‐ray systems. The purpose of the current study is to quantify patient and staff radiation exposure using DARCA on a modality already equipped with dose‐reducing technology. Additionally, we assessed applicability of 1 dose area product to effective dose conversion factor for both DARCA and conventional coronary angiography (CCA) procedures.Methods and ResultsTwenty patients were examined using DARCA and were compared with 20 age‐, sex‐, and body mass index–matched patients selected from a prior study using CCA on the same x‐ray modality. All irradiation events are simulated using PCXMC (STUK, Finland) to determine organ and effective doses. Moreover, for DARCA each frame is simulated. Staff dose is measured using active personal dosimeters (DoseAware, Philips Healthcare, The Netherlands). With DARCA, median cumulative dose area product is reduced by 57% (ie, 7.41 versus 17.19 Gy·cm2). Effective dose conversion factors of CCA and DARCA are slightly different, yet this difference is not statistically significant. The occupational dose at physician's chest, leg, and collar level are reduced by 60%, 56%, and 16%, respectively, of which the first 2 reached statistical significance. Median effective dose is reduced from 4.75 mSv in CCA to 2.22 mSv in DARCA procedures, where the latter is further reduced to 1.79 mSv when excluding ventriculography.ConclusionsDuring invasive coronary angiography, DARCA reduces radiation exposure even further toward low‐dose values on a system already equipped with advanced image processing and noise reduction algorithms. For both DARCA and CCA procedures, using 1 effective dose conversion factor of 0.30 mSv·Gy−1·cm−2 is feasible.

Impact of tumor anatomic characteristics on patient radiation dose during transarterial chemoembolization

Objective: The aim of the study was to determine the association between anatomic tumor characteristics and the radiation dose in patients with hepatocellular carcinoma undergoing transarterial chemoembolization (TACE). Materials and Methods: A retrospective study was performed over a 42 months period. A total of 51 TACE procedures were included in the study. Information collected included: Gender, BMI, height, weight, cumulative dose area product (KAP), cumulative reference air kerma (RAK), maximum tumor diameter, multinodular tumors, and embolization material. Parametric univariate and simple linear regression analysis were used to determine associations between quantitative variables. Results: A total of 51 procedures in 37 patients, 19 women (51%) and 18 men (49%), with a mean age of 56 years (±17.3 years) and a mean BMI of 24 kg/m2 were included in the study. Overall, patient radiation dose was as follows: Mean KAP of 542.2 Gy* cm2 (±307 Gy* cm2) with a mean RAK of 2930.2 mGy (±1776.5 mGy). Higher patient radiation doses were observed in men (581.6 ± 262.9 Gy* cm2 vs. 497.8 ± 350.5 Gy* cm2) (P = 0.06) and in patients with higher BMIs (KAP: r = 0.37 [P = 0.01]; RAK: r = 0.4 [P = 0.01]). Patients with multinodular disease were found with lower radiation dose according to RAK (1710.7 ± 1118.6 mGy vs. 3227.7 ± 1789.1 mGy, P = 0.03). Furthermore, logistic regression analysis demonstrated that patients with multinodular disease received 10% lower dose, according to RAK, when compared to patients with single tumors (odds ratio 1.001, 95% confidence interval [CI], 1–1.002) (P = 0.02). Conclusion: TACE is an effective method to treat patients with HCC that may be performed within acceptable radiation dose limits. Anatomic tumor characteristics were found to be associated with patient radiation dose. Interestingly, multi-tumor disease was found to cause a radiation dose reduction of 10%.

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.

Modern Image Acquisition System Reduces Radiation Exposure to Patients and Staff During Complex Endovascular Aortic Repair.

Radiation damage during complex endovascular aortic repair (EVAR) is of major concern to patients and medical staff. This study investigates primarily the influence of different acquisition systems (Allura ClarityIQ vs. Allura Xper, Philips Healthcare, Best, the Netherlands) on radiation dose. Secondly, radiation exposure was analysed for operator positions as well as for procedure and patient specific parameters. This was a retrospective study of prospectively collected data. The study prospectively included 62 consecutive patients (mean age 71.2±8.4 years; 63% males) who underwent complex EVAR including fenestrated or branched EVAR of the thoraco-abdominal or the aortic arch from 30 June 2015 to 20 May 2016. In half the patients an advanced dose and real time image noise reduction technology (Allura ClarityIQ) was used, and in the other half the reference acquisition system (Allura Xper) was used. Patient demographics included age, gender, and body mass index. Sixty-two patients with mean age of 71.2±8.4 years (63% males; 39/62) were treated using either Allura ClarityIQ or Allura Xper. Patients treated using Allura ClarityIQ had lower cumulative dose area product (18,948.3±14,648.5cGycm2vs. 38,512.4±24,105.4cGycm2, p<0.001) and air kerma (2237.9±1808mGy vs. 4031±3260.2mGy, p=.010) in comparison with patients treated using Allura Xper. Advanced dose and real time image noise reduction technology, such as Allura ClarityIQ, is a useful tool to lower the amount of radiation for patient and staff during complex endovascular aortic procedures.

Patient radiation exposure for endovascular deep venous interventions

ObjectiveThe study aimed to assess the cumulative radiation exposure from preoperative, periprocedural, and follow-up imaging to patients who underwent common endovascular deep venous interventions for acute and chronic central venous outflow obstructive diseases; namely, deep vein thrombosis (DVT) thrombolysis, unilateral chronic iliofemoral venous stenting, and inferior vena cava (IVC) reconstruction in a single center. MethodsPatients who had DVT thrombolysis of upper extremity (UE) DVT and lower extremity (LE) DVT, unilateral chronic iliofemoral venous stenting, and endovascular IVC reconstruction between May 1, 2012, and July 31, 2017, in a single unit were retrospectively reviewed. Demographic data, anatomic DVT, imaging, technical details of the index procedure, follow-up, and radiation exposure measured in dose-length product, dose-area product (DAP), and fluoroscopy time (FT) from related computed tomography scans and interventions were analyzed. Mann-Whitney U tests were performed to assess for significance of differences between subgroups. A P value of less than .05 was considered significant. ResultsIn total, 20 UE DVT thrombolysis, 91 LE DVT thrombolysis, 56 unilateral chronic iliofemoral venous stenting, and 39 endovascular IVC reconstruction patients were included in the study, with the following median ages: 39 years (range, 20-67 years), 44 years (range, 15-78 years), 45 years (range, 20-80 years), and 35 years (range, 18 -73 years), respectively. The median cumulative DAP for the index DVT thrombolysis was 9.2 Gycm2 (range, 0.2-176.0 Gycm2) for LE DVT and 2.0 Gycm2 (range, 0.1-11.7 Gycm2) for UE DVT (P < .0001). The median cumulative FT for the index thrombolysis was 981 seconds (range, 20-4890 seconds) and 837 seconds (range, 19-2895 seconds) for LE DVT and UE DVT, respectively (P = .18). For unilateral chronic iliofemoral venous stenting, the median cumulative DAP and FT were 32.4 Gycm2 (range, 0.1-289.6 Gycm2) and 660 seconds (range, 246-4200 seconds), respectively. Meanwhile, the median cumulative DAP and FT for the endovascular IVC reconstruction were 60.8 Gycm2 (range, 2.5-269.1 Gycm2) and 2846 seconds (range, 836-11682 seconds), respectively. The median DAP for secondary procedures during follow-up was 6.6 Gycm2 (range, 0.8 186.5 Gycm2), 1.9 Gycm2 (range, 0.2-111.7 Gycm2), and 24.3 Gycm2 (range, 0.2-157.5 Gycm2) for LE DVT thrombolysis, unilateral chronic iliofemoral venous stenting, and endovascular IVC reconstruction, respectively. ConclusionsPatient radiation exposure for endovascular deep venous interventions for central venous outflow obstruction measured in DAP and FT seemed to be less than and at most similar to anatomically comparable arterial interventions in the literature. However, these patients were usually much younger than those with arterial diseases and may need secondary interventions involving further radiation exposure in their lifetime.

Electrophysiological procedures for the use of the RPC: without hindrance and negligible radiation

Background: Fluoroscopy is the main visualization technique for EP procedures. A radiation protection cabin (RPC) shielded with 2 mm lead-equivalent walls was tested as an alternative protection tool (Cathpax®, Lemer Pax). Methods: To assess the scattered radiation to the operator inside the RPC an electronic personal dosimeter (EPD; Mk2, Thermo Electron) was placed at the neck level of the operator. A second EPD was located outside the RPC at 150 cm height from the floor, to record the presumable head radiation dose. Results: Radiation doses were measured in a total of 138 consecutive patients (age 54±16 yrs, BMI 28±5 kg/m2 (18-45), 64% male) undergoing a variety of ablation procedures (SVT=75, AFL=32, AF=17, VT=14). Median fluoroscopy time was 39 min (7-140), the cumulative dose-area product (DAP) 4702 cGy.cm2 (493-65620). Doses outside the RPC showed a median of 135 µSv (1-4881). Doses inside the RPC were detected only at sensitivity threshold or background levels (mean 0.2SD0.7 µSv, median 0.0, range 0-4). The dose reduction to the operator was highest for AF ablations (354 vs 0.5 µSv, respectively; p&lt;0.001). The total accumulated dose outside the RPC was 37883 µSv for all 138 procedures, whereas for the protected operator inside only 30 µSv. Conclusions: There were highly concordant low dose values measured for the operator inside the RPC in comparison to high doses outside the RPC. The use of a RPC represents a major benefit over a lead apron and contributes to a significant dose reduction as low as reasonably achievable (ALARA principle).

Patient Radiation Dose in Neurointerventional Radiologic Procedure: A Tertiary Care Experience.

PurposeNeurointerventional radiology procedures often require a long time to perform. Patient radiation dose is an important issue due to the hazards of ionizing radiation. The objective of this study was to measure the peak skin dose (PSD) and effective dose to estimate the deterministic and stochastic effects of a therapeutic interventional neuroradiologic procedure.Materials and MethodsThe cumulative dose (CD) and dose area product (DAP) were automatically recorded by a fluoroscopic machine and collected prospectively between April and November 2015. The study included 54 patients who underwent therapeutic neurointerventional radiology procedures. The CD of each patient was used to estimate the peak skin dose and the DAP was also calculated to estimate the effective dose.ResultsThe average estimated peak skin dose was 1,009.68 mGy. Two patients received radiation doses of more than 2 Gy, which is the threshold that may cause skin complications and radiation-induced cataract. The average effective dose was 35.32 mSv. The majority of patients in this study (85.2%) who underwent therapeutic neurointerventional radiologic procedures received effective doses greater than 20 mSv.ConclusionNot all therapeutic neurointerventional radiology procedures are safe from deterministic complications. A small number of patients received doses above the threshold for skin complications and radiation induced cataract. In terms of stochastic complications, most neurointerventional radiology procedures in this study were quite safe in terms of radiation-induced cancer.

Radiation Exposure to Patients With Acute Deep Venous Thrombosis Treated With Thrombolysis

Catheter thrombolysis of acute deep venous thrombosis (DVT) of the upper extremity (UE) and lower extremity (LE) is being increasingly carried out following emerging evidence to support that it reduces the risk for development of post-thrombotic syndrome. Such intervention and its potential secondary procedures may expose the patients to significant cumulative radiation over time. Furthermore, these patients are often relatively younger than those with arterial diseases. The study aimed to assess the cumulative radiation exposure to patients who had thrombolysis for acute DVT of the LE and UE. Patients who had catheter-directed thrombolysis or pharmacomechanical catheter thrombolysis for acute DVT involving the LE and UE in a single unit between May 1, 2012, and April 30, 2016, were identified retrospectively. Demographic data, anatomic DVT, imaging, technical details of the index thrombolysis, follow-up, and estimated radiation exposure measured in dose-area product (DAP) and fluoroscopy time (FT) from related interventions were collected and analyzed. DAP refers to the radiation absorbed by irradiated tissue multiplied by the area irradiated, which gives a rough estimation of the risk of stochastic effects. Mann-Whitney test was performed to assess for statistical differences between subgroups, and P < .05 was considered significant. There were 91 patients (39 men) with LE DVT and 20 patients (12 men) with UE DVT identified. The mean (range) ages of patients undergoing thrombolysis in the LE DVT and UE DVT groups were 43.5 (15-78) years and 39.1 (20-67) years, respectively. The median (range) cumulative DAP for the index thrombolysis was 9238 (204-175,983) mGy∙cm2 for LE DVT and 1982 (115-11,736) mGy∙cm2 for UE DVT (P < .0001). The median cumulative FT for the index thrombolysis was 981 (20-4890) seconds and 837 (19-2895) seconds for LE DVT and UE DVT, respectively (P = .18). The mean follow-up for LE and UE DVT was 16.4 (1-50) months and 4.3 (1-19) months, respectively. During the follow-up, 36 (40%) patients with LE DVT had secondary procedures involving the use of fluoroscopy including venography, thrombolysis, venoplasty, and stent extension. The median (range) cumulative DAP and FT for the secondary procedures in the LE DVT group were 6564 (800-186,495; n = 35) mGy∙cm2 and 876 (96-12,910; n = 32) seconds, respectively. Patients with acute DVT who had thrombolysis appeared to be exposed to radiation that was comparable to that with simple LE arterial angioplasty but much less than with endovascular aortic aneurysm repair reported in the literature. However, these patients were usually much younger than those with arterial diseases and may need secondary interventions involving further radiation exposure in their lifetime. Therefore, further studies should investigate the long-term side effects of radiation exposure in these patients and ways of reducing it, including the use of intravascular ultrasound and magnetic resonance imaging technology.