Surgical resection is a critical step in the overall treatment of ETMR. In an ideal scenario, a child’s neurosurgeon will be able to perform a complete (or gross-total) resection of the tumor. However, in certain situations the location of the tumor may not allow the entire tumor to be completely removed or there may be metastatic spread of the tumor. Even in the case of a “complete” resection, we know that microscopic tumors cells remain in the brain after surgery and further therapy is needed to cure patients with ETMR.
Chemotherapy is administered after surgery in an effort to kill any remaining tumor cells. Chemotherapy may also be useful in cases where a complete surgical is not possible at diagnosis and may shrink the remaining tumor, allowing for a complete surgical resection in due time.
A number of different chemotherapy medications are given in combination to attack the tumor cells in various ways. The hope is that attacking the tumor in multiple ways will increase the effectiveness of treatment and prevent the tumor cells from becoming resistant to a single point of attack.
Since ETMR is an aggressive tumor, it requires aggressive chemotherapy treatment. Most of the time, the regimen chosen to treat ETMR will involve intravenous chemotherapy which needs to be administered in a hospital. Some regimens will also include chemotherapy taken by mouth. Chemotherapy may also be given into the spinal fluid in an effort to prevent metastatic spread of the tumor.
We strongly encourage that all ETMR patients have genetic sequencing of their tumor specimen performed. This genetic information may provide important guidance about which chemotherapy treatments will work best for the individual’s tumor.
Radiation therapy is one of the most effective treatments available for ETMR. Unfortunately, radiation therapy also has devastating long-term effects on the developing brain. Given the very young age of most ETMR patients, the decision to administer radiation therapy must be made carefully. One of the main goals of our Medical Advisory Board is to provide individualized guidance regarding administering or withholding radiation therapy, as well as the timing and type of radiation given.
Newer radiation therapy techniques may reduce certain long-term effects of radiation. Proton beam radiation and stereotactic radiosurgery provide more focused treatments than conventional radiation and may help to decrease the radiation exposure of healthy brain tissue. However, these newer techniques are not risk-free and still require a high level of expertise and careful planning tailored to the individual child.
Stem Cell Transplant
Stem cell transplant allows for physicians to administer high-dose chemotherapy to patients and is typically given towards the end of therapy as a “consolidation” treatment. This treatment may be a particularly important step for patients who are unable to undergo radiation therapy due to their age or the tumor’s location.
Unlike patients with blood cancers, such as leukemia, who receive bone marrow from a donor, ETMR patients who undergo a stem cell transplant are given their own cells. Early on in their treatment course, patients undergo a collection of their blood stem cells in a process called “pheresis”. During pheresis, blood is removed from the patient, the stem cells are separated and collected, and the remaining blood cells are returned to the patient. The collected stem cells are then frozen until they are needed later in therapy.
Following administration of high-dose chemotherapy, patient’s stem cells are unfrozen and given back to the patient intravenously. These stem cells allow the patient’s bone marrow to recover more quickly from the high-dose chemotherapy, reducing the infection risks and making the overall process much safer.
During the course of treatment, ETMR patients will undergo surveillance assessments to monitor the effectiveness of their treatment. MRI of the brain and spine should be performed at specific time points to ensure that the tumor is responding as desired and to look for any sign of metastatic spread. As ETMR is a tumor that can spread through the spinal fluid, it is also recommended that spinal taps be performed on a routine basis to look for any tumor cells that may be circulating in the spinal fluid. Once treatment is completed, surveillance should be continued to follow the patient closely for any signs of relapse. Given the aggressive nature of ETMR, it is recommended that these scans be done at relatively short intervals so that any potential recurrence can be identified quickly.
Many patients with ETMR will unfortunately experience relapse of their tumor during or following therapy. There are no clear guidelines for managing relapsed ETMR. However, there are case reports of relapsed patients who were still able to become long-term survivors following salvage treatment. In these cases, it appears that employing a biological treatment approach based on the genetic profile of the patient’s tumor was a critical component to the treatment’s success. It is strongly encouraged that all relapsed patients have genetic sequencing of their tumor performed to help guide their treatment. Our Medical Advisory Board is able to assist with formulating a treatment plan based on these molecular results and past experience with relapsed patients.