Open-configuration magnetic resonance (MR) guided microwave thermocoagulation treatment for breast tumors: Preliminary report of hepatic metastases and resected breast tumors

Abstract

11095 Background: Minimally invasive therapies such as radiofrequency ablation, focused ultrasound surgery, and cryotherapy for early stage primary breast cancers may be appropriate in carefully selected patients. In this study, open-configuration magnetic resonance (MR)-guided microwave thermocoagulation treatment was used for breast tumors, and the efficacy of this treatment was assessed. Methods: We used MR-guided microwave thermocoagulation treatment on eight patients with metastatic liver tumors from breast cancer. A 0.5 T open-configuration MR system and a microwave coagulator were used. Near-real-time MR images and real-time temperature images were collected and displayed on the monitor. Secondly, it was examined whether the description of breast tumors was possible with open- configuration MR device, and simulated a tumor puncture while imaging a real-time MR image. The resected breast tumor was punctured while confirming the tumor with open-configuration MR system, and microwave thermocoagulation was enforced. Tumor tissue viability after microwave thermocoagulation was assessed by hematoxylin and eosin and NADH vital staining. Results: The visibility of the tumor by MR imaging was not disturbed throughout the procedure. In 8 patients, 11 hepatic metastases were treated by MR-guided microwave thermocoagulation treatment successfully without any major adverse event. Five of the 8 patients are alive with new metastatic foci with a mean observation period of 25.9 months (range 1 - 43 months). It was able to be confirmed that viability of the tumor had disappeared by the microwave thermocoagulation in resected breast tumors. Conclusions: This technique is feasible and safe to treatment of breast tumor with real-time observation. Open-configuration MR-guided microwave thermocoagulation therapy appears to be a feasible method with advantages to add to the growing list for nonsurgical ablation therapy of early stage primary breast cancer and should be investigated in further comparative studies. No significant financial relationships to disclose.