Treatment of grade II-III intracranial meningioma with helical tomotherapy.

ABSTRACT

Meningiomas account for 30-35% of intracranial tumors. Grade I meningiomas are most common and carry the best prognosis. Grade II and III meningiomas are more aggressive and the outcomes after surgical resection alone remain unsatisfactory. The main objective of this retrospective, single-center study was to assess our results of treatment of grade II-III intracranial meningioma with helical tomotherapy (HT). We retrospectively reviewed patients with histologically proven (WHO 2007) grade II-III meningioma irradiated with HT. Patients were treated one session a day, 5 days a week, to a total dose of 59.4 Gy and 68.4 Gy delivered in 33 and 38 fractions of 1.8 Gy each to the LR PTV and HR PTV, with or without simultaneous integrated boost. From May 2011 to January 2015, 19 patients (15 with grade II and 4 with grade III meningiomas) were treated. Median follow-up for patients with Grade II or Grade III meningiomas, was 29.2 months (range, 10.7-52.4) and 21.3 months (range, 2.4-51.3), respectively. Disease free survival at 1, 2 and 3 years was 89.2%, 83.6% and 56.3% respectively. Overall survival at 1, 2 and 3 years was 94.7%, 94.7% and 78.9%, respectively. No patient had neurological toxicity greater than grade 2 in the acute period. During follow-up, only one patient had neurological toxicity greater than or equal to grade 3. The management of grade II to III meningiomas using HT with doses exceeding 60 Gy is associated with good local control and acceptable survival results.