Hydrocephalus well managed: ETV for tectal gliomas has a success rate exceeding 70% and as high as 90% (102).
Controversy over need for treatment of this tumor: The natural history of midbrain lesions is not well known. Some reports of spontaneous tumor regression and regression after biopsy or shunting have caused controversy over the necessity of any treatment beyond the management of associated hydrocephalus. Lesions typical of tectal gliomas on imaging studies need treatment for hydrocephalus only and rarely progress over many years (33). Intrinsic pilocytic astrocytomas located in the midbrain may be cured by gross total resection, but long-term follow-up is necessary (44).
Other focal tumors of brainstem
Radiation: Stereotactic radiosurgery may be an effective primary treatment or adjunct to open surgery for focal brainstem gliomas. After gamma knife radiosurgery, the condition of most patients improved or stabilized but worsened in some patients (46).
Dorsally Exophytic Gliomas
Long term survival expected: Dorsally exophytic brainstem gliomas are most commonly pilocytic astrocytomas, which have an excellent prognosis after gross total or near total resection. Subsequent progression may require re-resection or radiation therapy. Long-term survival is common; in a series of 18 patients, a 94% survival rate was found with median survival of 113 months (26, 59).
Diffuse Intrinsic Pontine Gliomas
External beam radiation therapy provides temporary improvement: Radiation transiently improves the neurological condition of 85% of patients with diffuse intrinsic pontine gliomas, but the disease usually progresses within 3–4 months. No treatment has been shown to be effective at the time of progression. Median survival is 10–12 months. Only 10% of patients survive beyond 2 years after diagnosis (94). Children under the age of 3 years, young adults over 18 years, and those with NF1 may have a better prognosis.
Excellent long-term survival: Most cervicomedullary tumors are low-grade, and patients have excellent long-term survival after surgical resection alone (99-101). In the largest reported series of cervicomedullary tumors, near total resection was achieved in 90% of patients with subtotal resection achieved in the remaining reported patients. 100% survival was reported at the time of publication, with a mean reported survival of 48 months (100, 101).