Stereotactic body radiation therapy in patients with unresectable hepatocellular carcinoma and portal vein tumor thrombosis

Table 1 Baseline clinical characteristics of the study group, n (%)

Patient characteristics	Value (n = 30)
Age (median in years) (range)	65 (38-83)
Gender
Male	27 (90)
Female	3 (10)
Viral serology
Hepatitis B positive	5 (16.7)
Hepatitis C positive	5 (16.7)
Child-Pugh class at diagnosis
Child-Pugh class A	16 (53.3)
Child-Pugh class B	14 (46.7)
ALBI score (median) (range)	-2.34 (-1.11-3.43)
ALBI grade
Grade 1	7 (23.3)
Grade 2	21 (70)
Grade 3	2 (6.7)
Number of liver lesions
One	22 (73.3)
Two	6 (20)
Three	1 (3.3)
Four	1 (3.3)
Thrombus classification (Japanese)
VP2	1 (3.3)
VP3	8 (26.7)
VP4	18 (60)
VV2	1 (3.3)
VV3	2 (6.7)
Prior focal treatment
TACE	7 (23.3)
TARE	5 (16.7)
RFA	2 (6.7)
Cryoablation	1 (3.3)
Prior systemic therapy
Sorafenib	6 (20)
Lenvatinib	16 (53.3)
Atezolizumab + bevacizumab	1 (3.3)
Baseline AST (IU/mL) (mean ± SD)	46 ± 12
Baseline ALT (IU/mL) (mean ± SD)	49 ± 15

ALBI: Albumin-Bilirubin; TACE: Transarterial chemoembolization; TARE: Transarterial radioembolization; RFA: Radiofrequency ablation; AST: Aspartate aminotransferase; ALT: Alanine aminotransferase.

Table 2 Treatment characteristics of the study group, n (%)

Treatment characteristics	Value (n = 30)
Dose fractionation
30 Gy/6 #	1(3.3)
30 Gy/5 #	4 (13.3)
50 Gy/5 #	5 (16.7)
40 Gy/5 #	6 (20)
48 Gy/4 #	1 (13.3)
35 Gy/5 #	6 (20)
33 Gy/6 #	1(3.3)
36 Gy/3 #	3 (10)
48 Gy/6 #	1(3.3)
45 Gy/5 #	2 (6.7)
Treatment volumes
GTV diameter (median cm) (range)	6.1 (2.54-10.63)
GTV volume (median cc) (range)	49.05 (8.6-308)
PTV diameter (median cm) (range)	7.9 (3.7-20.54)
PTV volume (median cc) (range)	165.22 (27.3-453.6)
Serum AFP (prior to SBRT) (mean ± SD) (ng/mL)	7181.14 ± 17948	P value = -0.049
Serum AFP (3 months after SBRT) (mean ± SD) (ng/mL)	2183.44 ± 7323

GTV: Gross tumor volume; PTV: Planning target volume; AFP: Alpha-fetoprotein; SBRT: Stereotactic body radiation therapy.

Table 3 Survival characteristics of the study group, n (%)

Time	OS	PFS
Median	13 months	10.2 months
6-month	71	72
1-year	53	33

OS: Overall survival; PFS: Progression-free survival.

Table 4 Log rank test for various factors influencing the overall survival

Factor	Comparison (median overall survival)	Log-rank χ2 (P value)
Child-Pugh class at baseline; A vs B	13 months vs 10 months	2.6 (0.106)
CP class 2 weeks post SBRT; A vs B vs C	17 months vs 13 months vs 3 months	5.3 (0.069)
ALBI grade at baseline; Grade 1 vs Grade 2 vs Grade 3	17 months vs 11 months vs 1 month	2.35 (0.309)

SB: Stereotactic body radiation therapy; ALBI: Albumin-Bilirubin; SBRT: Stereotactic body radiation therapy.

Table 5 Cox proportional hazard analysis of factors affecting the overall survival

Factor	Hazard ratio (95%CI)	P value
Age	0.998 (0.891-1.11)	0.967
Baseline AFP	1.000 (0.96-1.43)	0.265
Baseline bilirubin	0.897 (0.32-2.49)	0.834
Child-Pugh score at baseline	0.594 (0.22-1.58)	0.296
ALBI score at baseline	1.217 (0.26-5.6)	0.801
GTV diameter	0.77 (0.40-1.47)	0.435
GTV volume	0.992 (0.956-1.02)	0.992
PTV diameter	0.996 (0.663-1.49)	0.985
PTV volume	1.080 (0.97-1.19)	0.446

AFP: Alpha-fetoprotein; ALBI: Albumin-Bilirubin; GTV: Gross tumor volume; PTV: Planning target volume; CI: Confidence interval.