Abstract
P 051
Cyberknife radiosurgery of meningeomas involving the orbit
Martin M. Nentwich1, Ulrich C. Schaller1, Annemarie Klingenstein1, Alexander Muacevic2, Berndt Wowra2, Jörg-Christian Tonn3, Anselm Kampik1
1Augenklinik der Ludwig-Maximilians-Universität München, München; 2Europäisches Cyberknife Zentrum München-Großhadern, München, 3Neurochirurgische Klinik der Ludwig-Maximilians Universität, München
Objective
Meningeomas, limited to the orbit, intracranial tumors invading the orbit or optic nerve sheath meningeomas, may cause visual symptoms such as decrease in visual acuity and visual field defects. The treatment of clinical manifest or radiologically progressing meningeomas poses a therapeutic challenge to orbital-, neuro- and radiosurgeons. Often microsurgical resection has to leave some residual tumor parts with the risc of recurrance.
Methods
Radiosurgery is to be investigated as additive therapeutic instrument aiming for local tumor control and preservation of visual function.
Results
In a first series, 2 patients with meningeomas involving the orbit and one patient with optic nerve sheath meningeoma were treated with Cyberknife radiosurgery. In all patients good local tumor control with an increase in visual acuity and reduced visual field defects was seen.
Patient 1 (meningeoma of the sphenoid bone with orbital involvement) was treated with Cyberknife radiosurgery due to progrssive loss of visual acuity from 1,0 to <0,05 and worsening visual fields despite two previous operations (orbital decompression and tumor debulking). After radiosurgery, a 16 months follow-up shows visual acuity of 1,0 and complete regression of visual field defects.
Patient 2 (meningeoma of the fissura orb. sup. with intraorbital involvement) shows 18 months after multisession radiosurgery of the residual tumor after microsurgical excision a preservation of visual acuity of 0,8 and a regression of visual field defects.
Patient 3 with microsurgically inoperable optic nerve sheath meningeoma was primarily treated with multisession radiosurgery due to reduced visual acuity to 0,5 and almost complete loss of visual field. After 7 months follow-up, visual acuity was 0,63 and her visual field has improved markedly.
Conclusions
Image-guided radiosurgery is a novel treatment method of orbital meningeomas with the capacity to reduce optic nerve damage due to irradiation by delivering treatment in several sessions. A combination of micro- and radiosurgical techniques seems to achieve good local tumor control with preservation of visual function. However, further studies are needed to determine optimal therpeutic strategies.
Seitenanfang