Application of ultrasound combined with microbubbles in conversion therapy for advanced liver cancer

Ultrasound combined with microbubbles (USMB) at a low mechanical index has been shown to enhance blood perfusion and drug delivery, suggesting its potential to augment tumor immunotherapy. This study aims to evaluate whether the addition of USMB to conversion therapy can improve tumor response and local perfusion in patients with advanced hepatocellular carcinoma (HCC), while maintaining a comparable safety profile. This study enrolled 40 patients with unresectable advanced hepatocellular carcinoma (HCC) who underwent conversion therapy, including locoregional interventional therapy, targeted therapy, and immunotherapy. All patients underwent two contrast-enhanced ultrasound (CEUS) examinations after the conversion therapy to assess changes in perfusion. The experimental group (n = 16) received adjuvant ultrasound-mediated microbubble (USMB) treatment in the interval between the two examinations, whereas the control group (n = 24) did not. Following conversion therapy, the maximum diameter of the viable tumor in the combination treatment group [Formula: see text] was significantly smaller than that in the control group [Formula: see text] [Formula: see text]. Moreover, the reduction rate of the maximum viable tumor diameter was significantly greater in the combination treatment group [Formula: see text]. Although the combination group demonstrated a higher clinical benefit rate, no statistically significant difference in treatment response according to modified Response Evaluation Criteria in Solid Tumors (mRECIST) was observed between the two groups [Formula: see text]. In addition, CEUS evaluation showed an increase in the blood flow perfusion index in the combination group following ultrasound treatment. USMB can improve local blood flow perfusion in advanced liver cancer and may enhance the efficacy of conversion therapy without increasing treatment-related adverse effects.