Magnetic resonance-guided high-intensity focused ultrasound treatment of locally advanced pancreatic adenocarcinoma: preliminary experience for pain palliation and local tumor control

The purpose of this study was to evaluate the feasibility of magnetic resonance-guided focused ultrasound (MRgFUS) ablation for pain palliation and local tumor control in selected patients with unresectable primary pancreatic adenocarcinoma. After providing dedicated informed consent, 7 patients with histologically proven unresectable pancreatic adenocarcinoma underwent MRgFUS treatment on a dedicated 3-T unit featuring a dedicated ablation system. All lesions were evaluated for device accessibility before the treatment. Procedures of MRgFUS were performed with the patients under general anesthesia with constant controlled respiration. Clinical assessment included evaluation of symptom severity using a visual analog scale before and after the treatment. Imaging follow-up, including both computed tomographic and magnetic resonance examinations, was performed immediately after the treatment and at 3 and 6 months to evaluate the effects of MRgFUS on the targeted tumor and the occurrence, if any, of procedure-related complications. The MRgFUS ablation was successfully performed in 6 patients; no adverse events were observed during or after the procedure. In a single patient, lesion accessibility was limited at treatment time, and the procedure was suspended. The visual analog scale score decreased in all patients from a mean (SD) of 7 (1) to 3 (1) after the treatment. Follow-up imaging results revealed negligible (n = 1) or no (n = 5) tumor regrowth within the ablation area. One patient died because of a metastatic disease 13 months after the treatment, whereas the other 5 are nonprogressing survivors at 6 and 8 months after the treatment. Our preliminary clinical experience suggests that MRgFUS is a feasible and repeatable ablative technique in selected patients with unresectable and device-accessible pancreatic adenocarcinoma.