Phase I dose-escalation study of helical intensity-modulated radiotherapy-based stereotactic body radiotherapy for hepatocellular carcinoma

// Jun Won Kim 1 , Jinsil Seong 2 , Ik Jae Lee 1 , Joong Yeol Woo 2 , Kwang-Hyub Han 3 1 Department of Radiation Oncology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea 2 Department of Radiation Oncology, Yonsei Cancer Hospital, Yonsei University College of Medicine, Seoul, Korea 3 Department of Internal Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea Correspondence to: Jinsil Seong, email: jsseong@yuhs.ac Keywords: stereotactic body radiotherapy, hepatocellular carcinoma, dose escalation, intensity-modulated radiotherapy Received: March 20, 2016 Accepted: April 16, 2016 Published: May 18, 2016 ABSTRACT Background: Phase I trial was conducted to determine feasibility and toxicity of helical intensity-modulated radiotherapy (IMRT)-based stereotactic body radiotherapy (SBRT) for hepatocellular carcinoma (HCC). Results: Eighteen patients (22 lesions) were enrolled. With no DLT at 52 Gy (13 Gy/fraction), protocol was amended for further escalation to 60 Gy (15 Gy/fraction). Radiologic complete response rate was 88.9%. Two outfield intrahepatic, 2 distant, 4 concurrent local and outfield, and 1 concurrent local, outfield and distant failures (no local failure at dose levels 3–4) occurred. The worst toxicity was grade 3 hematologic in five patients, with no gastrointestinal toxicity > grade 1. At median follow-up of 28 months for living patients, 2-year local control, progression-free (PFS), and overall survival rates were 71.3%, 49.4% and 69.3%, respectively. Multi-segmental recurrences prior to SBRT was independent prognostic factor for PFS ( p = 0.033). Materials and Methods: Eligible patients had Child-Pugh’s class A or B, unresectable HCC, ≤ 3 lesions, and cumulative tumor diameter ≤ 6 cm. Starting at 36 Gy in four fractions, dose was escalated with 2 Gy/fraction per dose-level. CTCAE v 3.0 ≥ grade 3 gastrointestinal toxicity and radiation induced liver disease defined dose-limiting toxicity (DLT). Conclusions: Helical IMRT-based SBRT was tolerable and showed encouraging results. Confirmatory phase II trial is underway.