S238
Tumours of the eNS- Meningiomas
management of these unresectable meningiomas with their increased patient morbidity and mortality remains a serious clinical problem for skull base surgeons. We report on a series of 25 patients with unresectable meningiomas treated between 1982 and t994 . The majority of lesions involved extensive areas of the skull base, cavernous sinus, and petroclival region. A rare subset extensively transgressed the skull base invading the paranasal sinuses and infratemporal and pterygopalat ine fossae. The age and sex distribution was similar to lesions considered resectable . Although the morbidity at 16% was higher in the unresectab le group there waS no operative mortality. Histology revealed no frankly malignant lesions. Management strategies available include 1) observanon alone 2) hormonal manipulat ion (anti-progesterone agents, somatostatin) 3) radiotherapy (gamma knife, helium charged particle, proton beam, brachytherapy, conventional radiotherapy) and 4) re-operation. The average follow-up has been 7 years . All patients are alive with residual disease. 90% of patients are fully functional. 80% of patients have stable disease with no evidence of prog ression. In summa ry, a multi-modality approach including repeat surgery, hormonal manipulation and radiation can result in prolonged functional survival in this group of patients.
IP-5-597!
Gamma knife treatment of meningioma
Zhu Jiankum , Dai Wenwei , Jiankum Wenwei. Departmentof Neurosurgery, the 2nd Affiliated Hospital of GuangzhouMedical College, Guangzhou. China 141 Patients with mening iomas have been treated with Gamma Knife. 54 patients were examined between 2 and 18 months after treatment. 17 (31.5%) showed a reduction in tumor volume . 34 (63%) patients had no change and 3 (5.5%) had tumor growth. 7 (13%) patients showed radiation-induced edema and were treated with dexamethasone and dehydrative agents. 3 patients underwent operation because the effect of the conservative therapy was not good. Gamma Knife is regarded as a relatively safe and effective method in the treatment of meningioma. It's a benef icial addition to neurosurgery.
IP-5-598! proliferative Surgical resection, pathological changes and the potential of meningiomas after radiosurgery Ying Mao, Liang-Fu Zhou, Fu-Lin Zhang . Department of Neurosurgery, Hua
Shan Hospital, SMU,Shanghai, PR China Introduction: Radiosurgery is an effective modality in the treatment of certain brain tumors. However, craniotomy is still needed in some patients after treatment with radiosurgery due to severe postoperative complications or tumor enlargement. Method: We investigated the surgical findings, the pathological characteristics and the proliferative potential of the tumors in 7 patients with meningiomas who underwe nt radiosurgery from 5-23 ms (mean, 12.3 ms) before. Results: All patients were female, aged 33 to 51 years (mean, 44.3 years). The causes of surgery are: 1. Increased intracranial pressure due to brain edema that is hard to be controlled nonsurgically (5 cases) . 2. Tumor enlargement (2 cases). Postoperative pathological examination showed that the changes in tumors and the surrounding brain tissue after radiosurgery were similar to that of radiation injury: tumor cells were still found in the lesions intermixed with necrosis. Histologically Classifications of these tumors were fibrous meningiomas (3 cases) , meniongiothelial type (2 cases), clear cell type (1 case), and atypical meningioma (1 case). We also investigated the tumor proliferative potential using the monoclonal antibody PC-10 as markers that react with PCNA and found that the proliferative potential of these tumors still remained high many months after radiosurgery, although enough radiation had been given. The percentage of positively stained cells ranged from 15% to 70% (mean. 47.1%). Because of the limited group of cases , the relationship between histological classifications and the tumor proliferative indices remain unknown. Conclusion: Radiation-induced brain edema and the high proliferative potential may be two main factors affecting the prognosis of meningiomas treated radiosurgically. Refined treatment parameters of radiosurgery are suggested.
IP-5-599 I Clinical features of elderly patients with meningioma Yoji Node, Akira Terarnoto. Department of Neurosurgery, Nippon Medical School 1-1-5. Sendagi, Bunkyo-ku, Tokyo 113. Japan Clinical features of 20 elderly patients with meiningioma over 70 years of age were examined. They constituted 13% of all meningiomas (159 cases) during 19n to 1995. Ten were male and 10 were female. The mean age on admision was 76 years (70-86 years). Results: (1) Sex difference was 1.89 (Female/male) in patients under the age of 70, but in elderly patients, there was no sex difference (1.00). (2) Clinical symptoms were divided into three groups: acute (epilepsy etc.), gradual (hemiparesis etc.) and incidental types . In elderly patients , there were gradual (55%) and incidental (45%) types. (3) Main origins of tumors were falx (35%),
Thursday, 10 July / 997 convexity (25%), and sphenoid ridge (20%). (4) 108 cases (78%; 1081139 ) were operated on in patients below 70 years. In elderly patients, 40% was operated on (8120 cases). (5) Simpson's grade was as follows: one patient was grade I (13), five were grade II (63%), and two cases were grade III (25%). (6) Pathological findings. Meningotheliomatous type was most frequent (75%) . There was no "malignanf ' meningioma (In patients below 70 years of age malignant meningioma was present in 6%). (7) There was no postoperative neurological deficit and mortality rate after surgery was 0%. Conclusion: In elderly patients clinical symptomes, main origins of tumors and pathological findings were different from the features in patients below 70 years. On the other hand, satisfactory postoperative results were obtained.
IP-5-600 ' Meningiomas: Prognostic markers for recurrence Gregory M. Malham 1 , Beth J. Synek 2 , Karen M. Holdaway 3 , Raewyn
J . Thomsen 2, Christopher E. Furneaux 1, Bruce C. Baguley 3. 1 Department of Neurosurgery, Auckland Hospital, 2 Departmentof Pathology, 3 Department of Cancer Research Laboratory, University of Auckland, Auckland, New Zealand Introduction: The correlation between clinical behaviour and histolog ic appearance of meningiomas remains imprecise since a histologically benign tumour may recur following apparent gross total resection. We wished to employ new techniques to aid conventional histology in the prognostication of recurrence and outcome in meningiomas. Recent reports have suggested that staining of the argyrophilic nucleolar organiser region (AgNOR) , as well as immunohistochemical labelling of Ki-67 and proliferating cell nuclear antigen (PCNA), in paraffin-embedded archival meningioma tissue ca n be used as predictive markers of meningioma recurrence. DNA content of tumour cells and fraction of cells in the S-phase of the cell cycle have also been reported to predict recurrence of meningiomas. Methods: A retrospective analysis was made of 202 procedures in 182 patients treated surgically between 1985 and t99 1. Recurrence or regrowth of meningioma was confirmed radiologically (by CT scan) and surgically with a follow-up period of 5-11 years. The extent of surgical resection was coded according to Simpson's grading from the surgeon's intraoperative impression. Formalin-fixed, paraffin-embedded tissue blocks of the tumour were retrieved and sections subjected to analysis. Sections were stained for the Ki·67 antigen as a measure of cycling cells, for the proliferati ng cell nuclear antigen (PCNA) as a measure of S-phase cells, and for silver uptake by nucleolar organizing region proteins as a measure of RNA synthesis. Cells, after dewaxing , were stained with propidium iodide and assessed for DNA ploidy and S-phase fraction by flow cytometry. Prognostic factors were analysed with a multivariate model using SigmaStat (Jandel Scientific, USA). Survival and recurrence were calculated from date of surgery. Results: 98% (179/ 182) of patients were assessab le. For Grade 1 and 2 resections the recurrence rate was 13% (17/131 ). The recurrence rate for benign tumours was 4.5% (6/17) and for more aggressive forms was 8% (11/17). For Grade 3, 4 and 5 resections, recurrence rate was 31% (15/48) , regardless of histological type. Neither histological markers of cell proliferation (Ki-67 or PCNA) or RNA synthesis (AgNOR) predicted meningioma recurrence. Flow cytometric analysis indicated that both DNA ploidy and S-phase fraction were significantly correlated (P < 0.05) with recurrence of meningiomas . Discussion and Conclusions: In this large study of 182 patients, flow cytometric tests for cell proliferation were superior to immunohistochem ical staining in predicting recurrence of meningioma. The degree of aneuploidy is highly correlated with recurrence.
IP-5-601 I The study of factors predictive of recurrence of meningiomas after surgical treatment
Tiecheng Lang, Xiaodong Jiang, Yanhui Sun. Dept. Neurosurgery, 1st Hospital
of Jiamusi MedicalCollege, Jiamusi, China Introduction: Meningioma is a common intracranial tumor. Most meningiomas are benign tumors, which can be removed completely, but their recurrence rate is high, about 9-22%. This paper analyses the factors of 12 recurrent meningiomas in 105 cases of meningiomas after total resection, and discusses prevention and treatment of these tumors. Methods: The Study subjects were divided into two groups , one included 12 cases of recurrent meningiomas, the other one included 26 non-recurrent cases who were random sampled from non-recurrent cases followed up after being completely removed. Comparison and analysis were made between the two groups with regard to site of recurrence, operation and histological pattern. Results: There were no significant differences between the two groups with regard to ages of patients, sites of origin and histological patterns. However, the recurrence group showed more cells growing actively, polymorph ic nucleus and focal necrosis. ConclUsions: Factors responsible for complete removal of intracranial meningiomas after complete removal were as follows: The meningiomas were removed completely, but the tumor cells growed act ively and show ed malignant