Initial clinical experience with frameless optically guided stereotactic radiosurgery/radiotherapy in pediatric patients.
OBJECTIVE
The objective of this study is to report our initial experience treating pediatric patients with central nervous system tumors using a frameless, optically guided linear accelerator.


METHODS
Pediatric patients were selected for treatment after evaluation by a multidisciplinary neuro-oncology team including neurosurgery, neurology, pathology, oncology, and radiation oncology. Prior to treatment, all patients underwent treatment planning using magnetic resonance imaging (MRI) and treatment simulation on a standard computed tomography scanner (CT). For CT simulation, patients were fitted with a customized plastic face mask with a bite block attached to an optical array with four reflective markers. After ensuring adequate reproducibility, these markers were tracked during treatment by an infra-red camera. All treatments were delivered on a Varian Trilogy linear accelerator. The follow-up period ranges from 1-18 months, with a median follow-up of 6 months.


RESULTS
Nine patients, ages ranging from 12 to 19 years old (median age 15 years old), with a variety of tumors have been treated. Patients were treated for juvenile pilocytic astrocytoma (JPA; n = 2), pontine low-grade astrocytoma (n = 1), pituitary adenoma (n = 3), metastatic medulloblastoma (n = 1), acoustic neuroma (n = 1), and pineocytoma (n = 1). We followed patients for a median of 12 months (range 3-18 months) with no in-field failures and were able to obtain encouraging toxicity profiles.


CONCLUSIONS
Frameless stereotactic optically guided radiosurgery and radiotherapy provides a feasible and accurate tool to treat a number of benign and malignant tumors in children with minimal treatment-related morbidity.
Keshavarzi
Sassan
S
Department of Surgery, Division of Neurosurgery, University of California, San Diego, 200 W. Arbor Drive, Suite 8893, San Diego, CA 92103-8893, USA. skeshavarzi@ucsd.edu
Meltzer
Hal
H
Ben-Haim
Sharona
S
Newman
Charles Benjamin
CB
Lawson
Joshua D
JD
Levy
Michael L
ML
Murphy
Kevin
K