Meningiomas: genetics, malignancy, and the role of radiation in induction and treatment. The Richard C. Schneider Lecture

Review of meningioma diagnosis and management

Meningiomas are the most common intracranial tumors in adult patients. Although the majority of meningiomas are diagnosed as benign, approximately 20% of cases are high-grade tumors that require significant clinical treatment. The gold standard for grading central nervous system tumors comes from the World Health Organization Classification of Tumors of the central nervous system. Treatment options also depend on the location, imaging, and histopathological features of the tumor. This review will cover diagnostic strategies for meningiomas, including 2021 updates to the World Health Organization's grading of meningiomas. Meningioma treatment plans are variable and highly dependent on tumor grading. This review will also update the reader on developments in the treatment of meningiomas, including surgery, radiation therapy and monoclonal antibody treatment.

A Probability-Based Investigation on the Setup Robustness of Pencil-beam Proton Radiation Therapy for Skull-Base Meningioma

Introduction

The intracranial skull-base meningioma is in proximity to multiple critical organs and heterogeneous tissues. Steep dose gradients often result from avoiding critical organs in proton treatment plans. Dose uncertainties arising from setup errors under image-guided radiation therapy are worthy of evaluation.

Patients and Methods

Fourteen patients with skull-base meningioma were retrospectively identified and planned with proton pencil beam scanning (PBS) single-field uniform dose (SFUD) and multifield optimization (MFO) techniques. The setup uncertainties were assigned a probability model on the basis of prior published data. The impact on the dose distribution from nominal 1-mm and large, less probable setup errors, as well as the cumulative effect, was analyzed. The robustness of SFUD and MFO planning techniques in these scenarios was discussed.

Results

The target coverage was reduced and the plan dose hot spot increased by all setup uncertainty scenarios regardless of the planning techniques. For 1 mm nominal shifts, the deviations in clinical target volume (CTV) coverage D99% was -11 ± 52 cGy and -45 ± 147 cGy for SFUD and MFO plans. The setup uncertainties affected the organ at risk (OAR) dose both positively and negatively. The statistical average of the setup uncertainties had <100 cGy impact on the plan qualities for all patients. The cumulative deviations in CTV D95% were 1 ± 34 cGy and -7 ± 18 cGy for SFUD and MFO plans.

Conclusion

It is important to understand the impact of setup uncertainties on skull-base meningioma, as the tumor target has complex shape and is in proximity to multiple critical organs. Our work evaluated the setup uncertainty based on its probability distribution and evaluated the dosimetric consequences. In general, the SFUD plans demonstrated more robustness than the MFO plans in target coverages and brainstem dose. The probability-weighted overall effect on the dose distribution is small compared to the dosimetric shift during single fraction.

Primary Extracranial Fibrous Meningioma of the Maxillary Sinus: A Case Report and Literature Review

Meningioma is a common neoplasm of the central nervous system; however, primary extracranial meningioma of the paranasal sinus, especially the maxillary sinus, is rare. We report a case of primary extracranial meningioma (fibrous type) of the maxillary sinus and present a literature review of the imaging features that correlate with fibrous meningioma.

Stereotactic radiosurgery for treatment of radiation-induced meningiomas: a multiinstitutional study

OBJECTIVE

Radiation-induced meningiomas (RIMs) are associated with aggressive clinical behavior. Stereotactic radiosurgery (SRS) is sometimes considered for selected RIMs. The authors investigated the effectiveness and safety of SRS for the management of RIMs.

METHODS

From 12 institutions participating in the International Radiosurgery Research Foundation, the authors pooled patients who had prior cranial irradiation and were subsequently clinically diagnosed with WHO grade I meningiomas that were managed with SRS.

RESULTS

Fifty-two patients underwent 60 SRS procedures for histologically confirmed or radiologically suspected WHO grade I RIMs. The median ages at initial cranial radiation therapy and SRS for RIM were 5.5 years and 39 years, respectively. The most common reasons for cranial radiation therapy were leukemia (21%) and medulloblastoma (17%). There were 39 multiple RIMs (35%), the mean target volume was 8.61 ± 7.80 cm3, and the median prescription dose was 14 Gy. The median imaging follow-up duration was 48 months (range 4-195 months). RIM progressed in 9 patients (17%) at a median duration of 30 months (range 3-45 months) after SRS. Progression-free survival at 5 years post-SRS was 83%. Treatment volume ≥ 5 cm3 predicted progression (HR 8.226, 95% CI 1.028-65.857, p = 0.047). Seven patients (14%) developed new neurological symptoms or experienced SRS-related complications or T2 signal change from 1 to 72 months after SRS.

CONCLUSIONS

SRS is associated with durable local control of RIMs in the majority of patients and has an acceptable safety profile. SRS can be considered for patients and tumors that are deemed suboptimal, poor surgical candidates, and those whose tumor again progresses after removal.

Characterization of Progesterone Receptor Expression in Intracranial Meningiomas of Patients Treated in a High-Complexity Hospital in Bogota, Colombia

Background Meningiomas are the single most common brain tumor. The incidence of these tumors increases with age; different studies have shown that meningiomas usually appear after the age of 50. These tumors are more common in women than in men, and women are twice as likely to suffer from the condition. Surgery is the primary form of treatment, which can be curative with complete resection. If the tumor is unresectable or other treatments such as surgery and radiotherapy have failed, hormonal therapy or chemotherapy may be considered. There is limited information about the clinical, demographic, and histopathological characteristics of these tumors in the population of Bogotá, Colombia. Objective To evaluate the expression of progesterone receptors in patients over 18 years old who have been diagnosed with meningiomas in a high-complexity hospital in Bogota, Colombia, and to describe the demographic and histopathological characteristics of these patients. Methods This is a descriptive and retrospective case series. Patients with meningioma who underwent surgical resection at a high-complexity hospital in Bogota, Colombia, from 2016 to 2019 were retrospectively identified and studied. Demographic variables, such as age and gender, were extracted from the clinical chart. Indirect immunoperoxidase staining was carried out for the progesterone receptor (PR) and Ki67. PR is analyzed as positive and negative, and the Ki67 proliferation index was determined. Results Thirty-two meningiomas from patients who underwent surgery were available for analysis. Twenty-five (78.1%) were positive for PR, 71.8% were females, and 93% were World Health Organization (WHO) grade I. Meningothelial (28%), fibrous (25%), and transitional (25%) meningiomas were the most frequent subtypes, correspondingly. The Ki67 mean value was 1.14 (0.11-10.71). Conclusion Our case series showed a greater frequency of meningiomas in women, with a high PR expression and a low Ki67 proliferation rate. These data correlate with literature worldwide.

Evaluation of surgical outcome of giant intracranial meningiomas

Background

The surgery of giant intracranial meningiomas (GIM) is difficult due to its large size, prominent vascularity, including and limiting visualization of various neurovascular structures, and severe cerebral edema. In this study, we will evaluate the surgical outcome of giant meningiomas according to our experience at our hospital in management of giant intracranial meningioma.

Main body

A retrospective analysis of 48 patients with histologically proven meningioma (≥ 6-cm diameter) who underwent surgical treatment at Benha University hospitals over a period of 5 years (June 2014/June 2019) is presented. Details regarding clinical presentation, imaging findings, surgical results and complications, and follow-up status were collected. The study group was composed of 41 females and 7 males. The age of the study group ranged from 38 to 69 years with an average of 49 years. The mean follow-up period was 36 months. Different approaches were used according to tumor location with the aim of gross total removal. Gross total removal was achieved in 90% of cases (43 cases). There were 2 cases with intraoperative complications not related to surgery. Recurrence was present in 4 cases. Mortality in this series was 4% (2 cases) with no reported intraoperative mortality.

Conclusion

Management of giant intracranial meningioma is a relatively common practice in neurosurgical centers in developing countries with the aim of radical total surgical removal being the first and most optimum option. Large size makes surgery difficult, but young age, meticulous surgical techniques, proper localization, trying to minimize operative time, and Simpson grade are of special value. Interdisciplinary cooperation is essential to avoid the common complications like pulmonary embolism (PE), postoperative hematoma in tumor bed that leads to bad surgical outcome.

Pediatric meningiomas: 10-year experience with 39 patients

OBJECTIVE

The purpose of this article was to study the characteristics of pediatric meningiomas, including the clinical symptom, anatomic location, radiological finding, treatment approaches, and long-term surgical outcome as well as the possible influence factors of the prognosis.

METHODS

We retrospectively reviewed the medical records and follow-up data of 39 pediatric patients who were treated by operation for intracranial meningiomas in West-China Hospital between 2009-2019.

RESULTS

The incidence of pediatric meningioma was 0.74%. The mean age at surgery was 12.2 years and the ratio of male to female was 1.3. Three cases (7.7%) were related to neurofibromas. WHO grade I was found in 26 patients (66.7%) and higher grades was seen in 13 (33.3%). The most common location sites were convexity (35.9%). Gross total excision was achieved in 28 patients (71.8%). The mean follow-up period was 54.4 months. The recurrence rate was 41.9%. By survival analysis, only gross total resection (p = 0.028) was associated with favorable outcome.

CONCLUSION

Meningiomas in children are very rare and have a slight male predominance. Pediatric meningiomas are more commonly located in intraventricular and have higher incidence rate of high-grade than that in adults. Although being challenging, the gross total excision should be underdone to achieve a better prognosis.

Particle therapy in the future of precision therapy

The first hospital-based treatment facilities for particle therapy started operation about thirty years ago. Since then, the clinical experience with protons and carbon ions has grown continuously and more than 200,000 patients have been treated to date. The promising clinical results led to a rapidly increasing number of treatment facilities and many new facilities are planned or under construction all over the world. An inverted depth-dose profile combined with potential radiobiological advantages make charged particles a precious tool for the treatment of tumours that are particularly radioresistant or located nearby sensitive structures. A rising number of trials have already confirmed the benefits of particle therapy in selected clinical situations and further improvements in beam delivery, image guidance and treatment planning are expected. This review summarises some physical and biological characteristics of accelerated charged particles and gives some examples of their clinical application. Furthermore, challenges and future perspectives of particle therapy will be discussed.

Children's Cancer and Leukaemia Group (CCLG): review and guidelines for the management of meningioma in children, teenagers and young adults

Primary tumours of the meninges are rare accounting for only 0.4-4.6% of all paediatric tumours of the central nervous system. Due to the rarity of these tumours in children, and the consequent absence of collaborative prospective trials, there is no clear consensus on how the unique characteristics of paediatric meningiomas impact clinical status, management approach, and survival. Much of the evidence and treatment recommendations for paediatric meningiomas are extrapolated from adult data. Translating and adapting adult treatment recommendations into paediatric practice can be challenging and might inadvertently lead to inappropriate management. In 2009, Traunecker et al. published guidelines for the management of intracranial meningioma in children and young people on behalf of UK Children's Cancer and Leukaemia Group (CCLG). Ten years later we have developed the updated guidelines following a comprehensive appraisal of the literature. Complete surgical resection is the treatment of choice for symptomatic meningiomas, while radiotherapy remains the only available adjuvant therapy and may be necessary for those tumours that cannot be completely removed. However, significant advances have been made in the identification of the genetic and molecular alterations of meningioma, which has not only a potential value in the development of therapeutic agents but also in surveillance of childhood meningioma survivors. This guideline builds upon the CCLG 2009 guideline. We summarise recommendations for the diagnosis, treatment, surveillance and long-term follow-up of children and adolescents with meningioma.

Predictors of Treatment Response and Survival Outcomes in Meningioma Recurrence with Atypical or Anaplastic Histology

BACKGROUND

Recurrence rates for atypical and anaplastic meningiomas range between 9% and 50% after gross total resection and between 36% and 83% after subtotal resection. Optimal treatment of recurrent meningiomas exhibiting atypical/anaplastic histology is complicated because they are often refractory to both surgery and radiation.

OBJECTIVE

To evaluate clinical determinants of recurrence and treatment-specific outcomes in patients with recurrent meningiomas exhibiting atypical/anaplastic histology at our institution.

METHODS

A cohort study was conducted using clinical data of all patients treated for meningiomas with atypical/anaplastic histology at first recurrence between January 1985 and July 2014 at a tertiary cancer center. Predictors of second recurrence were analyzed using competing risks regression models.

RESULTS

Nine hundred eighteen patients with meningioma were screened, of whom 60 (55% female) had recurrent disease with atypical/anaplastic histology at a median age of 58.1 yr at diagnosis. The median follow-up from the time of first recurrence was 36.7 mo, with 32 (53%) patients alive at last follow-up. There was no effect of extent of resection at first recurrence on time to a subsequent recurrence. Inclusion of radiation as primary or adjuvant therapy at first recurrence reduced the risk of progression or subsequent recurrence compared to surgery alone (P = .07).

CONCLUSION

Treatment of recurrent meningiomas with atypical/anaplastic histology remains challenging. Our data, from one of the largest cohorts, suggest better tumor control with the addition of radiation and challenges the importance of extent of resection at first recurrence. A multicenter effort is needed to confirm these findings and propose treatment guidelines.

High-Dose Radiation-Induced Meningiomas. Report of Five Cases and Critical Review of the Literature

Radiotherapy is an important modality for the treatment of tumors and arteriovenous malformations affecting the central nervous system, even though several significant side effects have been described (radionecrosis, tumors, etc.). Meningiomas induced by high-dose radiation therapy are uncommon. In this study we describe five cases treated at our institute and review all previously published reports of meningioma occurring after high-dose radiotherapy. These tumors develop mainly in patients irradiated in childhood; their incidence peaks in the second decade of life, there is a predominance in females and a high frequency of malignant forms. Although rare, meningiomas may represent a late complication of radiation treatment. The behavior of the radiation-induced variety of meningioma seems to differ from that of its “spontaneous” counterpart. The use of radiotherapy should be carefully evaluated for relatively benign or congenital lesions which generally affect young patients with a long life expectancy.

New Neoplasm During GH Replacement in Adults With Pituitary Deficiency Following Malignancy: A KIMS Analysis

CONTEXT

Data on the association between growth hormone (GH) replacement in patients with GH deficiency (GHD) after malignancies and new neoplasms show conflicting results.

OBJECTIVE

To clarify the incidence of new malignant neoplasm in childhood-onset (CO) and adult-onset (AO) adult cancer survivors (CSs).

DESIGN

Retrospective comparison of CO-CS and AO-CS with CO idiopathic GHD (IGHD) and AO nonfunctioning pituitary adenoma (NFPA) patients and with the general population [standardized incidence ratio (SIR)].

SETTING

Data from the Pfizer International Metabolic Database study (KIMS).

PATIENTS

CO-CS [n = 349; 50.4% females; mean baseline (MBL) IGF-I standard deviation score (SDS), -2.4], IGHD (n = 619; 35.7% females; MBL IGF-I SDS, -3.4), AO-CS (n = 174; 42.5% females; MBL IGF-I SDS, -1.4), and NFPA (n = 2449; 38.1% females; MBL IGF-I SDS, -1.0).

MAIN OUTCOME MEASURES

SIRs of malignant neoplasms.

RESULTS

After a median follow-up of 5.9 years (2192 patient-years), 15 CO-CS (4.3%) had developed 16 new neoplasms. The SIR was 10.4 [95% confidence interval (CI), 5.9 to 16.9] and 6.5 (95% CI, 3.0 to 12.4) after exclusion of seven patients with skin cancers. In IGHD, three malignant neoplasms (0.5%) were observed after a median follow-up of 5.4 years (3908 patient-years; SIR, 0.47; 95% CI, 0.09 to 1.37). New malignant neoplasms occurred in three AO-CS (1.7%; SIR, 1.1; 95% CI, 0.2 to 3.2) and 146 NFPA patients (153 cases, 6.0%; SIR, 1.1; 95% CI, 0.9 to 1.2) after a median follow-up of 4.9 (1024 patient-years) and 5.6 years (15,215 patient-years).

CONCLUSIONS

The risk of second malignant neoplasms was increased in CO-CS but not in AO-CS, which illustrates the need to closely follow patients on GH replacement because of a prior malignancy.

Pediatric intracranial clear cell meningioma: a clinicopathological study of seven cases and literature review

BACKGROUND

In this study, we reported seven cases of pediatric intracranial clear cell meningiomas (CCMs) in our institution and reviewed the relevant literature to investigate the clinicopathological characteristics, treatment options, and prognosis of these rare tumors.

METHODS

From January 2005 to June 2016, we retrospectively reviewed seven pediatric intracranial CCMs in terms of their clinical data, preoperative MRI features, and prognosis. Moreover, a critical review of the English language literature was also conducted.

RESULTS

The patients consisted of two males and five females with a median age of 10.5 years (range 6-15 years) at initial surgery. Petroclival and cerebellopontine angle area was the most common location site (5/7). Accordingly, the most common initial manifestation was hearing loss (3/7), and the mean interval from onset of symptoms to admission was 6.8 months (1.5-24 months). Gross total resection was achieved in five patients. Of the six tumors with immunohistochemical records, MIB-1 labeling index varied from 3 to 20 % (mean 8.1 %). During the follow-up period (mean 76.9 months, range 16-180 months), four patients had experienced tumor recurrences and three patients died due to recurrences.

CONCLUSIONS

Pediatric intracranial CCMs have a tendency to recur. There is a significant relationship between MIB-1 labeling index and recurrence. Gross total resection is recommended; if not available, adjuvant radiotherapy should be used to reduce the recurrent rate. In addition, postoperative MRI follow-up should be monitored at an interval time after resection.

Microsurgical resectability, outcomes, and tumor control in meningiomas occupying the cavernous sinus

OBJECTIVE

Cavernous sinus meningiomas (CSMs) represent a cohort of challenging skull base tumors. Proper management requires achieving a balance between optimal resection, restoration of cranial nerve (CN) function, and maintaining or improving quality of life. The objective of this study was to assess the pre-, intra-, and postoperative factors related to clinical and neurological outcomes, morbidity, mortality, and tumor control in patients with CSM.

METHODS

A retrospective review of a single surgeon's experience with microsurgical removal of CSM in 65 patients between January 1996 and August 2013 was done. Sekhar's classification, modified Kobayashi grading, and the Karnofsky Performance Scale were used to define tumor extension, tumor removal, and clinical outcomes, respectively.

RESULTS

Preoperative CN dysfunction was evident in 64.6% of patients. CN II deficits were most common. The greatest improvement was seen for CN V deficits, whereas CN II and CN IV deficits showed the smallest degree of recovery. Complete resection was achieved in 41.5% of cases and was not significantly associated with functional CN recovery. Internal carotid artery encasement significantly limited the complete microscopic resection of CSM (p < 0.0001). Overall, 18.5% of patients showed symptomatic recurrence after their initial surgery (mean follow-up 60.8 months [range 3–199 months]). The use of adjuvant stereotactic radiosurgery (SRS) after microsurgery independently decreased the recurrence rate (p = 0.009; OR 0.036; 95% CI 0.003–0.430).

CONCLUSIONS

Modified Kobayashi tumor resection (Grades I–IIIB) was possible in 41.5% of patients. CN recovery and tumor control were independent of extent of tumor removal. The combination of resection and adjuvant SRS can achieve excellent tumor control. Furthermore, the use of adjuvant SRS independently decreases the recurrence rates of CSM.

A rare case of extracranial meningioma in parapharyngeal space presented as a neck mass

BACKGROUND

Meningiomas are the most common intracranial tumor, but rarely, they can develop extracranially, usually in the neck. There are very few cases of parapharyngeal meningioma reported in literature and little is known about their biological behavior and operative management. We present a patient with a primary parapharyngeal meningioma that presented as an anterior neck mass.

CASE PRESENTATION

The patient is a 55-year-old female who presented with neck mass. A CT scan and MRI revealed a large, well defined, mildly enhancing soft tissue mass located in the right carotid sheath extended from the level of the thyroid gland into the skull base jugular foramen superiorly. Cervical exploration with partial excision of the mass was performed. Histological examination revealed meningiothelial cells with intranuclear inclusions, arranged in a syncytial pattern. Mutiple psamoma bodies these findings are consistent with the diagnosis of meningioma.

CONCLUSION

Extracranial meningiomas are quite rare. The diagnosis of these types of tumors is challenging due to the non specific nature of the symptoms. The anatomic complexity of the region of parapharyngeal space also makes their detection difficult. Imaging modalities can aid in the diagnosis, but pathological examinations are essential in confirming a definite diagnosis.

Benign versus atypical meningiomas: risk factors predicting recurrence

OBJECTIVE

The aim of the study is to determine which clinic, radiologic, and surgical characteristics of benign and atypical meningioma are associated with tumor progression.

METHODS

335 patients who underwent gross-total resection of intracranial benign and atypical meningiomas between 2000 and 2009 were followed during the period of at least 3 years. Clinical, radiological and surgical features possibly associated with progression-free survival and influencing tumor recurrence were assessed.

RESULTS

291 lesions were benign (WHO Grade I) and 44 were atypical (WHO Grade II). In the median follow-up period of 82 months 34 meningiomas recurred. The 3-, 5- and 10-year progression-free survival (PFS) rates for benign and atypical tumors were 99.7 and 81.4%, 97.5 and 69.7%, 87.5 and 69.7%, respectively. In a Kaplan-Meier analysis subpial plane of surgical dissection (pial invasion) was associated with increased tumor progression both in benign (p=0.0084) and atypical cohort (p=0.0104), and bone involvement (p=0.0033) and peritumoral brain edema (p=0.0073) were associated with increased tumor progression only in atypical meningiomas. In a multivariate analysis pial invasion and WHO Grade II type were significantly associated with tumor recurrence. All recurrences in atypical meningioma group occurred within 4 years of the surgical resection.

CONCLUSION

Pial invasion is an important predictor of tumor recurrence in benign and atypical meningiomas. In atypical meningiomas bone involvement and large peritumoral brain edema are associated with increased tumor progression.

Double trouble: a tale of two radio-treatments

In recent years, an increasing number of patients are treated with radiation. In the early era of radiotherapy, which began soon after X-rays were discovered by Roentgen in 1895, tumours were irradiated with high doses of X-rays in a single fraction. The major initial setback was the damage caused to normal tissues; however, in recent times the use of stereotactic radiosurgery, which delivers high doses of radiation precisely to abnormal tissue targets while sparing the surrounding normal brain tissue, and particularly for surgically inaccessible tumours, has taken centre stage. Prophylactic whole brain radiation (in conjunction with aggressive chemotherapy) for childhood acute lymphoblastic leukaemia has been shown to improve patient survival, however, this is associated with complications in survivors. We report an interesting case of one of the longest survivors who has had double complications from radiotherapy-based interventions.

Genomic and transcriptome analysis revealing an oncogenic functional module in meningiomas

OBJECT

Meningiomas are among the most common primary adult brain tumors. Although typically benign, roughly 2%-5% display malignant pathological features. The key molecular pathways involved in malignant transformation remain to be determined.

METHODS

Illumina expression microarrays were used to assess gene expression levels, and Illumina single-nucleotide polymorphism arrays were used to identify copy number variants in benign, atypical, and malignant meningiomas (19 tumors, including 4 malignant ones). The authors also reanalyzed 2 expression data sets generated on Affymetrix microarrays (n = 68, including 6 malignant ones; n = 56, including 3 malignant ones). A weighted gene coexpression network approach was used to identify coexpression modules associated with malignancy.

RESULTS

At the genomic level, malignant meningiomas had more chromosomal losses than atypical and benign meningiomas, with average length of 528, 203, and 34 megabases, respectively. Monosomic loss of chromosome 22 was confirmed to be one of the primary chromosomal level abnormalities in all subtypes of meningiomas. At the transcriptome level, the authors identified 23 coexpression modules from the weighted gene coexpression network. Gene functional enrichment analysis highlighted a module with 356 genes that was highly related to tumorigenesis. Four intramodular hubs within the module (GAB2, KLF2, ID1, and CTF1) were oncogenic in other cancers such as leukemia. A putative meningioma tumor suppressor MN1 was also identified in this module with differential expression between malignant and benign meningiomas.

CONCLUSIONS

The authors' genomic and transcriptome analysis of meningiomas provides novel insights into the molecular pathways involved in malignant transformation of meningiomas, with implications for molecular heterogeneity of the disease.

Management of pediatric intracranial meningiomas: an analysis of 31 cases and review of literature

OBJECTIVE

The purpose of this study is to understand the epidemiology, clinical features, behavior, and the prognostic factors that influence the outcome of intracranial meningiomas in children.

METHODS

Thirty-one patients with age less than 18 years who underwent surgery for intracranial meningiomas during the period of at 1988-2012 at Voluntary Health Services Hospital, Chennai, India were studied. These formed 3.7 % of the total 831 cases of intracranial meningiomas operated at the institute.

RESULTS

The study group included 22 (71 %) males and 9 (29 %) females. The mean age of presentation was 15 years, with the youngest being 9 months old. Two (6 %) had evidence of neurofibromatosis type 2 (NF2). The most common symptoms at presentation were seizures in 11 (35.5 %), weakness of limbs in 11 (35.5 %), and raised intracranial pressure in 10 (32 %). Convexity meningiomas were seen in 16 (51 %) and skull base in 15(49 %). Multiple meningiomas was seen in two (6 %) of the patients and intraventricular location was found in one patient (3 %). Two (6 %) had evidence of NF2. Gross total excision was achieved in 26 (83 %) and subtotal excision in 5 (17 %). WHO grade I was found in 20 (64 %) and higher grade was seen in 11 (36 %). The mean follow-up was 46.2 months. Recurrence was seen in 20 patients (64 %). In patients with higher grade or with recurrence resurgery and radiotherapy was given. Three (9 %) had multiple recurrences. On a mean follow-up of 46.2 months, 25 patients (81 %) were neurologically intact, 5 (16 %) were having moderated disability, and 1 (3 %) patient died.

CONCLUSIONS

Childhood meningiomas are uncommon lesions with a slight male predominance. They can have a varied clinical presentation. Higher grade is found more frequently compared with adults. Gross total resection is the goal and in higher grade meningiomas radiotherapy helps as a good adjuvant. Though the rate of recurrence is high, resurgery and radiotherapy gives a good outcome.

Clinical features and treatment of World Health Organization grade II and III meningiomas in childhood: report of 23 cases

OBJECT

High-grade meningiomas in childhood are rare, and their clinical features are unknown. The objective of this study was to determine the clinical characteristics and prognosis of childhood high-grade meningiomas.

METHODS

Twenty-three patients with childhood high-grade meningiomas were treated at the Huashan Hospital. Clinical data were collected, tumor samples were reexamined, and prognoses were attained through follow-up visits and telephone interviews. Survival probability was calculated using the Kaplan-Meier method. A 2-sided probability level of 0.05 was chosen for statistical significance.

RESULTS

The series included 18 males and 5 females (mean age 12.1 years). The most common symptoms were headache and vomiting (43%). Three patients had accompanying neurofibromatosis type II (NF2). The high-grade meningioma cases with NF2 had larger tumor diameters than those without NF2 (p = 0.010). The skull base was the most common tumor site (39%). Complete resections were achieved in 11 patients after their initial operations. Adjuvant radiation therapy was performed in 9 cases. Follow-up evaluations were performed for 20 patients (mean follow-up 70 months). Ten patients experienced recurrences, 2 patients had lung metastases, and 7 patients died of the recurrence. The extent of surgery was significantly related to progression-free survival (PFS; p = 0.038). A negative progesterone receptor combined with strongly positive Bcl-2 immunoreactivity was significantly related to PFS (p = 0.001) and overall survival (p = 0.002). The MIB-1 labeling index was significantly related to overall survival (p = 0.018), whereas postoperative radiation therapy was not significantly related to PFS (p = 0.087) and overall survival (p = 0.40).

CONCLUSIONS

Childhood high-grade meningioma is a rare tumor type. Childhood high-grade meningioma has a male predominance and the basilar region is the most common tumor location. Patients with these tumors have high recurrence and mortality rates. The extent of resection is an important prognosis factor. A negative progesterone receptor combined with a strongly positive Bcl-2 immunoreaction might predict cancer recurrence. The MIB-1 labeling index correlates with the prognosis, and an MIB-1 labeling index > 3% increases the risk of recurrence in childhood high-grade meningioma. More cases should be collected, and longer follow-up periods should be obtained, to evaluate the effects of postoperative radiation therapy in childhood high-grade meningioma.

Radiation-associated meningiomas in children: clinical, pathological, and cytogenetic characteristics with a critical review of the literature

OBJECT

Radiation-associated meningiomas (RAMs) arise after treatment with radiation to the cranium and are recognized as clinically separate from sporadic meningiomas. Compared with their sporadic counterparts, RAMs are often aggressive or malignant, likely to be multiple, and have a high recurrence rate. However, limited information exists about the clinical, pathological, and cytogenetic features of RAMs in pediatric patients. The authors report the findings in 9 children with meningiomas following therapeutic radiation to the cranium. In addition, they performed a critical review of the English language literature on pediatric RAMs.

METHODS

Medical files were searched for patients who demonstrated meningiomas after a history of radiation to the brain. Only those patients in whom a meningioma occurred before the age of 18 years were included in this study. Clinical and demographic data along with the MIB-1 labeling index and cytogenetic studies were evaluated.

RESULTS

The patients consisted of 5 males and 4 females with a median age of 5 years (range 2-10 years) at radiation therapy. The latency period was a median of 10 years after radiation therapy (range 6-13 years). The MIB-1 labeling index was a median of 6.6% (range 4%-10%). Five patients (55.6%) displayed multiple meningiomas at the first presentation. Histological types included clear cell meningioma in 1 patient, fibroblastic meningioma in 2, chordoid meningioma in 2, meningothelial meningioma in 7 (atypical in 2 cases), xanthomatous meningioma in 1, and chordoid meningioma in 1. Cytogenetic studies showed that the loss of 22q12.2 was the most common abnormality (3 patients), followed by complex cytogenetic abnormalities (2 patients) and rearrangements between chromosomes 1 and 12 (1 patient) and a 1p deletion (1 patient).

CONCLUSIONS

In contrast to RAMs occurring in adults, those in pediatric patients show an increased incidence of multiplicity on first presentation and unusual histological variants, some of which are described here for the first time. There was no difference in the MIB-1 labeling index in children with RAMs as compared with that in children with non-RAMs.

Gamma knife radiosurgery of meningiomas involving the foramen magnum

Background:

Foramen magnum meningiomas represent a challenging clinical entity. Although resection is performed for those with a mass effect, complete resection is not always feasible. For some patients, stereotactic radiosurgery may be used as the primary treatment modality. We evaluatedthe long-term outcome of Gamma Knife radiosurgery (GKRS) for the treatment of patientswith a foramen magnum meningioma.

Materials and Methods:

Between 1991 and 2005, 222 patients with a meningioma in the posterior fossa were treated with GKRS at the University of Virginia. Of these patients, 5 had meningiomas involving the foramen magnum. At the time of GKRS, the median age of the patients was 60 years (range, 51–78). Three patients were treated with radiosurgery following an initial resection and 2 were treated with upfront radiosurgery. The patients were assessed clinically and radiologically at routine intervals following GKRS.

Results:

The median tumor volume was 6.8 cc (range 1.9–17 cc). The GKRS tumor received a marginal dose of 12 Gy (range 10–15), and the median number of isocenters was 5 (range 3–19). The mean follow-up was 6 years (range 4–13). One lesion increased in size following GKRS requiring a second treatment, resulting in size stabilization. At the time of the last follow-up, all meningiomas had either demonstrated no growth (n = 4) or reduction in size (n = 1). No patients experienced post-radiotherapy complications.

Conclusions:

GKRS affords a high rate of tumor control and preservation of neurologic function for patients with foramen magnum meningiomas. Further study of its role in the neurosurgical management of such patients seems warranted.

Possible involvement of brain tumour stem cells in the emergence of a fast-growing malignant meningioma after surgical resection and radiotherapy of high-grade astrocytoma: case report and preliminary laboratory investigation

The case of a 62-year old man diagnosed with radiation-induced meningioma (RIM) after treatment for astrocytoma with an unusually short latency period of 7 months is reported. The patient first presented with a 2-month history of memory decline. Magnetic resonance imaging (MRI) showed a tumour in the left parieto-temporal lobe. Gross total resection was performed and the tumour was confirmed to be an astrocytoma. The patient received cranial radiotherapy 2 weeks later, however 7 months after radiation treatment the patient presented with headache and vomiting. MRI showed massive meningeal enhancement in the left frontal lobe, which progressively enlarged. The patient's clinical condition deteriorated and a second craniotomy was performed with complete removal of the secondary tumour, which was shown to be a malignant meningioma. Immunohistochemical staining identified CD133-positive cells in both tumours. A rare fraction of brain tumour stem cells (BTSC) was isolated from the primary astrocytoma using a serum-free culture system, suggesting that BTSC may have been involved in the rapid emergence of RIM after resection and radiation of the primary astrocytoma.

Radiotherapy as an adjuvant in the management of intracranial meningiomas: are we practising evidence-based medicine?

Although increasingly used, the precise role of radiotherapy in the management of meningiomas is still disputed. The objective of this study, therefore, was to appraise the evidence for adjuvant radiotherapy in benign and atypical intracranial meningiomas, and to compare and contrast it with the current opinion and practice of neurosurgeons in the United Kingdom and the Republic of Ireland. The use of radiotherapy as a primary treatment strategy or its use in the treatment of recurrence was not considered. We performed a systematic review of the evidence for adjuvant radiotherapy in benign and atypical intracranial meningiomas, surveyed current opinion amongst neurosurgeons involved in such cases and ascertained local practice using data from the regional cancer registry. Overall, 10 cohorts were identified that fulfilled our eligibility criteria. Four studies showed significantly improved local control in patients receiving adjuvant radiotherapy for incompletely resected grade I meningiomas. Our survey demonstrated that the vast majority (98%) of neurosurgeons would not recommend adjuvant radiotherapy in grade I meningioma. In grade II meningioma, most (80%) would not advocate adjuvant radiotherapy if completely excised, but the majority (59%) would recommend radiotherapy in cases of subtotal resection. Significant variation in opinion between centres exists, however, particularly in cases of completely resected atypical meningiomas (p = 0.02). Data from the Eastern Cancer Registration and Information Centre appears to be in line with these findings: less than 10% of patients with grade I meningiomas, but almost 30% of patients with grade II meningiomas received adjuvant radiotherapy in the Eastern region. In conclusion, our study has highlighted significant variation in opinion and practice, reflecting a lack of class 1 evidence to support the use of adjuvant radiotherapy in the treatment of meningiomas. Efforts are underway to address this with a randomized multicentre trial comparing a policy of watchful waiting versus adjuvant irradiation.

Radiation-induced brain tumours after central nervous system irradiation in childhood: a review

OBJECTS

Radiation-induced cerebral tumours constitute a significant risk for subjects undergoing radiotherapy for the management of cerebral neoplasms. Age-related cerebral vulnerability could be a specific factor in the genesis of these complications.

METHODS

The pertinent literature of both paediatric and adult series has been reviewed. Three personal cases were added.

RESULTS

One hundred forty-two paediatric second brain tumours were evaluated. Out of them, 69 were malignant gliomas, 33 meningiomas, 8 sarcomatous lesions and 13 low-grade astrocytomas. The average latency period for the appearance of the second tumour was 8 years. Among the second tumours occurring in adults, meningioma is the most common. In this subgroup, the latency period ranged between 16 and 30 years.

CONCLUSION

Paediatric radiation-induced brain tumours differ from the adult counterpart for both the histological subtypes. These figures indicate a specific vulnerability of the infantile brain demonstrated by the most frequent occurrence of highly malignant lesions.

Radiation-induced meningioma

The long-term or delayed side effects of irradiation on neural tissue are now known to include the induction of new central nervous system neoplasms. However, during the first half of the 20th century, human neural tissue was generally considered relatively resistant to the carcinogenic and other ill effects of ionizing radiation. As a result, exposure to relatively high doses of x-rays from diagnostic examinations and therapeutic treatment was common. In the present article the authors review the literature relating to radiation-induced meningiomas (RIMs). Emphasis is placed on meningiomas resulting from childhood treatment for primary brain tumor or tinea capitis, exposure to dental x-rays, and exposure to atomic explosions in Hiroshima and Nagasaki. The incidence and natural history of RIMs following exposure to high- and low-dose radiation is presented, including latency, multiplicity, histopathological features, and recurrence rates. The authors review the typical presentation of patients with RIMs and discuss unique aspects of the surgical management of these tumors compared with sporadic meningioma, based on their clinical experience in treating these lesions.

Foramen magnum meningioma: Dysphagia of atypical etiology

INTRODUCTION

We present a case of a foramen magnum meningioma that highlights the importance of the neurologic exam when evaluating a patient with dysphagia. A 58-year-old woman presented with an 18-month history of progressive dysphagia, chronic cough and 30-pound weight loss. Prior gastroenterologic and laryngologic workup was unrevealing.

RESULTS

Her neurologic examination revealed an absent gag reflex, decreased sensation to light touch on bilateral distal extremities, hyperreflexia, and tandem gait instability. Repeat esophagogastroduodenoscopy was normal, whereas laryngoscopy and video fluoroscopy revealed marked hypopharyngeal dysfunction. Brain magnetic resonance imaging demonstrated a 3.1 x 2.7 x 2.9 cm foramen magnum mass consistent with meningioma. The patient underwent neurosurgical resection of her mass with near complete resolution of her neurologic symptoms. Pathology confirmed diagnosis of a WHO grade I meningothelial meningioma.

CONCLUSION

CNS pathology is an uncommon but impressive cause of dysphagia. Our case demonstrates the importance of a thorough neurologic survey when evaluating such a patient.

Intracranial meningiomas: an overview of diagnosis and treatment

Meningiomas are extraaxial central nervous system tumors most often discovered in middle to late adult life, and are more often seen in women. Ninety percent of meningiomas are benign, 6% are atypical, and 2% are malignant. Most patients in whom a meningioma is diagnosed undergo resection to relieve neurological symptoms. Complete resection is often curative. For the majority of incompletely resected or recurrent tumors not previously irradiated, radiotherapy is administered. Radiotherapy may be administered as either conventional external-beam radiation therapy or stereotactically by linear accelerator, Leksell Gamma Knife, or Cyberknife radiosurgery. Advocates of stereo-tactic radiotherapy have suggested this therapy in lieu of surgery particularly in high-risk patients, those with meningiomas in eloquent or surgically inaccessible locations, and elderly patients. When the meningioma is unresectable or all other treatments (surgery and radiotherapy) have failed, hormonal therapy or chemotherapy may be considered. Notwithstanding limited data, hydroxyurea has been modestly successful in patients with recurrent meningiomas.

Implicating chromosomal aberrations with meningioma growth and recurrence: results from FISH and MIB-I analysis of grades I and II meningioma tissue

The fluorescence in situ hybridization (FISH) technique was used in 111 WHO grades I and II meningioma patients. Clinical, radiological, pathological, and immunohistochemical data were compared to aberrations of chromosomes 1p, 14q, and 22q determined by FISH. Significant differences for MIB-1 labeling were found between grades I and II tumors (p < 0.001), and between grade I tumors that recurred and those that did not recur (p < 0.001). Chromosomal aberrations were detected with FISH analysis in nearly 50% of grade I, and in 93% of grade II meningiomas. The numbers of chromosomal aberrations correlated significantly to MIB-1 (p < 0.001), with signs of grossly invasive tumor growth (p < 0.001), and with tumor recurrence (p < 0.01). The findings suggest that adding FISH analysis may allow better prediction of possible meningioma recurrence and may be a useful adjunct for therapy decisions.

High incidence of meningioma in cranial irradiated survivors of childhood acute lymphoblastic leukemia

BACKGROUND

Most survivors of childhood acute lymphoblastic leukemia (ALL) and T-cell lymphoma (T-NHL) treated before 1990 received cranial radiation. This study assessed the occurrence of second tumors in irradiated and non-irradiated survivors.

METHODS

Two hundred and ten survivors of ALL and T-NHL were treated between 1974 and 1997 by several protocols. Imaging (MRI, CT) was performed every 3-6 years in 76/88 irradiated and 74/122 non-irradiated patients for the last 20 years.

RESULTS

From January 1998 through 2004, meningiomas were detected in 16 survivors (8 female, 8 male) at age 20-39 years (median 28.7); 15 were asymptomatic. Cranial imaging done 2-8 years previously in 11 revealed no abnormalities. Fifteen had been diagnosed with ALL or T-NHL 10-29 years earlier (median 21) and received cranial irradiation (24 Gy in 14) at age 2-14 years (median 7.6). Fifteen tumors arose in the convexity. Three patients had multiple lesions. Complete resection was performed in 12 patients, with one complication. One patient had a recurrence, and four with small tumors are under surveillance. Only one low-grade glioma and two basal-cell carcinomas were found. Only one of the 74 non-irradiated patients (median follow-up 14 years) developed meningioma. The Kaplan-Meier estimate of incidence of meningioma was 14.8+/-7.6 at 20 years.

CONCLUSIONS

Survivors of childhood ALL treated with cranial radiation require prolonged surveillance because of a high incidence of late meningiomas. Early detection, when the tumor is still small, facilitates resection and may reduce complications.

Intensity-Modulated Radiotherapy for Complex-Shaped Meningioma of the Skull Base: Long-Term Experience of a Single Institution

PURPOSE

We analyzed our long-term experience with intensity-modulated radiotherapy (IMRT) in patients with complex-shaped meningioma of the skull base.

PATIENTS AND METHODS

Between January 1998 and December 2004, 94 patients with complex-shaped meningioma were treated using IMRT at our institution. Tumor distribution was: World Health Organization (WHO) Grade 1 in 54.3%, WHO Grade 2 in 9.6%, and WHO Grade 3 in 4.2%. In 31.9% of patients, the clinical and radiologic characteristics of the tumor were consistent with the diagnosis of meningioma. Twenty-six patients received radiotherapy as primary treatment and 14 patients postoperative for residual disease. Fifty-four patients were treated after local recurrence. Median target volume was 81.4 mL, median total dose was 57.6 Gy given in 32 fractions.

RESULTS

Median follow-up was 4.4 years. Overall local control was 93.6%. Sixty-nine patients had stable disease based on computed tomography/magnetic resonance imaging (MRI), whereas 19 had a tumor volume reduction after IMRT. Six patients showed local tumor progression on MRI 22.3 months' median after IMRT. Three patients died from non-treatment-related conditions after IMRT. In 39.8% of the patients, preexisting neurologic deficits improved. Worsening of preexisting neurologic symptoms was seen in 4 patients and 2 patients developed new clinical symptoms from local tumor progression. Transient side effects such as headache were seen in 7 patients. Treatment-induced loss of vision was seen in 1 of 53 reirradiated patients with a Grade 3 meningioma 9 months after retreatment with IMRT.

CONCLUSION

These data demonstrate that IMRT is an effective and safe treatment modality for long-term local control of complex-shaped and otherwise difficult to treat meningioma.

Stereotactic radiation treatment for recurrent nonbenign meningiomas

Object

The authors analyzed the results of stereotactic radiosurgery (SRS) and stereotactic radiotherapy (SRT) for the treatment of recurrent meningiomas that were described at initial resection as showing aggressive, atypical, or malignant features (nonbenign).

Methods

Twenty-five patients who underwent SRS and/or SRT for nonbenign meningiomas between December 1992 and August 2004 were included. Thirteen of these patients underwent treatment for multiple primary or recurrent lesions. In all, 52 tumors were treated. All histological sections were reviewed and reclassified according to World Health Organization (WHO) 2000 guidelines as benign (Grade I), atypical (Grade II), or anaplastic (Grade III) meningiomas. The median follow-up period was 42 months.

Seventeen (68%) of the cases were reclassified as follows: WHO Grade I (five cases), Grade II (11 cases), and Grade III (one case). Malignant progression occurred in eight cases (32%) during the follow-up period; these cases were considered as a separate group. The 3-year progression-free survival (PFS) rates for the Grades I, II, and III, and malignant progression groups were 100, 83, 0, and 11%, respectively (p < 0.001). In the Grade II group, the 3-year PFS rates for patients treated with SRS and SRT were 100 and 33%, respectively (p = 0.1). After initial treatment, 22 new tumors required treatment using SRS or SRT; 17 (77%) of them occurred inside the original resection cavity. Symptomatic edema developed in one patient (4%).

Conclusions

Stereotactic radiation treatment provided effective local control of “aggressive” Grade I and Grade II meningiomas, whereas Grade III lesions were associated with poor outcome. The outcome of cases in the malignant progression group was intermediate between that of the Grade II and Grade III groups, with the lesions showing a tendency toward malignancy.

Progesterone and estrogen receptors: opposing prognostic indicators in meningiomas

OBJECT

The preponderance of progesterone receptors (PRs) and the scarcity of estrogen receptors (ERs) in meningiomas are well known. The expression of PRs may relate to tumor grade and recurrence. Cytogenetic abnormalities are associated with aggressive behavior, recurrence, and progression. In this study, the authors focus on the prognostic implications of hormone receptors in meningiomas to help determine the clinical and biological aggressiveness of tumors and their correlations with cytogenetic abnormalities.

METHODS

Two hundred thirty-nine patients with meningiomas were separated into three groups. Group 1 (PR-positive group) comprised patients whose meningiomas displayed expression of PRs alone. Group 2 (receptor-negative group) included patients whose lesions did not have receptors for either progesterone or estrogen. Group 3 (ER-positive group) included patients whose tumors displayed expression of ERs. Clinical and histological findings, proliferative indices, tumor recurrence, and cytogenetic findings were analyzed by performing the Fisher exact test. Compared with the receptor-negative (Group 2) and ER-positive (Group 3) groups, the PR-positive group (Group 1) had a statistically significant lower proliferative index and a smaller number of patients in whom there were aggressive histopathological findings or changes in karyotype. In Groups 1, 2, and 3, the percentages of cases with aggressive histopathological findings were 10, 31, and 33%, respectively; the percentages of cases with chromosomal abnormalities were 50, 84, and 86%, respectively; and the percentages of cases in which there initially was no residual tumor but recurrence was documented were 5, 30, and 27%, respectively. A statistically significant increase in the involvement of chromosomes 14 and 22 was identified in receptor-negative and ER-positive de novo meningiomas, when compared with the PR-positive group. Abnormalities on chromosome 19 were statistically significantly higher in receptor-negative meningiomas than in PR-positive tumors.

CONCLUSIONS

The expression of the PR alone in meningiomas signals a favorable clinical and biological outcome. A lack of receptors or the presence of ERs in meningiomas correlates with an accumulation of qualitative and quantitative karyotype abnormalities, a higher proportional involvement of chromosomes 14 and 22 in de novo tumors, and an increasing potential for aggressive clinical behavior, progression, and recurrence of these lesions. Sex hormone receptor status should routinely be studied for its prognostic value, especially in female patients, and should be taken into account in tumor grading. The initial receptor status of a tumor may change in progression or recurrence of tumor.

Single voxel proton MR spectroscopy findings of typical and atypical intracranial meningiomas

PURPOSE

To prospectively define proton magnetic resonance spectroscopy (MRS) findings of meningiomas, and describe the ability or inability of short- and long-echo MRS to differentiate typical and atypical meningiomas in vivo.

MATERIAL AND METHODS

Seventeen patients with pathologically confirmed typical meningiomas and six with atypical meningiomas were evaluated with conventional MR imaging and MRS before resection. MRS studies using point-resolved spectroscopy (PRESS) localisation, at short- and long-echo time (TR 2000 ms, TE: 30 and 144 ms, 64-96 acquisition) were acquired on a 1.5 T scanner. MRS data obtained from these patients were compared with histopathological findings. Mean cellular proliferation (MIB-1) antibody staining against the Ki-67 antigen was also determined in all meningiomas.

RESULTS

Prominent choline (Cho) was present in all meningiomas. Alanine (Ala) was observed in 21 cases of the 23 meningiomas. Acetylaspartate (NAA) and creatine (Cr) were either not observed or detected in minimal amounts in at all both groups of meningiomas on long TE (144 ms) spectra. The mean Cho/Cr values in the four atypical meningiomas were 4.44+/-0.30 (mean+/-standard deviation) and 3.39+/-0.52 in the 12 typical meningiomas on short TE spectra. Cho/Cr ratio could not be determined in the other seven cases because of a lack of creatine peak. Of the five meningiomas in which a lactate peak was detected, four were in typical cases and only one was in atypical meningioma. Mean MIB-1 proliferation index was 3.7% in typical meningiomas and 10% in atypical meningiomas.

CONCLUSION

Prominent Cho, absence or low amount of NAA and Cr, and presence of Ala were common characteristics of spectral pattern of both atypical and typical meningiomas on MRS. MRS cannot reliably differentiate typical intracranial meningiomas from atypical meningiomas preoperatively. Mean MIB-1 proliferation index was well correlated with histopathology findings.

Diagnosis and treatment of atypical and anaplastic meningiomas: a review

Atypical and anaplastic meningiomas are uncommon tumors with a poorer prognosis than benign meningiomas. We reviewed the current literature and attempted to integrate and summarize available information to determine a logical approach to these tumors. Both tumors are rare and are often integrated with benign meningiomas when treatments are evaluated. In addition, because there has not been one histopathological classification scheme for atypical and anaplastic meningiomas in the past, there are numerous inconsistencies in the literature. Malignant progression with accumulation of mutations in a benign meningioma can result in an atypical and/or anaplastic meningioma. Both tumors are difficult to manage and have high recurrence and poor survival rates. The extent of tumor resection and histological grade are the key determinants for recurrence. In addition, metastases are unusual, but they do occur. We also review the evidence available that has resulted in the current World Health Organization classification. Radiation therapy can be used as an adjunctive treatment after both total and subtotal resection. In addition, the role of stereotactic radiosurgery is increasing, along with a possible role for brachytherapy. There are no effective chemotherapeutic agents available. A treatment algorithm is suggested.

Salvage chemotherapy with CPT-11 for recurrent meningioma

BACKGROUND

A prospective Phase II study of irinotecan (CPT-11) in adult patients with recurrent surgery and radiotherapy-refractory WHO Grade I meningioma.

METHODS

Sixteen patients (5 men; 11 women) ages 48-70 years (median 62.5), with recurrent meningioma were treated. All patients had previously been treated with surgery (complete in 4; partial in 9; biopsy in 3) and involved-field radiotherapy (median dose 54 Gy; 12 following first surgery and 4 following second surgery). Additionally, eight patients underwent re-operation (complete in 2; partial in 6) and eight patients were treated with salvage stereotactic radiosurgery. No patient was treated with prior chemotherapy. CPT-11 was administered intravenously every 3 weeks (350 mg/m2/day in patients on non-enzyme inducing anticonvulsants [NEIAED]; 600 mg/m2/day in patients on enzyme-inducing anticonvulsants [EIAED]) for 9 weeks (operationally defined as a single cycle). Neurological and neuroradiographic evaluation were performed every 10 weeks.

RESULTS

All patients were evaluable. A median of two cycles of CPT-11 (range 1-4) was administered. CPT-11 related-toxicity (> or = grade 3) included diarrhea (6 occurrences, 19% all cycles administered), granulocytopenia (6, 19%), leukopenia (5, 16%), thrombocytopenia (3, 10%) and anemia (3, 10%). Four patients required transfusion (3 RBC and 1 platelet). One patient developed neutropenic fever without bacteriologic confirmation. No treatment-related deaths occurred. No patient demonstrated a neuroradiographic complete or partial response (PR), 13 patients (81%) demonstrated stable disease but disease progressed after 2 cycles of CPT-11, and 3 patients (19%) had progressive disease (PD) following a single cycle of CPT-11. Time to tumor progression ranged from 2.5 to 5.0 months (median 5.0 months). Survival ranged from 4 to months (median 7.5 months).

CONCLUSIONS

The primary objective was to estimate the 6-month progression-free survival (PFS) after study entry. As no patient demonstrated PFS at 6-months, the study was stopped prematurely as specified by study design. Using CPT-11 in this moderately toxic dose schedule failed to demonstrate efficacy in this cohort of adult patients with recurrent surgery and radiotherapy-refractory meningioma.

Intracranial meningiomas: diagnosis and treatment

Meningiomas are extra-axial CNS tumors which have a female predominance and occur in middle-to-late adult life. Most meningiomas (90%) are benign, 6% are atypical and a small proportion (2%) are malignant. Most patients diagnosed with a meningioma undergo surgical resection to relieve neurological symptoms. Complete surgical resection is often curative. For most incompletely resected or recurrent tumors not previously irradiated, radiotherapy is administered. Radiotherapy may be administered as either conventional external beam irradiation or stereotactically by linear accelerator, gamma knife or cyberknife radiosurgery. Advocates of stereotactic radiotherapy have suggested this therapy in lieu of surgery particularly in poor surgical risk patients, patients with meningiomas in eloquent or surgically inaccessible locations and in patients of advanced age. When the meningioma is unresectable or all other treatments (e.g., surgery and radiotherapy) have failed, hormonal chemotherapy may be considered. Notwithstanding limited data, hydroxyurea has been modestly successful in patients with recurrent meningiomas.

Radiation induced meningioma with a short latent period following high dose cranial irradiation – Case report and literature review

Radiation induced meningiomas (RIM) are rare late complications in patients who have received high dose irradiation for brain tumors. The mean latency period for induction of RIM in most of the series is 18.7+/-10.2 years. There are only 9 reported cases of RIM following high dose cranial irradiation with unusually short latency periods of less than 5 years. Herein, we report a child diagnosed with RIM with an unusually short latency period of 14 months. An 11-year old male child underwent gross total resection of medulloblastoma. Following surgery he received high dose craniospinal irradiation. Postoperative computed tomography scan (CT scan) after 1 month did not show features of any residual tumor, recurrence or tumor at a new site. The child was asymptomatic for 14 months and then presented with complaints of headache and vomiting. CT scan head showed multiple solid homogenously enhancing lesions in bilateral basifrontal and right basitemporal region. Histopathology of the lesions turned out to be atypical meningioma.