Efficacy and tolerance of intensity modulated radiation therapy for skull base meningioma

Abstract Summary We sought to evaluate long-term clinical outcomes of 46 patients treated with radiation therapy for skull base meningioma. Materials and methods Between January 2009 and 2014, 46 patients with skull base meningioma were treated with normofractionated intensity modulated radiation therapy in stereotactic conditions (50%) or with helical tomotherapy (50%). Most of the lesions were localized in the cavernous sinus (59%). The mean PTV was 47.2 mL (1.1 - 223). Results After treatment, 5 lesions exhibited a partial response radiologically and 39 lesions were stable. At treatment time, 35 patients were symptomatic, with a mean of two symptoms per patient. The most frequent symptoms were visual impairment (41%), cranial nerve dysfunction (20%) and headache (16%). The median follow-up was 42 months (range: 10 - 76). After radiotherapy, 71% of the patients exhibited an improvement of at least one symptom, with a median interval of 15.6 months (range: 5.3 - 30.5). The most frequent improved symptoms were cranial nerve deficits (47%), visual impairment (45%) and headache (42%). The clinical response was correlated with CTV margin (p = 0.06), extended clinical follow-up (p = 0.004) and larger PTV (p = 0.05) by univariate analysis. Taking in account correlation factors, in multivariate analysis, solely CTV was a favorable significant factor of clinical improvement (p = 0.049; HR: 5 95% CI (1.1 – 28)). We observed three cases of trigeminal nerve dysfunction at 4.2, 5.7 and 24.6 months, separately; two cases of visual disturbance at 10.1 and 24 months, separately; two cases of neurocognitive disorders appearing at 12.9 and 35.2 months, separately; and one case of stroke at 20.3 months. Conclusion Radiotherapy for skull base meningiomas is an effective and safe treatment, leading, in most cases, to clinical improvement. The addition of a CTV margin to meningioma volume improved the symptoms improvement of the patients.