Targeted Treatment For Central Nervous System (CNS) Cancers
Targeted proton therapy for tumors of the brain and spine (also called the central nervous system) typically delivers less radiation to surrounding healthy tissue, and can result in fewer side effects than X-ray radiation. Advanced proton therapy allows doctors to more selectively place high-dose radiation within sensitive brain and spine areas, while simultaneously reducing the dose to surrounding critical tissue.
The clinical and scientific teams have more than 90 years of combined experience treating patients with proton therapy. Learn more about the experts at the center.
From diagnosis through treatment and recovery, Scripps offers comprehensive cancer care. Learn how proton therapy can complement cancer care.
Proton therapy for central nervous system (CNS) tumors
Central nervous system (CNS) tumors are notoriously difficult to treat. While high doses of radiation are routinely required for cure, radiation can damage nearby tissues, including critical areas of the brain, brain stem, pituitary gland, and nerves that affect vision and hearing.
Ideally, radiation treatment for spine and brain tumors will:
- Target the tumor only
- Protect your healthy brain tissue
- Protect surrounding areas from radiation damage
- Maintain your quality of life during treatment
- Reduce side effects of treatment
Targeting CNS tumors with radiation can be especially challenging because:
- Radiation to healthy tissues around the tumor can affect your brain, spine, vision and hearing, which are very sensitive to radiation even at low dosages. Damage to them can have significant side effects that can impair your quality of life.
- If cancer comes back after radiation therapy, treatment options may be limited. Retreating cancer with X-ray radiation in or near the same area is challenging and potentially very risky. The dose of radiation required to effectively treat the tumor may be too toxic for surrounding healthy tissues, but a lower dose may not be enough to kill the cancer cells.
With any radiation techniques, the potential for serious complications can be high in some cases. This can lead to a difficult choice between giving:
- a less-than-optimal dose to the tumor (which reduces the chance of a cure); or
- an ideal dose to the tumor with a higher risk of radiation to healthy tissues.
Benefits of proton therapy for CNS tumors
Proton therapy is an extremely precise form of radiation treatment that can target CNS tumors within these sensitive areas. Because proton beams can be carefully controlled and directed to deposit their maximum energy directly in the tumor, exposure to sensitive healthy tissues in and around the tumor can be reduced. This accuracy is further enhanced by Scripps’ advanced imaging and pencil-beam scanning technologies.
As a result, some patients with tumors in and around the brain or spine can be treated with higher radiation doses, which may improve their chance of cure.
- Proven therapy. Studies examining proton therapy for CNS show favorable results when compared to X-ray therapy. A study of proton therapy for intracranial meningiomas reported overall survival rates of approximately 92 percent.
- More precise targeting of tumors. Advanced pencil-beam scanning, available in Southern California exclusively at Scripps, enables physicians to “paint” the protons onto the tumor in layers so that they conform to even the most irregular tumor shapes.
- Reduced radiation exposure to surrounding tissues. Numerous studies have shown that proton therapy spares more healthy tissue than a conventional and/or intensity-modulated X-ray (IMRT) therapy. Researchers compared treatment plans for patients with benign meningioma (a CNS tumor) and found that, compared with X-ray therapy, proton therapy decreases the risk of radiation-associated second tumors by half and delivers significantly lower doses to the brain and critical structures of vision and hearing.
- Advanced pencil-beam scanning further reduces radiation to nearby tissue. Scripps Proton Therapy Center’s precisely targeted pencil-beam scanning technique (IMPT) further reduces the amount of radiation to surrounding tissues, even when compared with conventional passively scattered protons. The radiation dose from pencil-beam scanning that extends outside of the target has been shown to be substantially less than both passively scattered protons and intensity-modulated X-ray therapy (IMRT).
- Reduced risk of second cancers. Many studies have shown an increased rate of secondary cancer in surrounding areas in patients who receive X-ray radiation therapy. Because proton therapy lowers the dose to normal tissue, studies predict a lower risk of secondary cancer.
Because proton therapy can better concentrate its radiation dose to the target and limit it elsewhere, it is ideally suited for treating areas that have previously received X-ray radiation therapy. Treating previously irradiated areas is challenging and very risky with any radiation therapy. Tissues around the recurrent tumor don’t “forget” the previous radiation dose, and any added dose continues to increase the risk of normal tissue injury. By reducing the radiation dose given to these previously treated tissues, protons can help to reduce (but not eliminate) some of the risks associated with re-irradiation.
Scripps Proton Therapy Center provides advanced radiation treatments for cancerous and non-cancerous brain and spine tumors including:
When you are living with cancer, you may need more than expert medical treatment. Our staff is here to help you and your family every step of the way, from scheduling appointments and answering questions to finding support services and other resources.
We offer a wide variety of services to help speed your recovery, including:
- Home health care services
- Nutrition services through Scripps Center for Weight Management and Scripps Center for Integrative Medicine
- Psychological and emotional care
- Cancer support groups
- Complementary medicine through Scripps Center for Integrative Medicine cancer care program
Proton therapy is a highly precise form of external radiation therapy that can be used for tumor control in select patients. All cancer treatments have advantages and disadvantages. Be sure to discuss these, as well as your treatment options, with your cancer specialist.
Supporting evidence for proton therapy for CNS tumors
- Spot-scanning proton radiation therapy for recurrent, residual or untreated intracranial meningiomas
- Assessment of radiation-induced second cancer risks in proton therapy and IMRT for organs inside the primary radiation field
- Comparison of risk of radiogenic second cancer following photon and proton craniospinal irradiation for a pediatric medulloblastoma patient
- Modeling intracranial second tumor risk and estimates of clinical toxicity with various radiation therapy techniques for patients with pituitary adenoma
- Photon and proton therapy planning comparison for malignant glioma based on CT, FDG-PET, DTI-MRI and fiber tracking
- Projected second tumor risk and dose to neurocognitive structures after proton versus photon radiotherapy for benign meningioma
- Proton versus photon radiotherapy for common pediatric brain tumors: comparison of models of dose characteristics and their relationship to cognitive function