Aim: To determine whether the use of high-intensity focused ultrasound (HIFU) ablation combined with cisplatin, compared with HIFU ablation, and cisplatin alone, facilitates tumor necrosis and reduces tumor volume in an animal model.
Materials and methods: The cervical cancer cell line SiHa was cultured and injected subcutaneously into female BALB/c nude mice. Animals that developed tumors were randomized to four groups: treatment with HIFU ablation and cisplatin (i.p. injection, 100 mg/mouse twice per week); cisplatin treatment alone; HIFU ablation alone; and control. The dimensions of the tumor were measured transcutaneously using a vernier caliper. After mice were sacrificed, tumor excised, and triphenyl tetrazolium chloride (TTC) staining was carried out to investigate the area of coagulation necrosis in the tumors.
Results: Out of the 32 animals that developed tumors, 25 had tumors able to be measured through subcutaneous palpation in the pretreatment period (control, n=7; HIFU ablation, n=7; cisplatin, n=6; combination of HIFU ablation and cisplatin, n=5). In the group receiving HIFU ablation with cisplatin, tumor volume decreased significantly when compared with the other groups. TTC staining showed that necrosis was induced in the central zone of the tumors that were ablated by HIFU, and chemotherapy enhanced the effect of HIFU ablation in the combination therapy group.
Conclusion: HIFU ablation combined with cisplatin facilitates reductions in tumor volume and increases in tumor necrosis and could be useful as another option in treating patients with cervical cancer.