A Brain Tumor Is Not a Single Disease
Brain tumors are divided into primary (arising from the brain) and metastatic (spreading from elsewhere in the body). Primary tumors include glioma (astrocytoma, oligodendroglioma, glioblastoma), meningioma (about 90% benign), pituitary adenoma, acoustic neuroma arising from the balance nerve (vestibular schwannoma) and lymphoma. Metastatic tumors most often originate from the lung, breast, melanoma and kidney and are frequently multifocal. The treatment plan is built individually according to the tissue diagnosis (pathology), genetic markers (IDH, MGMT, 1p/19q) and the patient's general condition. For this reason a diagnosis of 'brain tumor' alone is not a treatment prescription.
What Does 'Maximal Safe Resection' Mean?
The single principle of modern brain tumor surgery is to protect healthy functional brain tissue while removing the tumor. The volume of tumor removed influences survival and time to recurrence, especially in gliomas; the function preserved determines the patient's quality of life. An overly aggressive resection can cause loss of strength or speech, while an insufficient resection can lead to early recurrence. The technologies that help strike this balance include the high-magnification microscope, MRI/CT-based neuronavigation, functional MRI and DTI tractography that map the motor and language pathways before surgery, awake craniotomy when needed, and fluorescence-guided (5-ALA) resection that makes tumor tissue visible under light in gliomas. Not all of these technologies are required in every patient; the location of the lesion and surgical experience determine which is used.
For Which Tumor Is Surgery the Priority, and for Which Is It an Alternative?
Situations where surgery is the first choice include: symptomatic or rapidly growing meningioma, glioma in a resectable location, pituitary adenoma causing vision loss or secreting hormones (via the endoscopic transsphenoidal route), a solitary brain metastasis accompanying a controlled primary disease, and childhood embryonal tumors. By contrast, in some tumors surgery alone is not sufficient or an alternative is more appropriate: in lymphoma (PCNSL) the treatment is not resection but chemotherapy and radiotherapy after biopsy; in deep-seated gliomas such as those of the brainstem or thalamus, biopsy and Gamma Knife come to the fore; with more than five metastases, Gamma Knife or whole-brain radiotherapy is preferred; for a small asymptomatic meningioma or small acoustic neuroma, observation or Gamma Knife is considered. The decision is always multidisciplinary; the neurosurgeon, neuroradiologist, radiation oncologist and medical oncologist evaluate together.
The Surgical Process and Recovery
During preparation a detailed neurological examination, contrast MRI, and when needed functional MRI and DTI tractography, a multidisciplinary meeting and an anaesthetic assessment are carried out. In surgery the patient is positioned according to the tumor location; most cases are operated under general anaesthesia, while tumors close to a functional area are operated awake when required. A shave as narrow as possible within the hairline is sufficient; shaving all the hair is now rarely necessary. The bone flap is removed, the dura is opened, the tumor is removed under the microscope with navigation guidance, and the layers are closed one by one. The procedure can take 2–8 hours depending on the tumor type. Afterwards there is usually 24–48 hours of intensive care followed by a total hospital stay of 3–7 days; the extent of resection is assessed with a control MRI, and adjuvant treatment (radiotherapy/chemotherapy) is planned if the pathology result indicates it.
Risks and Realistic Expectations
Brain tumor surgery is major surgery, and its risks must be discussed honestly: bleeding, infection, a temporary or permanent neurological deficit depending on the tumor location, brain swelling lasting a few days after surgery and the risk of seizures can be listed. These rates vary according to the location and size of the tumor, the patient's age and accompanying conditions; an experienced team and multidisciplinary planning markedly reduce these risks. Outcomes differ greatly by tumor type: in a benign meningioma long-term control is usually possible, in a low-grade glioma long-term control can be achieved but there is a possibility of recurrence, and in high-grade tumors such as glioblastoma the goal is to prolong time while preserving quality of life. We do not promise a guaranteed result; expectations are shared openly before surgery.