1. How should brain metastases from non-small cell lung cancer be treated?
The treatment plan for patients with non-small cell lung cancer depends on the size of intrapulmonary lesions, the size of extra-pulmonary lesions, the number and location of metastases, the patient’s age and functional status, etc. Commonly used treatment methods include symptomatic treatment, surgical treatment, radiotherapy and chemotherapy.
2. What are the main symptomatic treatments for brain metastasis of non-small cell lung cancer?
Symptomatic treatment for brain metastasis of non-small cell lung cancer mainly includes: (1) To reduce tumor edema, mannitol and dexamethasone (8~32mg/d)/methylprednisolone can be used, but long-term use of steroid hormone has side effects such as osteoporosis, weight gain, bleeding tendency and abnormal blood sugar. (2) Control of seizures can be achieved by considering treatment with antiepileptic drugs in patients with seizures, but attention needs to be paid to rash, dizziness, drowsiness and the rare but more serious Stevens-Johnson syndrome.
3. Is surgical treatment of brain metastases from non-small cell lung cancer meaningful? Which sites of lung cancer brain metastases are suitable for surgical treatment?
Surgery plays an important role in the treatment of brain metastases from non-small cell lung cancer and is usually the key to determine the length of patient survival.
The purpose of surgical treatment is to reduce the occupying effect, restore cerebrospinal fluid access, improve the patient’s neurological function, improve the quality of life, clarify the pathological diagnosis, and prolong the patient’s survival.
For single brain metastases, surgical resection of brain metastases and primary lung foci can give patients a chance of long-term survival or even cure.
For multiple brain metastases with isolated lesions causing obvious occupying effect, cerebral edema or neurological dysfunction, surgery should also be considered to reduce intracranial pressure and improve neurological function, as well as to obtain space for further radiotherapy.
For occult lung cancer (asymptomatic in the chest), surgery should be considered immediately to remove the lesion if the first symptom comes from neurological symptoms caused by brain metastases, in order to quickly reduce the occupying effect and clarify the pathological diagnosis.
For an isolated intracranial occupancy of unknown pathological nature (e.g., meningioma or metastasis), surgical resection of the lesion should be considered to clarify the diagnosis and lung cancer stage.
Surgery should be considered especially for those located in the cerebral hemispheres, cerebellum and ventricles.
4. Do I need whole brain radiotherapy for non-small cell lung cancer brain metastasis?
Whole brain radiotherapy (WBRT) is one of the main treatments for non-small cell lung cancer brain metastases and can be used for patients with multiple brain metastases or very low KPS scores, commonly with a 2-week 30Gy/10-times regimen. Whole brain radiotherapy + hormone can provide patients with significant symptom relief, but not long-term tumor control. The risk of intracerebral radionecrosis with conventional-dose whole-brain radiotherapy is less than 1%. 2% to 18% of patients develop radiation encephalopathy, mostly within 2 years after treatment. Prophylactic radiotherapy can reduce the probability of brain metastasis in non-small cell lung cancer.
5. Which patients with lung cancer brain metastases are suitable for stereotactic radiosurgery (including gamma knife) treatment?
Stereotactic radiosurgery (SRS) is mainly suitable for the treatment of small metastases with low peri-tumor edema, insignificant occupying effect and no serious neurological dysfunction, especially small solid metastases located in the basal ganglia, thalamus, brainstem and other deep areas that are difficult to be treated surgically, with a diameter of 3 cm or less, without bleeding or cystic changes.
The single dose of stereotactic radiosurgery is usually 10-25 Gy, and most patients can receive a dose of 17-20 Gy. A low dose is preferable for brain metastases adjacent to the brainstem, optic cross and optic nerve sites. Patient age, KPS score, primary tumor status, and extracranial condition are important predictors. About 5% to 18% of patients will have acute toxic reactions such as headache, nausea, vomiting, increased neurological dysfunction and seizures; the risk of late symptomatic radionecrosis is 2% to 6%.
6. Which patients with lung cancer brain metastases are suitable for intensity-modulated radiotherapy?
Intensity-modulated radiotherapy (IMRT) can be used to treat metastases of 3-6 cm. The risk of cerebral edema and radiation necrosis increases with larger lesions.
7. Is chemotherapy useful for patients with brain metastases from lung cancer?
Patients with brain metastases from lung cancer have certain degree of destruction of the blood-brain barrier due to the process of brain metastasis, whole brain radiotherapy and mannitol dehydration, etc. Chemotherapy can also play a role. Generally, platinum-containing chemotherapy drugs are used. Temozolomide is also effective for recurrent and progressive brain metastases. Chemotherapy is mainly used as a combination therapy with radiotherapy or as a salvage measure for patients with recurrence after radiotherapy. It is usually effective in relieving non-small cell lung cancer metastases, prolonging patient survival and improving the quality of survival.