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

Abstract

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

Long-term strategies support autonomy in radiation safety in invasive cardiology

“…The most crucial factor is evaluation of the ratio between radiographic and fluoroscopic DAP fractions: DAP R fractions amounting to 71% (Table 2, period I at baseline [21]) or -in a multicenter field study [16] -80% of total DAP will result in 2.4-fold or 4.0-fold efficacy, respectively, during radiography compared to fluoroscopy, for whatever optimization achieved: times on beam, collimation, DED, dose intensities, or pulse rates. Consequently, in daily work, for example, overall DAP reduction owing to optimized fluoroscopic time on beam (from 195 to 114 s) and radiographic time on beam (from 548 to 180 frames) amounted to 12% and 48%, respectively, with up to 59% by pre-selection of short radiographic runs (Fig.…”

“…2 and Table 2, periods I-III, VII). Fluoroscopy time remains a well-accepted parameter for interventional experience; its poor correlation [16] with overall DAP, however, evidently suggests minor relevance for patient radiation exposure, at least during CA. In addition to optimization of time on beam and collimation, DED R of 80 nGy/frame enabled adequate diagnostic image quality and DAP levels for CA with left ventricular angiography of 6.0 Gy cm 2 : equivalent to $30% of the 2013 German median DAP of 19.8 Gy cm 2 [14,23].…”

“…It depends on body mass index, age, sex [16-18], procedure complexity [20] and interventional experience [16-18], catheterization mode [10], technology [12,16], as well as equipment handling techniques such as optimization of time on beam [21,22], collimation [21], magnification, copper filtering [16], pulsing and detector entrance dose [10,12,23], and preference for less-irradiating angulations [25]. CA is both a well-accepted target and marker intervention for radiation safety efforts [13,16].By implementation of radiation-reducing interventional techniques and by application of new technologies, we have since 1997 succeeded in decreasing median dose area products (DAP) for CA from 33.8 to 0.6 Gy cm 2 [10,21]. Comprehensive long-term assessment of multiple key dose parameters has provided step-bystep support with this plan-do-check-act approach.…”

“…It depends on body mass index, age, sex [16-18], procedure complexity [20] and interventional experience [16-18], catheterization mode [10], technology [12,16], as well as equipment handling techniques such as optimization of time on beam [21,22], collimation [21], magnification, copper filtering [16], pulsing and detector entrance dose [10,12,23], and preference for less-irradiating angulations [25]. CA is both a well-accepted target and marker intervention for radiation safety efforts [13,16].…”

Role of Experience, Leadership and Individual Protection in the Cath Lab – A Multicenter Questionnaire and Workshop on Radiation Safety

“…In addition, estimated DAP, radiographic runs, frame numbers and fluoroscopy times correlated quite well with actually achieved values. BMI, male sex and age were positively correlated to dose-related parameters, owing to the increasing complexity of expected coronary heart disease [19,20]. Higher patient doses upon use of advanced flat-panel technology can be explained by a tendency to employ higher pulse rates and/or greater pre-set detector-dose intensities during radiography [21,24].…”