Embolization Plus Immediate Ablation Promising for Unresectable Liver Tumors
By Thomas R. Collins
Medscape Medical News
January 19, 2010 (Hollywood, Florida) — Treatment with embolization using microspheres followed by immediate radiofrequency ablation is showing promising results in patients with liver tumors that are too complex or too big to be treated with surgery, according to early results from a study presented here at the 2010 Symposium on Clinical Interventional Oncology.
All 19 patients in whom the combination was used were disease-free at their last follow-up (average follow-up, 17 months; range, 1 to 33 months), said lead investigator Franco Orsi, MD, from the Unit for Interventional Radiology at the European Institute of Oncology in Milan, Italy.
Researchers are continuing to follow the patients.
Because of the potential risks to liver function with surgical management, many patients are not candidates for liver resection. Many nonsurgical cases are treated with radiofrequency ablation. But liver tumors that are large and/or located in vital areas could have even worse outcomes when radiofrequency ablation is used by itself.
As a result, Dr. Orsi and colleagues treated these more difficult tumors with ablation immediately after embolization, when the lesions are at their most vulnerable. Dr. Orsi said he is unaware of similar work being conducted anywhere else.
"The idea was to combine the 2 techniques in order to take advantage of the hypoperfusion and ischemic effect of the microbland embolization to enhance the necrotic effect of the ablation," Dr. Orsi told meeting attendees.
The microbland embolization technique uses microspheres to block blood vessels immediately around the tumor, even those as small as 10?microns in diameter. The "bland"-ness of the spheres means that there is no chemotherapeutic component, he explained.
Immediately after embolization, during the same session, surgeons performed ablation.
Most of the liver tumors, all of which were considered unresectable, were metastases stemming from a variety of tumors elsewhere — colorectal, the bile duct, the lung, the uterus, and the breast. Two of the lesions were primary liver tumors.
The average age of the patients was 65.3 years, and half were male. The average tumor size was 3.8?cm.
There were 2 instances that Dr. Orsi described as "major complications." One patient had biliary damage and was treated with percutaneous left hepatic biliary drainage, and another had liver bleeding, requiring arterial coil embolization.
Studies have shown that 80% to 100% of tumors 3?cm in diameter or smaller are completely killed by radiofrequency ablation alone. But for those in the 3.5 to 5.0?cm range, studies have shown that only 50% to 80% get completely ablated with that technique. For those larger than 5?cm, only 25% get ablated completely, studies have found, Dr. Orsi reported.
"This is because the type of vessel we need to embolize is around 10 to 120?microns" and cannot be closed off with standard techniques, Dr. Orsi said. The microspheres can shut down even these tiniest of vessels.
"A combined technique in the same session is absolutely feasible and it might prevent multiple hospital admissions, so it can be even considered cheaper" than standard practice, Dr. Orsi said.
The microspheres also help visually to identify the tumor, making treatment during ablation more precise, he told Medscape Oncology after his presentation.
If the patients continue to show good results, the technique could be used more widely, said William Rilling, MD, director of vascular and interventional radiology at the Medical College of Wisconsin, Milwaukee, who attended Dr. Orsi's presentation and moderated other sessions at the meeting.
"The cases he showed were very challenging cases without great surgical options, so the very aggressive protocol that he used was pretty impressive," Dr. Rilling told Medscape Oncology.
He noted the wide variety of metastases the study treated. "We run into more and more patients like that all the time," he said, "because patients are living longer with cancer in general."
This study did not receive commercial support. Dr. Orsi and Dr. Rilling have disclosed no relevant financial relationships.
2010 Symposium on Clinical Interventional Oncology. Presented January 16, 2010.
