Chordomas (Skull Base and Spinal Column)
Chordomas are tumors that tend to arise within the spine (especially the sacrum) or within the base of the skull. These tumors develop from remnants of the notochord, an embryonic structure that is involved in development of the bony skull and spine. The notochord eventually forms the central parts of the spinal intervertebral disks. These tumors are usually slow-growing, but they may invade nearby structures, tend to recur after treatment and can destroy surrounding bone and tissue.
Symptoms
Chordomas are usually slow growing and, therefore, may grow to a large size before causing symptoms. The pressure that a growing tumor exerts on the surrounding brain or cranial nerves usually causes the symptoms of a chordoma. With a skull base chordoma, symptoms usually develop with compression of the brainstem or cranial nerves. These symptoms can include headaches, weakness or numbness in the limbs or face, double vision and hearing loss. The symptoms tend to increase in severity as the tumor grows in size. With cordomas arising in the spine, symptoms can include tingling, numbness or weakness in the arms or legs and loss of bladder or bowel control.
Diagnosis
The diagnosis of a chordoma is based on your symptoms, physical exam and specialized imaging studies of the brain and skull base or of the spinal column. A high resolution CT scan with 3-Dimensional reconstructions will often be obtained to understand the extent of bony destruction and involvement by the chordoma. The scan also provides detail information regarding the exact size, location and other structures involved by the chordoma. The scan is often performed with a contrast dye to help identify the relationship of any major arteries to the chordoma and to make the border of the tumor more visible in relation to the surrounding normal anatomy. The MRI scan can also help identify the extent of any compression of the brain, cranial nerves or spinal cord. In some cases, otolaryngologists and neurological surgeons may employ an MRI or CT scan for frameless stereotactic guidance. The high-resolution CT scan is processed by a computer to create a 3-Dimensional model of the skull base that can be used in the operating room when performing endoscopic minimally invasive skull base surgery. In some cases of a spinal column chordoma, a needle biopsy of the tumor will be performed to confirm the diagnosis. In these circumstances, the surgical team is often ready to perform an operation soon afterwards in order to prevent spread of any of the tumor cells.
Treatment
The initial treatment for a chordomas is usually surgery to remove as much of the tumor as safely possible. Surgery to remove skull base chordomas can be performed using endoscopic or minimally-invasive skull base techniques or with Traditional or open skull base techniques depending on the exact location and extent of your particular tumor. Surgery for removal of spinal column chordoma is usually performed open surgical en bloc resection of the tumor. Depending on the location of the tumor, en bloc resection may not always be possible without the risks if serious neurological or vascular complications. Even in cases of total resection, these tumors have a tendency towards recurrence, therefore surveillance repeat MRI or CT scans are conducted for a period of time following initial treatment. Depending on the particular location of the tumor, surgery may involve a team of physicians including, neurosurgery, ENT surgery, plastic surgery, urology and vascular surgery.
Following surgery, radiation therapy may be used as a follow-up treatment, especially in cases with residual tumor. In addition, non-invasive, stereotactic radiosurgery (CyberKnife and Gamma Knife) or proton beam irradiation may be used as adjunct treatment. Stereotactic Radiosurgery uses numerous finely focused beams of radiation to accurately target the tumor and while minimizing the effects to any surrounding tissue. The target tumor is usually outlined on a 3-Dimensional model of the brain by the neurosurgeon and the radiation oncologist prior to the procedure.
After surgery, each patient is reviewed at our Multi-Disciplinary Tumor Board with an expert team of neuro-oncologists, medical oncologists, neuro-pathologists, neuro-radiologists and neurosurgeons. Together the tumor board recommends the best treatment options for each patient, incorporating ongoing national clinical trials and the latest treatment protocols.