Bone is often the most common site of metastasis for many types of malignant tumors, and metastases may occur throughout the body. The rapid development and large size of some sites of bone metastases and the large number of important surrounding blood vessels and nerves often make them a challenge for clinical treatment. Surgical resection is usually the treatment of choice. However, metastatic lesions that recur after one or several surgical resections are usually larger in extent and have more indistinct boundaries with normal tissues than the initial lesions, which is related to the fact that the previous surgery destroyed the normal physiological barrier while removing the tumor. As the number of tumor recurrences increases, the difficulty of surgery increases significantly. Sometimes recurrent tumors leave both doctors and patients feeling desperate and helpless. With the advancement of medical technology, a number of minimally invasive or non-invasive treatments have emerged in recent years to bring new hope for bone tumors that cannot be surgically removed. Among them, ultrasound focused therapy is a new direction to break the treatment dilemma. Ultrasound focused therapy (HIFU) uses an ultrasound generator to generate multiple beams of ultrasound to focus on the target area of the tumor to produce thermal effects and kill the tumor tissue. The target area can form a high temperature treatment point of 70℃~100℃ within 0.5-1 second, and the tumor tissues will lose the ability of proliferation, infiltration and metastasis due to the coagulative necrosis caused by the thermal and cavitation effects. It is similar to the principle of using focusing mirror to gather sunlight which can generate great energy to make fire. There is a large amount of scientific literature proving that HIFU knife in clinical application can effectively kill tumors, inhibit tumor proliferation, greatly reduce the rate of tumor metastasis, and significantly prolong the life of patients. Initially, HIFU knife was applied in the treatment of gynecological tumors, such as uterine fibroids and cervical cancer, etc. Based on the successful experience in the treatment of gynecological tumors, it was later widely extended to be used in the treatment of tumors of various systems. Malignant tumors in orthopedics are characterized by unclear boundaries, difficult resection and prone to local recurrence and metastasis, especially lesions that recur again after surgical resection, where the normal anatomical barrier is broken and the tumor extent is difficult to determine, which has become a major problem in surgical treatment. HIFU knife is also a kind of physical therapy, unlike microwave and other physical therapies, HIFU knife only produces thermal effect on the focused area and does not damage the surrounding normal tissues. However, HIFU knife is positioned in the target area by ultrasound, because ultrasound does not have the function of temperature measurement, so that the doctor does not have precise control over the temperature and range of the target area during the treatment, and often accidentally injures the nerves and other normal structures of the neighboring tumors. The improved MR guided focused ultrasound therapy (MRgFUS) perfectly combines the ultrasound focused therapy with the temperature measurement function of MRI, enabling the doctor to detect the local temperature in real time during the treatment, which not only further enhances the efficiency of tumor treatment, but also reduces the rate of accidental injury to the surrounding normal tissues from the thermal effect. Most patients feel significant pain relief after MRgFUS treatment, tumor tissue necrosis occurs in the treated area within a few days after the procedure, and tumor size can be significantly reduced. Although there are still some limitations of ultrasound focused therapy for some specific sites of tumors at this stage. However, its non-invasive nature and tumor killing effect regardless of the type of tumor still have great advantages and attraction. Some of the tumors that cannot be treated with MRgFUS include some tumors that have other objects between the ultrasound generator and the tumor (usually their own bones) obscuring them or tumors surrounded by heat-conductive materials such as metal prosthesis, internal fixation, etc., which can greatly interfere with the effect of thermal effect. In such cases, the use of puncture radiofrequency ablation treatment is an option. Radiofrequency (RF) treatment technology is to precisely output ultra-high frequency electric waves through specific puncture guide needles to produce local high temperature in local tissues, which can play the role of thermal coagulation or tumor ablation and shrinkage. The first RF ablation technique was used for transcatheter treatment of cardiac arrhythmias and other heart diseases, and then it was gradually extended to the treatment of herniated discs and bone tumors. Compared with ultrasound focused therapy, a different mechanism is used to produce the same thermal effect to kill tumor tissue. At the same time, the various antigens in the tumor cells lysed by heat apoptosis can also activate their own immune system to further attack the tumor cells. Clinical studies have shown that the tumor tissues near the RF ablation site undergo significant necrosis and liquefaction, and repeated treatments can also control the scope and growth rate of larger tumors. And its trauma is the size of a needle hole, and you can get out of bed on the day of treatment. The accuracy of treatment can be greatly improved if the puncture is performed under CT or x-ray guidance. The first two methods are to treat tumors through high temperature thermal effect, so does low temperature have any effect on tumors? The answer is yes. Cryoablation is a medical technology that applies freezing to eliminate target tissues. The history of medicine shows that cryotherapy first appeared in the treatment of dermatological diseases more than 3500 years ago, and humans have understood the destructive effect of extremely low temperature on tissues since then. The establishment of truly “modern” cryotherapy began in the late 1990s and is attributed to two major advances: imaging technology and new refrigeration equipment. Thanks to the widespread use of ultrasound and CT, it is possible to accurately insert cold probes under the monitoring and guidance of imaging technology, observe the freezing process in real time, and finely control the extent of freezing, thus ensuring effective freezing of the target tissue without damaging or minimizing damage to normal tissue. Similar to radiofrequency ablation, cryopreservation technology has been extended from transcatheter treatment of heart disease to gynecology, gastroenterology and bone tumors. It is suitable for patients who are intolerant to the severe pain caused by high temperature radiofrequency, and the treatment causes less collateral damage to the neurovascular surrounding the tumor. With the advancement of engineering and medical science, new treatment technologies have shown a spurt of development, which has brought a boon to patients with bone metastases. Minimally invasive, effective killing and precise guidance are the main directions of non-surgical surgical treatment. For now, surgical resection is still the preferred primary treatment, but for tumors that cannot be removed surgically, the use of minimally invasive treatment can also achieve similar treatment goals and greatly improve the quality of life. Tips: The Department of Bone Oncology of the First People’s Hospital of Shanghai Jiao Tong University is specialized in the treatment of bone tumors. It carries out various minimally invasive treatment techniques all year round, including radiofrequency ablation technology, cryoablation technology, magnetic resonance mediated ultrasound focused therapy, etc., and formulates individualized treatment plans according to different conditions of patients to minimize pain and improve survival quality.