Interdisciplinary management of meningioma involving the cavernous sinus

The thesis consists of two parts: an anatomical study of the complex anatomy of the cavernous sinus (CS) and its surrounding structures, and a rerospective clinical study involving 104 patients with CS meningioma who were treated at the University Hospital of Philipps University, Marburg. The aim of the anatomical study was to improve our surgical technique and results through better understanding of the complex anatomical relationships in the CS region. We used 3 skull base approaches commonly used to expose the CS to study this anatomy. Using 5 cadaver heads, each approach was performed 10 times in the same way as live surgery. The extent of exposure and the anatomical landmarks necessary to perform each approach were identified and documented. The second part of this thesis consists of a retrospective study of 104 patients harboring CS meningiomas, who were treated in the departments of Neurosurgery and Radiotherapy of Philipps University, Marburg, between 1997 and 2003. The clinical data, as well as the results and morbidity of treatment were documented analysed. Additionally, post treatment quality of life was assessed using one of the most widely used assessment instruments, which is the Medical Outcome Study Short Form 36 (SF-36). This questionnaire comprises 36 items, which measure patients’ responses in 8 different health domains. There were 80 females and 24 males with an average age of 56 years. The mean follow-up period was 40 months. The most common tumor origin was the medial sphenoid ridge and the petroclival region. Sixty-eight patients in this series underwent at least one surgical resection. Among the patients who were operated upon at our institute, the rate ot total resection was 59.5%.The most common post operative complication was new cranial nerves dysfunction, encountered in 45.9% of our patients but it was permanent in only 13.5% of cases. Seventy-nine patients received SRT either as unique treatment (36 cases) or after subtotal surgical resection (43 cases). The median target volume was 11.8 ml and the mean dose was 55.8 Gy.Apart from temporary local alopecia and local radiodermatitis, symptoms related to acute post-irradiation toxicity were generally uncommon and easily controlled by steroid medication. Late radiation toxicity was also uncommon. Local tumor control was achieved in all but 2 cases, and about 50% of patients showed tumor regression in follow-up according to our definition of tumor shrinkage and enlargement. Two mortalities occurred during the follow-up period: one surgically-treated patient died one year after surgery from an unrelated cause; and the other was treated by a combination of surgery and SRT and died from tumor progress 16 months after treatment. Questionnaires from a total of 96 patients were eligible for analysis. These patients were subdivided into 3 groups according to their treatment protocols. The first group included 22 patients who were surgically treated, the second group included 34 patients who were treated uniquely with fractionated stereotactic radiotherapy (SRT), and the third group included 40 patients who were treated with a combination of microsurgery and SRT. there was no statistically significant difference in all tested domains of post-treatment life quality between the three treatment protocols; however, patients of the second group had the best values in all but one domain. SRT seems to be an efficient and safe initial or adjuvant treatment for meningiomas involving the CS as proved by tumor control rates and long term life quality scores. On the other hand, surgery still plays an important role in the management of these tumors especially in the presence of optic compression, brain stem compression and large tumor volume. In certain cases, both modalities should be combined in order to optimize the management