Phase I Radiation Dose-Escalation Study to Investigate the Dose-Limiting Toxicity of Concurrent Intra-Arterial Chemotherapy for Unresectable Hepatocellular Carcinoma

Concurrent intra-arterial chemotherapy and radiotherapy (iA-CCRT) can increase the response rate in hepatocellular carcinoma (HCC), but may cause a higher toxicity. We conducted this Phase I study to investigate the dose-limiting toxicity of iA-CCRT for HCC. In total, 52.5 Gy in 25 fractions was prescribed as planning target volume (PTV) 1 at dose level 1. The dose escalation was 0.2 Gy per fraction and up to 2.5 Gy, with 62.5 Gy at level 3. Concurrent intra-arterial 5-fluorouracil was administered during the first and fifth weeks of radiotherapy (RT). Toxicities were graded using the Common Toxicity Criteria for Adverse Events, version 4.0. Results: Seventeen patients with HCC were analyzed: four at dose level 1, 6 at level 2, and 7 at level 3. The mean irradiated dose administered to the uninvolved liver at each dose level was 21.3, 21.6, and 18.2 Gy, respectively. There was no grade ≥3 gastrointestinal toxicity; two patients experienced grade 3 hyperbilirubinemia. All patients had Child-Pugh class A disease, but 3 patients developed class B disease after iA-CCRT. During a median follow-up of 13 months, the median progression-free survival (PFS) and overall survival (OS) were 10 and 22 months, respectively. Patients treated at dose level 3 showed improved PFS and OS. Conclusions: Radiation dose escalation of iA-CCRT did not cause any significant toxicities in patients with advanced HCC. Further large-scale studies with long-term follow-up are needed to determine the efficacy and feasibility of higher doses of iA-CCRT.