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Unresectable meningiomas of the skull base: Management strategies
Thursday, 10 July /997
IP-5-591 I Surgical management of petroclival meningiomas via a simple suboccipital retrosigmoid approach
G. Carvalho, M. Tatagiba, M. Samii. Department of Neurosurgery, Hannover,
Germany Introduction: Surgical treatment of petroclival (PC) meningiomas has shown considerable improvement in recent years thank at least in part to new skull base technique, including the introduction of the modern transpetrosal approaches. However, in a subgroup of patients the transpetrosal approaches may not be indicated: either because of the increased surgical complications related to this approach, or because of the unnecessary large exposure in individual cases. Methods: Between t979 and 1994. 70 consecutive cases of PC meningiomas underwent surgery in our Department. Suboccipital retrosigmoid approach was applied as a single approach in 24 cases. The indications for removal of PC meningiomas via a retrosigmoid approach and the completeness of tumor resection was retrospectively evaluated. Results: Suboccipital retrosigmoid approach was performed in the following cases of PC meningiomas: 1) tumor involving the PC region with major extension into the posterior fossa; 2) tumors involving the PC region and extending into the middle fossa, however without infiltration of the cavernous sinus (CS); 3) tumors extending into the middle fossa and CS, in which total resection from the CS is not attempted; 4) in old patients, or patients with decreased clinical condition, in whom brainstem decompression from the posterior fossa tumor portion is the goal of the surgery. Total tumor removal (Simpson I and II) was achieved in 14 cases (58%). Taking the criteria for patients' selection into consideration, in patients that radical removal was aimed, radical resection was achieved in 72% of the cases. Discussion/Conclusion: Different surgical approaches have been proposed to PC meningiomas. Extensive exposure of the petroclival region may in some case be unnecessary and may significantly increase the risks of postoperative morbidity. Simple suboccipital approach represents a suitable alternative for the transpetrosal exposures. It has the advantages to be easily and rapidly performed and do not expose intrapetrosal structures. In our experience, complete resection of a large group of PC meningiomas can be satisfactorily accomplished by the retrosigmoid approach. Deliberate incomplete tumor resection may be indicated in individual cases.
I P-S-S92I
Jugular foramen meningiomas: Surgical treatment
Ricardo Ramina, Ari A. Pedrozo, Murilo S. Meneses, Mauricio Coelho Neto, Daniel B. Almeida. CuritibaSkull Base Foundation, Curiliba, Brazil Tumors of the jugular foramen are rare and present difficul1ies in the surgical treatment due to involvement of vital structures at skull base. In our series of 56 cases of jugular foramen lesions, eight patients presented with meningiomas (6 female and 2 male). Caudal cranial nerves palsies were the most frequent clinical presentation. Preoperative evaluation with MRI, CT-scan. angiography was performed and disclosed tumor extension within the posterior fossa, high cervical region and petrous bone in all cases. Surgical removal of the lesions was performed through a craniocervical approach with neck/petrous bone dissection and posterior fossa craniectomy. Three patients presented with "aggressive" meningiomas with extensive local infiltration (histological findings of microcystic meningioma) and one was malignant. Total removal was not possible in these cases and postoperative radiotherapy was carried out. Complications of surgery included CSF-Ieak in 2 patients and swallowing disorders in 2 (one patient required tracheostomy). There was no perioperative mortality. Three patients with "aggressive" lesions died of tumor progression (2.8 months and 5 years after operation) in spite of extensive surgical removal and radiotherapy.
I P-S-S93I Meningiomas of the foramen magnum: Results of surgical treatment in 26 cases C.L. Solero, G. l.asio, S. Giombini, G. Broggi, M. Savoiardo 1. 1 Departments of
Neurosurgery and Neuroradiology, IslituroNazionaleNeurologico, Milano, Italy From 1960 to 1995 26 patients (19 females and 7 males) have been operated on at the Neurosurgical Department of the Istituto Nazionale Neurologico for a meningioma of the Foramen Magnum. Most of the patients had a clinical history of long standing, the presenting symptom has been occipito-nuchal pain the vast majority of patients. On admission 3 patients only had a normal neurological examination; 1 had a isolated deficit of the Xlth cranial nerve, while in all the other cases a motor deficit, more or less profound and of variable distribution was evident. The MRI has been diagnostic in every case (16 patients), and after its introduction in clinical practice angiography has never been done, because the position of the vertebral artery and its eventual encasement in the tumor are quite evident on MRI. The dural insertion of the tumor was purely anterior in 4 cases, antero-lateral in 20 and postero-lateral or posterior in 2. The first 8 patients were operated in prone position without magnification: the mortality rate was 50%, 1 patient only was found in good neurological conditions during the follow-up. The remaining 18 patients have been operated with microtechnique, ultrasonic
Tumours ofthe eNS - Meningiomas
S237
aspirator for extensive debulking of the tumor, intraoperative monitoring of the Xlth and Xllth cranial nerves (since 1988), in sitting position. A postero-Iateral approach has been adopted in 15 cases and a lateral approach in 3. There has been no mortality in these 18 cases; total removal of the meningioma was achieved in 15 cases; the tumor was sub-totally removed in 3 patients: in all of them the meningioma was inserted on the dura of the anterior rim of the foramen magnum; in 1 a postero-Iateral approach had been utilized while the other 2 a far lateral approach had been adopted. At the clinical follow-up control 1 patient only was found in worse neurological conditions than pre-operatively, while all the other patients were found to be improved. There has been 1 recurrence 13 years after the first operation and the tumor was subtotally resected by a postero-Iateral approach. From our experience it appears that the main factor conditioning sub-total removal of foramen magnum meningiomas is the degree of adhesion of the tumor to the wall of the vertebral artery. A postero-Iateral approach seems adequate in the majority of cases, while a far lateral approach should be adopted in the cases with anterior dural insertion, pretty rare in our series.
IP-S-S94I
Treatment strategy for skull base meningiomas
Nobuo Aoki, Satoshi Nakamura, Masahiro Izawa, Osami Kubo, Kintomo Takakura. Dept. of Neurosurgery, Tokyo Women's Medical College,
8-1 Kawada-cho, Shinjuku-ku, Tokyo 162, Japan We studied the treatment strategy for skull base meningiomas based on recent four years experience after introduction of Gamma Knife radiosurgery. We investigated 74 cases of skull base meningiomas treated in recent four years. 58 cases were treated with surgery or surgery plus radiosurgery, and the diagnosis was made by pathological specimen. 16 cases were diagnosed radiologically, and treated with radiosurgery only. These cases were divided into three groups; 43 cases of the surgery group, 15 cases of the surgery plus radiosurgery group, and 16 cases of the radiosurgery group. Grade of surgical resection, surgical complication, volume of radiated tumor, clinical course after treatment, and short time recurrence rate are discussed. The total resection group had good outcome and no short time recurrence. Surgical complications did not correlate with the grade of resection or size of tumor. Some aged patients had critical complication after radical surgery. With radiosurgery a good local control was obtained. Total resection without surgical complication is the best treatment for skull base meningioma. Grade of surgical resection should be designed carefully to prevent surgical complications. Gamma Knife radiosurgery was thought to be the best alternative and additional therapy for local control of skull base meningioma.
IP-S-59SI
The !T'a~agement of invasive transbasal menmqiomas
Fred Gentili, Patrick Gullane, Dale Brown, Jonathan Irish. Divisionof
Neurosurgery, University of Toronto, Toronto, Canada Although generally benign and slow growing, meningiomas can exhibit variable degrees of aggressiveness and pose significant management problems. Transbasal meningiomas are a rare subset of tumors that extensively transgress the skull base invading the paranasal sinuses, infratemporal and pterygopalatine fossae. We report on 18 patients treated between 1982 and 1995. The sex distribution was similar to meningiomas in more typical locations favoring women. 2:1. The age ranged from 30 to 72 years (mean 50.3 years). The majority of tumors (8) involved the anterior and/or lateral skull base. One third of patients presented to the ENT surgeon with hoarseness and nasal obstruction. All patients were treated with a combined transbasal craniotomy and a mid-face or infratemporal approach. Serious complications occurred in 16% of patients with no operative mortality. Average follow-up was 8 years. All patients are alive and fully functional with 7 patients showing no evidence of recurrence. Nine patients have evidence of local disease but remain asymptomatic. Two patients with more diffuse disease have undergone adjuvant radiation therapy. Histopathological analysis revealed no tumor to be frankly malignant. All lesions had infiltration of dura and 5 patients had involvement of bone, muscle, mucosa, lymphatics and neural structures. In conclusion, a rnultl-dlsciplinary approach combining craniotomy and anterior or anterolateral skull base resection and lateral rhinotomy provides the optimal management of transbasal meningiomas with acceptable morbidity, mortality and excellent long-term survival.
I P-S-S96I Unresectable meningiomas of the skull base: Management strategies Fred Gentili, Patrick Gullane. Divisionof Neurosurgery, Universityof Toronto,
Toronto, Canada Despite the use of modern skull base approaches and microsurgical techniques certain meningiomas arising from the skull base cannot be totally resected. The
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
IP-5-591 I Surgical management of petroclival meningiomas via a simple suboccipital retrosigmoid approach
G. Carvalho, M. Tatagiba, M. Samii. Department of Neurosurgery, Hannover,
Germany Introduction: Surgical treatment of petroclival (PC) meningiomas has shown considerable improvement in recent years thank at least in part to new skull base technique, including the introduction of the modern transpetrosal approaches. However, in a subgroup of patients the transpetrosal approaches may not be indicated: either because of the increased surgical complications related to this approach, or because of the unnecessary large exposure in individual cases. Methods: Between t979 and 1994. 70 consecutive cases of PC meningiomas underwent surgery in our Department. Suboccipital retrosigmoid approach was applied as a single approach in 24 cases. The indications for removal of PC meningiomas via a retrosigmoid approach and the completeness of tumor resection was retrospectively evaluated. Results: Suboccipital retrosigmoid approach was performed in the following cases of PC meningiomas: 1) tumor involving the PC region with major extension into the posterior fossa; 2) tumors involving the PC region and extending into the middle fossa, however without infiltration of the cavernous sinus (CS); 3) tumors extending into the middle fossa and CS, in which total resection from the CS is not attempted; 4) in old patients, or patients with decreased clinical condition, in whom brainstem decompression from the posterior fossa tumor portion is the goal of the surgery. Total tumor removal (Simpson I and II) was achieved in 14 cases (58%). Taking the criteria for patients' selection into consideration, in patients that radical removal was aimed, radical resection was achieved in 72% of the cases. Discussion/Conclusion: Different surgical approaches have been proposed to PC meningiomas. Extensive exposure of the petroclival region may in some case be unnecessary and may significantly increase the risks of postoperative morbidity. Simple suboccipital approach represents a suitable alternative for the transpetrosal exposures. It has the advantages to be easily and rapidly performed and do not expose intrapetrosal structures. In our experience, complete resection of a large group of PC meningiomas can be satisfactorily accomplished by the retrosigmoid approach. Deliberate incomplete tumor resection may be indicated in individual cases.
I P-S-S92I
Jugular foramen meningiomas: Surgical treatment
Ricardo Ramina, Ari A. Pedrozo, Murilo S. Meneses, Mauricio Coelho Neto, Daniel B. Almeida. CuritibaSkull Base Foundation, Curiliba, Brazil Tumors of the jugular foramen are rare and present difficul1ies in the surgical treatment due to involvement of vital structures at skull base. In our series of 56 cases of jugular foramen lesions, eight patients presented with meningiomas (6 female and 2 male). Caudal cranial nerves palsies were the most frequent clinical presentation. Preoperative evaluation with MRI, CT-scan. angiography was performed and disclosed tumor extension within the posterior fossa, high cervical region and petrous bone in all cases. Surgical removal of the lesions was performed through a craniocervical approach with neck/petrous bone dissection and posterior fossa craniectomy. Three patients presented with "aggressive" meningiomas with extensive local infiltration (histological findings of microcystic meningioma) and one was malignant. Total removal was not possible in these cases and postoperative radiotherapy was carried out. Complications of surgery included CSF-Ieak in 2 patients and swallowing disorders in 2 (one patient required tracheostomy). There was no perioperative mortality. Three patients with "aggressive" lesions died of tumor progression (2.8 months and 5 years after operation) in spite of extensive surgical removal and radiotherapy.
I P-S-S93I Meningiomas of the foramen magnum: Results of surgical treatment in 26 cases C.L. Solero, G. l.asio, S. Giombini, G. Broggi, M. Savoiardo 1. 1 Departments of
Neurosurgery and Neuroradiology, IslituroNazionaleNeurologico, Milano, Italy From 1960 to 1995 26 patients (19 females and 7 males) have been operated on at the Neurosurgical Department of the Istituto Nazionale Neurologico for a meningioma of the Foramen Magnum. Most of the patients had a clinical history of long standing, the presenting symptom has been occipito-nuchal pain the vast majority of patients. On admission 3 patients only had a normal neurological examination; 1 had a isolated deficit of the Xlth cranial nerve, while in all the other cases a motor deficit, more or less profound and of variable distribution was evident. The MRI has been diagnostic in every case (16 patients), and after its introduction in clinical practice angiography has never been done, because the position of the vertebral artery and its eventual encasement in the tumor are quite evident on MRI. The dural insertion of the tumor was purely anterior in 4 cases, antero-lateral in 20 and postero-lateral or posterior in 2. The first 8 patients were operated in prone position without magnification: the mortality rate was 50%, 1 patient only was found in good neurological conditions during the follow-up. The remaining 18 patients have been operated with microtechnique, ultrasonic
Tumours ofthe eNS - Meningiomas
S237
aspirator for extensive debulking of the tumor, intraoperative monitoring of the Xlth and Xllth cranial nerves (since 1988), in sitting position. A postero-Iateral approach has been adopted in 15 cases and a lateral approach in 3. There has been no mortality in these 18 cases; total removal of the meningioma was achieved in 15 cases; the tumor was sub-totally removed in 3 patients: in all of them the meningioma was inserted on the dura of the anterior rim of the foramen magnum; in 1 a postero-Iateral approach had been utilized while the other 2 a far lateral approach had been adopted. At the clinical follow-up control 1 patient only was found in worse neurological conditions than pre-operatively, while all the other patients were found to be improved. There has been 1 recurrence 13 years after the first operation and the tumor was subtotally resected by a postero-Iateral approach. From our experience it appears that the main factor conditioning sub-total removal of foramen magnum meningiomas is the degree of adhesion of the tumor to the wall of the vertebral artery. A postero-Iateral approach seems adequate in the majority of cases, while a far lateral approach should be adopted in the cases with anterior dural insertion, pretty rare in our series.
IP-S-S94I
Treatment strategy for skull base meningiomas
Nobuo Aoki, Satoshi Nakamura, Masahiro Izawa, Osami Kubo, Kintomo Takakura. Dept. of Neurosurgery, Tokyo Women's Medical College,
8-1 Kawada-cho, Shinjuku-ku, Tokyo 162, Japan We studied the treatment strategy for skull base meningiomas based on recent four years experience after introduction of Gamma Knife radiosurgery. We investigated 74 cases of skull base meningiomas treated in recent four years. 58 cases were treated with surgery or surgery plus radiosurgery, and the diagnosis was made by pathological specimen. 16 cases were diagnosed radiologically, and treated with radiosurgery only. These cases were divided into three groups; 43 cases of the surgery group, 15 cases of the surgery plus radiosurgery group, and 16 cases of the radiosurgery group. Grade of surgical resection, surgical complication, volume of radiated tumor, clinical course after treatment, and short time recurrence rate are discussed. The total resection group had good outcome and no short time recurrence. Surgical complications did not correlate with the grade of resection or size of tumor. Some aged patients had critical complication after radical surgery. With radiosurgery a good local control was obtained. Total resection without surgical complication is the best treatment for skull base meningioma. Grade of surgical resection should be designed carefully to prevent surgical complications. Gamma Knife radiosurgery was thought to be the best alternative and additional therapy for local control of skull base meningioma.
IP-S-59SI
The !T'a~agement of invasive transbasal menmqiomas
Fred Gentili, Patrick Gullane, Dale Brown, Jonathan Irish. Divisionof
Neurosurgery, University of Toronto, Toronto, Canada Although generally benign and slow growing, meningiomas can exhibit variable degrees of aggressiveness and pose significant management problems. Transbasal meningiomas are a rare subset of tumors that extensively transgress the skull base invading the paranasal sinuses, infratemporal and pterygopalatine fossae. We report on 18 patients treated between 1982 and 1995. The sex distribution was similar to meningiomas in more typical locations favoring women. 2:1. The age ranged from 30 to 72 years (mean 50.3 years). The majority of tumors (8) involved the anterior and/or lateral skull base. One third of patients presented to the ENT surgeon with hoarseness and nasal obstruction. All patients were treated with a combined transbasal craniotomy and a mid-face or infratemporal approach. Serious complications occurred in 16% of patients with no operative mortality. Average follow-up was 8 years. All patients are alive and fully functional with 7 patients showing no evidence of recurrence. Nine patients have evidence of local disease but remain asymptomatic. Two patients with more diffuse disease have undergone adjuvant radiation therapy. Histopathological analysis revealed no tumor to be frankly malignant. All lesions had infiltration of dura and 5 patients had involvement of bone, muscle, mucosa, lymphatics and neural structures. In conclusion, a rnultl-dlsciplinary approach combining craniotomy and anterior or anterolateral skull base resection and lateral rhinotomy provides the optimal management of transbasal meningiomas with acceptable morbidity, mortality and excellent long-term survival.
I P-S-S96I Unresectable meningiomas of the skull base: Management strategies Fred Gentili, Patrick Gullane. Divisionof Neurosurgery, Universityof Toronto,
Toronto, Canada Despite the use of modern skull base approaches and microsurgical techniques certain meningiomas arising from the skull base cannot be totally resected. The
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