Spinal metastases

Introduction to spinal metastases The spine is a predilection for multiple cancer metastases in the body. The most cancers that metastasize to the spine are lung cancer, breast cancer, kidney cancer, prostate cancer, and thyroid cancer. The most common symptom in patients with spinal metastatic cancer is back pain, often several weeks or months before other neurological symptoms. At present, there are three main methods for the treatment of spinal metastases: chemotherapy, radiotherapy and surgical methods. The goal of endoscopic surgery for metastatic tumors is to maximize the quality of life. Once the diagnosis of metastases is established, surgery or surgery combined with other treatments can play a role in relieving pain, improving or maintaining nerve function and restoring spinal integrity. The treatment of spinal metastases requires multidisciplinary involvement such as bone oncology, oncology, general medicine, radiology, radiotherapy, and neurology. basic knowledge The proportion of illness: 0.0005%-0.0007% Susceptible people: no special people Mode of infection: non-infectious Complications: hypotension, narcolepsy, dizziness

Spinal metastasis cancer etiology

Transfer method

Metastatic lesions invade the spine through a variety of mechanisms, including blood-borne, direct spread, and dissemination through the cerebrospinal fluid. The tumor dissemination mechanism is closely related to the biological behavior of the primary tumor. Blood-borne dissemination through veins or arteries is considered to be the most common route of primary tumor metastasis to the spine. Due to the abundant arterial blood supply of the vertebral body, the tumor cells are transferred from the distant primary to the spine and form metastatic lesions. The venous dissemination pathway is usually performed by Batson's plexus, a venous network without a venous valve in the longitudinal direction, connecting the vertebral vein and many other venous return pathways, including the vena cava, portal vein, azygous vein, intercostal vein, pulmonary vein, and renal vein system. Changes in the pressure of the main body lumens (such as the chest, abdomen, and pelvis) cause blood to flow through the Batson plexus, with the result that the tumor cells remain in the spine through retrograde or antegrade venous stasis. Regardless of the arterial or venous route, tumor-borne dissemination of the tumor usually causes multiple lesions of the spine. Direct spread of the primary tumor can also form metastases in the spine. Chest, abdomen or pelvic lesions can locally invade the spine, causing symptomatic spinal metastases.

Lung cancer can invade the thoracic vertebra or invade the neck-thoracic junction. In addition, prostate, bladder, and colorectal cancer can be infiltrated into the lumbar spine or atlas. Tumor cells in the cerebrospinal fluid can form spinal or spinal cord metastases by shedding or planting, which often occurs after brain or cerebellar metastatic or primary tumor surgery, similar to blood-borne dissemination, causing multiple lesions. Spinal tumors are classified into three categories based on anatomical distribution: epidural, extramedullary-dural, intramedullary. The vast majority of spinal metastases occur in the epidural, the vertebral part of the spine and surrounding tissues. Most of the epidural metastases occur in the vertebral body with or without infiltration into the vertebral body, followed by the paravertebral region and the epidural space. Intradural and intramedullary metastases are rare and generally spread through the cerebrospinal fluid. Metastases can occur in all segments of the spine, but the thoracic vertebra is the most common site, followed by the lumbar vertebrae, cervical vertebrae and atlas.

Spinal metastases prevention

Active treatment of primary cancer: If the primary cancer is present, or has not been treated, or relapsed after treatment, it is necessary to actively treat the primary cancer, otherwise the efficacy of metastases will be affected, and new metastases may appear. If the primary cancer is not found, the primary cancer should be actively searched for and treated.

Spinal metastatic cancer complications Complications, hypotension, narcolepsy, vertigo

Can be complicated by low orthostatic hypotension, lethargy, dizziness and so on.

Spinal metastasis of cancer symptoms Common symptoms Loss of appetite Spinal nerve root damage Spinal cord compression Motor dysfunction Sensory disorder Weight loss site Uncertain pain

Spinal metastases can cause a group of syndromes, including pain, active or autonomic dysfunction, and sensory disturbances, depending on the rate of tumor growth, the extent of bone involvement and destruction, the degree of nerve compression, and the extent of systemic disease. Rapid tumor growth can lead to rapid progression of symptoms. Dissolved tumors can lead to pathological fractures or deformities due to bone destruction. Metastatic tumors can also cause nerve root involvement and spinal cord compression, which in turn causes radiculopathy and myelopathy. In addition, signs of systemic disease, including wasting, loss of appetite, or organ failure. For large cases of metastatic sacral metastases, obvious paravertebral and even rectal masses can be found in the physical examination.

Pain

Pain is the most common complaint in patients with symptomatic spinal metastases, and can occur in 83-95% of patients, several weeks or months earlier than other neurological symptoms. The earliest symptom is the chest or back pain in the plane of the lesion. It is usually mild and intermittent. It often does not attract attention. It is treated with symptomatic treatment and gradually becomes persistent severe pain. The first symptom of 10% of cancer patients is spinal metastase-associated pain. There are three typical types of pain in patients with spinal metastases, including local pain, mechanical pain, and radiculopathy. The pain experienced by the patient may be one of these types, or it may be a combination of multiple types. Differentiating the type of pain in individual patients is a critical part of the diagnostic evaluation process. Local pain is caused by periosteal stretching and inflammation caused by tumor growth. It is described as deep "bite" or "sickness" pain, which often occurs at night, after remission, and anti-inflammatory drugs or corticosteroids can be used. Quickly relieved. Patients with this type of pain undergoing spinous process or palpation can cause spasms and tenderness. Unlike topical pain, the application of anti-inflammatory and analgesics to mechanical back pain is usually ineffective and varies with posture and activity. This type of pain is due to instability that is to be formed or has formed. Tumor-induced malformations or affected vertebral compression often lead to spinal instability, which increases the tension of the spinal support and stable structures, including muscles, tendons, ligaments, and joint capsules. This tension causes characteristic pain in spinal motion or axial load, which can be induced in the prone or supine position, but is usually relieved in the lateral position. Wearing a brace or surgical fixation can stabilize the spine and better relieve mechanical pain. When the tumor compresses the nerve root at the exit of the spinal nerve root, or because the compression fracture occludes the nerve root canal and invades the nerve root, spinal nerve root pain may occur, similar to the root pain associated with disc herniation, often described It is violent and penetrating. In the cervical spine, such as compression of the upper cervical nerve root, can cause pain in the occipital region. Compression of the neck 4 nerve root can cause neck-like pain. Compression of the lower cervical nerve can cause arm pain and finger pain, and the pain is aggravated when coughing and exerting force. Extramedullary-dural metastases can cause irritation or invasion of nerve roots, causing blunt or radicular pain. Unlike typical radiculopathy, this pain is described as a severe burning sensation.

2. Neurological dysfunction

Another most common symptom in patients with spinal metastases is motor dysfunction. 60-85% of patients with metastatic spinal epidural compression (MESCC) have one or more groups of muscle weakness. This muscle weakness may be related to myelopathy and radiculopathy. The nerve structure may be directly compressed by the tumor, or the pathological fracture may cause the fracture block to protrude into the spinal canal or nerve root canal. Patients with MESCC may have varying degrees of autonomous dysfunction, such as bowel, bladder, or sexual dysfunction, which are often not detected unless the doctor directly asks for a diagnosis. The most common symptom of this type of patient is bladder dysfunction (usually urinary retention), which is clearly associated with the degree of motor dysfunction. Patients with motor dysfunction can develop complete paralysis if left untreated. Sensory disturbances include paralysis, hyperesthesia, and paresthesia usually occur in synchrony with motor dysfunction and pain associated with the dermatophyte. Patients with myelopathy may have sensory abnormalities in the banded distribution of the chest and abdomen. Patients with thoracic MESCC may describe a chest discomfort, similar to the feeling of a tight shirt or corset, which is essentially similar to the discomfort described by patients with thoracic transverse myelitis. When the diagnosis of spinal cord compression is clear, the patient's neurological function is closely related to its prognosis. Most patients have symptoms of pain before neurological dysfunction, but because back pain is very common in the general population, diagnosis delays often occur in patients with spinal metastases who initially complained of new back or neck pain. Therefore, clinicians should be highly alert to patients with back pain and a tendency to have a tumor. In addition, compared with the cervical vertebrae and lumbar vertebrae, non-tumor-induced pain is not common, so pain in this area should be considered in the tumor.

Examination of spinal metastases

Film degree exam

1. X-ray film: a long-term primary evaluation method for patients with new symptoms associated with the spine, mainly due to its simple technology, low price and wide application. Therefore, X-ray films are effective screening test tools for confirming solubility and sclerosing damage, pathological fractures, spinal deformities, and large agglomerates. Breast cancer and prostate cancer can produce sclerosing damage, but most spinal metastases are solvable, and X-ray films do not show a change before more than half of the vertebral body is involved. Because of this relative insensitivity, definitive diagnosis often requires the integration of other imaging techniques. Radionuclide scanning (bone scan) is a sensitive method for identifying areas of increased metabolic activity in the skeletal system. Before the 30-50% of the vertebral body is partially affected, the tumor-related changes cannot be shown by X-ray films, and the bone scan can detect metastases earlier, with a resolution of 2 mm. It has been reported that the sensitivity of radionuclide bone scan for detecting spinal metastases is 62-89%. However, since the radionuclide scan detects enhanced metabolic activity, and inflammation or infection also enhances metabolic activity, it is not specific for metastatic lesions. The low resolution of the image hinders the effect of scintigraphy. It should be combined with CT or MRI images to exclude benign performance and surgical exploration if necessary.

2. SPECT (single photon emission CT): is a more advanced way of radionuclide bone scan, providing 3D images of suspicious spinal metastases. This technique has a more detailed image of the lesion than the planar scan and adds sensitivity and specificity. And, unlike other inspection techniques, SPECT images can distinguish between metastatic lesions and benign lesions. In the detection of spinal metastases, SPECT is an effective and relatively inexpensive detection tool when planar scans are not diagnosed. Positron emission tomography (PET) using fluorodeoxyglucose (FDG) as a tracer is also an integral monitoring tool routinely used to detect metastatic lesions and tumor staging. PET equipment has been shown to be superior to planar scintigraphy in the detection of spinal metastases, and early detection of tumors can be achieved by direct measurement of tumor metabolic activity rather than indirect markers of bone metastasis. PET scans are also used to identify the cystic and necrotic areas of the tumor, and this information can increase the diagnostic rate of biopsy sampling and help to develop a surgical intervention plan. However, the resolution of PET is limited and it is necessary to combine CT or MRI images. In addition, PET scanning is time consuming and expensive. The latest generation of multi-row CT scanning devices provides highly detailed images of spinal bone anatomy and tumor invasion. Increased sagittal and coronal digital reconstruction further enhances the level of detail in CT images. When myelography combined with CT imaging, high-precision performance of the space occupied by neurons can be obtained to identify the compressed structure, which helps to determine the cause of spinal cord compression, and whether the tumor is invading the spinal canal or the fracture of the pathological fracture. Projected backward into the spinal canal. Because of the thorough identification of regional anatomical structures, it can help guide surgical approaches, surgical procedures, and determine the extent of internal fixation. CT examinations are highly valuable in the development of surgical intervention programs. In addition to CT scans of the affected part of the spine, CT scans of the main body cavity should be performed to determine the primary tumor of the patient for patients with suspected spinal metastases who are unable to determine the primary tumor. In addition, CT angiography can assess the blood supply and reflux of spinal metastases.

3. Magnetic Resonance Imaging: It is considered to be the gold standard imaging device for assessing spinal metastases. In the detection of spinal lesions, MR images are more sensitive than standard X-ray films, CT, and radionuclide scans. This sensitivity is largely due to the excellent resolution of the MR image to the soft tissue structure of the spine, including the disc, spinal cord, nerve roots, meninges, and spinal muscles and ligaments. MR images can show bone and soft tissue boundaries, providing anatomical details of tumor invasion or compression of bone, nerve, and paravertebral structures. A set of MR images includes T1, T2 weighted images of 3 standard axes (axial, sagittal, and coronal) after application of contrast agent. In addition, the fat suppression study can further explain the principle of lesion signal enhancement in spinal bone tissue due to the high intensity signal of intramural fat in T1-weighted images. Diffusion-weighted imaging, although unconventional, distinguishes between pathological and non-pathological compression fractures.

4. Conventional digital subtraction angiography: an important tool for assessing spinal metastases. For patients with metastatic tumors with abundant blood supply (kidney cell tumor, thyroid tumor, angiosarcoma, leiomyosarcoma, hepatocyte tumor and neuroendocrine tumor), it is of great significance to understand the blood supply of metastases, such as surgery. Preoperative embolization of metastases can also be performed by angiography, which is an effective treatment for patients who cannot be operated. After embolization, it can reduce the amount of blood loss during operation and contribute to the complete resection of the lesion. In addition, control of intraoperative bleeding, reduce blood supply to metastases can potentially shorten the operation time, prevent postoperative hematoma caused by incision rupture and nerve tissue degeneration.

Percutaneous biopsy

Advances in imaging technology have led to improvements in the detection of cancerous lesions, but the diagnosis usually requires biopsy from spinal lesions. More than 10-20% of spinal metastatic cancer tissue sources are unclear, and if surgical biopsy does not yield immediate results, transcutaneous biopsy is required because most treatment decisions are based on tumor histology findings. Advances in biopsy technology have resulted in a diagnosis accuracy rate close to 90%, and many biopsies are now available in outpatient clinics. When considering a possible primary tumor, the surgeon should consult with the planned biopsy procedure because some primary tumors can be disseminated by biopsy needles and local recurrences, such as chordoma.

Diagnosis and differentiation of spinal metastases

diagnosis

Diagnosis can be based on medical history, clinical symptoms, and laboratory tests.

Differential diagnosis

Patients with suspected spinal metastases should undergo a thorough diagnostic examination, including medical history and physical examination. Warning signs include symptoms of spinal damage (night pain, neurological dysfunction, gait instability) and systemic symptoms (weight loss and organ failure). Investigate the patient's smoking history, environmental or occupational exposure history, and travel history. The consultation should address conditions that increase the likelihood of cancer (HIV, inflammatory conditions, and carcinoma in situ) as well as recent cancer screening and family history. Blood cell count, biochemical and prostate specific antigens were measured, and when multiple myeloma was considered, plasma and urine protein electrophoresis analysis was performed.

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