The two main indications for Gamma Knife® surgery in children are the treatment of arteriovenous malformations (AVMs) and brain tumors. While historically most radiosurgical treatments have been delivered to adults, in the past twenty years there has been increasing emphasis on treating children with radiosurgical techniques with satisfying results.
AVMs are one of several types of structural vascular malformations that involve the brain and spinal cord. AVMs may present with hemorrhage, ischemic phenomena, headaches or seizures with neurologic deficits related to the AVMs location. Many AVMs present acutely, with hemorrhage, necessitating urgent surgical excision. However, when AVMs are deeply located, near or in eloquent functional cortex, or otherwise difficult to remove surgically, they may be amenable to radiosurgical treatment.
- Treatment Options for AVMs - While most AVMs require treatment after detection, the type of treatment may be controversial. Treatment may involve microsurgical removal, endovascular embolization, radiosurgical treatment, or a combination. Generally, accessible AVMs (size and location) are recommended for surgical excision, but each case requires inividualized treatment.
- Role of Gamma Knife in AVMs - Gamma Knife® radiosurgery provides a minimally invasive approach to treat AVMs, with the highest obliteration rates occurring in patients with smaller volume lesions. The effect on the AVM may take two to three years and repeat Gamma Knife® radiosurgery is occasionally required.
- Complications and Outcomes - These include incomplete AVM obliteration, radiation-induced edema or necrosis, and potential risk of radiation injury to surrounding eloquent brain. Also, hemorrhage remains a risk for the patient until during the window after treatment and before complete AVM obliteration occurs. However, depending on the location and size of the AVM, obliteration rates in children range from 50-80%.
Brain tumors are the most common solid tumor seen in children. There are a great number of brain tumor types that occur in children, found anywhere along the neuraxis, ranging from low-grade to high grade.
- Treatment Options for Brain Tumors - In general, surgical excision of most brain tumors is preferred, but Gamma Knife® radiosurgery provides an additional treatment option for localized recurrent, residual, or in some cases, newly diagnosed pediatirc brain tumors. A. mullti-disciplinary neuro-oncology team evaluates each patient individually, taking into account the pre- and post-operative neurologic status, tumor location and pathology. All treatment options, including observation with serial scans, further surgery, chemotherapy or fractionated radiotherapy are considered along with the option of radiosurgery.
- Role of Gamma Knife in Brain Tumors - Generally, Gamma Knife® radiosurgery provides only part of the overall treatment plan. Commonly treated pediatric tumors include recurrent or residual astrocytomas, higher grade gliomas, neurofibromatosis, glioneural tumors, primitive neuro-ectodermal tumors, ependymomas, pituitary and germ cell tumors and pineal region tumors.
- Complications and Outcomes - Tumor control with radiosurgery can be quite satisfying, but risks of radiation-induced edema or necrosis as well as risk to surrounding eloquent brain remain.
Referring Your Pediatric Patients
To refer a pediatric patient to Gamma Knife of St. Louis:
Telephone 800-416-9956 or 314-454-4454
Mail, courier or delivery address (for US mail, Fed-Ex, UPS etc)
St Louis Children's Hospital
One Children's Place, 4S-20
St. Louis, MO 63110-1077