4th European Live Summit on Retrograde CTO Revascularization - May 8–9, 2015, in Zurich, Switzerland

1. The CTO dose registry: a
tool for optimizing patient radiation
protection
Carlo Maccia (PhD)
Centre d’Assurance de qualité des Applications Technologiques dans le
domaine de la Santé (CAATS)
Bourg-La-Reine - France

2. GENERAL FRAMEWORK
• The increasing number and complexity of CTO
procedures has led to a higher number of
patients at risk for tissue reactions and skin
injuries.
• Monitoring of their dose indicators is essential
in recognizing these patients, optimizing their
radiation protection and organizing their follow
up.

3. Angular distribution of x-ray beams and
overlaps CTO - LAD and Right Coronary
artery
1st attempt
(280 impacts)
2nd attempt
(241 impacts)

4. 2nd attempt: 1 day later

5. Objectives of the CTO dose registry
• Assess patient radiation protection practices
and implement optimization strategies
• Provide a tool for educational purposes in
radiation protection
• Better define high dose procedures
• Define trigger levels for different procedures
(antegrade, retrograde)
• Give guidelines about thresholds

6. Objectives of the CTO dose registry
• Set up a core team of 4-5 experts (medical
physicist, interventional cardiologist, nurse or
radiographer(?), bio-medical engineer(?)) to
review cases
• Define incidents/accidents, according to Basic
Euro CTO Club, Safety Standards, European
Basic Safety Standards, local laws…

7. RECOMMANDATIONS
• There must be a commitment of major CTO
participating centers to be able to keep the
registry up and running at all times, and to
update and adapt to new demands or
regulations continuously :
– New x-ray systems like hybrid cath-labs and new
medical interventional procedures
– More staff involved including new medical
specialists

8. RECOMMANDATIONS
• Registry should be easily accessed and the
forms should be easy to fill in
• Registry could include reporting dose levels
relevant to tissue reactions like RIHD (radiation-
induced heart diseases) or cancer
• Some trigger events should be included
whatever the procedure
– wrong patient, wrong procedure, unintended
exposure of pregnant patient

9. RECOMMANDATIONS
• Registry should offer information and benefits
to the participating center, like :
– a list of things that could go wrong and ways to
avoid them
– as well as general (cumulative dose is usually only
an indicator, less and less accurate the further from
the isocenter one is working)
– tailored advice including expert review or training
programme if needed.

10. RECOMMANDATIONS
• There should be interaction with the users
(provided they have agreed)
a) to get more information about some
cases
b) to offer optimization means

11. RECOMMANDATIONS

12. THE REGISTRY OUTCOMES
• Graphs and histograms per procedure (median
and 3rd quartile) because outliers are easy to
identify
• Explanation of outstanding values
• Graphs of AK (Cumulative Air Kerma at IRP) vs
number of patients, or per patient if repeated
procedures in same location, and/or for the
same lesion

13. THE REGISTRY OUTCOMES
• Estimated peak skin dose at different levels of accuracy
depending on the amount of information given by the
machine
• All information from the manufacturer from both fluoro
and cine runs
– Patient Dose Structured Report
– Dose report
– DAP and/or AK information
– Fluoro time
– Statistics on local, international or published average
for the procedure

14. PROMOTION OF THE CTO DOSE
REGISTRY
• A means of promotion of the CTO dose registry could
be a certificate underscoring that the participating
center is part of a recognized international quality
system (EuroCTO club for instance)
• CTO dose registry slides should be included in training
material in the ERCTO website
• To give talks about CTO dose registry in invited lectures
in training courses and professional meetings

15. TECHNICAL POINTS
• Organizing data collection (SDR report)
• Ensuring quality of data
• Maintaining database
• Handling data
• Data analysis
• Preparing a EuroCTO club final document.
• Publishing a paper

16. LOCAL DOSE REGISTRY RESULTS
18 months follow-up (n = 810)
0
30
60
90
120
150
180
210
240
DAP (Gy.cm2) Air-Kerma (cGy) Fluoroscopy Time
(min)
Equip 1
Others

17. LOCAL DOSE REGISTRY RESULTS
18 months follow-up (n = 810)
0
50
100
150
200
250
300
350
400
450
DAP (Gy.cm2) Air-Kerma (cGy) Fluoroscopy Time
(min)
Antegrade
Retrograde

18. LOCAL DOSE REGISTRY RESULTS
18 months follow-up (n = 810) : mean
DAP values by cardiologist
0
50
100
150
200
250
A B C D F E G H I
DAP (Gy.cm2)

19. LOCAL DOSE REGISTRY RESULTS
18 months follow-up (n = 810) : mean
AK values by cardiologist
0
500
1000
1500
2000
2500
3000
3500
4000
4500
A B C D F E G H I
AK (mGy)

20. Conclusion
 Use the best dose reduction options available
as frequently as possible
 Manage radiation as well as you manage
drugs or contrast agents
 Collaborate with medical physicist
(dosimetry)
 Complying with it will lead to substantial dose
savings for both patient and operator.