HIFU for the treatment of difficult colorectal liver metastases with unsuitable indications for resection and radiofrequency ablation: A phase I clinical trial.

Abstract

e16715 Background: Previous studies showed that high intensity focused ultrasound (HIFU) treatment could treat liver tumor and pancreatic cancer, with fewer serious adverse reactions.To evaluate the safety and efficacy of HIFU for patients with colorectal liver metastases(CRLM) that were contraindicated for resection and radiofrequency ablation. Methods: Patients between 20 to 80 years of age with 1-3 liver metastases from colorectal cancer were included. The primary colorectal lesions were thoroughly resected and any case with extra-hepatic metastasis was excluded. Ultrasound guided HIFU system was employed and target region ablation was achieved with repeated sonications from the deep to shallow regions of the tumor section by section. Results: Thirteen patients were enrolled. Pain was the most common adverse events(AEs) (n = 8), followed by fatigue (n = 7), increased aspartate aminotransferase (AST) (n = 7), increased alanine aminotransferase(ALT) (n = 5), and skin edema (n = 4). No grade≥3 AEs occurred.The majority of patients (76.9%) had a complete response and the remaining three patients achieved partial response. The objective response rate was 100% after the first HIFU treatment. Nine patients relapsed but most were isolated only in the liver (8/9). The median follow-up was 25 months. The 2-year progression-free survival (PFS) was 16.7%, and median PFS was 9 months. Notably, the 2-year overall survival (OS) was 77.8%, and median OS was 25 months. Conclusions: This study indicates that HIFU treatment is safe, has an excellent tumor response and long-termprognosis even when the foci in risky locations, and is probably a considerable option for patients who were unsuitable for other local treatments.