Concomitant hepatic radiation and intraarterial fluorinated pyrimidine therapy: correlation of liver scan, liver function tests, and plasma CEA with tumor response.

Sixteen patients with metastatic disease to the liver (12 colorectal and four unknown primary tumors) were treated in a pilot study of hepatic irradiation (2500-3000 rads in 10-12 fractions) delivered concomitantly with continuous short-term intraarterial infusion of 5-fluorouracil (1 g/d) or FUDR (0.5 mg/kg/d) via a percutaneously placed hepatic artery catheter. Abnormal liver function tests, including SGOT, LDH, and alkaline phosphatase, decreased in all patients by day 7-10 of treatment, and other metabolic factors, including serum cholesterol, calcium, albumin, phosphorous, and uric acid, also decreased, often to subnormal levels by termination of treatment (day 15-20). These chemical alterations did not correlate with tumor response in that the identical pattern was observed in responders (ten patients) as well as nonresponders (six patients). Objective determinants of response were assessed by serial monitoring of the plasma carcinoembryonic antigen (CEA) and liver scan. In 14 patients with elevated CEA levels, tumor response (nine patients), nonresponse (four patients), and relapse (five patients) was predicted and confirmed by sequential monitoring of CEA. In one patient, a paradoxical decrease in plasma CEA was associated with progressive disease. The liver scan identified all responding patients but was difficult to quantitate and was delayed for months following subjective clinical response and changes in plasma CEA levels.