疼痛是常困擾及嚴重影響癌症病人生活品質的症狀之一，骨轉移疼痛更是照護上困難處理的問題。除了鴉 片類止痛藥物處置及緩和性放射治療之外，磁振導航聚焦超音波熱治療（Magnetic Resonance-guided Focused Ultrasound, MRgFUS）提供了非侵入性之疼痛處置的新選擇。MRgFUS治療原理為利用核磁共振導航系統來精 確定位，將超音波聚焦於骨頭疼痛處區域，加熱至60°C以上，以熱消融（Thermal Ablation）破壞骨頭表面引發 疼痛的神經組織及標靶腫瘤，同時保留周圍的正常組織，達到疼痛緩解與局部腫瘤控制的治療目的。MRgFUS 於2012年通過美國FDA核准使用於骨轉移疼痛處置，2014年通過台灣衛生福利部許可，同年臺北醫學大學附設 醫院率先引進MRgFUS ExAblate® System，至2015年底已完成56個骨轉移個案的緩解疼痛治療。MRgFUS適用於 緩和放射治療骨轉移無效者，及骨轉移但不願意接受放射線治療者。MRgFUS採單次治療方式，恢復期短，合 併症少，少數病人在治療過程中會出現疼痛、皮膚灼傷、神經損傷、深層靜脈血栓或顯影劑過敏。在一跨國多 中心的研究指出：治療後3天平均疼痛強度分數（10 cm-VAS）從5.9降至3.8，治療後第三個月的平均疼痛強度降 至1.8，且發現治療區有骨密度新增情形。整體而言，此新治療提供有效的骨轉移疼痛處置，進而改善病人的生 活品質。

Bone metastases are commonly associated with debilitating pain in patients with advanced cancer, often influencing their quality of life. Current treatment options for pain control of bone metastases consist of systemic therapies (such as chemotherapy, analgesics, biphosphonates and hormonal therapy) and local treatments (e.g., surgery, palliative radiotherapy and so on). Unfortunately, many patients with bone metastases still suffered severe pain due to most medical therapies do not achieve a long-term-efficacy, cause side effects or who do not respond to radiation therapy. Magnetic resonance-guided focused ultrasound (MRgFUS) is a noninvasive thermal ablation that enables the physician to perform localized treatment of bone metastases. The possible mechanism of MRgFUS for pain palliation may be thermal periosteal denervation in bone surface surrounding the tumor. In October 2012, the U.S. Food and Drug Administration (FDA) has approved the MRgFUS (ExAblate® MRgFUS system, InSightec, Inc., Haifa, Israel) for pain palliation associated with bone metastases. In 2014, ExAblate® MRgFUS system had also been approved by Ministry of Health and Welfare in Taiwan. The Taipei Medical University Hospital (TMUH) has installed MRgFUS system in 2014, and 56 cancer patients who diagnosed with bone metastases had received this system for palliation of their pain till the end of 2015. Earlier evidence showed that patients who treated with MRgFUS for treating their pain of bone metastases reported significant decrease in pain severity and pain interference, improving their quality of life, a reduction in their use of analgesics, and increase of bone density at the site of treated osteolytic metastases at 3 months post treatment follow-up. Therefore, MRgFUS was demonstrated to be effective palliative treatment for the painful bone metastases and assessed the potential of the technique for localized tumor control.