Treatment > Surgery
Surgery in the treatment of brain tumors has three goals:1. To establish the tumor cell type and grade by providing a sample of the tumor to a pathologist.
2. To relieve internal compression. As described on the "Symptoms" page, a tumor mass within the closed box of the skull can raise intracranial pressure. Removal of some or all of the tumor restores the contents of the box to normal and lets the elevated intracranial pressure return to normal.
3. To reduce tumor burden. In other words, to reduce the number of tumor cells. In some tumors - such as meningiomas located on the surface of the brain, some pineal region tumors and some benign tumors within the substance of the brain (usually in children and young adults) - surgery can totally remove all of the tumor, reduce the tumor burden to zero and cure the patient. In other tumors - such as gliomas - surgery can reduce the number of tumor cells, leaving fewer tumor cells to be treated by radiation and chemotherapy.
Surgical Methods
Craniotomy: A procedure in which a trapdoor in the skull is opened. This allows the surgeon to find and remove a brain tumor. Typically, these operations are done under general anesthesia. In some cases craniotomies are done under local anesthesia when it is necessary to map important functional regions of the brain by stimulating its surface with an electric current in order to study the effects in an awake patient. In general the scalp incisions, bone openings and exposures of the brain in traditional craniotomy tend to be larger than necessary to ensure that the surgeon can actually find the brain tumor within the craniotomy opening. The incorporation of stereotactic methods into brain tumor surgery has significantly reduced the invasiveness of surgical procedures to biopsy and remove brain tumors.
Stereotactic Procedures: Stereotactic surgery is a method for precisely localizing areas inside the head. Three-dimensional coordinates, calculated with respect to external reference points, are utilized to allow the surgeon to select a precise approach to intracranial lesions. This technique is used to biopsy and remove brain tumors.
Stereotactic Biopsy: In this procedure a probe is directed by means of an instrument called a stereotactic frame to an intracranial tumor. The position of the tumor within the patient's head has been determined by computed tomography (CT scanning) and or Magnetic Resonance Imaging (MRI). Samples of the tumor are obtained by the probe. Several sites within the tumor can be sampled by this method.
Computer-assisted volumetric stereotaxis: This is a method for gathering, storing and reformatting imaging-derived, three-dimensional volumetric information defining an intracranial lesion with respect to the surgical field. With this technique a surgeon can plan and simulate the surgical procedure beforehand, in order to reach deep-seated or centrally located brain tumors employing the safest and least invasive route possible.
Volumetric stereotaxis has major advantages for brain tumor patients, which include the smallest possible skin incision, craniotomy and brain incision. This minimizes injury to normal brain tissue. Secondly, since the surgeon knows exactly where tumor ends and normal brain begins, a more complete tumor removal can be accomplished with much less risk to surrounding brain tissue. Finally, the postoperative neurologic results are better than those associated with conventional (non-stereotactic, non-volumetric) surgical techniques.
Many tumors can be cured by complete surgical removal. These include meningiomas, acoustic neurinomas, craniopharyngiomas, pilocytic astrocytomas, some oligodendrogliomas and gangliogliomas, colloid cysts, choroid plexus papillomas, hemangioblastomas and some pineal region tumors such as teratomas, pinealocytomas. The consistent feature with all of these tumors is the fact that they are all histologically circumscribed. That means that there is a clear microscopic interface where tumor cells stop and normal tissue begins. However, there are many brain tumors which comprise a solid tumor tissue mass (which can be removed surgically) surrounded by regions of brain tissue infiltrated by isolated tumor cells (which usually cannot be removed). In addition, sometimes potentially curable tumors involve structures which cannot be removed such as vital arteries or veins. In many of these cases postoperative adjuvent therapy - radiation and/or chemotherapy - is advised.