Lung cancer is one of the most common malignant tumors and is also among the cancers most likely to metastasize to the brain. I have treated nearly 2,000 cases of lung cancer with the CyberKnife, and most of these patients came to me after developing brain metastases. There are many treatment options for lung cancer with brain metastasis, especially in cases of lung adenocarcinoma with gene mutations. Patients may choose targeted drug therapy or radiosurgery.

I often ask myself a question: If a doctor stands in the patient's shoes, how should lung cancer with brain metastases be treated?

Brain metastasis from lung cancer represents stage IV lung cancer, meaning advanced disease. If a patient has an EGFR gene mutation and brain metastases only, what treatment strategy should we offer?

From the patient's perspective, I usually recommend taking a first-generation targeted drug while performing CyberKnife treatment for both the brain metastases and the primary lung tumor. My treatment approach is often questioned by lung cancer specialists because I do not follow the guidelines that recommend starting with a third-generation targeted drug. However, my purpose—standing from the patient's viewpoint—is to delay the use of third-generation drugs, thereby reserving more treatment options for the future.

Recently, a patient with lung cancer and brain metastasis came for follow-up. She was deeply grateful for the scientific and reasonable treatment strategy I had provided.

In January 2014, the patient underwent an MRI due to headaches, which revealed a tumor in the right cerebellum, diagnosed as a brain metastasis. A chest CT showed a right peripheral lung tumor. I explained my treatment plan to the patient and her family in detail, and they placed great trust in me.

We first used CyberKnife to treat the right cerebellar metastasis, which relieved her headaches. Then we performed a biopsy of the lung tumor and conducted gene testing. The biopsy confirmed lung adenocarcinoma with an EGFR mutation. I advised the patient to take a first-generation targeted drug while receiving high-dose CyberKnife radiotherapy for the lung tumor. After CyberKnife treatment, she continued the same drug. When resistance to the first-generation drug occurs, we then switch to a third-generation targeted therapy. As of now, the patient has lived a high-quality life for 11 and a half years. Follow-up MRI showed edema in the right cerebellum, which I believe to be radiation-induced brain injury. PET-CT confirmed that there was no recurrence of the cerebellar tumor, the lung cancer has been cured, and there are no tumors elsewhere in the body.

The combination of CyberKnife and targeted therapy has enabled long-term, high-quality survival for patients with advanced lung cancer.