Long-Term Outcome of Gamma Knife Radiosurgery for Brain Cavernoma: Factors Associated with Subsequent De Novo Cavernoma Formation.

BACKGROUND: We aimed to evaluate the factors associated with de novo brain cavernoma formations after patients underwent gamma knife radiosurgery (GKRS) and confirmed whether developmental venous anomaly (DVA) presented with a cavernoma and whether the cavernoma was included in the GKRS target location.

METHODS: From January 2003 to December 2008, 95 patients underwent radiosurgery for brain cavernoma at our institution. Of these, 15 with multiple cavernomas related to familial cavernoma or with a history of surgical treatment for cavernoma were excluded. A total of 80 patients (44 men and 36 women; average age, 39.4 years) with sporadic cavernoma were retrospectively analyzed by considering the patient characteristics, including sex, age, target volume, radiation dose, clinical symptoms, cavernoma location, radiosurgery complications, and morphology of DVA.

RESULTS: The average target volume, mean radiation dose, and mean target percentage were 1019.2 mm3, 13.7 Gy, and 51.1%, respectively. Nineteen patients showed cavernomas associated with DVA; of these, de novo cavernoma formations were noticed in 4 patients at a median of 49.5 months after undergoing GKRS. All de novo cavernomas were related to the presence of DVA and were located near the brainstem or cerebral peduncle. De novo cavernomas occurred when DVAs were not included in the GKRS-target location.

CONCLUSIONS: All de novo cavernomas were located near the brainstem or cerebral peduncle, and they occurred in the presence of DVAs. The presence of DVA in the radiosurgery target location might be potentially an important factor associated with de novo cavernoma formation.