The Time Course of Dynamic Computed Tomographic Appearance of Radiation Injury to the Cirrhotic Liver Following Stereotactic Body Radiation Therapy for Hepatocellular Carcinoma

This study aimed to evaluate the dynamic computed tomographic (CT) appearance of focal radiation injury to cirrhotic liver tissue around the tumor following stereotactic body radiation therapy (SBRT) for hepatocellular carcinoma (HCC). Seventy-seven patients with 92 HCCs were observed for >6 months. Sixty-four and 13 patients belonged to Child-Pugh class A and B, respectively. The median SBRT dose was 48 Gy/4fr. Dynamic CT scans were performed in non-enhanced, arterial, portal, and venous phases. The median follow-up period was 18 months. Dynamic CT appearances were classified into 3 types: type 1, hyperdensity in all enhanced phases; type 2, hypodensity in arterial and portal phases; type 3, isodensity in all enhanced phases. Half of the type 2 or 3 appearances significantly changed to type 1, particularly in patients belonging to Child-Pugh class A. After 3-6 months, Child-Pugh class B was a significant factor in type 3 patients. Thus, dynamic CT appearances were classified into 3 patterns and significantly changed over time into the enhancement group (type 1) in most patients belonging to Child-Pugh class A. Child-Pugh class B was a significant factor in the non-enhancement group (type 3).