Brain metastasis is the spread of malignant tumors from other parts of the body to the brain and is one of the major causes of disability and death in patients with systemic cancer. Approximately 15%-30% of patients with tumors will develop intracranial metastases to produce symptoms and seek medical attention, and 50% of patients will have positive autopsies. The majority of common intracranial metastases are cancer metastases, accounting for more than 90% of cases. The most common brain metastases are lung metastases (40-60%), followed by breast cancer metastases (15-25%), gastrointestinal origin and melanoma. Half of these brain metastases are multiple intracranial metastases. There are three routes for malignant tumors to metastasize into the skull: transcytosis, translymphatic, and direct invasion, with transcytosis being the most common route. The metastatic route and metastatic site are related to the site of the primary tumor. For example, lung cancer, breast cancer and skin cancer mainly metastasize via blood stream, and are prone to form multiple metastatic cancers in the brain. Digestive tract cancer tumors are more likely to metastasize via the lymphatic system and spread to the meninges. The median survival of patients with brain metastases is short, only 1-2 months, and can be extended to 3-6 months after whole brain radiotherapy.
Clinical manifestations
1.Increased intracranial pressure and general symptoms
90% have headache, 70% have nausea and vomiting, more than 70% have optic papillar edema, 30%-40% have fundus hemorrhage, about 20% have visual loss, about 15% have abducens nerve palsy, about 15% of patients have different degrees of consciousness impairment and may have brain herniation symptoms. The general condition of the patient is poor and there may be significant wasting. 20% of the patients have seizures, mostly limited seizures. Psychiatric symptoms may also be present. The common manifestations are unresponsiveness and indifference. In the case of meningeal metastasis, there are signs of increased intracranial pressure and meningeal irritation, and local signs are rare.
2.Local symptoms
Brain metastases cause heavy damage to the brain, and often have multiple metastases, with significant local symptoms and wide range of involvement. More than 40% of patients have hemiparesis, about 15% have hemianesthesia, about 10% have aphasia, and about 5% have hemianopia. Patients located in the cerebellum may have nystagmus and ataxia, and may also have posterior cranial nerve symptoms, such as difficulty in swallowing and easy choking.
Examination
1.Blood test: Half of the patients have accelerated blood sedimentation, increased white blood cell count and decreased red blood cell count and hemoglobin in peripheral blood picture. There are also specific tumor-related indexes to indicate the nature and severity of tumor.
2.CT scan: It can not only localize the tumor, but also show the size, shape and changes of brain tissue and ventricle, especially easy to find multiple tumors, tumor-like round or irregular shape, high density or mixed density image, mixed density is often a necrotic cystic lesion within the tumor, then it shows a low density area. Most of them have obvious block or ring image enhancement after intensification, and there are often low-density brain edema bands around the tumor. Ventricular compression and deformation can be seen, and cerebellar tumor can be symmetrically enlarged above the third ventricle.
3.MRI: MRI is a more important examination than CT, which can not only increase the detection rate of lesions, especially for some small lesions. It can also accurately show the relationship between tumor and important neural structures, and identify primary brain tumor and secondary metastases. Nowadays, PET-MRI can more accurately examine the metastasis and occurrence of tumors throughout the body.
Intracranial multiple metastases
Metastases of various shapes and sizes
Diagnosis
This disease should be considered first in patients with significant symptoms of increased intracranial pressure and poor general condition with severe restrictive signs. Since brain metastases from the lung are common, a chest X-ray or CT should be taken, and if tumors are found, or if there is a history of malignant tumors from other sites, the diagnosis can usually be established. CT and MRI scans are of high diagnostic value for localization and characterization as well as detection of multiple tumors.
Treatment
Treatment of intracranial metastases is difficult. Most of the treatment is mainly comprehensive, with surgery supplemented by radiation therapy (including gamma knife, X-knife, radio-wave knife, etc.) and chemotherapy, which can relieve patients’ symptoms and prolong their lives. The specific treatment method generally needs to be considered according to the patient’s age, general condition, neurological function status, primary tumor site and treatment, the presence of multiple metastases outside the brain, and the number, size and location of brain metastases.
Surgical resection of brain metastases is an important means to improve the prognosis of patients. In patients with superficial tumor site, non-critical functional areas, no serious systemic diseases, acute intracranial pressure elevation and newly diagnosed brain metastases, surgical treatment of single brain metastases has become the standard treatment option. Surgical treatment includes tumor resection and palliative or decompressive surgery. For single brain metastases, if the general condition is good, the primary tumor has been resected and no other metastases are found, tumor resection can be performed. If the primary tumor has not been resected but can be removed, and the brain symptoms, especially the symptoms of increased intracranial pressure, are significant, brain tumor resection can be performed first. After the increase of intracranial pressure is relieved, resection of the primary tumor can be performed again. When removing the tumor, it is generally easy to separate from the brain tissue, and the scope of resection should be more extensive, striving for total resection. If the tumor site is deep or multiple tumors, as well as meningeal metastasis, decompression surgery can be performed to reduce the symptoms. The most important advantage of surgical resection is that it can quickly relieve the neurological symptoms caused by brain tissue edema, stroke, various occupying effects caused by lesion compression and elevated intracranial pressure, so that the local lesion can be effectively controlled and the quality of survival can be effectively improved, and it can help doctors to obtain the pathological basis of the patient’s metastases and help to decide the next treatment plan.
For those who have unresectable primary tumors, multiple metastases in the body and very poor general condition, surgery is not recommended. Hormones, dehydrating drugs and symptomatic treatment can be given to relieve symptoms for a short period of time.
Radiation therapy is an important treatment method for brain metastases. Those with good general condition and normal blood picture after surgery can be given radiation therapy, and those with unresectable tumors without multiple metastases are also indications for radiation therapy. Tumors that are not suitable for surgery but sensitive to radiotherapy, such as nasopharyngeal tumor, should also be given radiotherapy. Meanwhile, radiotherapy is also an important adjuvant treatment for brain metastases after surgical resection.
Chemotherapy can be given to those who have normal blood and liver and kidney functions in general. Carazolam, cyclohexylnitrosourea and anti-cancer drugs can be given according to the type of primary tumor. Chemotherapy can be selected according to the pathological nature of the primary focus, and the most effective method is direct intrathecal injection.
CLS biological cell therapy is a method to stimulate and enhance the body’s own immune function by using biotechnology and biological agents to culture and amplify immune cells collected from the patient’s body and then transfuse them back into the patient’s body to achieve the purpose of tumor treatment. CLS cell therapy can not only effectively restore and strengthen its immune anti-tumor effect, but also increase the radiosensitivity of cancer cells, completely destroy the residual cancer cells in the body, reduce the recurrence and metastasis of tumor, and improve the cure rate.