Radiation Segmentectomy Studied to Treat Liver Cancer

April 27, 2018—The Radiological Society of North America (RSNA) announced that findings from a study of radiation segmentectomy (RS) as a curative treatment option for patients with early stage hepatocellular carcinoma (HCC) were published online by Robert J. Lewandowski, MD, et al in RSNA's Radiology. The study's Senior Investigator is Riad Salem, MD, who is Chief of Vascular Interventional Radiology in the Department of Radiology at the Northwestern University Feinberg School of Medicine in Chicago, Illinois.

RSNA noted many patients are not candidates for curative options for early stage HCC such as surgery, liver transplantation, and radiofrequency ablation because of the presence of other conditions. In addition, these treatments carry significant costs and potential complications.

Catheter-based RS therapy delivers beads embedded with radioisotope yttrium-90 (Y-90) to destroy tumors in the liver while sparing much of the surrounding healthy tissue. Cone-beam CT imaging is used to distinguish segments of the liver, provide a detailed view of its complex vasculature, and focus delivery of the Y-90 to the relevant segment. Dr. Salem explained, "Cone-beam CT has revolutionized our ability to perform segmental injections isolated to very small tumors, sparing the majority of normal tissue. Before cone-beam CT, we had the ability to focus radiation, but not with this level of accuracy."

As summarized by RSNA, the investigators studied long-term outcomes in 70 early stage HCC patients who had undergone RS between 2003 and 2016. They analyzed the patients' responses to treatment based on two commonly used sets of criteria.

Based on one set of criteria, 90% of patients showed a positive response to the therapy, of which 59% showed complete response. Based on the second set of criteria, 71% achieved a positive response, of which 16% achieved complete response.

RS controlled the target tumor, slowed the time to disease progression, and improved survival outcomes at rates comparable to radiofrequency ablation, surgery, and transplantation for early stage HCC patients.

Approximately three-quarters of patients had no progression of cancer in the target tumor 5 years after treatment. Median overall survival was 6.7 years, and 1-, 3-, and 5-year survival probabilities were 98%, 66%, and 57%, respectively. The 1-, 3-, and 5-year overall survival probability was 100%, 82%, and 75%, respectively, in patients with a baseline tumor size ≤ 3 cm.

The investigators concluded that RS provides response rates, tumor control, and survival outcomes comparable to curative-intent treatments for selected patients with early stage HCC who have preserved liver function. The investigators continue to follow the patients from the study group as they work on ways to optimize the treatment, noted RSNA.

In the society's announcement, Dr. Salem commented, "The results show that we are able to impart curative outcomes to these patients. Our numbers with RS match or outperform those of other curative treatments in terms of tumor control, survival rate, and recurrence."

Dr. Salem continued, "We want to see these outcomes validated in patients over the longer term. We also want to minimize the time from clinic visit to treatment and fine-tune dosimetry so that we can find the optimal dose that will kill the tumor. In the right patient setting, RS can be considered curative."