Results From the Coiling vs Surefire Infusion System in Y90 Trial: An Interview With Aaron Fischman, MD

In March, data from the Coiling vs Surefire Infusion System in Y90 (COSY) clinical trial were presented at the Society for Interventional Radiology meeting in San Diego.  Results showed significant reductions in the endpoints of fluoroscopy time, procedure time, radiation dose, and contrast dose when using the Surefire Infusion System (Surefire Medical) without coiling. The randomized prospective study evaluated the primary endpoint of fluoroscopic time between Surefire selective internal radiation therapy (SIRT) vs a standard microcatheter and investigated the feasibility and benefits of performing SIRT planning without the need to place permanent coils. 

Selective internal radiation therapy is a direct-to-tumor minimally invasive radiation therapy generally used to treat selected patients with primary or secondary liver tumors. The Surefire Infusion System has an expandable tip designed to minimize reflux and maximize direct-to-tumor delivery of embolic agents. It is used for diagnostic and therapeutic radioembolization or chemoembolization procedures. 

The study used a sample size of 30 in which half of the patients had permanent embolic coils placed in blood vessels to protect healthy tissue from damage. The other half underwent the procedure using the Surefire Infusion System without coiling. Interventional Oncology 360 spoke with principal investigator Aaron Fischman, MD, assistant professor of radiology and surgery at the Icahn School of Medicine at Mount Sinai in New York. 

Q: Could you describe the COSY study methods?

A: The concept behind this study was to compare standard coil embolization that’s typically done during Yttrium-90 (Y90) administration to the use of the Surefire Infusion System, and the hypothesis was that by using the system we would accomplish several things. One would be to decrease the radiation dose and fluoroscopy time of the procedure. Another endpoint that we thought would decrease would be the procedure time, the contrast dose used, and the use of coils, and we knew that by using the Surefire we would use no coils so we designed it in such a way that we would only include patients that had arteries that we thought should be coiled during the procedure and then randomized those patients to coil embolization vs the Surefire. The study was performed between March 2013 and September 2013. A manuscript describing the results has been submitted for publication.

Q: Can you explain a little bit about the differences between the two methods that you compared—the actual procedures themselves?

A: All the procedures were performed under conscious sedation using typical monitoring by interventional radiology nursing. We used right femoral artery access in both procedures. The first part of Y90 therapy is to do a planning angiogram, so we performed a diagnostic angiogram and then randomized patients into the 2 arms. The diagnostic angiogram consisted of a superior mesenteric artery angiogram and a celiac artery angiogram and then the patients were divided into 2 groups. One arm received treatment with the Surefire system, the other received a standard microcatheter with coil embolization of the gastroduodenal artery and any other vessels that were considered nontarget vessels that were potentially at risk for nontarget embolization during the Yttrium infusion. 

The coil embolization arm received standard embolization using Interlock-18 detachable coils (Boston Scientific) until the operator felt it was adequate for occlusion and then the microcatheter was advanced into the target vessel. The procedure was completed by infusing technetium labeled macroaggregated albumin (MAA). 

In the Surefire arm, the target vessel was identified and the Surefire catheter was advanced into the target vessel without doing any sort of coil embolization. The catheter was deployed in the target artery and MAA was infused from that location. Approximately 2 weeks later, both patients groups were brought back for their Yttrium therapy. The same procedure was performed, so that the Surefire arm got the Surefire catheter, the coil embolization arm got a standard microcatheter and the Y90 was delivered in the same exact location where the MAA was delivered several weeks earlier. Then we measured the same endpoints during both procedures as well as safety endpoints up to 30 days. 

Q: What do you feel were the most striking results?

A: The primary endpoint in the study was fluoroscopy time during the mapping study. We anticipated that it would be somewhat lower, but it was significantly lower by a factor of 3. We measured the fluoroscopy time starting after all the diagnostic angiograms were performed; we didn’t measure any of the access fluoroscopy time or time spent catheterizing the celiac because we felt that was unrelated to whether the procedure was performed or which group was being analyzed. We measured the fluoroscopy time from the time that the catheter was deployed to when the procedure was completed, and the average fluoroscopy time in the coil embolization arm was 6 minutes vs 1.8 minutes in the Surefire arm. 

Q: What were the conclusions that you reached?

A: About half the patients were treated for primary hepatocellular carcinoma. The other half had metastatic disease such as colon cancer, neuroendocrine cancer, stomach cancer and bile duct cancer. The secondary endpoints that we looked at were the total procedure time, the contrast dose, and the radiation dose, which is measured off of the fluoroscopy machine—all of those endpoints were also significantly decreased. We also looked at differences in the amount of dose delivered during the actual Y90 therapy and there was no statistical difference between the dose delivered in both groups. We concluded that the use of Surefire in this patient population was safe, without major or minor adverse events, and the procedure was considered successful in every case. We were able to successfully deliver the intended dose in all patients and the hypotheses that the procedure would be shorter, involve less radiation, and use less iodinated contrast—the hypotheses were all true.

Q: Did this study raise any questions that you think will be addressed in further follow-up study?

A: Yes and no. Follow-up studies that look at the use of this device to eliminate coil embolization and to successfully protect nontarget embolization or reflux in the liver and outside the liver can and should be performed. In some ways, it does change our clinical practice because sometimes coil embolization may be too time consuming or unsafe for certain reasons. 

Q: What is the most important takeaway from this for IO clinicians to remember?

A: I think the important takeaway is that this is a technically feasible option for patients having this procedure. I believe it increases the safety of the procedure. It has the potential to theoretically decrease the cost of the procedure. It’s safe and it decreases the radiation dose to both operators and patients, which is always a good thing. 

Editor's note: Disclosure: Dr. Fischman reports receiving grants from Surefire Medical. 

Suggested citation: Ford J. Results from the Coiling vs Surefire Infusion System in Y90 trial: an interview with Aaron Fischman, MD. Intervent Oncol 360. 2014;2(5):E40-E42.