Phase I Study of Hyperfractionated Radiation Therapy with Protracted 5-Fluorouracil Infusion in Patients with Locally Advanced Pancreatic Cancer

Abstract

Objective: This study investigated the maximum-tolerated dose of hyperfractionated radiation therapy with protracted 5-fluorouracil (5-FU) infusion in patients with locally advanced, unresectable pancreatic cancer. Methods: Five cohorts of patients were scheduled to receive escalating doses of hyperfractionated radiation therapy (range, 45.6–64.8 Gy). All patients received two fractions of 1.2 Gy each (separated by 6 h) per day for 5 days a week, and received protracted 5-FU infusion (200 mg/m²/day) during the radiation course. The maximum-tolerated dose was defined as one dose level below the dose at which more than one third of 3–6 patients experienced dose-limiting toxicity. Results: Twenty-nine patients were enrolled in this study. The most common toxicities were nausea/vomiting and anorexia. Although 1 patient developed bleeding from a gastric ulcer 3 months after the completion of chemoradiotherapy, the maximum-tolerated dose was not reached even at the highest dose level (level 5, 64.8 Gy). The median survival time was 12.2 months and the 1-year survival rate was 55.0%. Conclusion: The toxicity associated with our regimen was tolerable up to dose level 5 (64.8 Gy). We are currently conducting a phase II study of this hyperfractionated radiation therapy with protracted 5-FU infusion at a dose of 64.8 Gy.