Abstract
Background: Intracranial epidermoid tumors are commonly found in the
cerebellopontine angle where they usually present with either trigeminal
neuralgia or hemifacial spasm. Radiosurgery for these tumors has rarely
been reported. The purpose of this study is to assess the safety and clinical
outcome of the treatment of cerebellopontine epidermoid tumors with gamma
knife radiosurgery.
Methods: This is a retrospective study involving 12 patients harboring
cerebellopontine angle epidermoid tumors who underwent 15 sessions of gamma
knife radiosurgery. Trigeminal pain was present in 8 patients and hemifacial
spasm in 3 patients. All cases with trigeminal pain were receiving medication and
still uncontrolled. One patient with hemifacial spasm was medically controlled
before gamma knife and the other two were not. Two patients had undergone
surgical resection prior to gamma knife treatment. The median prescription dose
was 11 Gy (10–11 Gy). The tumor volumes ranged from 3.7 to 23.9 cc (median
10.5 cc).
Results: The median radiological follow up was 2 years (1–5 years). All tumors were
controlled and one tumor shrank. The median clinical follow‑up was 5 years. The
trigeminal pain improved or disappeared in 5 patients, and of these, 4 cases stopped
their medication and one decreased it. The hemifacial spasm resolved in 2 patients who
were able to stop their medication. Facial palsy developed in 1 patient and improved
with conservative treatment. Transient diplopia was also reported in 2 cases.
Conclusion: Gamma knife radiosurgery provides good clinical control for
cerebellopontine angle epidermoid tumors.