SIR: High-dose Y-90 safe, efficacious liver tumor treatment
Outpatient intra-arterial yttrium-90 (Y-90) radioembolization provides an anti-tumoral effect in liver cancer patients where chemotherapy failed, according to a multi-institutional study presented at the Society of Interventional Radiology's 36th annual scientific meeting in Chicago. The study examined the impact of treating liver tumors with higher doses of Y-90 than previously tried.

"The surgical removal of liver tumors offers the best chance for a cure," explained Riad Salem, MD, MBA, director, interventional oncology, division of interventional radiology, department of radiology at Northwestern University in Chicago. "For many reasons, a majority of patients are not candidates for surgical resection. Liver tumors are often inoperable because the tumors may be too large or numerous or have grown into major blood vessels or other vital structures. Historically, chemotherapy drugs become less effective as the disease progresses."

Salem and colleagues sought to assess the safety, response rate and survival outcomes in patients treated with Y-90 radioembolization, a palliative treatment for liver tumors.

The four-year prospective study looked at 151 patients (55 percent male; average age 64 years) with liver metastases from colorectal, neuroendocrine and other cancers. In the U.S., 20,000 cases of primary liver cancer and 150,000 cases of metastatic disease are diagnosed each year.

With the Y-90 radioembolization treatment, microspheres are injected through a catheter from the groin into the liver artery supplying the tumor. The beads become lodged within the tumor vessels where they exert local radiation that causes cell death. This technique allows for a higher, local dose of radiation to be used, with no danger from radiation to the healthy tissue in the body, said Salem.

In this study, several subgroups showed high rates of progression-free survival, such as 186 days for neuroendocrine patients compared to 95 days for colorectal cancer patients. "These rates are an excellent indicator of the treatment's effectiveness," said Salem. Ninety-six percent of adverse events, such as heartburn, fatigue and hyberbilirubinemia, were non-serious.

"Now we know that patients can actually tolerate much higher doses of radiation than previously thought, which provides results in patients progressing on standard chemotherapy," noted Salem. "While patients aren't cured, their lives are being extended with less down time and their quality of life is improving."