The purpose of radiation therapy is to kill or stop the growth of tumor cells. Radiation can serve different roles in the treatment of chordoma, which can vary based on where the radiation is being delivered and the stage of the disease.
Read more on making decisions about radiation for skull base tumors
Chordomas are generally treated with a beam of radiation that is delivered to the tumor from a machine. This is called external beam radiation.
Particle therapy is a type of external beam radiation therapy that uses beams of charged particles instead of x-rays to damage cancer cells and stop them from growing. The two types of particle therapy most commonly used to treat chordoma are proton therapy and carbon ion therapy. These treatments can deliver radiation very precisely to the tumor while limiting the amount of radiation that reaches nearby healthy tissues.
Proton and carbon ion treatment centers are expensive to build and are not available at every hospital. Proton therapy is becoming more widely available, including at many centers in the United States and in several countries throughout Europe and Asia. Carbon ion therapy is less widely available and is currently offered at a smaller number of centers in countries such as Austria, China, Germany, Italy, and Japan.
Photon radiation therapy uses high-energy x-rays beams and can be delivered in a few different ways. Intensity-modulated radiation therapy (IMRT) uses advanced computer planning to shape the radiation dose to the tumor while limiting radiation to nearby healthy tissues. Volumetric modulated arc therapy (VMAT) is a type of IMRT in which the treatment machine rotates around the patient while delivering radiation, allowing very precise delivery and often a faster treatment.
Stereotactic radiosurgery (SRS) and stereotactic body radiation therapy (SBRT) are highly focused forms of photon radiation that deliver larger doses per treatment to a small, clearly defined target. SRS is most often used for tumors or targets in the skull base, while SBRT is used for targets elsewhere in the body.
In some cases, different types of radiation therapy may be combined. For example, a patient may receive both photon therapy and proton therapy, depending on the tumor’s location, the treatment goals, and which nearby healthy tissues need to be protected. Whatever type of radiation is used, image guidance is common to help the radiation team confirm the patient’s position and aim the treatment accurately.
More research is needed to understand how photon therapy, proton therapy, carbon ion therapy, SRS, and SBRT compare with one another in treating chordoma, including which approaches are most effective for different tumor locations and situations. It is very important to be treated at a center and by a team with extensive experience caring for people with chordoma.
Chordomas require very high doses of radiation to be controlled. Specifically, a total dose of at least 70 to 74 Gray (Gy) is recommended for particle and photon therapies when given over several weeks. SRS and SBRT deliver an equivalent biologic dose but in fewer treatments. See the treatment guidelines for new diagnosis for more information.
If your tumor comes back after your initial radiation, the option of further radiation will depend on factors such as the location of the new tumor growth, the amount of previous radiation, and how long it has been since the previous dose of radiation. A specialized center and a radiation oncologist with experience in chordoma should help guide these decisions. See the treatment guidelines for local recurrence for more information.
Lower doses of radiation are sometimes used to help slow the growth of recurrent or advanced tumors and ease symptoms such as pain or symptoms caused by pressure on nerves or other nearby structures. Radiation may also be combined with drug therapies, such as targeted therapy or immunotherapy, in some treatment plans or clinical trials. Researchers are still studying when these combinations are most helpful and how to use them safely.
Before you begin radiation treatments, you will visit with the radiation oncologist. The doctor will discuss your treatment plan with you, including what side effects you might expect from the treatments.
If you have a skull base or cervical tumor, radiation technicians will fit you for a mask that will be used to stabilize your head and neck during the treatments. Something similar may also be done if your tumor is on the thoracic, lumbar, or sacral spine.
The radiation technicians will see you at each visit. You may need to remove certain parts of clothing and then the tech will have you lay down on a special table, called a treatment couch, which is used to accurately position you. If you have a mask, the technician will attach your mask to the treatment couch. This can cause some patients to feel anxious or claustrophobic. If this happens to you, ask your technicians about things other patients have found helpful in dealing with this feeling.
Proton beam, carbon ion, and IMRT/VMAT photon radiation are typically given in small doses during daily sessions (usually around 35-40) over 6-8 weeks. The dose of radiation delivered during each session is called a fraction. The radiation from each fraction accumulates over time until the total dose is reached. The treatments themselves last just a minute or two.
SRS and SBRT deliver equivalent doses using photons over a shorter amount of time (usually 1-5 sessions) and, therefore, are often used for smaller tumors. This is called hypofractionation and is also delivered in minutes.
During treatment, you will have a check-up with your radiation oncologist every few weeks. After you complete all radiation treatments, your doctors will likely recommend waiting 2-3 months before doing imaging to allow time for any swelling or inflammation that might have been caused by the treatments to subside.
The amount of radiation required to treat chordoma is higher than what healthy tissue can handle. For this reason, it is important for the radiation dose to be focused on the tumor while avoiding important nearby structures such as the brain, brainstem, nerves, or spinal cord. However, even with highly focused radiation, short- and long-term side effects are still possible.
Acute, short-term side effects you might experience during radiation treatments can vary depending on the location of your tumor. A rash and skin irritation at the site of radiation are very common. Your care team can suggest types of lotion or cream that can help protect your skin and soothe irritation. Nausea and fatigue are experienced by most patients at some point during radiation treatments. Most of these side effects will resolve after radiation ends. Long-term or late effects can develop several years after treatment. Talk with your radiation oncologist about the risks involved in your radiation treatment plan.
Despite these possible side effects, most patients receiving radiation say they feel good enough to continue daily activities.
Can develop during radiation and up to 3 months after
|
Skull base |
Mobile spine |
Sacrum |
|---|---|---|
|
Localized hair loss Mouth, throat, or skin irritation Changes to smell and taste Pain Difficulty swallowing Blurry vision Headaches or ear aches Nausea Fatigue |
Localized hair loss Throat or skin irritation Pain Difficulty swallowing Cough Fatigue |
Diarrhea Pain Fatigue Changes in bowel or bladder function |
Can develop several years after radiation
|
Skull base |
Mobile spine |
Sacrum |
|---|---|---|
|
Hearing loss Ringing in ears Hormonal imbalances, Cataracts Altered sense of smell and taste Difficulty with short-term memory and speed of thinking Inflammation of the brain tissue Balance difficulties Numbness on the face |
Insufficiency fracture Difficulty with swallowing Damage to the spinal cord (rare) Numbness along the back |
Insufficiency fracture Changes in bowel, bladder, and/or sexual function Numbness down legs |
Learn from chordoma experts about the types of radiation used to treat chordoma
The resources and information below can help you make the most informed decisions about your treatment.
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 child’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.