Schematic diagram of the new cancer pain management concept Ideal cancer pain control goals are: good sleep at night, elimination of pain during quiet time and elimination of pain during physical activity, with the ultimate goal of improving the patient’s quality of life/survival. In the past, the concept of cancer pain management was that neurointervention was considered when all other antinociceptive therapies failed to provide effective analgesia. However, in this state, the vicious circle of pain has been formed, and most of the pain has evolved into intractable pain, and it is difficult for neurointerventional therapy to be fully effective. Since neurointerventional therapy has the advantages of precise analgesic effect and does not directly affect the patient’s general state, level of consciousness and mental activities, it should be intervened at an appropriate time in the early stage of cancer pain treatment, and should never be regarded as the last resort of anti-pain treatment when all kinds of therapies are ineffective. The new concept of cancer pain treatment suggests that neurointerventional therapy, in combination with WHO three-step therapy and other antinociceptive treatments, can effectively improve the overall level of antinociceptive therapy, which is of great significance in improving the quality of life of cancer patients. The expanded WHO three-step analgesic program also emphasizes the principle of multidisciplinary treatment and comprehensive control of cancer pain. Basic principles of neuro-intervention 1. The analgesic principles, advantages and disadvantages of neuro-interventional therapy techniques should be explained to patients in detail beforehand. 2. The operation technique, indications and possible complications of neuro-interventional therapy should be carefully discussed. 3. The cause of pain should be clarified beforehand. 4, imaging guidance is important for nerve destructive treatment, especially when performing sympathetic nerve block or other special operations. 5, as far as possible in the pain of early intervention, and should not wait until analgesic drugs, radiotherapy and surgical treatment can not control. 6, should not rely solely on neurointerventional therapy to control pain, to focus on the joint application of internal, surgical and psychological treatment. 7, for afferent nerve block pain, body nerve intervention is generally ineffective or ineffective. 8, for the abdominal plexus, hypogastric plexus, odd ganglion and other sympathetic sources of pain, should be used as early as possible physical or chemical neurointerventional therapy techniques for nerve destruction; for the early sympathetic pain, local anesthetic can be used to repeat the block. Indications and contraindications for neurointervention Indications The following pains are preferred for neurointervention: ① somatic neuralgia limited to several spinal cord segments; ② sympathetic-mediated thoracic, abdominal and pelvic pain; ③ sympathetic-related extremity pain. Destruction of the nerve responsible for pain can partially or completely abort the pain within its corresponding innervation range. For trunk and limb pain caused by cancer invading somatic nerves, physical or chemical destruction of nerve roots is more effective. For very limited somatic neuropathic pain in the trunk, head and neck, peripheral nerve destruction is often effective. For sympathetic-related pain in the extremities, sympathetic nerve block is often a satisfactory analgesic. In addition, for disseminated cancer pain, intrathecal micromorphine pump placement can be considered as appropriate, and transsphenoidal pituitary block can also be used as appropriate. For patients with half of the body pain below the level of the 4th cervical vertebra, and the survival period is less than 1 year, transcutaneous thalamotomy (radiofrequency thermocoagulation) can be considered. Contraindications ① patients and family members do not agree; ② bleeding tendency, especially attention to radiation, chemotherapy patients; ③ can not maintain a specific position; ④ general condition is very poor. Commonly used neurological interventions Spinal nerve intervention Spinal nerve intervention is a simpler method of neurological intervention, which can be used for the elderly and patients with poor general conditions. However, it should be noted that this technique may lead to dysfunction of the body (especially motor function), and it should be repeatedly explained to the patients and their families in advance. The advantage of this technique is that it does not require particularly complicated medical equipment and can be carried out at the grassroots level; if the analgesia is not complete, it can be repeated. The pain it targets is limited to somatic nerves, and it is not effective for visceral pain, discharge pain, and afferent nerve block pain. When the pain site is in more than 2 places, the site with severe pain should be treated first; for bilateral pain, the side with heavier pain should be treated first, and then the opposite side should be treated after 1~2 days. When the main pain is removed, the original secondary pain will be revealed as the new main pain, which can still continue to be treated with neuro-interventional therapy, and the intervention method can be chosen from physical or chemical methods. The technique emphasizes strict asepsis and as little preoperative medication as possible. Commonly used methods include subarachnoid space spinal nerve posterior root block (destruction), epidural nerve block (destruction), nerve root intervention and peripheral nerve intervention. Cranial nerve interventional therapy Cranial nerve interventional therapy is often less effective than spinal nerve because of the following reasons: (1) the distribution of its nerves is complex, and the effect of 1~2 nerve block is incomplete; (2) the tumor’s enlargement and infiltration bring more difficulties to the operation of cephalic and facial nerve block, which is originally narrow in the territory; (3) the distribution and function of cranial nerves often limit the disfiguring treatment due to the specificity of cranial nerve distribution and function. Commonly used methods include trigeminal nerve block, glossopharyngeal nerve block, vagus nerve block and superior laryngeal nerve block, etc. Physical or chemical methods are available. Sympathetic interventional therapy ① For diffuse surgical scar after radical mastectomy, burning neuralgia in the ipsilateral upper limb, axilla and shoulder, etc., and swelling, bruising and burning pain in the upper limb caused by upper thoracic tumors invading brachial plexus nerves or large blood vessels, cervical sympathetic interventional therapy is effective; ② For chest pain, upper limb pain and epigastric pain caused by metastasis of lung cancer and malignant tumors, thoracic sympathetic ganglion interventional therapy is available; ③ For pancreatic, hepatic and liver pain, chest pain, upper limb pain and epigastric pain due to metastasis of malignant tumors, chest pain is effective. ③ For pain caused by tumors of pancreas, liver, gallbladder, stomach and other upper abdominal organs or metastatic cancer pain in the upper abdomen, abdominal plexus intervention can often be completely controlled, but sometimes it needs to be combined with spinal nerve block to achieve the best curative effect; if the tumor invades the abdominal wall and posterior peritoneum at the same time, it often manifests as deep pain in the upper abdomen and lower back, and the effect of abdominal plexus intervention is mostly unsatisfactory, and the effect can be perfected if subarachnoid block is performed in combination. If combined with subarachnoid block, the analgesic effect can be perfected; ④ For the pain originated from tumors in the lower abdomen and pelvic visceral organs, it is feasible to intervene in the lower abdominal plexus; ⑤ For the oedema and burning neuralgia caused by tumors in the pelvis and pelvic visceral organs in the lower limbs with impaired lymphatic reflux, it can be relieved by intervening in lumbar sympathetic ganglion; ⑥ For the pain of anal pain or metastatic pain of anus after rectal cancer, it is feasible to intervene in the odd ganglion. Commonly used drugs include anhydrous ethanol, phenol glycerin and local anesthetics. Commonly used physical methods include radiofrequency thermocoagulation technology. Electrical stimulation treatment At present, the main ones used for pain treatment are spinal cord electrical stimulation, deep brain stimulation and motor cortex stimulation. Spinal cord stimulation is generally effective for limited pain caused by tumors, especially for neuropathic pain caused by tumors with the best effect. Deep brain stimulation and motor cortex stimulation are stimulation modalities in which electrodes are placed stereotactically into the gray matter around the aqueducts and periventricular gray matter or motor cortex to treat intractable pain that cannot be alleviated by other methods. Central target-controlled analgesic system placement The operation of central target-controlled analgesic system placement is to place a special catheter in the subarachnoid space, and then the programmable analgesic pump is placed under the patient’s skin, and the catheter is connected to the pump with subcutaneous tunnels, and the drug reservoir inside the pump can store morphine or other drugs or medications, and the infusion system of the pump can input medications into the cerebrospinal fluid of the subarachnoid space through the catheter in a sustained, slow, and uniform speed to achieve the purpose of pain control. The purpose of pain control is achieved. As morphine directly acts on endorphin receptors in the spinal cord and brain, a small amount of morphine in the pump can achieve satisfactory analgesic effect, and its dosage is equivalent to 1/300 of the oral dosage, which reduces the side effects brought by morphine systemic medication. The catheter can be put into the cerebral ventricle to avoid poor cerebrospinal fluid reflux caused by the destruction of vertebrae. Other Percutaneous Vertebroplasty For the vast majority of patients, percutaneous puncture injection of biomaterials (mostly polymethylmethacrylate) into the vertebral body can provide immediate pain relief. For vertebral bodies accompanied by bone destruction or compression fracture, it can also increase the strength and stability of the vertebral body, effectively preventing the vertebral body from further collapsing and spinal deformation. Pain relief and improved mobility occur within 24 hours of treatment, and pain relief has been reported in >70% of patients with vertebral malignancies. This technique is primarily indicated for painful vertebral fractures caused by bone malignancies. Neurosurgical treatment Neurosurgical treatment mainly includes peripheral neurotomy, dorsal root ganglionectomy, dorsal root into the medullary area destruction, spinal cord anterolateral column amputation, spinal cord median incision, medial thalamus destruction, cingulate destruction, midbrain destruction and pituitary gland removal, etc., most of which are seldom used nowadays because of excessive side effects. Currently, dorsal root entrapment area destruction is more frequently used, which mainly destroys the nociceptive nerve fibers consisting of the lateral part of the dorsal root branches and the excitatory medial part of the posterior lateral fasciculus, and at the same time partially preserves the inhibitory neural structures in the dorsal root entrapment area and attenuates the local excitability of the afferent fibers that feel the nociceptive stimulation, and suppresses the injurious nerve impulses that originate from the reticular thalamic pathway of the spinal cord. It is more effective for neurogenic pain caused by malignant tumors of bone and joint.