Treating Liver Cancer with 90Y Associated With Tolerable Rate of Biliary Toxicity

The arsenal for the minimally invasive therapy of primary liver cancer (HCC) or metastatic liver cancer is ever expanding. Now, Yttrium-90 (90Y) radioembolization is showing promise as an effective treatment for both HCC and metastatic disease.

This therapy is currently being used only in clinical trials. The early and late complications of 90Y therapy are now being reported and compared to other forms of therapy.

A recent study has shown that biliary complications of 90Y therapy for liver cancer are similar in type and incidence as TACE (trans-arterial chemoembolization) or ablation therapy; however, the incidence is higher in patients being treated for metastatic disease compared to hepatocellular carcinoma.

The study was designed to report specifically on the biliary complications of 90Y therapy, and to compare it to the biliary complications of other therapies.

In the study, 327 patients who had been treated with 90Y were prospectively followed.

Methodology
Patients were treated with 90Y therapy at 2 institutions. Imaging, liver function tests, and serum total bilirubin measurements were performed.

Results
Biliary complications seen on imaging occurred in 10% of patients after 90Y therapy. Biliary sequelae caused unplanned interventions in 6 patients (1.8%).

There were biochemical toxicities in 22.3% of patients, with 9.5% having bilirubin toxicity specifically.

Of all patients treated for HCC, only 3.6% had biliary findings on follow-up.

Of all patients treated for metastatic disease, 19% had biliary findings.

In this series, 10% of patients had biliary complications. As documented with other treatment modalities, there is increased incidence of biliary complications in patients treated for metastatic disease versus those patients with HCC.

These researchers believe that the cause of this is 2-fold. First, the cirrhosis seen with HCC has a protective effect on the plexus. In patients with metastatic disease, their previous chemotherapy is toxic to the biliary plexus, leaving it more prone to radiation damage.

As seen in other modalities, risk factors for biliary sequelae included previous TACE, and the presence of a biliary enteric anastomosis.

The incidence of biliary strictures seems to be lower than the incidence reported with RFA. The incidence of liver function tests and bilirubin toxicity is comparable to that seen in other modalities, and is probably caused by a combination of disease progression (cirrhosis) and radiation toxicity.

Reviewer’s Comments
This is a study based on a volume of prospective data from 90Y patients as an interim report. This report documents the biliary sequelae following treatment with 90Y as being similar to those found in other locoregional therapies such as TACE or ablation, with interventions needed in only 2% of patients.

These findings include biliary necrosis, focal dilation, stricture formation, biloma formation, radiation cholecystitis, abscess formation, and biochemical toxicities.

Also, as described with other therapies, the incidence of biliary findings is greater in patients with metastatic disease when compared to patients being treated for HCC.

Author: Sharon Gonzales, MD

Atassi B, Bangash AK, et al. Biliary Sequelae Following Radioembolization With Yttrium-90 Microspheres. J Vasc Interv Radiol; 2008; 19 (May): 691-697