Preliminary experience using high intensity focused ultrasound for treating liver metastasis from colon and stomach cancer

Purpose: To determine the efficacy and safety from our preliminary results of using high intensity focused ultrasound (HIFU) to treat liver metastasis from colon and stomach cancer. Materials and methods: Ten patients with liver metastasis from colon cancer and three from stomach cancer underwent HIFU under general anesthesia. HIFU was performed using an extracorporeal, ultrasound-guided focused system. Complications during the study, extent of coagulative necrosis at two-week follow up, and evidence of tumor on further follow up were analyzed. Patients were divided into four categories: (I) complete ablation with no evidence of recurrence on follow up; (II) apparent complete ablation of target mass with new foci of disease in the target organ or distant malignancy and no local tumor progression; (III) local tumor progression after apparent complete ablation; (IV) partial ablation. Results: Mean follow-up period was 22 weeks in the colon cancer group and 58 weeks in the stomach cancer group. The sum of total lesion size was between 1.8 cm and 21.4 cm (mean: 8.4 cm ± 6.7 cm) for the colon cancer group and between 1.7 and 16.3 cm (mean: 8.8 cm ± 7.3 cm) for the stomach cancer group. In the colon cancer group, one patient was categorized as category I, one as category II, three as category III, and the remaining five as category IV. The stomach cancer group showed two patients as category I, and one as category II. Conclusion: For treating liver metastasis from colon and stomach cancer HIFU seems safe but its efficacy is questionable. Further research is warranted.