Overview

Approximately 190,000 patients per year are diagnosed in the United States with a brain tumor.  Of note, most “brain” tumors do not arise from the brain itself but are actually metastases from cancers arising elsewhere in the body, notably cancers of the breast, lung and colon.  Overall, approximately 10-15% of cancer patients develop brain metastases sometime during the course of their disease.

The brain is a complex organ comprised of multiple components.  A major portion of the brain is the cerebrum, which is divided into right and left hemispheres.  Each hemisphere is further divided into different lobes: frontal, parietal, temporal and occipital.

Other components of the brain include the cerebellum which is involved in balance and fine motor functions, the brainstem which controls basic functions including respiration.  Various glands are also located within the brain, notably the pituitary gland which produces hormones involved in a variety of important functions including growth and blood pressure management. 

Given its complex composition, it is not surprising that a large variety of primary brain tumors may arise.  In fact, there are over 100 distinct tumor types, ranging from benign to highly malignant. 

It is also not surprising that brain tumor patients present with a large spectrum of signs and symptoms.  For example, pituitary tumors may lead to double vision (diplopia) by disruption of the optic nerve pathways.  Cerebellar tumors present with problems with gait and balance.  A common symptom, however, in many patients, regardless of the tumor site, is headache.

Interested in learning more about specific Brain Tumors?

Click here for the American Cancer Society (ACS) website (Brain Tumor Section).

Role of Radiation Therapy                                     

Patients with central nervous system (brain) tumors are commonly treated with Radiation Therapy.  In patients with malignant (cancerous) brain tumors, treatment involves maximal surgical resection (if possible) followed by adjuvant Radiation Therapy.  Most patients with high grade tumors also receive chemotherapy during, and often also after, radiation [view paper]. 

Radiation Therapy is also commonly used to treat benign (non-cancerous) and low grade brain tumors.  It may be delivered alone as definitive treatment or after an incomplete tumor resection [view paper]. 

Another group of CNS tumor patients commonly treated with Radiation Therapy are patients with metastases to the brain from tumors in the body, e.g. lung cancer, colon cancer or other sites.  Select patients may undergo surgery plus post-operative radiation to the brain to reduce the risk of recurrence [view paper]. Alternatively, patients may be treated with radiation alone [view paper]. 

Radiation Therapy Techniques                                                                  

A wide variety of radiation therapy techniques are commonly used in patients with CNS tumors.  The most common approach is 3-dimensional conformal radiation therapy (3DCRT).  The 3DCRT technique uses multiple shaped beams which reduce the dose to the surrounding normal tissues. 3DCRT represents a major advancement over conventional RT providing the ability to deliver treatment more focused on the tumor itself.

Intensity Modulated Radiation Therapy (IMRT)                                          

In recent years, a sophisticated form of 3DCRT known as intensity modulated radiation therapy (IMRT) has been receiving increasing attention in patients with brain tumors.  Unlike conventional approaches, IMRT using highly modulated beams designed using sophisticated computerized optimization planning. When cast into the patient, these modulated beams better conform the radiation dose to the shape of the tumor in 3D, further reducing the volume of normal surrounding tissues receiving high doses.

Multiple investigators have reported promising results using IMRT in brain tumor patients [view paper 1, paper 2]. IMRT is particularly appealing in patients with benign meningiomas since these tumors are often highly irregular in shape [view paper]. 

A survey of practicing radiation oncologists in the United States performed by Dr. Mundt and colleagues found that the CNS were the 3rd most common site treated with IMRT.

IMRT plan in a patient with a right-sided malignant brain tumor

Brain tumor patients are UCSD are commonly irradiated with IMRT.  Ask your radiation oncologist whether IMRT is the right treatment for you.

Stereotactic Radiosurgery                                                                  

Stereotactic Radiosurgery (SRS) is the use of high doses of radiation delivered to small volumes within the brain with high precision.  Treatment may be delivered in a single fraction or a limited number of fractions. 

SRS is delivered at UCSD on the Varian Trilogy linear accelerator.  Trilogy provides the ability to deliver SRS with a variety of approaches, including intensity modulated radiation therapy (IMRT).  Such flexibility allows the Radiation Oncologist to choose the treatment approach most appropriate for the individual patient.

Varian Trilogy

Unlike other SRS approaches (GammaKnife, CyberKnife), Trilogy uses a sophisticated optically-based image-guided treatment system, whereby infrared cameras in the treatment room are used to track the position of the patient in real-time during treatment.  Real-time tracking SRS to be delivered without the need for a frame attached to the patient’s skull, as is commonly used in other SRS systems.  Frameless SRS is the preferred method of SRS delivery at UCSD and is used on the great majority of patients.

Interested in a comparison of competing SRS technologies?  Click here for a lecture delivered by Dr. Kevin Murphy of this issue.

Patient undergoing frameless SRS treatment on the Trilogy

Multiple clinical studies have demonstrated that SRS is a highly effective approach, particularly in many patients with brain metastases [view paper] and benign meningiomas [view paper 1 and paper 2]. 

Ask your physician whether SRS is appropriate for the treatment for you.  Click here to see a detailed overview of the frameless SRS Trilogy planning and treatment process.

Gliasite                                                                                               

An internal form of radiation therapy (brachytherapy), Gliasite involves the introduction of a balloon catheter into the brain at the time of surgery.  A radioactive solution containing Iodine-125 is later instilled into the balloon, delivering high doses of radiation locally to the tumor.

A patient with a Gliasite Catheter

Gliasite treatment is delivered continuously over 3-7 days as an outpatient.  At the end of treatment, the Iodine solution is removed via a small port located under the scalp.

Multiple investigators have reported that Gliasite is a safe and effective means of delivering high doses of radiation to patients with primary and metastatic brain tumors.  It is particularly useful in patients who have received prior external beam irradiation [view paper 1 and paper 2]. 

Ask your physician whether Gliasite is an appropriate treatment for you.

UCSD Central Nervous System (Brain) Tumor Team                             

The UCSD CNS (Brain) Tumor Team is comprised of dedicated professional with considerable experience in the treatment of benign and malignant brain tumors. 

Kevin Murphy, M.D. Chief, CNS (Brain) Tumor Service Department of Radiation Oncology

Dr. Murphy has considerable experience treating brain tumors in both adults and children.  He and his team are committed to providing brain tumor patients with access to the latest radiotherapy approaches, including IMRT, Gliasite, and frameless stereotactic radiosurgery (SRS). 

Director of the Stereotactic Radiosurgery Service, Dr. Murphy has one of the largest experiences in the world with frameless stereotactic radiosurgery using the Varian Trilogy.  He is a frequent invited lecturer on Trilogy Radiosurgery in the United States and abroad [What’s New].   

Working closely with Dr. Murphy in the care of adult and pediatric CNS (brain) tumor patients treated in the Department is Radiation Nurse, Michelle Russell, R.N.

Michelle Russell, R.N. Radiation Nurse Department of Radiation Oncology

The treatment of brain tumor patients is a team approach. Dr. Murphy thus works together with a number of professionals from other UCSD Departments, including neurosurgery, medical oncology and pediatric oncology. All brain tumor patients are presented and discussed at a multi-disciplinary Brain Tumor Conference.

John Alksne, M.D. Professor, Neurological Surgery

Other members of the UCSD involved in the care of patients with brain tumors include Medical Oncologist William Read, M.D. and Neurosurgeons David Barba, M.D., Hoi Sang U, M.D., Michael Levy, M.D. and Hal Meltzer, M.D.

William Read, M.D. Medical Oncologist

David Barba, M.D. Neurosurgeon

Hoi Sang U, M.D. Neurosurgeon

Michael Levy, M.D. Pediatric Neurosurgeon

Hal Meltzer, M.D. Pediatric Neurosurgeon

CNS (Brain) Tumor Publications by UCSD Radiation Oncology Faculty         

Listed below are CNS (Brain) Tumor Articles published by members of the UCSD Department of Radiation Oncology.  For a full list of published articles by UCSD Radiation Oncology faculty see Research section

Schomas DA, Roeske JC, Macdonald RL, Mehta N, Sweeney PJ, Mundt AJ. Predictors of tumor control in patients treated with linac-based stereotactic radiosurgery for metastatic disease to the brain. Am J Clin Oncol 2005;28:180

Ioffe V, Miller M, Sandhu APS, et. al. Radiosurgical treatment of brain metastases in a community oncologic practice. Commun Oncol 2004;1:149

Engelhard HH, Stelea A, Mundt AJ. Oligodendroglioma and anaplastic oligodendroglioma: clinical features, treatment and prognosis. Surg Neurol 2003;60:443

Biswas T, Sandhu APS, et al. Low dose radiosurgery for benign intracranial lesions. Am J Clin Oncol. 2003;26:325

Torres IJ, Mundt AJ, et al. A longitudinal neuropsychological study of partial brain radiation in adults with brain tumors. Neurology 2003;60:1113

Mansur DB, Hekmatpanah J, Wollman R, Macdonald L, Nicholas K, Beckman E, Mundt AJ. Low grade gliomas treated with adjuvant radiation therapy in the modem imaging era.  Am J Clin Oncol 2000;23:222

Connell PP, Mansur DB, Macdonald L, Nicholas KE, Mundt AJ. Tumor size predicts control in benign meningiomas.  Neurosurgery 1999;44:1194

Ayyangar KM, Jiang SB. Do we need Monte Carlo treatment planning for linac-based radiosurgery? A case study.  Med Dosim 1998;23:161

Kowalczuk A, Macdonald RL, Amidei C, Dohrmann G, Erickson RK, Hekmatpanah J, Krauss S, Krishnasamy S, Masters G, Mullan SF, Mundt AJ, et al.  Quantitative imaging study of extent of surgical resection and prognosis of malignant astrocytomas.  Neurosurgery 41997;41:1028

Jaffey P, Mundt, AJ, et al.  The clinical significance of extracellular matrix in gangliogliomas.  J Neuropath Exp Neurol 1996;55:1246\

Saunders WM, Winston KR, Siddon RL, Svensson GH, Kijewski PK, Rice RK, et al. Radiosurgery for arteriovenous malformations of the brain using a standard linear accelerator: rationale and technique. Int J Radiat Oncol Biol Phys 1998;15:441