Arterial Embolization Using Microspheres for Hypervascular Liver Metastases Refractory to Standard Treatments: A Multicenter Prospective Clinical Trial.

PURPOSE: To evaluate the clinical utility of bland arterial embolization using microspheres in patients with hypervascular liver metastases refractory to standard treatments. MATERIALS AND METHODS: Primary endpoints of this prospective single-arm non-comparative study were objective response and disease control rates (ORR and DCR), based on the modified Response Evaluation Criteria in Solid Tumors at 4 weeks after embolization. Secondary endpoints were ORR according to primary tumor, overall survival, progression-free survival (PFS), and safety. RESULTS: Twenty-five patients with a median age of 66 years (range, 40-95 years) were enrolled in this study. The median maximum diameter of liver metastasis was 3.7 cm (range, 2.0-15.2 cm). Primary lesions were colorectal cancer in 12 patients (48%, 12/25), other cancer in 7 (28%, 7/25), neuroendocrine tumor in 4 (16%, 4/25), and sarcoma in 2 (8%, 2/25). ORR and DCR were 52% (13/25) and 72% (18/25) in all patients, 42% (5/12) and 75% (9/12) in colorectal cancer patients, and 62% (8/13) and 69% (9/13) in other malignant tumor patients (p = 0.43, p > 0.99). Median survival time was 19 months in all patients, 19 months in colorectal cancer patients, and 8 months (p = 0.16) in other malignant tumor patients. Median PFS time was 4 months in all patients, 4 months in colorectal cancer patients, and 6 months (p = 0.0085) in other malignant tumor patients. There were no grade-3 or -4 adverse events. CONCLUSION: Microsphere embolization appears to be an effective and safe treatment for hypervascular liver metastases refractory to standard treatments.