Gamma knife Radiosurgery for Third Ventricular Colloid Cysts

Abstract

Abstract Background: Colloid cysts often occur in the third ventricle, and they are considered benign slowly growing lesions. They commonly present with symptoms of intracranial hypertension and rarely sudden death due to acute hydrocephalus. Management options include cerebrospinal fluid diversion procedure by shunt, endoscopic or transcranial surgical excision and stereotactic aspiration. Complications associated with excisional procedures make them undesirable to some patients. Stereotactic radiosurgery has emerged as a non-invasive less risky treatment option. To date, there is no clinical series in literature reporting on this treatment modality. Objective: To determine the efficacy and safety of gamma knife radiosurgery in the treatment of third ventricular colloid cysts. Patients and methods This is a retrospective study involving 13 patients with third ventricular colloid cysts that underwent gamma knife radiosurgery. Gamma knife radiosurgery was used as a primary treatment in all the patients. The median prescription dose was 12 Gy (11-12 Gy). The tumor volumes ranged from 0.2 to 10 cc (median 1.6 cc). Results The median follow up was 50 months (18-108 months). Tumor control was achieved in 100% of the patients. Complete or partial response was observed in 12 patients (92%). Eight patients (62%) had hydrocephalus on imaging at initial diagnosis. Seven of these patients had VP shunt insertion before GK. One patient required shunt insertion after GK. Conclusion GK for third ventricular colloid cysts is a promising treatment, as regards efficacy and safety, to be added to other treatment options. A longer follow up is required to confirm long-term control.