Overview                                                                   

Pediatric Cancers consist of a wide variety of tumors arising in children involving nearly every organ of the body.  However, of the 11 major cancers in children, leukemias and brain tumors account for over 50% of the approximately 10,000 cases of childhood cancers diagnosed each year in the United States.

A variety of brain tumors arise in children, notably tumors of the brainstem and cerebellum (medulloblastoma). 

Other pediatric cancers include Willm’s Tumor, rhabdomyosarcoma, neuroblastoma and retinoblastoma.  Many of these tumors are extremely uncommon. In fact, the total number of new cases of Willm’s Tumor, Ewing’s sarcoma and rhabdomyosarcoma combined is less than 1,000.

Interested in learning more about pediatric cancer? Check out the American Cancer Society website.

Role of Radiation Therapy                                     

Radiation therapy has long occupied an important role in the treatment of childhood cancers.  In years past, children were commonly treated with large fields and relatively high doses resulting in untoward toxicities, particularly related to impaired growth of bones and soft tissues.  Today, considerable effort is made to limit the overall use of radiotherapy in these children and, when delivered, to minimize both the volume and dose prescribed.  By doing so, many of the long-term toxicities common in years past should be less common in the coming years.

Radiotherapy is currently used in a wide variety of childhood cancers including Willm’s Tumor (view paper), soft tissue sarcoma (view paper) and rhabdomyosarcoma (view paper).  In most, radiotherapy is delivered following surgery to children with “high risk” features, e.g. residual disease and involved lymph nodes.

Children with brain tumors are also commonly treated with radiotherapy, including brain stem gliomas (view paper) and medulloblastomas (view paper).  Radiotherapy is often used in conjunction with chemotherapy, either sequentially or concomitantly.

Radiotherapy is also used in children with acute leukemia, for example as a means of reducing relapse in the central nervous system (CNS) (view paper).  Children with leukemia may also receive total body irradiation (TBI) in conjunction with high dose chemotherapy. 

Radiation Therapy Techniques                              

A wide variety of radiotherapy techniques are currently used in childhood cancers.  The most common is 3D conformal radiotherapy (3DCRT) which uses multiple beams to focus treatment on the target while shielding as much as possible the surrounding normal tissues.

3DCRT Treatment Plan in a Child with Stage IV Wilm’s Tumor

In some childhood tumors, it is important to deliver treatment to larger volumes.  An important example is childhood medulloblastoma.  In these children, radiotherapy fields include the brain and the entire spine in order to irradiate the entire cranio-spinal axis.  Such an approach is referred to as “craniospinal” irradiation.

Cranio-spinal Irradiation in a Child with Medulloblastoma

Select childhood tumors may be treated with a novel form of radiotherapy treatment planning and delivery, known as intensity modulated radiotherapy (IMRT).

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 3-dimensions, further reducing the volume of normal surrounding tissues receiving high doses.

IMRT Plan in a child with a retroperitoneal rhadomyosarcoma

Stereotactic Radiosurgery                                       

While typically reserved for the treatment of adults, stereotactic radiosurgery (SRS) is receiving increasing attention is childhood cancers.  SRS is the delivery of high doses in a single fraction (or limited number of fractions) to a small target volume with high precision. 

SRS is a particularly appealing approach in children due to the low dose delivered to surrounding normal tissues.  It is also a potentially valuable treatment option in children who develop recurrent disease.

At UCSD, SRS is delivered 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 allows 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 (children and adults alike).

Pediatric patient undergoing frameless stereotactic radiosurgery

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

Pediatric Anesthesia                                                                         

After an initial consultation with the doctor, it may be determined that your child will require anesthesia during radiation treatment. This is often the case for pediatric patients, particularly for younger children.

Our dedicated staff is highly experienced with the treatment of children under anesthesia. The Radiation Oncology Department works closely with the Department of Anesthesia to ensure that both the radiotherapy and anesthesia are administered safely and effectively.

If your child is to receive anesthesia here is some helpful information for you to have regarding the treatment:

• For daily anesthesia your child will need to have a central line. A central line is like an intravenous catheter (IV) and is placed in a vein in your child’s chest during a short surgery. This line enables the anesthesiologists to administer daily medication to your child without the use of needles. The appropriate dosage of medication needed for daily anesthesia is pre-determined.
• Your child should have an empty stomach before receiving anesthesia.
• All anesthesia cases are thus done early in the morning.
• Children are monitored after treatment by the nursing staff and anesthesiology
• Although treatment time may only take 30 minutes, you should expect to stay for approximately one hour or more after treatment until your child wakes up and the nurse feels safe to let him/her go home.

UCSD Pediatric Oncology Team                                                    

The UCSD Pediatric Cancer Team is comprised of dedicated professional with considerable experience in the treatment of children with cancer. 

Kevin Murphy M.D. is the Chief of the Pediatric Oncology Service in the UCSD Department of Radiation Oncology.

Kevin Murphy, M.D. Chief, Pediatric Oncology Service Department of Radiation Oncology

Arno J. Mundt, M.D. Chair, Department of Radiation Oncology

Dr. Murphy has considerable experience treating children with cancer.  He and his team are committed to providing pediatric cancer patients with access to the latest radiotherapy approaches, including IMRT and frameless stereotactic radiosurgery (SRS). 

Working closely with Dr. Murphy in the care of pediatric atients treated in the Department are Radiation Nurses, Michelle Russell, R.N. and Beth Mooney, R.N., B.S.N..

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

Beth Mooney, R.N., B.S.N. Radiation Nurse Department of Radiation Oncology

The treatment of pediatric cancer patients is a team approach. Dr. Murphy thus works together with a number of pediatric oncology specialists from Rady Children’s Hospital including pediatric oncologists Jennifer Willert, M.D, Bill Roberts, M.D., Eric Anderson, M.D., Jenny Kim, M.D., and pediatric surgeons Michael Levy, M.D., Hal Meltzer, M.D. and Nicholas Saenz, M.D.

Jennifer Willert, MD Pediatric Hematology/Oncology

William Roberts, M.D. Pediatric Hematology/Oncology

Eric Anderson, M.D. Pediatric Hematology/Oncology

Jenny Kim, M.D. Pediatric Hematology/Oncology

Michael Levy, MD Pediatric Neurosurgeon

Hal Meltzer, M.D. Pediatric Neurosurgeon

Nicholas Saenz, M.D. Pediatric Surgical Oncologist

In July 2007, UCSD, Rady Children’s Hospital and St. Jude Children’s Research Hospital in Memphis formed an alliance that will enable the three institutions to combine their resources and expertise to pursue basic and translational research and clinical trials in childhood cancers. 

Clinical trials conducted by St. Jude will be available at Rady Children’s, allowing children in Southern California to benefit from the latest advanced approaches while staying close to their homes and families.  Leading biomedical researchers in San Diego will collaborate with their colleagues at St. Jude, bringing their unique expertise to the fight against childhood cancers. 

A first for St. Jude, this unprecedented alliance places UCSD and Rady Children’s Hospital alongside the international leader in the treatment of pediatric cancers.

Pediatric Oncology Publications by UCSD Radiation Oncology Faculty           

Listed below are Pediatric Oncology 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

Mell LK, Davis RL, Owens D. Association between streptococcal infection and obsessive-compulsive disorder, Tourette’s syndrome, and tic disorder. Pediatrics 2005;116:56-60

Mell LK, Ogren DS, Davis RL et al. Compliance with national immunization guidelines for children younger than 2 years, 1996-1999. Pediatrics 2005;115:461-7

Jose BO, Koerner P, Bertolone S, Patel CC, Spanos WJ, Paris KJ, Silverman CL, Yashar CM. Pediatric Hodgkin’s Disease. J Kentucky Med Ass 2004;102:104

Mell LK, Davis RL, Mullooly JP, Black SB et al. Polio extraimmunization in children younger than 2 years after changes in immunization recommendations. Pediatrics 2003;111:296-301

Lieu TA, Davis RL, Capra AM, Mell LK, et al. Variation in clinician recommendations for multiple injections during adoption of inactivated polio vaccine. Pediatrics 2001;107:E49

Davis RL, Lieu TA, Mell LK, et al. Impact of the change in polio vaccination schedule on immunization coverage rates: a study in two large health maintenance organizations. Pediatrics 2001;107:671-6

Christakis DA, Mell LK, et al. Association of lower continuity of care with greater risk of emergency department use and hospitalization in children. Pediatrics 2001;107:524-9

Christakis DA, Mell L, et al. The association between greater continuity of care and timely measles-mumps-rubella vaccination. Am J Public Health 2000;90:962-5

Czyzewski EAD, Goldman S, Mundt AJ, et al. Radiation therapy for consolidation of metastatic or recurrent sarcomas in children treated with intensive chemotherapy and stem cell rescue: a feasibility study.  Int J Radiat Oncol Biol Phys 1999;44:569

Sibley, G., Mundt, AJ, et al.  The Patterns of Failure Following Total Body Irradiation and Bone Marrow Transplantation +/- Local Radiation Therapy Boost for Advanced Neuroblastoma  Int  J Radiat  Oncol  Biol Phys 1995;32:1127