To report the results of a phase I/II study of helical IMRT-based stereotactic body radiotherapy (SBRT) for hepatocellular carcinoma (HCC).
Eligibility included Child-Turcotte-Pugh class A or B, ≤3 lesions, and cumulative tumor diameter ≤6 cm. Dose was escalated from 36 Gy to 60 Gy delivered in 4 fractions. Grade ≥3 gastrointestinal toxicities (CTCAE v3.0) or radiation-induced liver disease defined dose-limiting toxicity (DLT).
Thirty-two patients were enrolled: seven in dose levels 1-2 (36-44 Gy) and 25 in levels 3-4 (42-60 Gy). Failures included 1 local, 14 outfield intrahepatic, 2 distant, 1 concurrent local and outfield, 1 concurrent outfield and distant, and 1 concurrent local, outfield, and distant. Nine had grade 3 hematologic toxicities and 5 had grade 2 hepatic toxicities; no patient experienced DLT. Two-year local control (LFFS), outfield intrahepatic control (OutFFS), and overall survival (OS) rates were 80.9%, 46.7%, and 81.3%, respectively. Dose levels 3-4 and pre-radiotherapy multi-segment recurrence were independent prognostic factors for LFFS and OutFFS, respectively. Two-year LFFS, OutFFS, and OS were significantly higher for patients who were treated with dose-levels 3/4 for tumor(s) involving single segment compared with the rest of the patients.
Helical IMRT-based SBRT was safe and effective, and patients with multi-segment recurrences prior to SBRT need to be closely followed.