Radiation doses from venous access procedures

NCRP commentary no. 33-recommendations for stratification of equipment use and radiation safety training for fluoroscopy

National Council on Radiation Protection and Measurements Commentary No. 33 'Recommendations for Stratification of Equipment Use and Radiation Safety Training for Fluoroscopy' defines an evidence-based, radiation risk classification for fluoroscopically guided procedures (FGPs), provides radiation-related recommendations for the types of fluoroscopes suitable for each class of procedure, and indicates the extent and content of training that ought to be provided to different categories of facility staff who might enter a room where fluoroscopy is or may be performed. For FGP, radiation risk is defined by the type and likelihood of radiation hazards that could be incurred by a patient undergoing a FGP. The Commentary also defines six training groups of facility staff based on their role in the fluoroscopy room. The training groups are based on a combination of job descriptions and the procedures in which these individuals might be involved. The Commentary recommends the extent and content of training that should be provided to each of these training groups. It also provides recommendations on training formats, training frequency, and methods for demonstrating that the learner has acquired the necessary knowledge.

Catheter detection by transthoracic echocardiography during placement of peripherally inserted central catheters: a real-time method for eliminating misplacement

BACKGROUND

Although guidelines and protocols are available for central venous access, existing methods lack specificity and sensitivity, especially when placing peripherally inserted central catheters (PICCs). We evaluated the feasibility of catheter detection in the right atrial cavity using transthoracic echocardiography (TTE) during PICC placement.

METHODS

This single-center, retrospective study included consecutive patients who underwent PICC placement between January 2022 and March 2023. TTE was performed to detect the arrival of the catheter in the right atrial cavity. Catheter misplacement was defined as an aberrant catheter position on chest x-ray (CXR). The primary endpoint was predicting catheter misplacement based on catheter detection in the right atrial cavity. The secondary endpoint was optimizing catheter placement and examining catheter-associated complications.

RESULTS

Of the 110 patients identified, 10 were excluded because of poor echogenicity and vein access failure. The remaining 100 patients underwent PICC placement with TTE. The catheter was visualized in the right atrial cavity in 90 patients. CXR exams revealed catheter misplacement in seven cases. Eight patients with catheter misplacement underwent the same procedure in the other arm. In two patients, PICC placement failed due to anatomical reasons. Catheter misplacement was detected using TTE with sensitivity, specificity, positive predictive value, and negative predictive value of 97% confidence interval (CI; 91.31%-99.36%), 90% CI (55.50%-99.75%), 99%, and 75%, respectively.

CONCLUSIONS

TTE is a reliable tool for detecting catheter misplacement and optimizing catheter tip positioning during PICC placement.

Dose-Related Analysis in Percutaneous Central Venous Catheters Insertion: Experience of a Pediatric Interventional Radiology Center

Background: There are many techniques for long-term central venous catheter (CVC) placement, but none of them are specific for pediatric patients or focused on the delivered dose of ionizing radiation. Materials and Methods: This retrospective study examined a sample of pediatric patients who received percutaneous long-term CVC positioning in a tertiary care pediatric hospital. Effective dose, dose-area product (DAP) and length of time of exposition during the procedure were determined, using an appropriate technical procedure, exam and program set of the angiograph, and compared with an unpaired t-test analysis. Results: The study included 1410 enrolled patients, with a median age of 10 years (range 0.2–18 years), between 2016 and 2019. In 2016 (318 pts), the mean effective dose was 0.13 mSv and the mean DAP dose was 18.95 µGy/m² In 2017 (353 pts), the mean effective dose was 0.11 mSv and the mean DAP dose was 17.26 µGy/m². In 2018 (351 pts), the mean effective dose was 0.05 mSv and the mean DAP dose was 7.23 µGy/m². In 2019 (388 pts), the mean effective dose was 0.02 mSv and the mean DAP dose was 3.10 µGy/m². Conclusions: Medical and technical expertise led to a remarkable reduction in the radiation dose. Therefore, the authors’ hypothesis is that US- and fluoroscopy-guided percutaneous long-term CVC insertion technique is safer, more cost-effective and lower in terms of radiation exposure if correctly applied, compared to surgical or percutaneous by direct puncture techniques.

Percutaneous implantation of peripherally inserted totally implantable venous access systems in the forearm in adolescent patients

BACKGROUND

Children with different underlying malignant diseases require long-term central venous access. As for port systems in a pectoral position, peripherally implanted port systems in the forearm revealed high levels of technical and clinical success in adult cohorts.

OBJECTIVE

To investigate the technical and clinical outcomes of percutaneous central venous port implantation in the forearm in adolescents.

MATERIALS AND METHODS

Between April 2010 and August 2020, 32 children ages 9 to 17 years with underlying malignancy received 35 totally implantable venous access ports (TIVAPs) in the forearm. All venous port systems were peripherally inserted under ultrasound guidance. Correct catheter placement was controlled by fluoroscopy. As primary endpoints, the technical success, rate of complications and catheter maintenance were analyzed. Secondary endpoints were the side of implantation, vein of catheter access, laboratory results on the day of the procedure, procedural radiation exposure, amount of contrast agent and reasons for port device removal.

RESULTS

Percutaneous TIVAP placement under sonographic guidance was technically successful in 34 of 35 procedures (97.1%). Procedure-related complications did not occur. During the follow-up, 13,684 catheter days were analyzed, revealing 11 complications (0.8 per 1,000 catheter-duration days), Of these 11 complications, 7 were major and 10 occurred late. In seven cases, the port device had to be removed; removal-related complications did not occur.

CONCLUSION

Peripheral TIVAP placement in the forearms of children is a feasible, effective and safe technique with good midterm outcome. As results are comparable with standard access routes, this technique may be offered as an alternative when intermittent venous access is required.

Ionizing radiation exposure from dialysis tunneled catheters procedures: European directive and legal implications

BACKGROUND

Advances in medical imaging and interventional procedures have been associated with increased exposure to ionizing radiation. Thus, the International Commission on Radiological Protection (ICRP) established uniform safety standards to protect the general public against the dangers arising from ionizing radiations. In Europe, the ICRP standards are listed in the European Directive 2013/59/EURATOM, which should be transposed into national legislation by member states. They require that the administered dose must be part of the radiological report and identify the practitioners' responsibilities in justifying and optimizing the dose and correctly informing the patient.Despite these indications, the literature lacks information about the dose from fluoroscopically inserted dialysis tunneled central venous catheters (td-CVC). This study aimed to quantify the effective dose and organ dose to relevant organs in td-CVC to comply with the EU statements.

METHODS

We revised fluoroscopically-guided procedures of td-CVC insertion, considering dose per area product, fluoroscopic time, effective dose, organ dose, and anatomical district. We also compared these parameters with those of fluoroscopically inserted oncological central venous devices (Port-a-cath).

RESULTS

The dose-area product, fluoroscopic time, and organ dose for td-CVC were 13 ± 22.2 Gy*cm², 81 ± 129 s, and 1.9 ± 3.3 mSv. The radiological parameters for the left internal jugular, subclavian and femoral veins were similar but higher than for the right internal jugular vein. The radiological parameters were significantly higher for td-CVC than for Port-a-cath.

CONCLUSIONS

Fluoroscopically inserted td-CVC are associated with a relatively low dose of ionizing radiation, with considerable variability due to the anatomical puncture site and previous accesses' history. In light of the European Directive, it is a concern for nephrologists to be aware of the administered ionizing dose to comply with their legal responsibilities.

High resolution, 3-dimensional Ferumoxytol-enhanced cardiovascular magnetic resonance venography in central venous occlusion

BACKGROUND

Although cardiovascular magnetic resonance venography (CMRV) is generally regarded as the technique of choice for imaging the central veins, conventional CMRV is not ideal. Gadolinium-based contrast agents (GBCA) are less suited to steady state venous imaging than to first pass arterial imaging and they may be contraindicated in patients with renal impairment where evaluation of venous anatomy is frequently required. We aim to evaluate the diagnostic performance of 3-dimensional (3D) ferumoxytol-enhanced CMRV (FE-CMRV) for suspected central venous occlusion in patients with renal failure and to assess its clinical impact on patient management.

METHODS

In this IRB-approved and HIPAA-compliant study, 52 consecutive adult patients (47 years, IQR 32-61; 29 male) with renal impairment and suspected venous occlusion underwent FE-CMRV, following infusion of ferumoxytol. Breath-held, high resolution, 3D steady state FE-CMRV was performed through the chest, abdomen and pelvis. Two blinded reviewers independently scored twenty-one named venous segments for quality and patency. Correlative catheter venography in 14 patients was used as the reference standard for diagnostic accuracy. Retrospective chart review was conducted to determine clinical impact of FE-CMRV. Interobserver agreement was determined using Gwet's AC1 statistic.

RESULTS

All patients underwent technically successful FE-CMRV without any adverse events. 99.5% (1033/1038) of venous segments were of diagnostic quality (score ≥ 2/4) with very good interobserver agreement (AC1 = 0.91). Interobserver agreement for venous occlusion was also very good (AC1 = 0.93). The overall accuracy of FE-CMRV compared to catheter venography was perfect (100.0%). No additional imaging was required prior to a clinical management decision in any of the 52 patients. Twenty-four successful and uncomplicated venous interventions were carried out following pre-procedural vascular mapping with FE-CMRV.

CONCLUSIONS

3D FE-CMRV is a practical, accurate and robust technique for high-resolution mapping of central thoracic, abdominal and pelvic veins and can be used to inform image-guided therapy. It may play a pivotal role in the care of patients in whom conventional contrast agents may be contraindicated or ineffective.

Peripherally inserted central catheters: dependency of radiation exposure from puncture site and level of training

Background Several interventional procedures show a dependency on fluoroscopy times (FT) and level of training. Furthermore, FT and dose area products (DAP) vary depending on access site and target vessel for chest port implantations, but not for other thoracic interventions such as percutaneous coronary interventions. Purpose To evaluate the influence of the combination of venous access site and level of training on FTs and DAPs during peripherally inserted central catheters (PICC) implantations in a large cohort of patients. Material and Methods In this retrospective study, PICC implantations of 681 consecutive patients (385 women, 296 men; mean age = 55.0 ± 16.7 years) were analyzed. Two groups of junior (< 50 interventions) and senior (≥ 50 implantations) radiologists were investigated in respect to FT and DAP during PICC placement procedures. Statistical analysis included the Mann-Whitney U test and the Kruskal-Wallis test. P values < 0.05 were considered significant. Results Senior radiologists required significantly less FT (senior = 0.43 s, junior = 0.53 s, P = 0.041), but there was no significant difference in DAPs (senior = 56.3 µGy*m², junior = 60.6 µGy*m², P = 0.151). PICC implantations through the left side resulted in a significant reduction of the median FT by 60.9% (left = 0.45 s, right = 1.15 s, P = 0.010). Conclusion Due to considerable dose reduction, the left-sided puncture, especially via the basilic and brachial veins, performed by well-trained interventional radiologists seem to be the preferable approach for PICCs.

Radiation burden of pediatric ultrasound-guided percutaneous central venous access devices: A prospective cohort study

Permanent central venous access is essential for the management of many pediatric patients. Knowing the amount of ionizing radiation used during the insertion of these devices is important. Our aim was to identify the radiation used in percutaneous insertion of central venous access devices, and to correlate radiation exposure to patient weight.

METHODS

Data was prospectively collected during a 12-month period from August 2015 to August 2016 on all ultrasound-guided percutaneous central venous access device insertions. An image intensifier was used in all insertions with data on radiation dose and screening time extracted, when available. The total radiation dose was measured in mGym2 and the total radiation time in seconds. A p-value <0.05 was used to denote statistical significance.

RESULTS

A total of 145 central venous access devices were inserted (82 portacaths, 43 double lumen lines, 16 single lumen lines and 4 hemocaths) in 127 patients (Median Age: 5.5years (Range 0-17); Median Weight 21kg (Range 1.9-100)) with 15 patients requiring multiple insertions over the course of the study. Of these, 88 had data captured for total radiation dose and time used and a further 23 had screening time only recorded. Median radiation dose was 0.00599 mGym2 (range 0.000543-0.148) with a median fluoroscopic screening time of 18s (range 2-479). Median dose was higher for children <10kg compared to larger children, 0.00661 mGym2 (range 0.00202-0.0468) versus 0.005715 mGym2 (range 0.000543-0.148) respectively. Left-sided internal jugular vein (IJV) insertions also had a higher median radiation dose of 0.0091 mGym2 (range 0.00142-0.148 mGym2) versus 0.005245 mGym2 (range 0.000543-0.0285 mGym2) for right-sided IJV insertions.

CONCLUSION

The radiation burden to children from percutaneous ultrasound-guided central venous access device insertions is small, in the order of that received during a chest radiograph. Weight<10kg and access of the left IJV are associated with receiving higher doses.

STUDY TYPE

Cohort Study (Level of Evidence: II).

Totally Implantable Central Venous Port Catheters: Radiation Exposure as a Function of Puncture Site and Operator Experience

BACKGROUND

Totally implantable central venous port systems provide a safe and effective, long-term means of access for administration of hyperosmolar, local irritant medication, such as chemotherapy, antibiotics and parenteral nutrition.

AIM

To evaluate the combination of access site and level of experience on fluoroscopy times (FT) and dose area products (DAP) during implantation of port catheters in a large patient population.

MATERIALS AND METHODS

A total of 1,870 patients (992 women, 878 men; age: 61±13.14 years) were reviewed investigating two groups of junior (≤50 implantations) and senior (>50) radiologists.

RESULTS

Senior radiologists required less FT/DAP (0.24 s/57.3 μGy m2 versus 0.43 s/68.2 μGy m2, respectively; p<0.001). Right jugular vein access required the least FT/DAP (0.25 s/56.15 μGy m2) and right-sided implantation lower FT/DAP (right: 0.26 s/56.4 μGy m2, left: 0.40 s/85.10 μGy m2, p<0.001).

CONCLUSION

Due to DAP/FT reductions, the right jugular vein seems to be the most favorable implantation side for port systems. For further dose reduction, residents should be well-trained.

Impact of Allura Clarity Technology on Radiation Dose Exposure During Left Atrial Appendage Closure

BACKGROUND

To evaluate the impact of the Clarity IQ technology on reducing radiation risk in patients undergoing cardiac interventional radiology (IR) procedures.

MATERIAL/METHODS

Phantom studies were performed with two angiographic systems, FD10 Allura Xper and FD10 Allura Clarity. In the study, we performed left atrial appendage closure. Dosimetric measurements were performed with thermoluminescent dosimeters (TLD) placed inside a CIRS anthropomorphic phantom. Radiation risk was estimated based on the TLD readings and expressed as the dose absorbed by particular organs. The Mann-Whitney U test was carried out to test for significance of differences in the absorbed radiation doses between the techniques.

RESULTS

During left atrial appendage closure, the estimated dose absorbed by particular organs was lower in the case of the FD10 Allura Clarity system in comparison to the Allura Xper. In this procedure, dose reduction for particular organs ranged between 49-86%.

CONCLUSIONS

Application of the FD10 Allura Clarity system resulted in a significant dose reduction, thereby leading to a significant decrease in radiation risk for patients undergoing IR procedures.

Radiology Trainee vs Faculty Radiologist Fluoroscopy Time for Imaging-Guided Procedures: A Retrospective Study of 17,966 Reports Over a 5.5-Year Period

To evaluate differences in fluoroscopy time (FT) for common vascular access and gastrointestinal procedures performed by radiology trainees vs faculty radiologists. Report information was extracted for all 17,966 index fluoroscopy services performed by trainees or faculty, or both from 2 university hospitals over 66 months. Various vascular access procedures (eg, peripherally inserted central catheters [PICCs] and ports) and gastrointestinal fluoroscopy procedures (eg, upper gastrointestinal and contrast enema studies) were specifically targeted. Statistical analysis was performed. FT was recorded in 17,549 of 17,966 reports (98%) The 1393 procedures performed by nonphysician providers or transitional year interns were excluded. Residents, fellows, and faculty were primary operators in 5066, 6489, and 4601 procedures, respectively. Average FT (in seconds) for resident and fellow services, respectively, was less than that of faculty only for PICCs (75 and 101 vs 148, P < 0.01). For all other procedures, average FT of trainee services was greater than that for faculty. This was statistically significant (P < 0.05) for fellows vs faculty port placement (121 vs 87), resident vs faculty small bowel series (130 vs 96), and both resident and fellow vs faculty esophagram procedures (143 and 183 vs 126 ). FT for residents was significantly less than that for fellows only for PICCs (75 vs 101, P < 0.01). For most, but not all, fluoroscopy procedures commonly performed by radiology trainees, FT is greater than that for procedures performed by faculty radiologists. Better awareness and understanding of such differences may aid training programs in developing benchmarks, protocols, and focused teaching in the safe use of fluoroscopy for patients and operators.

Radiologist variability in assessing the position of the cavoatrial junction on chest radiographs

OBJECTIVE

To assess the variability in identifying the cavoatrial junction (CAJ) on chest X-rays (CXRs) amongst radiologists.

METHODS

23 radiologists (13 consultants and 10 trainees) assessed 25 posteroanterior erect CXRs (including 8 duplicates) and marked the positions of the CAJ. Differences in the CAJ position both within and between observers were evaluated and reported as limits of agreement (LOA), repeatability coefficients (RCs) and intraclass correlation coefficients and were displayed graphically with Bland-Altman plots.

RESULTS

The mean difference for within-observer assessments was -0.2 cm (95% LOA, -1.5 to +1.1 cm) and between observers, it was -0.3 cm (95% LOA, -2.5 to +1.8 cm). Intraobserver RCs were marginally lower for consultants than for trainees (1.1 vs 1.5). RCs between observers were comparable (2.1 vs 2.2) for consultants and trainees, respectively.

CONCLUSION

This study detected a large interobserver variability of the CAJ position (up to 4.3 cm). This is a significant finding considering that the length of the superior vena cava is reported to be approximately 7 cm. We conclude that there is poor consensus regarding the CAJ position amongst radiologists.

ADVANCES IN KNOWLEDGE

No comparisons exist between radiologists in determining CAJ position from CXRs. This report provides evidence of the large observer variability amongst radiologists and adds to the discussion regarding the use of CXRs in validating catheter tip location systems.

Review of the radiation exposure during screening of surgically implanted central venous access devices

PURPOSE

Ionizing radiation is used for the insertion of surgically implanted venous access devices (SIVADs) with children at the highest risk of cumulative radiation effects from these procedures. This study examines the radiation dose in a pediatric population during intraoperative radiological screening.

METHODS

A retrospective study looked at all pediatric patients in a tertiary hospital between January 2008 and January 2014 who had a surgically implanted venous access device inserted using intraoperative fluoroscopy. Patient demographics, reason for SIVAD insertion, the type and method of insertion, fluoroscopy time and radiation dose area product were determined.

RESULTS

A total of 505 patients had 682 SIVADs inserted, with 123 patients receiving multiple SIVAD over the six year period. There were two types of SIVAD inserted, 492 were totally implanted venous access devices (TIVAD) and 190 were tunneled central venous catheters (cuffed central line). Five hundred seven of the SIVAD inserted recorded the dose area product and fluoroscopy time. The median time for screening was 5seconds (range 1 to 275seconds) and the median dose area product was 0.00352mGym(2) (range 0.000001mGym(2) to 0.28mGym(2)). Of the 507 SIVAD that recorded the radiation data, 479 were open surgical cut-down insertion and 27 were percutaneous insertion. Percutaneously inserted surgically implanted venous access devices (mean 0.0060mGym(2)) had a longer dose area product than open insertion (mean 0.0034mGym(2); p=0.05).

CONCLUSION

Screening of SIVAD involves low levels of radiation exposure and is comparable to a chest x-ray or a transatlantic flight. The excess lifetime cancer risk to patients is estimated to be very low and is considered to be outweighed by the benefits of insertion. Open surgical cut-down insertion has a significantly reduced radiation exposure compared to percutaneous techniques. Although radiation dose is higher with percutaneous procedures, the clinical effects are considered minimal, and the resultant radiation risk is estimated to be very low. Radiation dose should not determine technique of insertion of SIVAD.

Radiation exposure and safety practices during pediatric central line placement

PURPOSE

Pediatric surgeons routinely use fluoroscopy for central venous line (CVL) placement. We examined radiation safety practices and patient/surgeon exposure during fluoroscopic CVL.

METHODS

Fluoroscopic CVL procedures performed by 11 pediatric surgeons in 2012 were reviewed. Fluoroscopic time (FT), patient exposure (mGy), and procedural data were collected. Anthropomorphic phantom simulations were used to calculate scatter and dose (mSv). Surgeons were surveyed regarding safety practices.

RESULTS

386 procedures were reviewed. Median FT was 12.8 seconds. Median patient estimated effective dose was 0.13 mSv. Median annual FT per surgeon was 15.4 minutes. Simulations showed no significant difference (p=0.14) between reported exposures (median 3.5 mGy/minute) and the modeled regression exposures from the C-arm default mode (median 3.4 mGy/minute). Median calculated surgeon exposure was 1.5 mGy/year. Eight of 11 surgeons responded to the survey. Only three reported 100% lead protection and frequent dosimeter use.

CONCLUSION

We found nonstandard radiation training, safety practices, and dose monitoring for the 11 surgeons. Based on simulations, the C-arm default setting was typically used instead of low dose. While most CVL procedures have low patient/surgeon doses, every effort should be used to minimize patient and occupational exposure, suggesting the need for formal hands-on training for nonradiologist providers using fluoroscopy.

Comparison between radiation exposure levels using an image intensifier and a flat-panel detector-based system in image-guided central venous catheter placement in children weighing less than 10 kg

BACKGROUND

Ultrasound-guided central venous puncture and fluoroscopic guidance during central venous catheter (CVC) positioning optimizes technical success and lowers the complication rates in children, and is therefore considered standard practice.

OBJECTIVE

The purpose of this study was to compare the radiation exposure levels recorded during CVC placement in children weighing less than 10 kg in procedures performed using an image intensifier-based angiographic system (IIDS) to those performed in a flat-panel detector-based interventional suite (FPDS).

MATERIALS AND METHODS

A retrospective review of 96 image-guided CVC placements, between January 2008 and October 2013, in 49 children weighing less than 10 kg was performed. Mean age was 8.2 ± 4.4 months (range: 1-22 months). Mean weight was 7.1 ± 2.7 kg (range: 2.5-9.8 kg). The procedures were classified into two categories: non-tunneled and tunneled CVC placement.

RESULTS

Thirty-five procedures were performed with the IIDS (21 non-tunneled CVC, 14 tunneled CVC); 61 procedures were performed with the FPDS (47 non-tunneled CVC, 14 tunneled CVC). For non-tunneled CVC, mean DAP was 113.5 ± 126.7 cGy cm(2) with the IIDS and 15.9 ± 44.6 cGy · cm(2) with the FPDS (P < 0.001). For tunneled CVC, mean DAP was 84.6 ± 81.2 cGy · cm(2) with the IIDS and 37.1 ± 33.5 cGy cm(2) with the FPDS (P = 0.02).

CONCLUSION

The use of flat-panel angiographic equipment reduces radiation exposure in small children undergoing image-guided CVC placement.

Risk factors of radiation dose in patients undergoing peripherally-inserted central catheter procedure using conventional angiography equipment and flat panel detector-based mobile C-arm fluoroscopy

BACKGROUND

Although peripherally-inserted central catheter (PICC) insertion is commonly performed under fluoroscopic guidance, few reports have addressed performance and dosimetry when PICC is inserted under C-arm fluoroscopy.

PURPOSE

To evaluate the risk factors of radiation dose in performing PICC insertion using flat panel detector-based mobile C-arm fluoroscopy and a conventional angiography machine.

MATERIAL AND METHODS

Ninety-eight patients underwent the PICC procedure using conventional angiography equipment (n=49) or flat panel detector-based mobile C-arm fluoroscopy (n=49). Data were prospectively analyzed from July to November 2012. Dose-area product (DAP), tube voltage, tube current, fluoroscopy time, and image quality measured on a 5-point scale were estimated and compared using appropriate statistical tests.

RESULTS

There were no significant differences in tube voltage, fluoroscopy time, and image quality between conventional angiography and mobile C-arm fluoroscopy. DAP, mean arm tube current, and tube current in chest fluoroscopy were significantly lower in mobile C-arm fluoroscopy than using the conventional angiography machine (P < 0.05). Multivariate analysis identified tube current in chest fluoroscopy, arm tube current, and fluoroscopy equipment as significant risk factors for elevated radiation dose in PICC insertion.

CONCLUSION

PICC insertion can be performed using flat panel detector-based mobile C-arm fluoroscopy instead of a conventional angiography machine. Image quality and fluoroscopy time were not different between the two systems and the use of C-arm fluoroscopy significantly reduced radiation dose.

Cumulative radiation dose in patients with hereditary hemorrhagic telangiectasia and pulmonary arteriovenous malformations

PURPOSE

To determine the cumulative effective dose (CED) of radiation from medical imaging and intervention in patients with hereditary hemorrhagic telangiectasia (HHT) who have pulmonary arteriovenous malformations and to identify clinical factors associated with exposure to high levels of radiation.

METHODS

All patients with at least 1 pulmonary arteriovenous malformation were identified from the dedicated patient database of a tertiary HHT referral centre. Computerized imaging and electronic patient records were systematically examined to identify all imaging studies performed from 1989-2010. The effective dose was determined for each study, and CED was calculated retrospectively.

RESULTS

Among 246 patients (mean age, 53 years; 62.2% women) with a total of 2065 patient-years, 3309 procedures that involved ionizing radiation were performed. CED ranged from 0.2-307.6 mSv, with a mean of 51.7 mSv. CED exceeded 100 mSv in 26 patients (11%). Interventional procedures and computed tomography (CT) were the greatest contributors, which accounted for 51% and 46% of the total CED, respectively. Factors associated with high cumulative exposure were epistaxis (odds ratio 2.7 [95% confidence interval, 1.1-6.3]; P = .02), HHT-related gastrointestinal bleeding (odds ratio 2.0 [95% confidence interval, 1.0-3.8]; P = .04) and number of patient-years (P < .0001).

CONCLUSIONS

Patients with HHT are exposed to a significant cumulative radiation dose from diagnostic and therapeutic interventions. Identifiable subsets of patients are at increased risk. A proportion of patients receive doses at levels that are associated with harm. Imaging indications and doses should be optimized to reduce radiation exposure in this population.

ICRP Publication 117. Radiological protection in fluoroscopically guided procedures performed outside the imaging department

An increasing number of medical specialists are using fluoroscopy outside imaging departments, but there has been general neglect of radiological protection coverage of fluoroscopy machines used outside imaging departments. Lack of radiological protection training of those working with fluoroscopy outside imaging departments can increase the radiation risk to workers and patients. Procedures such as endovascular aneurysm repair, renal angioplasty, iliac angioplasty, ureteric stent placement, therapeutic endoscopic retrograde cholangio-pancreatography,and bile duct stenting and drainage have the potential to impart skin doses exceeding Gy. Although tissue reactions among patients and workers from fluoroscopy procedures have, to date, only been reported in interventional radiology and cardiology,the level of fluoroscopy use outside imaging departments creates potential for such injuries.A brief account of the health effects of ionising radiation and protection principles is presented in Section 2. Section 3 deals with general aspects of the protection of workers and patients that are common to all, whereas specific aspects are covered in Section 4 for vascular surgery, urology, orthopaedic surgery, obstetrics and gynaecology,gastroenterology and hepatobiliary system, and anaesthetics and pain management.Although sentinel lymph node biopsy involves the use of radio-isotopic methods rather than fluoroscopy, performance of this procedure in operating theatres is covered in this report as it is unlikely that this topic will be addressed in another ICRP publication in coming years. Information on radiation dose levels to patients and workers, and dose management is presented for each speciality.

Reference levels for patient radiation doses in interventional radiology: proposed initial values for U.S. practice

PURPOSE

To propose initial values for patient reference levels for fluoroscopically guided procedures in the United States.

MATERIALS AND METHODS

This secondary analysis of data from the Radiation Doses in Interventional Radiology Procedures (RAD-IR) study was conducted under a protocol approved by the institutional review board and was HIPAA compliant. Dose distributions (percentiles) were calculated for each type of procedure in the RAD-IR study where there were data from at least 30 cases. Confidence intervals for the dose distributions were determined by using bootstrap resampling. Weight banding and size correction methods for normalizing dose to patient body habitus were tested.

RESULTS

The different methods for normalizing patient radiation dose according to patient weight gave results that were not significantly different (P > .05). The 75th percentile patient radiation doses normalized with weight banding were not significantly different from those that were uncorrected for body habitus. Proposed initial reference levels for various interventional procedures are provided for reference air kerma, kerma-area product, fluoroscopy time, and number of images.

CONCLUSION

Sufficient data exist to permit an initial proposal of values for reference levels for interventional radiologic procedures in the United States. For ease of use, reference levels without correction for body habitus are recommended. A national registry of radiation-dose data for interventional radiologic procedures is a necessary next step to refine these reference levels.

[A study of operator's hand and finger exposure dose reduction during angiographic procedures]

The number of examinations using interventional radiology (IVR) has increased recently. Because of the more advanced and more complex procedures for IVR, longer treatment time is required. Therefore, it is important to determine exposure doses. We measured operator exposure dose during IVR using a thermoluminescence dosimeter. The results revealed the dose equivalent to the operator's hands and fingers to be higher than that of other parts, although the effective dose for the operator was low. Moreover, we looked into the factors that affected exposure dose to the operator's fingers, and examined ways to reduce the dose. In regard to the exposed dose to the operator's fingers, dose reduction was possible as a result of a geometric arrangement of the fluoroscopic unit, the radiation field size, using a radiation protective device and deliberation to exposure dose reduction of the operator. It is possible to carry out IVR more safely using the method of exposure dose reduction to the operator's fingers.

Overview of contemporary interventional fluoroscopy procedures

Interventional fluoroscopy procedures are increasingly important in medical practice. As new procedures are introduced and validated, they tend to replace the equivalent surgical procedure. There is wide variation in patient dose, both among procedures and for a specific procedure. Stochastic risk is present, but interventional fluoroscopy procedures may also present deterministic risk. Radiation risk/benefit analyses are different for interventional fluoroscopy procedures than they are for diagnostic imaging procedures. The radiation risk component of an interventional fluoroscopy procedure is substantially less than the other procedural risks, and there is always clear and measurable benefit to the patient from a successful procedure. Optimizing patient dose will require both improvements in equipment technology and greater attention from regulators, accrediting bodies and medical organizations. Ensuring adequate operator training is essential.