Staying at the Forefront of International Cardiology Dose Regulations with DTS

With an increase in the number and complexity of catheter-based coronary interventions, there is growing concern about radiation exposure to patients and staff in cardiac catheterization labs.

Dr. Ananth Prasan was appointed staff specialist in cardiology at St George Private Hospital, Sydney, Australia, in 2003. His special interest is in managing radiation dose in the cath lab and he has co-authored several papers focused on radiation dose.

“In adult cardiology patients, coronary angiography represents just 12% of all radiology procedures, but contributes disproportionately to their collective radiation dose; 48% 1” remarked Dr.Prasan. “Radiation exposure is also an important issue for cath lab staff. An interventional cardiologist is exposed to two to three times more radiation per year than a radiologist 2.”

“Minimizing radiation dose has always been a priority for our Department at St George Private Hospital, and we make a conscious effort to keep informed of the latest clinical radiation dose management techniques and technologies,” he continued. “We were very excited to implement Canon Medical Systems' novel Dose Tracking System (DTS) when it was released ten years ago.”
Ananth Prasan MD, PhD, Cardiologist, St George Private Hospital, Australia
DTS is a patient-centric model that records the patient’s skin dose in realtime, according to imaging parameters and geometry. It displays an easy-to-read color-coded representation of the cumulative skin dose distribution on a patient graphic and the real-time peak skin dose and cumulative skin dose values at the current real-time beam projection.

This provides operators with an accurate demonstration of the dose received during an examination, enabling operators to modify their approach during procedures to avoid regions where dose thresholds could be exceeded and reduce the risk of skin burns. It also provides cumulative dose information for patients who require follow-up, helping us to make an informed decision about if it is safe to proceed with a case.

“It was clear that DTS would be an effective tool to help our department in dose reduction,” said Dr. Prasan. “It provides insights that you cannot gain from any other technology. However, we wanted a way to measure its effectiveness.”

Dr. Prasan and his colleagues at St George Private Hospital worked at one of the world’s first clinical sites to implement DTS technology. In 2016, they published their research on its impact on patient skin dose and total dose during coronary angiography and intervention in EuroIntervention, The Official Journal of EuroPCR, and the European Association of Percutaneous Cardiovascular Interventions (EAPCI) 3.

During their study, DTS was used in 1,077 patients who underwent coronary angiography, 460 of whom underwent a percutaneous coronary intervention (PCI). Peak skin was com- pared before and after the adoption of DTS at the site.
Figure 1: Reduction in peak skin dose due to DTS introduction for PCI procedures. The DTS resulted in an improvement in peak skin dose. Bars represent median and error bars 95% confidence interval.
“The benefits of DTS were experienced across a range of patient cohorts but were particularly evident during stent insertion where there was a 46% reduction in peak skin dose 4,” said Dr. Prasan. “Its benefits were not only obvious for skin dose -DTS also proved effective in reduc- ing the total procedural radiation dose.

“The ongoing real-time feedback that DTS provides is a critical tool in helping to modify the behavior of our operators to reduce radiation dose, particularly in long, complex interventions like CTO procedures,” he added. "DTS has dramatically lowered our department's total average case dose, reducing our staff's occupational radiation exposure.
It is easy to implement, use, and interpret and has accelerated the learning of correct imaging parameters for new staff and registrars."
Figure 1: Reduction in peak skin dose due to DTS introduction for PCI procedures. The DTS resulted in an improvement in peak skin dose. Bars represent median and error bars 95% confidence interval.

“The benefits of DTS were experienced across a range of patient cohorts but were particularly evident during stent insertion where there was a 46% reduction in peak skin dose 4, which in turn equals lower staff dose.”

Ananth Prasan MD, PhD, Cardiologist, St George Private Hospital, Australia
Through use of Canon Alphenix system, Dr. Prasan has access to many options for reducing dose.

“Canon has a long-standing commitment to dose reduction in interventional procedures, and it’s great to see this is a priority for them. The Alphenix provides us with an arsenal of innovations to minimize radiation dose, all without impacting image quality in the region of interest,” he said. “The automatic preset settings allow you to fine-tune and optimize your imaging parameters to maximize image quality and lower dose. Complex interventions are increasing, and with this comes longer cases, so the ability to adjust parameters and drop your frame rate without losing image quality becomes very important.”

He has found that Canon interventional systems provide images with high temporal and spatial resolution without appearing overprocessed or artificial.
“The images provides us with a good understanding of stent placement and overlap. We can obtain optimal visualization for a wide range of patient sizes and projections with fluoroscopy and minimize digital acquisitions as much as possible,” he explained.

Dr. Prasan is pleased that there is a universal trend in interventional cardiology to quantify and monitor actual patient procedural doses.

“Our department’s ten years’ experience with DTS has enabled us to be at the forefront of this trend and deliver the best patient outcomes,” he said. “We have a comprehensive range of tools available at our disposal to easily implement to suit various cases as required, and to ensure that each patient gets the lowest possible dose without impacting on image quality.” //

“Our department’s ten years’ experience with DTS has enabled us to be at the forefront of this trend and deliver the best patient outcomes.”

Ananth Prasan MD, PhD, Cardiologist, St George Private Hospital, Australia

References
1 Bedetti G, Botto N, Andreassi MG, Traino C, Vano E, Picano E. Cumulative patient effective dose in cardiology. Br J Radiol. 2008;81:699-705
2 Picano E, Vano E. The radiation issue in cardiology: the time for action is now. Cardiovasc Ultrasound. 2011 Nov 21;9:35. doi: 10.1186/1476-7120-9-35. PMID: 22104562; PMCID: PMC3256101.
3 Wilson S, Prasan A, Virdi A, Lassere M, Ison G, Ramsay D, Weaver J. Effect on patient peak skin and total dose during coronary angiography. EuroIntervention, 17(3), e2520-e2526.
4 Sharon M. Wilson, Ananth M. Prasan, Amy Virdi, Marissa Lassere, Glenn Ison, David R. Ramsay, James C. Weaver. Real-time colour pictorial radiation monitoring during coronary angiography: effect on patient peak skin and total dose during coronary angiography. EuroIntervention, 12(8), e939-e947.

St George Private Hospital, Australia