Department of Breast Surgical Oncology, Kawaguchi Kogyo General Hospital
【Introduction】 The therapeutic ultrasound for breast cancer which is one of the non-surgical ablations is in the trial setting to investigate to take place of the usual surgery. It must achieve to just the same efficacy and safety of the usual surgery. The monitoring of the treatment and follow-up is the compass to the goal. The clinical trials aiming to investigate the efficacy and the safety of the therapeutic ultrasound of breast cancer have been performed from 2004 to 2015. The using applications and the eligibility for breast cancer treatment are the fruits of the failure for 10 years. 【Methods】 Breast cancer were treated with MRI guided Focused Ultrasound Surgery （MRgFUS）. The excision study as the first step trial was that pathological inspection of excised specimen to investigate efficacy of MRgFUS （Journal of American College of Surgeons, 203: 54-63，2006）. The next step was the excisionless study. This study was the just follow-up after MRgFUS followed by radiotherapy. Treated cancerous lesion was investigated whether viable cancer remains or not by HE and single strand DNA stein of needle biopsy specimen. The endpoint of this study is 5years local recurrence rate. 【Results】 A case of III°grade breast skin burn was experienced in the excision study. The anterior vertical shift was observed in many cases and less treatment at the pectoral muscle side in some cases. One local recurrent case was experienced which was detected by follow-up MRI in the excisionless study. The cause was cancer displacement by the needle. There is no severe adverse event. 【Discussion】 The cause of III° skin burn in the excision study probably was not a system error but a human error. To ensure the safety, checking patient’s vital signs during the procedure, using the security camera, taking every three seconds MRI and emergency stop the treatment are all set. Learning from the skin burn case, the software was improved. That is the prohibition system of sonication when the skin energy density will be 750J in each sonication. The treatment simulation tells us the extent, especially the skin side, of the treatment energy. The length of the anterior vertical shift became predictable. To ensure the efficacy, thermometry, volumetry and dosimetry are established in this treatment system. Moreover the weighted elongate spot which targets the pectoral muscle side in the treatment early phase and then moves to the skin side seconds by seconds was developed to control the microbubble, the cavitation and the anterior vertical shift. All the computerized treatment process and the documents are preserved in the excisionless study. They are regularly monitored by the clinical research coordinators （CRC） for at least 5years. 【Conclusion】 The efficacy and the safety of MRgFUS of breast cancer are ensured by our monitoring system. Moreover the accumulated documents and data will improve the present system.