Gamma Knife Radiosurgery for Intracranial Meningiomas: Do we need to Treat the Dural Tail?

Objective: The dural tail (DT) has been described as a common feature in meningiomas. The histopathology of the DT is not well understood. Therefore, the necessity to include the DT in Gamma Knife (Elekta, Stockholm, Sweden) radiosurgery is still a matter of debate. In this analysis, we evaluated whether the complete tail should be included as a part of the target in Gamma Knife radiosurgery for meningiomas. Material and Methods: Between June, 2002 and December, 2010, Gamma Knife radiosurgery was performed in 395 patients with 471 meningioma. In 250 tumors the diagnosis was based on only MRI characteristics, in 221 tumors the histopathological diagnosis was confirmed histologically after surgery. A DT was found in 209 (44%) tumors. All tumors were treated with Gamma Knife radiosurgery with a median prescribed dose of 13 Gy (range: 10-22), resulting in a median marginal dose of 11 Gy (range 8.7-21). Only the part of the DT closely related to the tumor mass was included in the target definition. The median follow-up period was 48 months (range 12-123). Results: During follow-up on consecutive MRI examinations no tumor growth was found outside the target in the DT. Conclusion: It is not necessary to include the entire DT of meningiomas in Gamma Knife radiosurgery.