Treatment of a Meningioma Attached to the Optic Chiasm (Residual Tumor)
A 66-year-old female with a history of multiple meningiomas presented with a suprasellar tumor and a significant constriction of her peripheral visual field. This tuberculum sellae meningioma was resected via a pterional craniotomy (Simpson B), which resulted in complete loss of vision in her left eye. She was treated post-operatively with fractionated radiation therapy. Two years ago, the patient developed a recurrent meningioma at the posterior margin of the resection site. Most of this lesion was resected during a repeat craniotomy. However, a nodule of tumor was found to be quite adherent to the inferior surface of the optic chiasm and was not removed.
Because of both the prior history of radiation and the close proximity of this tumor to the optic chiasm in a woman who was already blind in the left eye, surgical resection was not an attractive option.
The patient was treated on the frameless CyberKnife at Stanford University with 5 fractions to a total dose of 30 Gy.
Outcome & Follow-Up
Six months following treatment, MR imaging demonstrated complete disappearance of the treated meningioma. One and one-half years later, the patient remains without tumor and retains all pre-radiosurgery visual capability.
Stanford University Medical Center, Stanford, CA USA