Delayed diagnosis of optic nerve glioma: a preventable cause of visual loss

Fractionated stereotactic radiotherapy (FSRT) for optic glioma

PURPOSE

To determine efficacy and toxicity of fractionated stereotactic radiotherapy (FSRT) in patients with optic glioma.

METHODS AND MATERIALS

Ten patients suffering from optic glioma were treated by FSRT between December 1990 and December 1995 at the German Cancer Research Center (DKFZ) in Heidelberg. Eight patients were treated for progressive recurrent tumor following partial tumor resection and 2 patients were treated postoperatively. Dose distributions were calculated by a 3D treatment planning system (Voxelplan, Heidelberg). Patients were treated with a noninvasive repeatable stereotactic fixation system using a manually driven midsize multileaf collimator attached to a linear accelerator. We applied a median prescribed total dose to the isocenter of 52.4 Gy with a median daily fraction size of 1.8 Gy.

RESULTS

All patients treated by definitive radiotherapy remained free from local tumor progression during the follow-up period (range 12-72 months) except the 1 patient treated for recurrence after previous radiotherapy. A complete remission was achieved in 3 patients with subsequent improvement of visual acuity. None of the patients with locally controlled tumor experienced any further impairment of vision. One patient developed new ACTH deficiency. No other clinically significant late effects attributable to radiotherapy were observed.

CONCLUSION

FSRT permits treatment of optic glioma with excellent tumor control and without clinically relevant morbidity. Compared to conventional techniques there is the potential of sparing the pituitary gland in chiasmatic lesions.

Juvenile pilocytic astrocytoma masquerading as amblyopia

PURPOSE

A healthy 13-year-old girl, previously diagnosed with amblyopia in her right eye, was seen in consultation after her vision continued to decrease.

METHODS

A complete ophthalmologic examination including visual field testing and optic nerve photography was performed in the neuro-ophthalmologic clinic. Magnetic resonance imaging study was also obtained.

RESULTS

Visual sensory deficits and pale optic nerves were noted on clinical examination. Visual field testing showed a chiasmatic junctional defect. Magnetic resonance imaging verified a large chiasmatic mass, histologically proven to be a juvenile pilocytic astrocytoma.

CONCLUSION

Early recognition of signs and symptoms of chiasmatic lesions is essential for preventing visual loss.

Optic pathway glioma infiltrating into somatostatinergic pathways in a young boy with gigantism. Case report

The authors report gigantism in a 16-month-old boy with an extensive optic pathway glioma infiltrating into somatostatinergic pathways, as revealed by magnetic resonance imaging and immunocytochemical studies. Stereotactic biopsies of areas showing hyperintense signal abnormalities on T2-weighted images in and adjacent to the involved visual pathways provided rarely obtained histological correlation of such areas. The patient received chemotherapy, which resulted in reduction of size and signal intensity of the tumor and stabilization of vision and growth velocity.