The challenge of inoperable hepatocellular carcinoma (HCC): results of a single-institutional experience on stereotactic body radiation therapy (SBRT)

To evaluate the feasibility and efficacy of stereotactic body radiation therapy (SBRT) in the treatment of hepatocellular carcinoma (HCC) unsuitable for standard loco-regional therapies.

Patients with 1–3 inoperable HCC lesions with diameter ≤6 cm were treated by SBRT. According to lesions size and liver function, two prescription regimens were adopted: 48–75 Gy in three fractions or 36–60 Gy in six fractions. SBRT was delivered using the volumetric modulated arc therapy technique with flattening filter-free photon beams. The primary end points of this study were in-field local control (LC) and toxicity. Secondary end points were overall survival (OS) and progression-free survival (PFS).

Forty-three patients with 63 HCC lesions were irradiated. All patients had Child–Turcotte–Pugh class A or B disease. Thirty lesions (48 %) were treated with 48–75 Gy in three consecutive fractions, and 33 (52 %) received 36–60 Gy in six fractions. Median follow-up was 8 months (range 3–43 months). Actuarial LC at 6, 12 and 24 months was 94.2 ± 3.3, 85.8 ± 5.5 and 64.4 ± 11.5 %, respectively. A biological equivalent dose (BED) >100 Gy and GTV size were significant prognostic factors for LC in univariate analysis (p < 0.001 and p < 0.02). Median OS was 18.0 ± 5.8 months. Actuarial OS at 6, 12 and 24 months was 91.1 ± 4.9, 77.9 ± 8.2 and 45.3 ± 14.0 %, respectively. Univariate analysis showed that OS is correlated with LC (p < 0.04), BED >100 (p < 0.05) and cumulative gross tumor volume GTV <5 cm (p < 0.04). Median PFS was 8 months, with a 1-year PFS rate of 41 %. A significant (≥grade 3) toxicity was observed in seven patients (16 %) 2–6 months after the completion of the treatment. No classic radiation-induced liver disease was observed.

Stereotactic body radiation therapy is a safe and effective therapeutic option for HCC lesions unsuitable to standard loco-regional therapies, with acceptable local control rates and low treatment-related toxicity. The significant correlation between LC and higher doses and between LC and OS supports the clinical value of SBRT in these patients.