Skull Base Tumor Treatment
Our Treatment Approach
The specialists at MD Anderson take a team approach to skull base tumors, bringing together extraordinary expertise from neurosurgery, head and neck surgery, plastic surgery, medical, and radiation oncology, and many other areas. We personalize your treatment to deliver the most advanced care with the least impact on your body.
Skull base tumor patients benefit from the most advanced technology and treatments, many available at only a few locations in the country. Your recommended therapy may include:
- Minimally invasive surgery
- Proton therapy
- Innovative radiotherapy delivery techniques
- Advanced reconstruction surgeries
- Chemotherapy, targeted therapy, and immunotherapy
And we’re constantly researching newer, safer, more-advanced treatments for skull base tumors. This means we are able to offer a range of clinical trials for new treatments.
Our Skull Base Tumor Treatments
If you are diagnosed with a skull base tumor, your doctor will discuss the best options to treat it. This depends on:
- The type of tumor
- The location and extent of the tumor
- Possible side effects of treatment
- Your health
Most skull base tumors require surgery. Some can be treated without surgery (for example with radiation or chemotherapy). Others do not need to be treated right away and can be watched closely over time, under the care of an experienced skull base specialist.
Your treatment for a skull base tumor will be customized to your particular needs. It may include one or more of the following.
Surgery
Like all surgeries, skull base tumor surgery is most successful when it is done by a surgeon with a great deal of experience in the procedure.
MD Anderson’s renowned skull base tumor surgeons work in multi-specialty teams. They perform hundreds of skull base tumor surgeries each year, using the most-advanced techniques.
The main types of skull base tumor surgery are:
Open surgery: Incisions are made in the skin or the membranes of the nose, mouth or throat to expose the bone of the skull base. The incision often can be hidden in the hair, skin creases, nose or mouth.
The affected bone is removed to expose the tumor and to identify the important nerves and blood vessels. After the tumor is removed, the membrane that protects the brain and the surrounding soft tissues is closed to seal off the skull base. Occasionally, when large skull base tumors are treated, plastic surgeons rebuild the soft tissues and bone to optimize function and appearance. When muscles and nerves are affected, highly specialized plastic surgeons may provide facial reanimation and complex craniofacial construction.
Minimally invasive endoscopic surgery: Using no incisions or a few small ones in the skull or back of the sinuses, the surgeon uses an endoscope to biopsy or remove the skull base tumor. This approach may:
- Lessen damage to healthy tissue
- Lessen time in hospital and recovery time
- Reduce complications
Image-guided surgery: CT (computed tomography) or MRI (magnetic resonance imaging) scans are taken before surgery. They then are used in the operating room to help guide the surgeon to the precise location of the tumor. This enhances the accuracy, precision and safety of surgery of the skull base.
Real-time MRI: Provides surgeons with precise, "live" images of the tumor and surrounding areas during surgery. This increases the surgeon’s accuracy and the chance for complete removal of the skull base tumor.
Radiation Therapy
New radiation therapy techniques and remarkable skill allow MD Anderson doctors to target skull base tumors more precisely, delivering the maximum amount of radiation with the least damage to healthy cells. MD Anderson provides unparalleled clinical expertise with the most advanced radiation treatments, including:
Intensity-modulated radiotherapy (IMRT): IMRT uses sophisticated computerized controls and software to deliver radiation beams in different angles to fit the exact shape of the skull base tumor. IMRT technology lowers the radiation dose to the normal tissue surrounding the tumor and lessens the side effect of treatment.
Stereotactic radiosurgery is the focused delivery of large doses of radiation to tumors in one or a few sessions without the need of a scalpel or any incision. This method provides the ability to targets skull base tumors with very high accuracy and precision. One of several radiosurgery techniques available at MD Anderson for skull base tumor treatment include:
- Gamma Knife delivers highly focused beams of radiation to treat small skull base tumors (usually those that are less than 3 centimeters in size). This is possible through the use of a special head frame placed by the Neurosurgeon to provide a stereotactic guidance system to target the tumor with high accuracy and precision. This eliminates unintended radiation dose and harm to the surrounding healthy tissue. Gamma Knife treatments are typically done in one day and do not require an overnight stay in the hospital.
- Stereotactic Body Radiation Therapy (SBRT) can treat tumors that are larger than 3 cm or located close to a sensitive structure, using a frameless custom mask, cushion and mouthpiece instead of a head frame. SBRT treatment usually consists of 3 to 6 radiation sessions given every other day and shortens the overall length of treatment from seven weeks to two weeks. Our team of radiation oncologists with expertise in treating skull base tumors will evaluate each case to determine the best radiotherapy approach to use.
Proton therapy delivers high radiation doses directly to the skull base tumor site, while decreasing the risk of damage to nearby healthy tissue. It is especially valuable for some cancers deep in the body (such as skull base tumors) because it is targeted to deposit energy only in the area of the tumor. For these patients, proton therapy can result in better cancer control with less impact on the body.
MD Anderson offers many new and advanced radiotherapy technologies to deliver precision radiation to your specific skull base cancer. Our expert radiation oncologists will evaluate each case to determine the best radiotherapy approach to use. Together, they work closely with our skull base surgeons, neurosurgeons, medical oncologists and other doctors specializing in skull base cancers to coordinate treatment tailored for you.
Reirradiation
Repeat radiation to the same area that has already received radiation is very challenging. It is necessary to deliver the radiation precisely and accurately to avoid unwanted reirradiation to the normal tissue. Each reirradiation plan is approached with the utmost care and thought, and each treatment is personalized to your needs. The goal of skull base reirradiation is to provide long-term cancer control but also to preserve quality of life. It is very important that the radiation oncologist and team have experience with reirradiation andof skull base tumors.
MD Anderson is a world leader in head and neck reirradiation. Advanced radiation techniques such as IMRT, proton therapy and stereotactic radiosurgery can be used to reirradiate skull base tumors when surgery is not possible. We also offer clinical trials for patients with unresectable tumors of the skull base who are receiving repeat radiation.
Palliative reirradiation: Stereotactic reirradiation of the skull base can be used to provide symptom relief from facial pain caused by cancer. A recent study performed at MD Anderson showed that Gamma Knife stereotactic radiosurgery reduced facial pain caused by certain skull cancers tumors and lessened the need to use narcotic pain-relievers.
Chemotherapy
Chemotherapy uses powerful drugs to kill cancer cells that multiply quickly. It may involve a single drug or a combination of two or more drugs, and can be used in combination with other treatments. MD Anderson offers the most up-to-date and advanced chemotherapy options.
Immunotherapy
Immunotherapy uses the body’s immune system to recognize and eliminate cancer. There are several types of immunotherapies offered at MD Anderson, and a patient's overall health and type of cancer determines the therapies available to them.
Targeted therapy
Targeted therapy, also called precision medicine, stops or slows the growth or spread of cancer by targeting specific molecules and cancer-causing genes. These therapies are often given along with another treatment like chemotherapy or radiation.
Our Skull Base Tumor Clinical Trials
Because of its status as one of the world’s premier cancer centers, MD Anderson leads numerous innovative clinical trials (research studies) for skull base tumors.
Studies of treatments based on tumor cell type may include laboratory or imaging tests to see if the treatment is working. Other studies track the quality of life of patients and their families. This may help lessen the effect of the tumor and its treatment on patients’ physical, mental and social well-being.
Skull base tumors are treated in our Brain and Spine Center, Head and Neck Center and Proton Therapy Center.
Patients with recurrent or second primary head and neck cancer who previously received radiation therapy to the head and neck region—especially those with unresectable tumors—have typically had a dismal prognosis and limited treatment options. Although radiation therapy offers high rates of local disease control, re-irradiating the region is usually avoided for fear of damaging previously irradiated healthy tissue, including vital structures such as the carotid arteries and neural structures. But advanced imaging and radiation therapy techniques are now being used to re-irradiate recurrent tumors while sparing nearby critical structures in patients with head and neck cancer.
For previously irradiated patients with recurrent head and neck cancer, surgery is historically considered the only potentially curative option. When these recurrent tumors are unresectable, chemotherapy provides a median survival of only 9–11 months—just a few months longer than with supportive care.
“These patients with unresectable tumors don’t have many options, and they die of very morbid disease,” said Jack Phan, M.D., Ph.D., an assistant professor in the Department of Radiation Oncology at The University of Texas MD Anderson Cancer Center.
But Dr. Phan and colleagues have shown that re-irradiating recurrent tumors, if done safely, can provide local tumor control and relieve symptoms. With the goal of also prolonging patients’ survival, Dr. Phan is now leading a clinical trial that explores re-irradiation in patients with unresectable recurrent head and neck cancer.
Overcoming challenges to re-irradiation
In the 1990s, several clinical trials studied re-irradiating recurrent head and neck tumors with conventional two-dimensional and three-dimensional conformal radiation therapy. “It did improve outcomes in a select group of patients, but the side effects were pretty horrendous,” Dr. Phan said. The practice was restricted to very high risk cases.
In 2013, believing that advances in technology could improve patient safety, MD Anderson physicians began using stereotactic techniques for re-irradiation in patients with unresectable recurrent head and neck cancers. Dr. Phan and colleagues visualize these tumors by creating a composite three-dimensional image from magnetic resonance imaging, computed tomography, and positron emission tomography–computed tomography scans taken with the patient in the treatment position. The composite image is used to plan the delivery of stereotactic body radiation therapy (SBRT) with a linear accelerator or stereotactic radiosurgery with a Gamma Knife.
“We’re at a point now where we can target the tumor with stereotactic precision and avoid the nearby normal, critical tissues,” Dr. Phan said. “We previously couldn’t visualize the tumor very well. Advances in radiation therapy are very closely tied to advances in medical imaging.”
Both stereotactic modalities deliver high doses of radiation to the tumor in very few fractions—typically three to five for SBRT and one to three for radiosurgery—with minimal doses to nearby structures. The patient is re-imaged in the treatment position before each treatment session to ensure precise targeting. SBRT is used for most recurrent head and neck tumors, with stereotactic radiosurgery reserved for small skull base tumors.
Clinical benefits of re-irradiation
Patients who previously received radiation therapy to the head and neck region and receive re-irradiation for recurrent head and neck cancer at MD Anderson are enrolled in an observational study. Data from this study are showing that patients benefit from re-irradiation.
“We currently re-irradiate about 100 patients a year—an increase from about 20 patients a year prior to 2011,” Dr. Phan said. “Many folks we treated 3–5 years ago with SBRT are still alive and doing well.”
In addition to potentially prolonging survival, re-irradiation can provide symptom relief. Dr. Phan and colleagues recently analyzed the outcomes of patients who received stereotactic radiosurgery as a palliative treatment for facial pain from unresectable recurrent skull base tumors. Most patients had significantly lower self-reported pain scores 6 months after treatment. Furthermore, many patients were able to reduce their doses of pain medication, and some patients were able to discontinue their pain medications altogether.
“This was the first study to document a decrease in narcotic use after palliative-intent re-irradiation for patients with pain from recurrent head and neck cancer,” Dr. Phan said. “And in our current clinical trial, re-irradiation with SBRT is being done with the goal of long-term cancer control.”
The current trial (No. 2016-1065) is enrolling patients who have one to three sites of unresectable recurrent or second primary head and neck cancer who previously received at least 30 Gy of radiation therapy for head and neck cancer. Each tumor must be smaller than 60 cm3, and the total tumor volume must be less than 100 cm3.
Patients enrolled in the trial are randomly assigned to one of two treatment groups. One group receives SBRT at a dose of 45 Gy in five fractions over 2 weeks, and the other group receives intensity-modulated radiation therapy (IMRT) or intensity-modulated proton therapy (IMPT) at a dose of 60–70 Gy in 33–35 fractions over 6 or 7 weeks.
The trial’s outcome measures include toxic effects, local tumor control, and patient-reported symptoms. “All three modalities used in the trial are highly conformal,” Dr. Phan said. “The question we have is, which modality will give better local tumor control and a better side effect profile?”
So far, patients in both treatment groups are doing well. “We only have 1 year of follow-up, but the local tumor control rate for all patients is 80%–90%,” Dr. Phan said, emphasizing that these results are too early for meaningful analysis. “We don’t know how these patients will do 5 years from now, but it’s promising.”
In the 1990s, re-irradiation for head and cancer was believed to cause carotid artery damage in 8%–13% of patients; however, Dr. Phan and his colleagues have not seen any carotid artery damage in patients in the observational study or the current clinical trial.
Future directions
Other clinical trials of stereotactic radiation techniques are expected to begin enrolling previously irradiated patients with head and neck cancer in the near future. Some of these trials will combine radiation therapy with immunotherapy.
A phase I trial will combine SBRT and an immune checkpoint inhibitor for patients with recurrent head and neck cancer and one to three head and neck lesions who have previously undergone radiation therapy to the head and neck region. “Head and neck tumors have a high risk of spreading regionally and distantly,” Dr. Phan said. “We hope the immunotherapy will help the body target any stray tumor cells outside the radiation field.” The researchers also hope that the radiation therapy will create an abscopal effect, i.e., that antigens released by the irradiated tumors will enhance the effect of immunotherapy on the non-irradiated metastatic lesions.
Dr. Phan and colleagues also want to see if re-irradiation plus immunotherapy can benefit patients with resectable disease. A trial combining re-irradiation and immunotherapy will enroll patients with resectable recurrent head and neck cancer who previously underwent radiation therapy. After resection of the recurrent disease, patients will receive lower-dose SBRT in combination with immunotherapy drugs. One of these drugs is a novel immune checkpoint inhibitor that also has the potential to reduce radiation-related inflammation. “This is exciting because re-irradiated patients have a high risk of severe scarring, and this scarring comes from inflammation,” Dr. Phan said.
Dr. Phan and his colleagues’ goal is to use highly conformal re-irradiation techniques to prolong survival without causing debilitating pain or scarring for patients with recurrent head and neck cancer. “We only have SBRT re-irradiation follow-up data up to 5 years, and we don’t know what long-term effects we may see,” Dr. Phan said. “But at the same time, many of these folks probably would have had 6 months to live without treatment.”
For more information, contact Dr. Jack Phan at 713-792-5373 or jphan@mdanderson.org. To learn more about clinical trials for patients with head and neck cancer, visit www.clinicaltrials.org and search by trial number or cancer type.
FURTHER READING
Phan J, Pollard C III, Brown PD, et al. Stereotactic radiosurgery for trigeminal pain secondary to recurrent malignant skull base tumors. J Neurosurg. In press.
OncoLog, April 2018, Volume 63, Issue 4
