Persistent retention of acetic acid is associated with complete tumour necrosis in patients with hepatocellular carcinoma undergoing percutaneous acetic acid injection.

BACKGROUND

Ultrasound (US)-guided percutaneous acetic acid injection therapy (PAIT) is effective for patients with hepatocellular carcinoma (HCC). This study aimed to determine the occurrence and predictive value of persistent intra-tumoral retention of acetic acid after PAIT.

METHODS

We prospectively studied 60 (52 M, mean age 68 +/- 10 years) patients with 72 HCC nodules (45 < or = 3 cm) treated with PAIT. The presence of post-treatment persistent retention of acetic acid, defined as a homogeneous and highly hyperechoid mass in US appearance 3 days after completion of the treatment, was correlated with the treatment response.

RESULTS

The mean size of the treated tumour was 2.9 +/- 1.0 cm (range 1.5-5 cm). Thirty (42%) HCC nodules showed complete tumour necrosis demonstrated by contrast-enhanced dynamic CT. Complete response was found in 22 (69%) of 32 nodules showing persistent intra-tumoral retention of acetic acid (P < 0.001). Small (< or = 3 cm) tumour size was also significantly associated with complete tumour necrosis (P = 0.001). There were no significant differences of the injection volume and treatment sessions between those with and without complete tumour necrosis in either small or large (> 3 cm) HCC (P > 0.1). Multivariate logistic regression analysis showed that persistent retention of acetic acid (odds ratio (OR) 10.4, 95% confidence interval (CI) 3.1-34.7; P < 0.001) and tumour size < or = 3 cm (OR 6.8, 95%, CI 1.8-25.8; P = 0.002) were independent factors predicting complete tumour necrosis.

CONCLUSIONS

The presence of persistent retention of acetic acid is associated with a favourable response and may predict complete tumour necrosis after PAIT.