Brain Tumor Treatment
Brain tumors, as well as spine tumors, have a host of emerging treatment options that can be used alone or in combination to give the best outcome for your specific cancer. That’s why careful diagnosis and grading is so important. As part of a research medical center, physicians at the Siteman Cancer Center at Barnes-Jewish Hospital and Washington University School of Medicine in St. Louis have access to a wide range of clinical trials to test new therapies as they emerge. Many of our doctors are principal investigators in these trials, which cover medical, surgical, and radiation therapies. Discuss with your physician how your cancer might benefit from clinical trials. Some tumors can be eradicated with treatment. Others are more likely to come back, and the goal of treatment is management, rather than cure.
Because many of our patients come from over 100 miles away, when you meet with a surgeon, you often see the radiation and medical oncologists at the same visit and get imaging for treatment planning.
Depending on the biology and genetics of the tumor, patients may be advised to have radiation and/or chemotherapy before surgery (neoadjuvant treatment). There are parts of the brain tumor that may not be amenable to surgery, so a combined approach is needed. Advance planning helps surgeons determine ahead of time: if they remove a tumor in a certain way, the patient might be eligible for a vaccine trial. While our oncologists often see patients from other medical centers for advanced treatment after surgery, doing the surgery here in conjunction with trials and advanced expertise may result in more effective coordinated care.
Making Surgery Safer and More Accurate
Advanced brain mapping: Mapping the brain is critical for neurosurgeons who not only want to get a detailed fix on areas targeted for surgery but also need to minimize the risks of surgical damage to healthy brain regions that perform essential tasks. Never is this more critical than in the brain and spinal cord.
For many years, neurosurgeons have accomplished the job using a time-intensive approach called functional magnetic resonance imaging (fMRI). Patients perform several simple tasks—saying their name or moving an arm, for example—while their brain is repeatedly scanned. They have now discovered that resting state fMRI is as useful for precisely mapping all of an individual patient’s critical brain networks: speech, motor control and others in one 15-minute session while the patient lies in the scanner and rests.
Intraoperative MRI: With the data from the genetic tumor map and the functional MRI, the surgery can commence. However, as the tumor is removed and cerebrospinal fluid drained, the map becomes inaccurate for tumor margins. That’s where real-time intraoperative MRI (iMRI) comes in to give the surgeons the updated information to complete the surgery accurately. They have done well over 1000 iMRI cases, a significant portion of which are gliomas, pituitary skull base tumors, and spinal tumors, including metastases from lung and breast cancers.
Surgery remains a mainstay treatment for brain tumors, but advances in technology and new clinical trials mean patients have more treatment options—some noninvasive—and quicker recoveries. Open surgery with robotic assist may be called for. Most skull-based surgery uses a more minimally invasive approach, like laser interstitial therapy or endonasal endoscopy to get to inaccessible tumors.
MRI-Guided laser interstitial therapy: Washington University neurosurgeons are among the first in the nation to use an MRI-guided, high-intensity laser probe designed especially for the treatment of inoperable brain tumors to “cook” cancer cells deep within the brain while leaving surrounding brain tissue undamaged. Patients who are candidates for this procedure will have a small burr hole the diameter of a pencil drilled through their skull. Neurosurgeons then use real-time MR imaging to guide the probe through the brain and into the tumor. Once inside the tumor, the laser discharges highly focused heat energy to coagulate and kill cancer cells. The technology is FDA-approved for several types of brain tumors: glial tumors, including gliomas; anaplastic astrocytomas, glioblastoma multiform, metastatic cancers that have spread from other regions of the body, some radiation-resistant tumors, and radiation necrosis due to prior radiation therapy.
Gamma Knife: Although Gamma Knife is a form of radiation, it is considered a surgical intervention because it can replace surgery. Some patients could have either, so the treatment is based on lifestyle and impact of recovery to the patient’s life.
Minimally invasive endoscopy: Many tumors of the skull base can be treated with endoscopic endonasal skull-base surgery, in which, rather than make an opening through the face or skull, the surgical team advances an endoscope through the nasal cavity to view the anatomy and perform the surgery. Endonasal procedures are done for conditions such as: pituitary tumors, chordomas, chondrosarcomas, craniopharyngiomas, cysts, and meningiomas.
Chemotherapy involves the administration of drugs, either orally or intravenously, to kill cancer cells. Malignant tumors need chemotherapy. Skull-based tumors are mostly treated with surgery and radiation. Therapy that falls under medical treatment has a wide range of approaches, including timing of treatment.
Before surgery: Sometimes a tumor is too large to allow resection without damaging adjacent structures. In those cases, chemotherapy and/or radiation before surgery may make it shrink, to protect those structures. Neoadjuvant, or preliminary, chemotherapy and/or radiation given before surgery can make the tumor more removable and help prevent recurrence.
After surgery: Most chemotherapy is given adjuvant (after surgery), sometimes in combinations of drugs that have been shown to work well together for your type of cancer, including pairing a standard-of-care drug with a drug in a clinical trial. For patients with cancer that has spread (metastatic), chemotherapy can improve survival and quality of life.
Biological therapy, sometimes called immunotherapy, is a treatment that uses materials made by the patient’s own body or in a laboratory to stimulate the immune system to fight disease. Siteman researchers are now participating in clinical trials to test this form of therapy. These trials are especially important for patients with metastatic and recurrent cancers.
Vaccines: Some clinical trials at Siteman will study the effectiveness of brain tumor vaccines. Creating a personalized vaccine begins with samples of DNA from a patient’s tumor and normal tissue and making a vaccine from the most likely proteins in mutant cancer genes to stimulate the patient’s T-cells to attack the cancer.
Another type of vaccine targets a genetic mutation unique to glioblastoma, the most common high-grade brain cancer and the most aggressive. Early data from these vaccine drugs shows that patients who received the vaccine in addition to the current standard therapy live more than twice as long as patients who received standard therapy alone. The side effects were, in most cases, no worse than those of a flu vaccine.
Checkpoint blockade: Another approach to immunotherapy is called a checkpoint blockade. Cancer cells shut off the T cells by activating a safety mechanism called the checkpoint system, preventing them from attacking the tissue. Drugs called checkpoint blockades disable the checkpoint, allowing the T cells to unleash destruction on the tumors. But the approach also increases the chances that those same immune cells erroneously will attack healthy tissue, causing serious autoimmune disease.
Genomic sequencing offers another step forward. By studying a patient’s DNA, researchers are learning which changes, or mutations, affect responses to a particular drug, including drugs on the market so treatments are given that are most likely to be effective.
Designed for recurrent glioblastoma, this therapy uses Treating Fields (TTFields) technology, a form of low intensity, alternating electric current that can exert physical forces on electrically charged cellular components within a tumor, preventing cells from dividing and causing cancer cell death. It is usually suggested when chemotherapy and radiation options are exhausted, and is designed to be worn as a helmet attached to a portable battery pack night and day.
Each new patient is presented at a multidisciplinary conference to personalize his or her management, including surgery, radiation oncology, chemotherapy, and pathology to take into account specific tumor characteristics. Radiation oncology has active trials for minimizing the duration and amount of radiation a patient receives to reduce long-term side effects. Siteman is a leader in using shorter radiation durations than the national average with the same outcomes.
External Beam Radiation
Ninety-five percent of radiation treatment at Siteman is external beam from outside the body. Some of the types of treatment they use include:
Proton Beam Therapy: The Proton Therapy Center at the Siteman Cancer Center is the only one located in Missouri and the surrounding region. Proton beam therapy’s main advantage is that radiation specialists can control radiation beams by depth, shape and radiation dose.
ViewRay MRI-Guided Radiation Therapy: This system is a breakthrough technology initially developed at Washington University. The integrated system combines radiation treatments with a continuous magnetic resonance imaging system. By using MRI to help guide radiation therapy treatments in real time, the radiation oncology team is able to see where the radiation dose is being delivered and determine if any subtle changes are occurring to the tumor or surrounding tissue. The ability for continuous soft-tissue imaging means that a patient’s treatment plan or radiation dose can be adjusted immediately if changes are noted.
Gamma Knife: Washington University School of Medicine offered the first Gamma Knife technology in Missouri. This technology enables physicians to treat brain targets that are surgically hard-to-reach or inaccessible with high accuracy and safety in a well-tolerated outpatient procedure. More than 3,400 patients have been treated at the Washington University Gamma Knife Center. Gamma Knife radiosurgery is a treatment option for a number of neurosurgical conditions, including intracranial metastatic brain disease, arteriovenous malformations (AVMs), acoustic neuromas or schwannomas, pituitary adenomas, and meningiomas. In some instances, it may be equivalent to an open neurosurgical procedure. Because it is generally performed on an outpatient basis, it is cost-efficient, preventing lengthy hospital stays, expensive medications, and occasional long-term rehabilitation.
Hyperfractionated radiation therapy: Useful in the treatment of brain stem gliomas, this radiation treatment divides the total dose of radiation into small doses called fractions that are given daily over several weeks. In contrast to the one-day radiosurgery, this technique is used for tumors located close to sensitive structures, such as the optic nerves or brain stem.
Radiation plus Hyperthermia: In the treatment of pineal astrocytic tumors, a novel clinical trial combines external radiation plus hyperthermia (heat) therapy to enhance the effectiveness of the radiation without upping the dosage.
Brachytherapy, installing radioactive seeds into recurrent glioblastomas, can deliver focal radiation, reducing the dose to normal structures. Clinical trials are exploring this, along with novel methods for delivering chemotherapy and radiotherapy locally to an infiltrating tumor.