Skin radiation injuries in patients following repeated coronary angioplasty procedures

Differential diagnosis of stage 2, 3 and 4 pressure injuries of the pelvis and lower extremity: a case series

Constant, unrelieved pressure of local tissue, particularly over bony prominences, may provoke damage that progresses to necrosis and pressure injury (PI). Differentiating PIs from conditions of similar appearance is imperative to minimising complications and implementing prompt treatment. This case series describes several conditions that may be mistaken for a PI. Outlined are the key differences in patient history, presentation and clinical cues that assist in correctly identifying the true pathology behind these conditions. Conditions reviewed included: pyoderma gangrenosum; necrotising fasciitis; genital herpes; Marjolin ulcer, Rosai-Dorfman disease; vascular disease; coagulopathies; calciphylaxis; trauma and surgical wounds; pilonidal cysts; graft-versus-host disease; hidradenitis suppurativa; Stevens-Johnson syndrome; epidermolysis bullosa; radiation wounds; spider bites; and end-of-life skin failure pressure ulcers (also known as Kennedy ulcers). Although commonly recognised and diagnosed, stage 2, 3 and 4 PIs occasionally prove to be difficult to pinpoint, with undefined characteristics and similarities in presentation to several other conditions. Therefore, it is clinically vital to be aware of their appearance, risk factors and aetiology in order to make an appropriate patient assessment and avoid misdiagnosis.

Pediatric Interventional Neuroradiology: Opportunities and Challenges

Pediatric interventional neuroradiology (PINR) is a relatively new field of diagnostic and therapeutic care in the pediatric population that has seen considerable advances in recent decades. However, it is still lagging behind adult interventional neuroradiology due to a variety of reasons, including the lack of evidence validating pediatric-specific procedures, the relative absence of pediatric-specific equipment, and the challenges in establishing and maintaining PINR competencies in a relatively small number of cases. Despite these challenges, the number and variety of PINR procedures are expanding for a variety of indications, including unique pediatric conditions, and are associated with reduced morbidity and psychological stigma. Continued technological advances, such as improved catheter and microwire designs and novel embolic agents, are also contributing to the growth of the field. This review aims to increase awareness of PINR and provide an overview of the current evidence base for minimally invasive neurological interventions in children. Important considerations, such as sedation, contrast agent use, and radiation protection, will also be discussed, taking into account the distinct characteristics of the pediatric population. The review highlights the usefulness and benefits of PINR and emphasizes the need for ongoing research and development to further advance this field.

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

PURPOSE

Institutional (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 METHODS

Data 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.

RESULTS

Local 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.

CONCLUSION

Procedure 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.

Reducing fluoroscopic and cineangiographic contribution to radiation exposure for chronic total coronary occlusion interventions

BACKGROUND

The treatment of chronic total coronary occlusions (CTO) carries the highest radiation exposure among percutaneous coronary interventions (PCI). In order to minimize radiation damage, we need to understand and optimize the contribution of all components of radiation exposure.

METHODS

A total of 1000 CTO procedures performed between 2011 and 2020 were compared according to implemented radiation modifications. Group 1 used the original set-up of the X-ray equipment (Artis Zee, Siemens). In group 2 a modified protocol aimed at reducing the fluoroscopy exposure, in group 3 further modifications aimed at reducing cineangiographic exposure.

RESULTS

Despite an increased lesion complexity, Air Kerma (AK) was reduced from 2619 mGy (1653-4574) in group 1 to 2178 mGy (1332-3500; p < 0.001) in group 2 by mainly reducing fluoroscopic contribution by 54.1%, the cineangiographic contribution was lowered by only 6.6%. In group 3 AK dropped drastically to 746 mGy (480-1225; p < 0.001) mainly by reducing the cineangiographic contribution by 53.4%, still there was a further reduction of fluoroscopy contribution of 8.2%. This also led to a reduction of the skin entry dose from 1038 mGy (690-1589) in group 2 to 359 mGy (204-591; p < 0.001) in group 3. This was achieved both in normal weight and obese patients, and both in antegrade and retrograde procedures.

CONCLUSIONS

The present study demonstrates that by modifying both the fluoroscopic and cineangiographic contribution to radiation exposure a drastic reduction of radiation risk can be achieved, even in obese patients. Currently accepted radiation thresholds may no longer be a limit for CTO PCI.

Development of Novel Real-Time Radiation Systems Using 4-Channel Sensors

Radiation-related tissue injuries after medical radiation procedures, such as fluoroscopically guided intervention (FGI), have been reported in patients. Real-time monitoring of medical radiation exposure administered to patients during FGI is important to avoid such tissue injuries. In our previous study, we reported a novel (prototype) real-time radiation system for FGI. However, the prototype sensor indicated low sensitivity to radiation exposure from the side and back, although it had high-quality fundamental characteristics. Therefore, we developed a novel 4-channel sensor with modified shape and size than the previous sensor, and evaluated the basic performance (i.e., measured the energy, dose linearity, dose rate, and angular dependence) of the novel and previous sensors. Both sensors of our real-time dosimeter system demonstrated the low energy dependence, excellent dose linearity (R2 = 1.0000), and good dose rate dependence (i.e., within 5% statistical difference). Besides, the sensitivity of 0° ± 180° in the horizontal and vertical directions was almost 100% sensitivity for the new sensor, which significantly improved the angular dependence. Moreover, the novel dosimeter exerted less influence on X-ray images (fluoroscopy) than other sensors because of modifying a small shape and size. Therefore, the developed dosimeter system is expected to be useful for measuring the exposure of patients to radiation doses during FGI procedures.

SURVEY OF KEY RADIATION SAFETY PRACTICES IN INTERVENTIONAL RADIOLOGY: AN IRISH AND ENGLISH STUDY

Interventional radiology is a rapidly evolving speciality with potential to deliver high patient radiation doses, as a result high standards of radiation safety practice are imperative. IR radiation safety practice must be considered before during and after procedures through appropriate patient consent, dose monitoring and patient follow-up. This questionnaire-based study surveyed fixed IR departments across Ireland and England to establish clinical practice in relation to radiation safety. Pre-procedure IR patient consent includes all radiation effects in 11% of cases. The patient skin dose surrogate parameter of Kerma to air at a reference point (Kar) is under-reported. Only 39% of respondents use a substantial radiation dose level and inform patients after these have been reached. Poor compliance with unambiguous, readily available best practice guidance was observed throughout highlighting patient communication, patient dose quantification and subsequent patient dose management concerns.

[Evaluation of Radiation Dose and Image Quality for Angiographic System with Spectral Shaping Filter]

Complex procedures for interventional radiology can result in high radiation doses to patients and physicians. A spectral shaping filter (SSF) has recently been developed and equipped with angiographic systems to modulate the X-ray beam spectrum. In our feasibility study, the radiation doses to patients and physicians, air kerma rate at image receptor, and image quality were evaluated when SSF was applied in fluoroscopy. Polymethyl methacrylate (PMMA) phantom, a catheter attached on the bottom was placed on the examination table. The entrance air kerma rate at patient entrance reference point, H* (10) rate at a distance of 100 cm from the center of PMMA, air kerma rate at image receptor and the fluoroscopic catheter images were recorded as a function of PMMA thickness. Contrast-to-noise ratio (CNR) was used for the objective image quality. As a subjective image quality evaluation, three physicians (cardiologist, neurologist, and radiologist) rated the catheter images by a Likert scale. With SSF, the entrance air kerma rate and H* (10) rate reduced by about 34 and 21%, respectively. The air kerma rate at image receptor in conventional filter mode increased when the PMMA was up to 10 cm and then CNR was also improved. However, no significant differences were found in the subjective image qualities. In conclusion, SSF was contributed to the reduction of the radiation doses to patients and physicians while the subjective image quality was not affected.

Radiation dose from percutaneous transluminal coronary angioplasty procedure performed using a flat detector for different clinical angiographic projections

The radiation dose from complex cardiac procedures is of concern due to the lengthy fluoroscopic screening time and vessel complexities. This study intends to assess radiation dose based on angiographic projection and vessel complexities for clinical protocols used in the performance of percutaneous transluminal coronary angioplasty (PTCA). Dose-area product (DAP), reference air kerma (K _a,r) and real-time monitoring of tube potentials and tube current for each angiographic projection and dose setting were evaluated for 66 patients who underwent PTCA using a flat detector system. The mean DAP and cumulative K _a,r were 32.71 Gy cm² (0.57 Gy), 51.24 Gy cm² (0.9 Gy) and 102.03 Gy cm² (1.77 Gy) for single-, double- and triple-vessel PTCA, respectively. Among commonly used angiographic projections, left anterior oblique 45°-caudal 35° reached 2 Gy in 55 min using a low-dose fluoroscopy setting and 21 min for a medium-dose setting. Use of a low-dose setting for fluoroscopic screening showed a radiation dose reduction of 39% compared with a medium-dose setting.

Radiation-Induced Skin Injuries to Patients: What the Interventional Radiologist Needs to Know

For a long time, radiation-induced skin injuries were only encountered in patients undergoing radiation therapy. In diagnostic radiology, radiation exposures of patients causing skin injuries were extremely rare. The introduction of fast multislice CT scanners and fluoroscopically guided interventions (FGI) changed the situation. Both methods carry the risk of excessive high doses to the skin of patients resulting in skin injuries. In the early nineties, several reports of epilation and skin injuries following CT brain perfusion studies were published. During the same time, several papers reported skin injuries following FGI, especially after percutaneous coronary interventions and neuroembolisations. Thus, CT and FGI are of major concern regarding radiation safety since both methods can apply doses to patients exceeding 5 Gy (National Council on Radiation Protection and Measurements threshold for substantial radiation dose level). This paper reviews the problem of skin injuries observed after FGI. Also, some practical advices are given how to effectively avoid skin injuries. In addition, guidelines are discussed how to deal with patients who were exposed to a potentially dangerous radiation skin dose during medically justified interventional procedures.

Assessment of Patient's Peak Skin Dose Using Gafchromic Films During Interventional Cardiology Procedures: Routine Experience Feedback

To assess the interest of Gafchromic films in detection of patient's peak skin dose (PSD) in interventional cardiology. A prospective study of 112 patients was conducted (July-December 2015). Three diagnostic and therapeutic procedures were evaluated: coronary angiography (CA), coronary angiography and coronary angioplasty for one or two vessels disease (CA-PTCA) and coronary angioplasty of complex chronic total occlusion (CTO). Dosimetric indicators (DIs) were collected and PSD were measured with Gafchromic films. Dose distribution was evaluated within 10 'Thorax Body-zone' defined by the system. Correlations between PSD and DI or dose distribution were computed. Delivered dose increased in complex procedures. The PSD were 0.121 ± 0.063 Gy for CA, 0.256 ± 0.142 Gy for CA-PTCA and 1.116 ± 0.721 Gy for CTO. High correlations were observed for PSD and DI as well for dose distribution within the 'Thorax Body-zone'. Film dosimetry is suggested for CTO procedures since the threshold of 2 Gy for skin injuries is likely to be exceeded.

DOSE MEASUREMENT USING GAFCHROMIC FILM FOR PATIENTS UNDERGOING INTERVENTIONAL CARDIOLOGY PROCEDURES

The aim of this study was to evaluate dose area product (DAP) and skin dose to patients undergoing coronary angiography (CA) and percutaneous transluminal coronary angioplasty (PTCA) using GafChromic XR film at King Khalid Hospital, Najran, Saudi Arabia. The entrance skin doses (ESDs) were calculated from DAP using GafChromic XR film placed on the patients back. The mean DAP obtained for patients undergoing CA and PTCA examinations were found to be 31.4 and 74.2 Gy cm2, respectively. The mean ESD using GafChromic XR film was found to be 0.264 and 0.596 Gy for CA and PTCA examinations, respectively.

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.

Radiation doses and estimated risk from angiographic projections during coronary angiography performed using novel flat detector

Coronary angiography (CA) procedure uses various angiographic projections to elicit detailed information of the coronary arteries with some steep projections involving high radiation dose to patients. This study intends to evaluate radiation doses and estimated risk from angiographic projections during CA procedure performed using novel flat detector (FD) system with improved image processing and noise reduction techniques. Real‐time monitoring of radiation doses using kerma‐area product (KAP) meter was performed for 140 patients using Philips Clarity FD system. The CA procedure involved seven standard projections, of which five were extensively selected by interventionalists. Mean fluoroscopic time (FT), KAP, and reference air kerma (Ka,r) for CA procedure were 3.24 min (0.5–10.51), 13.99 Gycm² (4.02–37.6), and 231.43 mGy (73.8–622.15), respectively. Effective dose calculated using Monte Carlo‐based PCXMC software was found to be 4.9 mSv. Left anterior oblique (LAO) 45° projection contributed the highest radiation dose (28%) of the overall KAP. Radiation‐induced risk was found to be higher in females compared to males with increased risk of lung cancer. An increase of 10%–15% in radiation dose was observed when one or more additional projections were adopted along with the seven standard projections. A 14% reduction of radiation dose was achieved from novel FD system when low‐dose protocol during fluoroscopy and medium‐dose protocol during cine acquisitions were adopted, compared to medium‐dose protocol.

PACS number(s): 87.50.cm, 87.55.de, 87.55.N, 87.59.cf, 87.59.Dj

Endovascular treatment of renal artery occlusion caused by aortic stentgraft migration

Renal function impairment during interventional procedures became a real clinical problem. Contrast related nephropathy is the most common cause of renal failure, however, the procedure-related technical troubles may cause unexpected renal dysfunction.Technical failure of EVAR resulting in acute renal dysfunction is presented. The postprocedural occlusion of the right renal artery was treated in chimney technique. Early reintervention allowed the kidney preservation and renal function restoration. It is impossible to avoid all the complications following treatment of aortic aneurysm, but they can be anticipated and comprehensively treated in collaboration with other specialists.

Reduction of radiation exposure during atrial fibrillation ablation using a novel fluoroscopy image integrated 3-dimensional electroanatomic mapping system: A prospective, randomized, single-blind, and controlled study

OBJECTIVE

We explored whether the use of a novel fluoroscopy image integrated 3-dimensional electroanatomic mapping (F-EAM) system could result in a reduction of overall fluoroscopy time and radiation doses during the whole procedure of atrial fibrillation (AF) ablation.

METHODS

Eighty patients (44 men (55%); mean age 63 ± 10 years) who underwent catheter ablation due to paroxysmal AF were recruited consecutively in the present study. Patients were randomized (1:1) into 2 arms for AF ablation: one using a conventional 3-dimensional electroanatomical mapping (EAM) system and the other using the F-EAM system.

RESULTS

Fluoroscopy time (10:42 [interquartile range {IQR} 8:45-12:46] minutes:seconds vs 1:45 [IQR 1:05-2:22] minutes:seconds; P < .001) and radiation doses (2440 [IQR 1593-3091] cGy·cm(2) vs 652 [IQR 326-1489] cGy·cm(2); P < .001) in the EAM group were significantly greater than those in the F-EAM group. The majority of reduction of radiation exposure was achieved after transseptal puncture, which was near-zero fluoroscopic exposure. In total, approximately 84% of fluoroscopy time and 73% of radiation doses have been reduced during the AF ablation procedure using the F-EAM system compared to using the conventional EAM system. However, procedure time did not differ significantly (1:39 [IQR 1:18-2:10] hours:minutes vs 1:37 [IQR 1:17-1:50] hours:minutes; P = .362). During follow-up (5.9 ± 1.3 months), 61 patients (76.3%) had no recurrence of atrial arrhythmias. The recurrence rate between the 2 groups did not differ.

CONCLUSION

AF catheter ablation using the F-EAM system was safe and resulted in a significant reduction of radiation exposure to patients and staff without complicating the workflow of the procedure. A near-zero fluoroscopic catheter ablation procedure could be performed without compromising acute/mid-term efficacy and safety.

Measurement of maximum skin dose in interventional radiology and cardiology and challenges in the set-up of European alert thresholds

To help operators acknowledge patient dose during interventional procedures, EURADOS WG-12 focused on measuring patient skin dose using XR-RV3 gafchromic films, thermoluminescent detector (TLD) pellets or 2D TL foils and on investigating possible correlation to the on-line dose indicators such as fluoroscopy time, Kerma-area product (KAP) and cumulative air Kerma at reference point (CK). The study aims at defining non-centre-specific European alert thresholds for skin dose in three interventional procedures: chemoembolization of the liver (CE), neuroembolization (NE) and percutaneous coronary interventions (PCI). Skin dose values of >3 Gy (ICRP threshold for skin injuries) were indeed measured in these procedures confirming the need for dose indicators that correlate with maximum skin dose (MSD). However, although MSD showed fairly good correlation with KAP and CK, several limitations were identified challenging the set-up of non-centre-specific European alert thresholds. This paper presents preliminary results of this wide European measurement campaign and focuses on the main challenges in the definition of European alert thresholds.

Patient dose map indications on interventional X-ray systems and validation with Gafchromic XR-RV3 film

To help avoiding secondary effects of interventional procedures like skin damage, a dose map method has been developed to provide an indication of the local dose on a surface representative of individual patient shapes. To minimise user interactions, patient envelope shapes are automatically determined depending on simple patient data information. Local doses are calculated in 1-cm² areas depending on the estimated air kerma, table and gantry positions and system settings, taking into account the table and mattress attenuations and estimated backscatter from the patient. These local doses are cumulated for each location of the patient envelope during the clinical procedure. To assess the accuracy of the method, Gafchromic XR-RV3 films have been used in several operating configurations. Good visual agreements on cumulated dose localisation were obtained within the 1-cm² precision of the map and the dose values agreed within 24.9 % accuracy. The resulting dose map method has been integrated into GE Healthcare X-Ray angiographic systems and should help in the management of the dose by the users during the procedure.

Patient's Radiation Exposure in Coronary Angiography and Angioplasty: The Impact of Different Projections

Introduction: We aimed to determine angiography projections with lower Dose Area Product (DAP) rate by measuring the mean DAP and fluoroscopy times in coronary angiography (CAG) and percutaneous coronary intervention (PCI) and calculating DAP rate in different projections.

Methods: DAP and fluoroscopy times were measured in all employed projections in real-time in 75 patients who underwent CAG or PCI by a single cardiologist in Madani Cardiovascular University Hospital (45 in CAG group and 30 in PCI group). DAP rate was calculated in both groups and in all projections. The projections with highest and lowest DAP rate were determined.

Results: Mean DAP was 436.73±315.85 dGy×cm² in CAG group and 643.26±359.58 dGy×cm² in PCI group. The projection 40° LAO/0° had the highest DAP rate in CAG group (28.98 dGy×cm²/ sec) and it was highest in 20° RAO/30° CR in PCI group (29.83 dGy×cm²/sec). The latter projection was also the most employed projection in PCI group.

Conclusion: The amount of radiation dose in this study is in consistent with the previous reports. Specific angiographic projections expose patients to significantly higher radiation and they should be avoided and replaced by less irradiating projections whenever possible.

Does the use of additional X-ray beam filtration during cine acquisition reduce clinical image quality and effective dose in cardiac interventional imaging?

The impact of spectral filtration in digital ('cine') acquisition was investigated using a flat panel cardiac interventional X-ray imaging system. A 0.1-mm copper (Cu) and 1.0-mm aluminium (Al) filter added to the standard acquisition mode created the filtered mode for comparison. Image sequences of 35 patients were acquired, a double-blind subjective image quality assessment was completed and dose-area product (DAP) rates were calculated. Entrance surface dose (ESD) and effective dose (E) rates were determined for 20- and 30-cm phantoms. Phantom ESD fell by 28 and 41 % and E by 1 and 0.7 %, for the 20- and 30-cm phantoms, respectively, when using the filtration. Patient DAP rates fell by 43 % with no statistically significant difference in clinical image quality. Adding 0.1-mm Cu and 1.0-mm Al filtration in acquisition substantially reduces patient ESD and DAP, with no significant change in E or clinical image quality.

Patient radiation exposure during carotid artery stenting

Objectives

The main purpose of this study was to document the radiation doses to patients during carotid stenting.

Material and method

Fluoroscopy and exposure time, air kerma and dose-area product during carotid artery stenting in 160 patients were retrospectively reviewed with regard to body mass index, degree of stenosis and use of cerebral protection devices.

Results

Total air kerma was lower than 0.5 Gy in 80%, 0.5–1 Gy in 17% and higher than 1 Gy (maximum 1.2) in 3% of patients. Mean total dose-area product value for carotid stenting was 54 Gy cm2. The mean air kerma (fluoroscopy), air kerma (exposure), total air kerma and dose-area product (fluoroscopy), dose-area product (exposure), total dose-area product of patients with body mass index within the range 25–29.9 and with body mass index >30 were significantly increased compared to that of patients with body mass index 18–24.9 (H = 40.2, df = 2; p = 0.0000001 and p = 0.000003, respectively).

Conclusion

Carotid artery stenting is a relatively safe radiological procedure in terms of the radiation dose acquired by the patient. The main factors contributing to possible radiation overdosing are body mass index value and complexity of the carotid lesion. Proper preoperative planning in obese and complicated patients may reduce the fluoroscopy time and contribute to reduced dose acquisition.

Effectiveness of low rate fluoroscopy at reducing operator and patient radiation dose during transradial coronary angiography and interventions

OBJECTIVES

This study sought to determine the efficacy of low rate fluoroscopy at 7.5 frames/s (FPS) versus conventional 15 FPS for reduction of operator and patient radiation dose during diagnostic coronary angiography (DCA) and percutaneous coronary intervention (PCI) via the transradial approach (TRA).

BACKGROUND

TRA for cardiac catheterization is potentially associated with increased radiation exposure. Low rate fluoroscopy has the potential to reduce radiation exposure.

METHODS

Patients undergoing TRA diagnostic angiography ± ad-hoc PCI were randomized to fluoroscopy at 7.5 FPS versus 15 FPS prior to the procedure. Both 7.5 and 15 FPS fluoroscopy protocols were configured with a fixed dose per pulse of 40 nGy. Primary endpoints were operator radiation dose (measured with dosimeter attached to the left side of the thyroid shield in μSievert [μSv]), patient radiation dose (expressed as dose-area product in Gy·cm(2)), and fluoroscopy time.

RESULTS

From October 1, 2012 to August 30, 2013, from a total of 363 patients, 184 underwent DCA and 179 underwent PCI. Overall, fluoroscopy at 7.5 FPS compared with 15 FPS was associated with a significant reduction in operator dose (30% relative reduction [RR], p < 0.0001); and in patient's dose-area product (19% RR; p = 0.022). When stratified by procedure type, 7.5 FPS compared with 15 FPS was associated with significant reduction in operator dose during both DCA (40% RR; p < 0.0001) and PCI (28% RR; p = 0.0011). Fluoroscopy at 7.5 FPS, compared with 15 FPS, was also associated with substantial reduction in patients' dose-area product during DCA (26% RR; p = 0.0018) and during PCI (19% RR; p = 0.13). Fluoroscopy time was similar in 7.5 FPS and 15 FPS groups for DCA (3.4 ± 2.0 min vs. 4.0 ± 4.7 min; p = 0.42) and PCI (11.9 ± 8.4 min vs. 13.3 ± 9.7 min; p = 0.57), respectively.

CONCLUSIONS

Fluoroscopy at 7.5 FPS, compared with 15 FPS, is a simple and effective method in reducing operator and patient radiation dose during TRA DCA and PCI.

Effectiveness of fluorography versus cineangiography at reducing radiation exposure during diagnostic coronary angiography

Coronary angiography is the gold standard for defining obstructive coronary disease. However, radiation exposure remains an unwanted hazard. Patients referred for coronary angiography with abdominal circumference<45 inches and glomerular filtration rate>60 ml/min were randomized to the fluorography (n=25) or cineangiography (n=25) group. Patients in the fluorography group underwent coronary angiography using retrospectively stored fluorography with repeat injection under cineangiography only when needed for better resolution per operator's discretion. Patients in the cineangiography group underwent coronary angiography using routine cineangiography. The primary end point was patient radiation exposure measured by radiochromic film. Secondary end points included the radiation output measurement of kerma-area product and air kerma at the interventional reference point (Ka,r) and operator radiation exposure measured by a dosimeter. Patient radiation exposure (158.2 mGy [76.5 to 210.2] vs 272.5 mGy [163.3 to 314.0], p=0.001), kerma-area product (1,323 μGy·m2 [826 to 1,765] vs 3,451 μGy·m2 [2,464 to 4,818], p<0.001), and Ka,r (175 mGy [112 to 252] vs 558 mGy [313 to 621], p<0.001) were significantly lower in the fluorography compared with cineangiography group (42%, 62%, and 69% relative reduction, respectively). Operator radiation exposure trended in the same direction, although statistically nonsignificant (fluorography 2.35 μGy [1.24 to 6.30] vs cineangiography 5.03 μGy [2.48 to 7.80], p=0.059). In conclusion, the use of fluorography in a select group of patients during coronary angiography, with repeat injection under cineangiography only when needed, was efficacious at reducing patient radiation exposure.

[Chronic radiodermatitis following coronaroplasty]

We report the case of a 72-year-old patient sent by his dermatologist in January 2009 for a back burn. His medical history reported one coronarography and two coronaroplasties between September and October 2005. This enabled us to form the diagnosis of chronic radiodermatitis after coronaroplasty from literature data. The occurrence of chronic radiodermatitis of the back and axilla area after cardiac catheterization has been observed in many countries. It almost always occurred in patients who underwent difficult and long-acting procedures leading to high doses radiation. There is not always acute radiodermatitis. Lesions appear between three and 30 months after exposure or even later. They are well-defined four-sided centimetrics lesions going from simple radiodystrophy to ulceration such as late radionecrosis requiring surgical coverage procedure.

A new reference point for patient dose estimation in neurovascular interventional radiology

In interventional radiology, dose estimation using the interventional reference point (IRP) is a practical method for obtaining the real-time skin dose of a patient. However, the IRP is defined in terms of adult cardiovascular radiology and is not suitable for dosimetry of the head. In the present study, we defined a new reference point (neuro-IRP) for neuro-interventional procedures. The neuro-IRP was located on the central ray of the X-ray beam, 9 cm from the isocenter, toward the focal spot. To verify whether the neuro-IRP was accurate in dose estimation, we compared calculated doses at the neuro-IRP and actual measured doses at the surface of the head phantom for various directions of the X-ray projection. The resulting calculated doses were fairly consistent with actual measured doses, with the error in this estimation within approximately 15%. These data suggest that dose estimation using the neuro-IRP for the head is valid.

Reference levels and patient doses in interventional cardiology procedures in Greece

OBJECTIVES

To present a national survey that was performed for the establishment of national reference levels (RLs) for interventional cardiology (IC) procedures and to estimate the effective dose (E) received by the patient during these procedures.

METHODS

Data concerning the fluoroscopy time and air kerma-area product (P KA) during coronary angiography (CA), percutaneous coronary intervention (PCI), pacemaker implantation (PMI) and radiofrequency cardiac ablation (RFCA) from 26 centres were collected. Moreover, measurements concerning the performance of X-ray systems used in IC were performed in order to set system-related reference levels. P KA to E conversion factors were also calculated.

RESULTS

The suggested P KA RLs for CA, PCI, PMI and RFCA are 53 Gycm(2), 129 Gycm(2), 36 Gycm(2) and 146 Gycm(2), respectively, and the estimated E to the patient from these procedures is 9.7 mSv, 26.8 mSv, 5.5 mSv and 20.4 mSv, respectively. Reference levels for the fluoroscopic dose rate and dose per frame during image acquisition at the entrance of a water phantom are 29 mGy/min and 0.23 mGy/frame, respectively.

CONCLUSIONS

The suggested RLs are comparable to those suggested by other studies. Additional information concerning the complexity of the procedures and patient pathology should be collected for future reevaluation of the suggested RLs.

KEY POINTS

• The radiation dose imparted during fluoroscopically guided interventional procedures can be high • Understanding of reference levels might help optimise interventional cardiological procedures • Optimisation by changing the systems' settings seems feasible in some cases • Procedure complexity and the patient's clinical problem should be taken into account.

ICRP PUBLICATION 120: Radiological protection in cardiology

Cardiac nuclear medicine, cardiac computed tomography (CT), interventional cardiology procedures, and electrophysiology procedures are increasing in number and account for an important share of patient radiation exposure in medicine. Complex percutaneous coronary interventions and cardiac electrophysiology procedures are associated with high radiation doses. These procedures can result in patient skin doses that are high enough to cause radiation injury and an increased risk of cancer. Treatment of congenital heart disease in children is of particular concern. Additionally, staff(1) in cardiac catheterisation laboratories may receive high doses of radiation if radiological protection tools are not used properly. The Commission provided recommendations for radiological protection during fluoroscopically guided interventions in Publication 85, for radiological protection in CT in Publications 87 and 102, and for training in radiological protection in Publication 113 (ICRP, 2000b,c, 2007a, 2009). This report is focused specifically on cardiology, and brings together information relevant to cardiology from the Commission's published documents. There is emphasis on those imaging procedures and interventions specific to cardiology. The material and recommendations in the current document have been updated to reflect the most recent recommendations of the Commission. This report provides guidance to assist the cardiologist with justification procedures and optimisation of protection in cardiac CT studies, cardiac nuclear medicine studies, and fluoroscopically guided cardiac interventions. It includes discussions of the biological effects of radiation, principles of radiological protection, protection of staff during fluoroscopically guided interventions, radiological protection training, and establishment of a quality assurance programme for cardiac imaging and intervention. As tissue injury, principally skin injury, is a risk for fluoroscopically guided interventions, particular attention is devoted to clinical examples of radiation-related skin injuries from cardiac interventions, methods to reduce patient radiation dose, training recommendations, and quality assurance programmes for interventional fluoroscopy.

Clinical factors increasing radiation doses to patients undergoing long-lasting procedures: abdominal stent-graft implantation

Background

An important negative factor of EVAR is the radiation acquired during long-lasting procedures. The aim of the study was to document the radiation doses of EVAR and to discuss potential reasons for prolongation of radiological procedures.

Material/Methods

Dose-area product (DAP) (Gy cm²) and air kerma (AK) (Gy) obtained during EVAR from 92 patients were analyzed retrospectively in regards to body mass index (BMI), angulations of aneurysm neck, length of aneurysm neck and occurrence of tortuosity of iliac arteries.

Results

Total AK for fluoroscopy differed significantly between normal BMI (373 mGy) and BMI 25–29.9 (1125 mGy) or BMI >30 (1085 mGy). Iliac artery tortuosities >45° and short aneurysm necks caused higher doses of total AK (1097 mGy and 1228 mGy, respectively) than iliac artery tortuosities <45° and long aneurysm necks (605 mGy and 720 mGy, respectively).

Conclusions

The main factors contributing to a high radiation dose being acquired by patients during EVAR are: BMI >25, tortuosity of iliac arteries >45° and short aneurysm necks.

Patients' radiation doses during thoracic stent-graft implantation: the problem of long-lasting procedures

BACKGROUND

This article investigates patient radiation doses during implantation of thoracic stent-graft. Aortic stengraft implantation can be disturbed by many factors, which, in turn, lead to prolongation of the procedure time and, as a consequence, increase the radiation dose.

METHODS

Measurements of radiation length (fluoroscopy and exposure), air kerma (AK) in grays, and dose-area product in grays·square centimeters were conducted simultaneously in 100 patients. The patients were analyzed retrospectively, regarding their body mass index (BMI), type of aneurysms, number of stent-graft parts, angulation of aorta, and coverage of the left subclavian artery.

RESULTS

Mean total dose-area product value for this kind of treatment was 361 Gy·cm2. This was caused by the fact that total mean AK was high for the cohort analyzed and reached 797 mGy. For 23 patients total AK was between 1 and 2 Gy, and for 3 it exceeded 2 Gy. In the remaining group, the maximal radiation dose was very high and exceeded 3 Gy. The total AK of patients with BMI within the range of 25 to 29.9 kg/m2 and with BMI greater than 30 kg/m2 significantly increased in comparison with the group of patients with BMI between 18 and 24.9 kg/m2 (p=0.00005 and 0.000001, respectively). During the study, a good correlation between AK and fluoroscopy time (r=0.6) and for AK (or dose-area product) and exposure time (r=0.66 or 0.81, respectively) was observed.

CONCLUSIONS

The main factors contributing to a high radiation dose being acquired by patients during thoracic stent-graft were BMI greater than 25 kg/m2, number of parts of the stent-graft, and angulation of the neck of aneurysm exceeding 60 degrees.

A national programme for patient and staff dose monitoring in interventional cardiology

A national programme on patient and staff dose evaluation in interventional cardiology made in cooperation with the haemodynamic section of the Spanish Society of Cardiology has recently been launched. Its aim is to propose a set of national diagnostic reference levels (DRLs) for patients as recommended by the International Commission on Radiological Protection and to initiate several optimisation actions to improve radiological protection of both patients and staff. Six hospitals have joined the programme and accepted to submit their data to a central database. First to be acquired were the quality control data of the X-ray systems and radiation doses of patients and professionals. The results from 9 X-ray systems, 1467 procedures and staff doses from 43 professionals were gathered. Provisional DRLs resulted in 44 Gy cm(2) for coronary angiography and 78 Gy cm(2) for interventions. The X-ray systems varied up to a factor of 5 for dose rates in reference conditions. Staff doses showed that 50 % of interventional cardiologists do not use their personal dosemeters correctly.

Automatic management system for dose parameters in interventional radiology and cardiology

The purpose of this work was to develop an automatic management system to archive and analyse the major study parameters and patient doses for fluoroscopy guided procedures performed in cardiology and interventional radiology systems. The X-ray systems used for this trial have the capability to export at the end of the procedure and via e-mail the technical parameters of the study and the patient dose values. An application was developed to query and retrieve from a mail server, all study reports sent by the imaging modality and store them on a Microsoft SQL Server data base. The results from 3538 interventional study reports generated by 7 interventional systems were processed. In the case of some technical parameters and patient doses, alarms were added to receive malfunction alerts so as to immediately take appropriate corrective actions.

Clinical determinants of radiation dose in percutaneous coronary interventional procedures: influence of patient size, procedure complexity, and performing physician

OBJECTIVES

The objectives of this work were to establish the primary clinical determinants of patient radiation dose associated with percutaneous coronary interventional (PCI) and to identify opportunities for dose reduction.

BACKGROUND

Use of X-ray imaging and associated radiation dose is a necessary part of PCI. Potential adverse consequences of radiation dose include skin radiation injury and predicted increase in lifetime cancer risk.

METHODS

Cumulative skin dose (CSD) (measured in gray [Gy] units) was selected as a measurement of patient radiation burden. Several patient-, disease-, and treatment-related variables, including 15 performing physicians, were analyzed in a multiple linear regression statistical model with cumulative skin dose CSD as the primary end point. The model results provide an estimate of the relative CSD increase (decrease) attributable to each variable.

RESULTS

Percutaneous coronary interventions performed on 1,287 male and 540 female patients were included. Median patient age was 68.6 years, median body mass index was 29.7 kg/m(2), and median weight was 88 kg. Median CSD was 1.64 Gy per procedure for male and 1.15 Gy for female patients. Increasing body mass index, patient sex, lesion complexity, lesion location, and performing physician were significantly associated with CSD. Physicians who performed more procedures were associated with lower CSD.

CONCLUSIONS

Several primary determinants of patient radiation dose during PCI were identified. Along with physician development of radiation-sparing methods and skills, pre-procedure dose planning is proposed to help minimize radiation dose for PCI.

Status of radiation protection in various interventional cardiology procedures in the Asia Pacific region

OBJECTIVE

Increasing use of interventional procedures in cardiology with unknown levels of radiation protection in many countries of Asia-Pacific region necessitates the need for status assessment. The study was part of an International Atomic Energy Agency (IAEA) project for achieving improved radiation protection in interventional cardiology (IC) in developing countries.

DESIGN

The survey covers 18 cardiac catheterisation laboratories in seven countries (Bangladesh, India, Malaysia, Myanmar, Singapore, Thailand and Vietnam). An important step was the creation of the 'Asian network of Cardiologists in Radiation Protection' and a newsletter. Data were collected on: radiation protection tools, number of IC laboratories, and annual number of various IC paediatric and adult procedures in the hospital and in the country. Patient radiation dose data were collected in terms of Kerma Area Product (KAP) and cumulative dose (CD).

RESULTS

It is encouraging that protection devices for staff are largely used in the routine practice. Only 39% of the angiographic machines were equipped with a KAP meter. Operators' initial lack of awareness on radiation-protection optimisation improved significantly after participation in IAEA radiation-protection training. Only two out of five countries reporting patient percutaneous coronary intervention radiation-dose data were fully within the international guidance levels. Data from 51 patients who underwent multiple therapeutic procedures (median 2-3) indicated a total KAP reaching 995 Gy.cm(2) (range 10.1-995) and CD 15.1 Gy (range 0.4-15.1), stressing the importance of dose monitoring and optimisation.

CONCLUSIONS

There is a need for interventional cardiology societies to play an active role in training actions and implementation of radiation protection.