Phase II Trial of High-Dose Conformal Radiation Therapy With Concurrent Hepatic Artery Floxuridine for Unresectable Intrahepatic Malignancies

Abstract

A phase II trial was conducted to determine if high-dose radiation with concurrent hepatic arterial floxuridine would improve survival in patients with unresectable intrahepatic malignancies. Three-dimensional conformal high-dose radiation therapy was delivered concurrently with hepatic arterial floxuridine in 128 patients. The radiation dose was based on a normal-tissue complication probability model and subjected the patient to an estimated maximum risk of radiation-induced liver disease of 10% to 15%. The study design provided more than 80% power to detect a two-fold increase in median survival compared with historical controls at a 5% significance level. The median radiation dose delivered was 60.75 Gy (1.5-Gy fractions bid). At a median follow-up time of 16 months (26 months in patients who were alive) the median survival was 15.8 months (95% CI, 12.6 to 18.3 months), significantly longer than in the historical control. The actuarial 3-year survival was 17%. The total dose was the only significant predictor of survival. Primary hepatobiliary tumors had a significantly greater tendency to remain confined to the liver than did colorectal cancer metastases. Overall toxicity was acceptable, with 27 patients (21%) and 11 patients (9%) developing grade 3 and 4 toxicity, respectively, and one treatment-related death. The results suggest that, compared with historical controls, high-dose focal liver irradiation with hepatic artery floxuridine prolongs survival in patients with unresectable chemotherapy-refractory metastatic colorectal cancer and primary hepatobiliary tumors. This provides a rationale for intensification of local therapy for unresectable hepatobiliary cancers and integration of this regimen with newer systemic therapy for patients with colorectal cancer.