Guidelines for newly diagnosed skull base tumors

The treatment recommendations you find here were developed by the Chordoma Global Consensus GroupA multidisciplinary, international group of over 60 doctors who have extensive experience caring for chordoma patients. The group is responsible for developing and publishing consensus guidelines, based on all available medical and scientific evidence, for the treatment of primary and recurrent chordoma. – a multidisciplinaryTreatment that involves a team of physicians from various disciplines. In the case of chordoma, these disciplines include sarcoma or bone pathology, radiology, spine surgery or skull base surgery, otolaryngology, radiation oncology, medical oncology, and palliative care., international group of over 60 doctors who specialize in caring for chordoma patients. The Chordoma Foundation and the European Society for Medical Oncology brought this group together to define the recommendations for treating chordoma based on all available medical and scientific evidence. The resulting consensus guidelines were published in the medical journal The Lancet Oncology in February 2015. You can also find these recommendations in our Expert Recommendations for the Diagnosis and Treatment of Chordoma booklet. Download or request a hard copy of the booklet »

Your first treatments will have a big impact on both your quality of life after treatment and the chances of the tumor coming back. In most cases, surgery is recommended as the first treatment for skull baseThe bones at the bottom part of the skull that separate the brain from other structures. The clivus is one of the bones of the skull base. tumors. Radiation therapy is generally recommended after surgery to kill any remaining tumor cells, and a radiation oncologist should be part of your care team even before surgery to plan with your surgeons for any radiation treatment you will receive after surgery.

Surgery

The goal of surgery for skull base tumors is complete resectionAll visible tumor has been removed, but not necessarily in one piece., or complete removal of all visible tumor tissue, whenever possible. Your doctors will need to do some additional tests before you have surgery. Even if you have already had CTA type of imaging scan that is used to help diagnose chordoma and can also be used to help guide the needle during a biopsy. They are also referred to as CT scans or “CAT” scans. or MRIA type of imaging scan that is used initially to help diagnose chordoma, as well as during follow up to check for recurrence or metastasis. scans, you may need more extensive imaging. This will help your surgeon see the tumor better and plan your surgery.

A type of imaging test called angiographyAn imaging test that is done before surgery to show the location of important blood vessels. should also be done. This test shows the location of blood vessels that need to be protected during surgery. You will also need an examination that measures the following:

• cranial nerve function
• visual acuity (how sharp your vision is)
• visual field
• hearing
• pituitary gland function

Completing this examination prior to surgery will allow your doctors to know what has changed if you experience side effects.

Learn more about surgery for chordoma »

Surgery should be performed in a medical center with substantial experience in skull base surgery. Your surgeons should be trained in both endoscopicUse of an instrument to look inside the body. Most skull base chordoma surgeries are done endoscopically through the nose. endonasal (through the nose) and transoral (through the mouth) approaches, as well as through the side of the head. Skull base operations are usually done by a team that includes a neurosurgeon and an ear, nose, and throat (ENT) surgeon. ENT surgeons are also called otolaryngologists.

Surgery in the skull base can cause damage to the brainstemThe brainstem is the lower part of the brain connected to the spinal cord. The brainstem relays all signals to and from the brain and the body and is responsible for maintaining consciousness, breathing, and heartbeat. and cranial nerves, which control important functions such as speech and swallowing. To reduce the risk of serious nerve injury, neurophysiological monitoringThe use of devices during surgery to monitor the functioning of neural structures such as the spinal cord, nerves, and brain. This is done to guide the surgeon during the operation, and to reduce the risk of damage to the patient’s nervous system. is recommended during surgery.

Because chordomas in the skull base often touch important nerves and blood vessels, it is not always possible to remove the tumor in one piece or with wide margins. For this reason, even if all visible tumor is removed, microscopic chordoma cells are likely to be left behind after surgery.

Read more about surgical marginsThe healthy tissue surrounding the tumor that is taken out along with the tumor to make sure that no cancer cells are left behind. Negative or wide margins mean no tumor cells can be detected in the healthy tissue, which lowers the chance of recurrence.  »

Therefore, radiation therapy is generally recommended after surgery to prevent any remaining cells from re-growing. If the entire tumor cannot be removed, your surgeon should remove as much of the tumor as possible, especially from around the brainstem and optic nerveThe nerve responsible for eyesight by sending signals from the eye to the brain., so that later radiation therapy can be more effective.

Radiation

It is important to have a detailed discussion with your radiation oncologist to understand the type of radiation therapy that is best for you and the short-term and long-term side effects of the treatment you can expect.

The most important thing to know about radiation is that high doses are required to control chordoma. Specifically, a dose of at least 74 GyEThe abbreviation for gray equivalents, which refers to the unit of measurement for an absorbed dose of radiation. is recommended. This dose should be given to any visible tumor as well as any areas where your doctors believe there may be microscopic tumor remaining after surgery. Even if the tumor was completely removed there could still be microscopic tumor cells nearby, and these can grow into tumors if they are not radiated. If an en-bloc resectionDuring surgery, removal of the entire tumor in one piece without cutting it into smaller pieces. is achieved the dose of radiation to the areas surrounding where the tumor was can be limited to 70 GyE.

The amount of radiation required to treat chordoma is higher than what healthy tissue can handle. For this reason, the radiation dose must be focused on the tumor while avoiding important nearby structures such as the brain, brainstem, nerves, or spinal cord. Radiation that is highly focused is called conformal radiationTypes of radiation that can focus the beam of radiation very accurately on the tumor while minimizing the amount of radiation that reaches the surrounding healthy tissue.. Your radiation oncologist should plan radiation therapy to deliver the necessary dose to the tumor without causing harm to surrounding tissues.

Types of radiation

A type of external beam radiationRadiation that is delivered from outside the body. called particle therapyA type of external beam radiation that uses beams of protons, neutrons, or positive ions for the treatment of cancer. is generally recommended for treating chordoma because it can be focused most precisely. Two different types of particles are commonly used: protons and carbon ions. It is not known whether there is any difference in effectiveness between proton beam therapyA type of particle therapy that uses beams of protons to kill cancer cells. and carbon ion therapyA type of particle therapy that uses beams of charged carbon ions to kill cancer cells. Carbon ion therapy can deliver high doses of radiation to a tumor while sparing surrounding normal tissue..

See a list of proton beam and carbon ion centers across the world from the Particle Therapy Co-Operative Group »

In some cases, highly focused photonA type of external beam radiation that uses x-rays to kill cancer cells. radiation can be a suitable alternative to particle therapy as long as a high enough dose can be delivered to the target area without damaging healthy tissue. Sometimes it may be helpful to combine photon radiation and particle therapy. For all types of external beam radiation, imaging is needed every day of treatment to make sure that the radiation is going to exactly the right place. This technique is called image guidanceThe use of frequent imaging, such as MRI or CT, during radiation treatments to help direct the radiation to the right place..

Another method of delivering radiation, called brachytherapyA type of radiation therapy in which a small amount of radioactive material is placed inside the body to kill cancer cells., involves inserting a small amount of radioactive material inside the body during surgery. This method is used infrequently, but can sometimes be helpful for delivering a high enough dose of radiation to the area near the brainstem or spinal cord. When it is used, it is usually given in combination with external beam radiation.

Learn more about the types of radiation used in chordoma treatment »

What matters most about radiation is that a high enough dose is delivered to the area that needs it while delivering a safe, lower dose to important nearby structures. Whether the right dose can be delivered with a particular type of radiation depends on a number of factors, including the shape of the area being radiated and the location of important structures that must be avoided. In general, the more precisely the radiation can be focused (the more conformal it is) the better.

The information on this page was developed by the Chordoma Foundation in consultation with members of the Chordoma Global Consensus Group. We would like to thank the members of the Chordoma Global Consensus Group for providing their expertise in the development of the original consensus guidelines and their review of this educational content.

The information provided herein is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your or your loved one’s physician about any questions you have regarding your or your loved one’s medical care. Never disregard professional medical advice or delay in seeking it because of something you have read on this Website.