Purpose: Responses to liver-directed therapy with yttrium 90 microspheres (SIR-Spheres) and adjuvant intraarterial chemotherapy have occurred in patients with unresectable colorectal hepatic metastases who had received less than one chemotherapy regimen. Now, SIR-Spheres are being used to treat patients with advanced disease who have received multiple chemotherapy regimens. A retrospective analysis was performed to determine the technical feasibility of SIR-Sphere treatment in this population.

Materials and methods: The medical records of 12 patients with hepatic metastatic disease and intrahepatic progression after multiple chemotherapy regimens for unresectable colorectal hepatic metastases who were treated with one or two infusions of SIR-Spheres were retrospectively analyzed for demographics, tumor characteristics, treatment details, response, and survival.

Results: Twelve patients underwent 17 outpatient infusions of SIR-Spheres. Percent hepatic tumor volume was less than 25% in four patients, 25%-50% in three, and more than 50% in five. Treatment in 11 patients with bilobar disease was accomplished via single infusions in six cases and sequential unilobar infusions in five patients. A single infusion was used to treat unilobar disease in the remaining patient. Median prescribed dose was 39.6 mCi (mean, 37.2 mCi; range, 17-67.5 mCi); the prescribed dose exceeded the delivered dose in six infusions (35%) as a result of embolic arterial occlusion. Radiologic response was stable in five of nine patients. Carcinoembryonic antigen levels decreased in four of seven patients. Four patients received chemotherapy concomitantly or after completion of treatment. Gastric ulceration in one patient was managed nonoperatively. Median survival times from diagnosis and treatment were 24.6 and 4.5 months, respectively.

Conclusions: Treatment with SIR-Spheres induces responses in patients with advanced unresectable colorectal hepatic metastases after multiple chemotherapy regimens. Inability to deliver the prescribed dose is related to the embolic effect of SIR-Spheres.