Stereotactic Guided Radiation Techniques in the Therapeutical Concept for Skull Base Meningiomas

• Main Authors: Hamm, Klaus, Henzel, M., Gross, M.W., Surber, G., Kleinert, G., Engenhart-Cabillic, R.
• Format: Conference Proceeding
• Language: English
• ISSN: 1531-5010; 1532-0065
• DOI: 10.1055/s-2006-957287

Objective: Microsurgical resection is still the treatment of choice for skull base meningiomas. But because the risk of postoperative neurological deficits is high, a complete tumor removal cannot be achieved in many of these cases. Therefore recurrences are still more probable. Stereotactic guided radiation therapy—radiosurgery (RS) or stereotactic radiotherapy (SRT)—offers an additional or alternate treatment option for those patients. We evaluate local control rates, symptomatology, and toxicity. Patients and Methods: Two hundred twenty-four patients were treated with stereotactic guided radiation techniques in both departments between 1997 and 2003. One hundred twenty-nine of 224 had recurrences after one to three previous tumor resections and 95/224 were treated with SRT/RS alone. Of these, 87.9% were benign, 7.8% were atypical, and 4.3% were malignant meningiomas. RS was only applied in 11 cases. These tumor volumes ranged from 0.16 ccm to 3.56 ccm. The other 213 patients had larger tumor volumes up to 135 ccm or a meningioma close to optical structures. Therefore 183 cases were treated with SRT in normal fractions of 1.8 to 2 Gy single dose up to 60 Gy. Hypofractionated SRT with single fraction doses of 5 or 4 Gy was applied in 30 cases. Follow-up data were available in 181 skull base meningiomas. Progression-free and overall survival rates, toxicity, and symptomatology were evaluated. Results: The median follow-up was 36 months. The overall survival and the progression-free survival rates for 5 years were 92.9% and 96.9%, respectively. Until now, two tumor progressions have occurred. Further follow-up is required. Tumor volume (TV) shrank about 19.7% 6 months (p