Optimizing radiation use during fluoroscopic procedures: a quality and safety improvement project

Fluoroscopically-guided interventions with radiation doses exceeding 5000 mGy reference point air kerma: a dosimetric analysis of 89,549 interventional radiology, neurointerventional radiology, vascular surgery, and neurosurgery encounters

Purpose

To quantify and categorize fluoroscopically-guided procedures with radiation doses exceeding 5000 mGy reference point air kerma (K_a,r). K_a,r > 5000 mGy has been defined as a “significant radiation dose” by the Society of Interventional Radiology. Identification and analysis of interventions with high radiation doses has the potential to reduce radiation-induced injuries.

Materials and methods

Radiation dose data from a dose monitoring system for 19 interventional suites and 89,549 consecutive patient encounters from January 1, 2013 to August 1, 2019 at a single academic institution were reviewed. All patient encounters with K_a,r > 5000 mGy were included. All other encounters were excluded (n = 89,289). Patient demographics, medical specialty, intervention type, fluoroscopy time (minutes), dose area product (mGy·cm²), and K_a,r (mGy) were evaluated.

Results

There were 260 (0.3%) fluoroscopically-guided procedures with K_a,r > 5000 mGy. Of the 260 procedures which exceeded 5000 mGy, neurosurgery performed 81 (30.5%) procedures, followed by interventional radiology (n = 75; 28.2%), neurointerventional radiology (n = 55; 20.7%), and vascular surgery (n = 49; 18.4%). The procedures associated with the highest K_a,r were venous stent reconstruction performed by interventional radiology, arteriovenous malformation embolization performed by neurointerventional radiology, spinal hardware fixation by neurosurgery, and arterial interventions performed by vascular surgery. Neurointerventional radiology had the highest mean K_a,r (7,799 mGy), followed by neurosurgery (7452 mGy), vascular surgery (6849 mGy), and interventional radiology (6109 mGy). The mean K_a,r for interventional radiology performed procedures exceeding 5000 mGy was significantly lower than that for neurointerventional radiology, neurosurgery, and vascular surgery.

Conclusions

Fluoroscopically-guided procedures with radiation dose exceeding 5000 mGy reference point air kerma are uncommon. The results of this study demonstrate that a large proportion of cases exceeding 5000 mGy were performed by non-radiologists, who likely do not receive the same training in radiation physics, radiation biology, and dose reduction techniques as radiologists.

Monitoring and Follow-Up of High Radiation Dose Cases in Interventional Radiology

RATIONALE AND OBJECTIVES

To assess the implementation of radiation dose monitoring software, create a process for clinical follow-up and documentation of high-dose cases, and quantify the number of patient reported radiation-induced tissue reactions in fluoroscopically guided interventional radiology (IR) and neuro-interventional radiology (NIR) procedures.

MATERIALS AND METHODS

Web-based radiation dose monitoring software was installed at our institution and a process to flag all procedures with reference point air kerma (K_a,r) > 5000 mGy was implemented. The entrance skin dose was estimated and formal reports generated, allowing for physician-initiated clinical follow-up. To evaluate our process, we reviewed all IR and NIR procedures performed at our hospital over a 1-year period. For all procedures with K_a,r > 5000 mGy, retrospective medical chart review was performed to evaluate for patient reported tissue reactions.

RESULTS

Three thousand five hundred eighty-two procedures were performed over the 1-year period. The software successfully transferred dose data on 3363 (93.9%) procedures. One thousand three hundred ninety-three (368 IR and 1025 NIR) procedures were further analyzed after excluding 2189 IR procedures with K_a,r < 2000 mGy. Ten of 368 (2.7%) IR and 52 of 1025 (5.1%) NIR procedures exceeded estimated skin doses of 5000 mGy. All 10 IR cases were abdominal/pelvic trauma angiograms with/without embolization; there were no reported tissue reactions. Of 52 NIR cases, 49 were interventions and 3 were diagnostic angiograms. Five of 49 (10.2%) NIR patients reported skin/hair injuries, all of which were temporary.

CONCLUSION

Software monitoring and documentation of radiation dose in interventional procedures can be successfully implemented. Radiation-induced tissue reactions are relatively uncommon.

Use of Iterative Cycles in Quality Improvement Projects in Imaging: A Systematic Review

PURPOSE

Studies suggest that quality improvement (QI) projects in health care lack scientific rigor, but the actual frequency of use of proven scientific QI methodology is unknown. The purposes of this study are to (1) conduct a systematic review of QI projects in radiology journals on the frequency of use of iterative cycles, a marker of proven QI methodology, and (2) assess association of the use of iterative cycles with characteristics of these projects.

MATERIALS AND METHODS

We searched English-language radiology journals on MEDLINE between 2008 and 2015 for published QI studies. Three reviewers appraised studies and extracted data. Use of iterative cycles was identified, and results were summarized qualitatively. χ² Analysis evaluated associations of iterative cycles with other data elements.

RESULTS

Of 3,134 potentially eligible citations, 44 studies met inclusion criteria. Only 46% of these used iterative cycles to refine intervention. Use of iterative cycles were associated with projects designed to improve process, QI expert support, reporting of unintended effect of intervention, and explicitly stated use of iterative cycles. General lack of scientific rigor was represented by failure to report baseline data (9%), describe unintended effects (66%), and discuss limitations (36%).

CONCLUSIONS

Our systematic review found fewer than half of the QI projects in radiology journals used iterative cycles to refine intervention, a scientific strategy central to many proven improvement methodologies. Use of iterative approach was associated with projects designed to improve processes, QI expert support, report of unintended effect, and explicitly stated use of iterative cycles.

Educational Effects of Radiation Reduction During Fluoroscopic Examination of the Adult Gastrointestinal Tract

RATIONALE AND OBJECTIVES

This study aimed to evaluate the effects of educating radiology residents and radiographers about radiation exposure on reduction of dose area product (DAP) and fluoroscopy time in diagnostic fluoroscopy of the gastrointestinal (GI) tract in adult patients.

MATERIALS AND METHODS

In April 2015, we offered 1 hour of education to radiology residents and radiographers on how to reduce radiation doses during fluoroscopic examinations. Fluoroscopic examinations of the GI tracts of adult patients performed from June 2014 to February 2016 were evaluated. A total of 2326 fluoroscopic examinations (779 and 1547 examinations before and after education, respectively) were performed, including 10 kinds of examinations. Fluoroscopy time and DAP were collected. A radiologist evaluated the number of spot images, captured images, cine video, captured video, and the use of collimation or magnification. We used the Mann-Whitney U test to assess the difference in fluoroscopy-related factors before and after education.

RESULTS

Median DAP decreased significantly after education, from 21.1 to 18.2 Gy∙cm² (P < .001) in all examinations. After education DAP decreased significantly in defecography (P < .001) and fluoroscopy time decreased significantly in upper gastrointestinal series with water-soluble contrast (P < .001). Spot and cine images that increased the radiation dose were used less frequently after education than before in some kinds of examinations, especially in defecography (P < .001). More images were collimated after education in barium swallow than before (P < .001).

CONCLUSIONS

Educating radiologist residents and radiographers could reduce DAP in fluoroscopy examinations of the GI tract in adult patients.

Combined Use of a Patient Dose Monitoring System and a Real-Time Occupational Dose Monitoring System for Fluoroscopically Guided Interventions

PURPOSE

To determine the effect on patient radiation exposure of the combined use of a patient dose monitoring system and real-time occupational dose monitoring during fluoroscopically guided interventions (FGIs).

MATERIALS AND METHODS

Patient radiation exposure, in terms of the kerma area product (KAP; Gy ∙ cm(2)), was measured in period 1 with a patient dose monitoring system, and a real-time occupational dose monitoring system was additionally applied in period 2. Mean/median KAP in 19 different types of FGIs was analyzed in both periods for two experienced interventional radiologists combined as well as individually. Patient dose and occupational dose were correlated, applying Pearson and Spearman correlation coefficients.

RESULTS

Although FGIs were similar in numbers and types over both periods, a substantial decrease was found for period 2 in total mean ± SD/median KAP for both operators together (period 1, 47 Gy ∙ cm(2) ± 67/41 Gy ∙ cm(2); period 2, 37 Gy ∙ cm(2) ± 69/34 Gy ∙ cm(2)) as well as for each individual operator (for all, P < .05). Overall, KAP declined considerably in 15 of 19 types of FGIs in period 2. Mean accumulated dose per intervention was 4.6 µSv, and mean dose rate was 0.24 mSv/h. There was a strong positive correlation between patient and occupational dose (r = 0.88).

CONCLUSIONS

Combined use of a patient dose monitoring system and a real-time occupational dose monitoring system in FGIs significantly lessens patient and operator doses.

Improving Performance During Image-Guided Procedures

OBJECTIVE

Image-guided procedures have become a mainstay of modern health care. This article reviews how human operators process imaging data and use it to plan procedures and make intraprocedural decisions.

METHODS

A series of models from human factors research, communication theory, and organizational learning were applied to the human-machine interface that occupies the center stage during image-guided procedures.

RESULTS

Together, these models suggest several opportunities for improving performance as follows: 1. Performance will depend not only on the operator's skill but also on the knowledge embedded in the imaging technology, available tools, and existing protocols. 2. Voluntary movements consist of planning and execution phases. Performance subscores should be developed that assess quality and efficiency during each phase. For procedures involving ionizing radiation (fluoroscopy and computed tomography), radiation metrics can be used to assess performance. 3. At a basic level, these procedures consist of advancing a tool to a specific location within a patient and using the tool. Paradigms from mapping and navigation should be applied to image-guided procedures. 4. Recording the content of the imaging system allows one to reconstruct the stimulus/response cycles that occur during image-guided procedures.

CONCLUSIONS

When compared with traditional "open" procedures, the technology used during image-guided procedures places an imaging system and long thin tools between the operator and the patient. Taking a step back and reexamining how information flows through an imaging system and how actions are conveyed through human-machine interfaces suggest that much can be learned from studying system failures. In the same way that flight data recorders revolutionized accident investigations in aviation, much could be learned from recording video data during image-guided procedures.

Improving our PRODUCT: a quality and safety improvement project demonstrating the value of a preprocedural checklist for fluoroscopy

RATIONALE AND OBJECTIVES

To implement a preprocedural checklist in gastrointestinal (GI)/genitourinary (GU) fluoroscopy suites to assist radiology residents in performing studies with optimal fluoroscopic technique with a goal to lower radiation dose delivered to patients and operators.

MATERIALS AND METHODS

We introduced a preprocedural checklist in the form of a mnemonic to first-year resident fluoroscopy operators. The checklist was augmented by teaching sessions at the fluoroscopy tower. Fluoroscopy time (FT) was collected for GI/GU fluoroscopy studies performed by first-year residents who did not use the checklist (year 1) and compared with FT from first-year residents who used the checklist for one full academic year (year 2). Residents in both groups were surveyed to assess their knowledge of radiation safety at the end of their respective radiology 1 (R1) academic years.

RESULTS

A total of 778 examinations were analyzed from year 1, and 941 total examinations from year 2. After implementation of the checklist, mean FT for all studies decreased by 41.1 seconds (P < .0001) in year 2 residents. Multivariate linear regression confirmed that year of examination was the strongest independent predictor of FT when other covariates such as resident age, gender, and experience and patient age and gender were included. Radiation safety knowledge was similar in both groups but self-reported confidence in safe fluoroscopy tower operation increased slightly in year 2 (P = .144).

CONCLUSIONS

A visual preprocedural radiation safety checklist in GI/GU fluoroscopy was associated with a reduction in mean FT and may contribute to a culture of radiation safety awareness.

Three-dimensional fusion computed tomography decreases radiation exposure, procedure time, and contrast use during fenestrated endovascular aortic repair

OBJECTIVE

Endovascular surgery has revolutionized the treatment of aortic aneurysms; however, these improvements have come at the cost of increased radiation and contrast exposure, particularly for more complex procedures. Three-dimensional (3D) fusion computed tomography (CT) imaging is a new technology that may facilitate these repairs. The purpose of this analysis was to determine the effect of using intraoperative 3D fusion CT on the performance of fenestrated endovascular aortic repair (FEVAR).

METHODS

Our institutional database was reviewed to identify patients undergoing branched or FEVAR. Patients treated using 3D fusion CT were compared with patients treated in the immediate 12-month period before implementation of this technology when procedures were performed in a standard hybrid operating room without CT fusion capabilities. Primary end points included patient radiation exposure (cumulated air kerma: mGy), fluoroscopy time (minutes), contrast usage (mL), and procedure time (minutes). Patients were grouped by the number of aortic graft fenestrations revascularized with a stent graft, and operative outcomes were compared.

RESULTS

A total of 72 patients (41 before vs 31 after 3D fusion CT implementation) underwent FEVAR from September 2012 through March 2014. For two-vessel fenestrated endografts, there was a significant decrease in radiation exposure (3400 ± 1900 vs 1380 ± 520 mGy; P = .001), fluoroscopy time (63 ± 29 vs 41 ± 11 minutes; P = .02), and contrast usage (69 ± 16 vs 26 ± 8 mL; P = .0002) with intraoperative 3D fusion CT. Similarly, for combined three-vessel and four-vessel FEVAR, significantly decreased radiation exposure (5400 ± 2225 vs 2700 ± 1400 mGy; P < .0001), fluoroscopy time (89 ± 36 vs 64 ± 21 minutes; P = .02), contrast usage (90 ± 25 vs 39 ± 17 mL; P < .0001), and procedure time (330 ± 100 vs 230 ± 50 minutes; P = .002) was noted. Estimated blood loss was significantly less (P < .0001), and length of stay had a trend (P = .07) toward being lower for all patients in the 3D fusion CT group.

CONCLUSIONS

These results demonstrate that use of intraoperative 3D fusion CT imaging during FEVAR can significantly decrease radiation exposure, procedure time, and contrast usage, which may also decrease the overall physiologic impact of the repair.