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.

Zusammenfassung

Ziel: Validierung der Langzeitwirksamkeit eines 90-minütigen Minikurses in strahlenreduzierender Arbeitstechnik in der invasiven Kardiologie.

Material und Methoden: Vor, 2 Monate und 2 Jahre nach dem Minikurs (Periode I, II und III) wurden folgende Dosisparameter analysiert, erhoben durch 7 Kardiologen im Verlauf von je 10 Koronarangiografien: Dosisflächenprodukt (DFP), radiografischer und fluoroskopischer DFP-Anteil, Anzahl radiografischer Bilder und Serien, und Durchleuchtungszeit.

Ergebnisse: In Periode I und II betrug das mediane Patienten-DFP 31,4 bzw. 15,8 Gy × cm² und sank bis Periode III nochmals auf 8,5 Gy × cm². Dieser Langzeiteffekt war verbunden mit einer kürzeren medianen Durchleuchtungszeit (180, 172 bzw. 120 Sekunden), weniger (12, 12, 10) und kürzeren (57, 52, 45 Bilder/Serie) Serien, sowie besserer Einblendung und Beschränkung auf hinreichende Bildqualität: radiografisches DFP/Bild (28,7, 17,0 bzw. 18,4 mGy × cm²) wie fluoroskopisches DFP/Sekunde (45,7, 24,2 bzw. 10,0 mGy × cm²) sanken signifikant. Die multivariate Regressionsanalyse bestätigte die zunehmende Effektivität des Minikurses von Periode II (–44,6 %) auf III (–60,7 %). Gleichzeitig sank der Einfluss der interventionellen Erfahrung der Untersucher (–8,6 % bzw. –4,9 % pro 1000 Koronarangiografien, jeweils durchgeführt bis zum Kurs). Die Anzahl der Koronarangiografien nach dem Kurs beeinflusste die Langzeitergebnisse nicht.

Schlussfolgerung: Das vorgestellte Kursprogramm ermöglicht im Langzeitverlauf eine signifikante, nachhaltige und fortschreitende Reduktion der Patientendosis in der diagnostischen Koronarangiografie. Eine selbstkontrollierende Dokumentation relevanter Dosisparameter ist bestens geeignet, individuelle strahlenhygienische Bemühungen der Untersucher zu überwachen und zu verbessern.

Key words

radiation safety - coronary angiography - radiography - fluoroscopy - education - QA/QC

• References

• 1 Thomson E. Strong effects by X-rays on tissue. Electrical Engineering 1896; 22: 534
• 2 Groedel FM, Lininger H, Lossen H (eds). Materialsammlung der Unfälle und Schäden in Röntgenbetrieben. Hamburg: Lucas, Gräfe & Sillem; 1925
• 3 ICRP. Recommendations of the International Commission on Radiological Protection. Ann ICRP 2007; 37: 1-332
• 4 Kuon E. Radiation exposure in invasive cardiology. Heart 2008; 94: 667-674
• 5 Pantos I, Patatoukas G, Katritsis DM et al. Patient radiation doses in interventional cardiology procedures. Curr Cardiol Rev 2009; 5: 1-11
• 6 AQUA-Bundesauswertung 2011 – Koronarangiographie und perkutane Koronarintervention (PCI). Qualitätsindikatoren. AQUA–Institut für angewandte Qualitätssicherung und Gesundheitsforschung; 31.05.2011: S 62 http://www.sqg.de/downloads/Bundesauswertungen/2011/bu_Gesamt_21N3-KORO-PCI_2011.pdf Accessed November 15, 2012
• 7 Bogaert E, Bacher K, Lemmens K et al. A large-scale multicentre study of patient skin doses in interventional cardiology: dose-area product action levels and dose reference levels. Br J Radiol 2009; 82: 303-312
• 8 Hirshfeld JW Jr, Balter S, Brinker JA et al. ACCF/AHA/HRS/SCAI clinical competence statement on physician knowledge to optimize patient safety and image quality in fluoroscopically guided invasive cardiovascular procedures: a report of the American College of Cardiology Foundation/American Heart Association/American College of Physicians Task Force on clinical Competence and Training. Circulation 2005; 111: 511-532
• 9 Chambers CE, Fetterly KA, Holzer R et al. Radiation safety program for the cardiac catheterization laboratory. Catheter Cardiovasc Interv 2011; 77: 546-556
• 10 Russo GL, Tedesco I, Russo M et al. Cellular adaptive response to chronic radiation exposure in interventional cardiologists. Eur Heart J 2012; 33: 408-414
• 11 Geisel D, Zimmermann E, Rief M et al. DNA double-strand breaks as potential indicators for the biological effects of ionising radiation exposure from cardiac CT and conventional coronary angiography: a randomized, controlled study. Eur Radiol 2012; 22: 1641-1650
• 12 Eisenberg MJ, Afilalo J, Lawler PR et al. Cancer risk related to low-dose ionizing radiation from cardiac imaging in patients after acute myocardial infarction. CMAJ 2011; 183: 430-436
• 13 Roguin A, Goldstein J, Bar Olivier. Brain malignancies and ionising radiation: more cases reported. EuroIntervention 2012; 8: 169-170
• 14 Berrington de Gonzalez A, Darby S. Risk of cancer from diagnostic X-rays: estimates for the UK and 14 other countries. Lancet 2004; 363: 345-351
• 15 Kuon E, Dahm JB, Empen K et al. Identification of less irradiating angulations in invasive cardiology. J Am Coll Cardiol 2004; 44: 1420-1428
• 16 Kuon E, Schmitt M, Dorn C et al. Predialing the number of cinegraphic frames enables an effective patient dose due to coronary angiography of 0.8 mSv. Fortschr Röntgenstr 2003; 175: 1706-1710
• 17 Kuon E, Empen K, Rohde D et al. Radiation exposure to patients undergoing percutaneous coronary interventions – Are current reference values too high?. Herz 2004; 29: 208-217
• 18 Kuon E, Empen K, Robinson DM et al. Efficiency of a minicourse in radiation reducing techniques: a pilot initiative to encourage less irradiating cardiological interventional techniques (ELICIT). Heart 2005; 91: 1221-1222
• 19 Georges JL, Livarek B, Gibault-Genty G et al. Reduction of radiation delivered to patients undergoing invasive coronary procedures. Effect of a programme for dose reduction based on radiation-protection training. Arch Cardiovasc Dis 2009; 102: 821-827
• 20 Mori S, Nishizawa K, Kondo C et al. Effective doses in subjects undergoing computed tomography cardiac imaging with the 256-multislice CT scanner. Eur J Radiol 2008; 65: 442-448
• 21 Hausleiter J, Meyer TS, Martuscelli E et al. Image quality and radiation exposure with prospectively ECG-triggered axial scanning for coronary CT angiography: The multicenter, multivendor, randomized PROTECTION-III study. JACC Cardiovasc Imaging 2012; 5: 484-493
• 22 Smith-Bindman R, Lipson J, Marcus R et al. Radiation dose associated with common computed tomography examinations and the associated lifetime attributable risk of cancer. Arch Intern Med 2009; 169: 2078-2086
• 23 Stumpp P, Gosch D, Kühn A et al. Performance of an automatic dose control system for CT: patient studies. Fortschr Röntgenstr 2013; 185: 144-152
• 24 Achenbach S, Barkhausen J, Beer M et al. Konsensusempfehlungen der DRG/DGK/DGPK zum Einsatz der Herzbildgebung mit Computertomographie und Magnetresonanztomographie. Fortschr Röntgenstr 2012; 184: 345-368
• 25 Einstein AJ, Elliston CD, Arai AE et al. Radiation dose from single-heartbeat coronary CT angiography performed with a 320-detector row volume scanner. Radiology 2010; 254: 698-706
• 26 Zimmermann E, Dewey M. Whole-heart 320-row computed tomography: reduction of radiation dose via prior coronary calcium scanning. Fortschr Röntgenstr 2012; 183: 54-59
• 27 Chen CM, Liu YC, Chen CC et al. Radiation dose exposure of patients undergoing 320-row cardiac CT for assessing coronary angiography and global left ventricular function. Int J Cardiovasc Imaging 2012; 28 (Suppl. 01) 1-5
• 28 Achenbach S, Marwan M, Ropers D et al. Coronary computed tomography angiography with a consistent dose below 1 mSv using prospectively electrocardiogram-triggered high-pitch spiral acquisition. Eur Heart J 2010; 31: 340-346
• 29 Hart D, Jones DG, Wall BF. Estimation of the effective dose in diagnostic radiology from entrance surface dose and dose-area product measurements. NRPB-R262 National Radiological Protection Board Chilton Didcot, Oxon OX11 0RQ, 1994: 36
• 30 Miller DM, Vañó E, Bartal G et al. Occupational Radiation Protection in Interventional Radiology: A Joint Guideline of the Cardiovascular and Interventional Radiology Society of Europe and the Society of Interventional Radiology. Cardiovasc Interv Radiol 2010; 33: 230-239
• 31 Fetterly KA, Mathew V, Lennon R et al. Radiation dose reduction in the invasive cardiovascular laboratory. Implementing a culture and philosophy of radiation safety. JACC: Cardiovascular Interventions 2012; 5: 866-873