Recurrent pediatric central nervous system low-grade gliomas: the role of surveillance neuroimaging in asymptomatic children.

OBJECT: Pediatric low-grade glioma (LGG) is the most common brain tumor of childhood. Except for the known association of gross-total resection and improved survival rates, relatively little is known about the clinical and radiographic predictors of recurrent disease and the optimal frequency of surveillance MRI. The authors sought to determine the clinical and radiographic features associated with recurrent or progressive disease in a single-institutional series of children diagnosed with primary CNS LGG.
METHODS: The authors performed a retrospective analysis of data obtained in 102 consecutive patients diagnosed at Rady Children's Hospital-San Diego between 1994 and 2010 with a biopsy-proven LGG exclusive of a diagnosis of neurofibromatosis. Tumor location, patient age, sex, and symptomatology were correlated with tumor progression or recurrence. Magnetic resonance imaging characteristics and neuroimaging surveillance frequency were analyzed in those children with progressive or recurrent disease.
RESULTS: Forty-six of 102 children diagnosed with an LGG had evidence of recurrent or progressive disease between 2 months and 11 years (mean 27.3 months) after diagnosis. In the larger group of 102 children, gross-total resection was associated with improved progression-free survival (p = 0.012). The location of tumor (p = 0.26), age at diagnosis (p = 0.69), duration of symptoms (p = 0.72), histological subtype (p = 0.74), sex (p = 0.53), or specific chemotherapeutic treatment regimen (p = 0.24) was not associated with tumor progression or recurrence. Sixty-four percent of children with recurrent or progressive disease were asymptomatic, and recurrence was diagnosed by surveillance MRI alone. All children less than 2 years of age in whom the tumor was diagnosed were asymptomatic at the time of progression (p = 0.04). Thirteen percent (6 of 46) of the children had disease recurrence 5 years after initial diagnosis; all of them had undergone an initial subtotal resection. Tumor progression was associated with either homogeneous or patchy T1-weighted post-Gd administration MRI enhancement in 94% of the cases (p = 0.0001).
CONCLUSIONS: Children diagnosed with recurrent LGG may be asymptomatic at the time of recurrence. The authors' findings support the need for routine neuroimaging in a subset of children with LGGs, even when gross-total resection has been achieved, up to 5 years postdiagnosis. The authors found that T1-weighted MR images obtained before and after Gd administration alone may be sufficient to diagnose LGG recurrence and may represent an effective strategy worthy of further validation in a larger multiinstitutional cohort.