LINAC radiosurgery for cavernous sinus meningiomas

Radiosurgery is increasingly used to treat unresectable cavernous sinus tumors. Since 1989, 24 patients with cavernous sinus meningiomas have been treated at Stanford University Medical Center with linear accelerator (LINAC) radiosurgery. The mean age of the patients was 47.8 years (range 28-78). The mean volume treated was 6. 83 cm3 (range 0.45-22.45 cm3), covered with an average of 2.3 isocenters (range 1-5). Radiation dose averaged 17.7 Gy (range 14-20 Gy). This group of patients was retrospectively studied by sending clinical questionnaires to both the patient/family and referring physicians, and reviewing clinic charts. In addition, follow-up imaging studies were obtained to measure residual tumor volume. Follow-up averaged 45.6 months (range 19-80). Tumor control (stabilization) following radiosurgery was noted in 15 (63%) and tumor shrinkage in 9 (37%). Seven meningiomas (29%) showed evidence of central tumor necrosis on MRI imaging 1-3 years after radiosurgery. Neurologic status was improved in 10 patients (42%) and unchanged in 12 patients (50%). There was 1 case of symptomatic brain necrosis and 1 case of radiation edema (asymptomatic). All other complications were transient, including 4 cases of trigeminal hypesthesia and 1 case of worsening diplopia. The 2-year actuarial tumor control rate was 100%. Although follow-up is still short, this experience corroborates prior reports that radiosurgery can be used to treat selected small cavernous sinus meningiomas with good to excellent clinical results and minimal morbidity.     

Stereotactic radiosurgery for cavernous sinus cavernous hemangioma--case report.

A 40-year-old female presented with cavernous sinus cavernous hemangioma manifesting as left abducens and trigeminal nerve pareses. Magnetic resonance imaging revealed a left cavernous sinus tumor. The tumor was partially removed. Histological examination of the specimen confirmed cavernous hemangioma. Radiosurgery was performed using the gamma knife. The tumor markedly decreased in size after radiosurgery and morbidity was avoided. Cavernous sinus cavernous hemangiomas may be difficult to treat surgically due to intraoperative bleeding and cranial nerve injury. Stereotactic radiosurgery can be used either as an adjunct treatment to craniotomy, or as the primary treatment for small cavernous sinus cavernous hemangioma.     

Stereotactic radiosurgery. VII. Radiosurgery versus conventionally-fractionated radiotherapy in the treatment of cavernous sinus meningiomas

Twenty-eight patients with meningiomas involving the cavernous sinus were referred to the radiosurgical service at St. Bartholomew's Hospital 1989-1998. The majority (8/13) of patients with small (< 3 cm diameter) tumours received radiosurgery whereas the majority of large tumours (> 3 cm diameter; 12/15) received conventionally-fractionated radiotherapy. Other treatment recommendations were fractionated radiosurgery (one case) and conventionally-fractionated radiotherapy to the whole meningeal base and a radiosurgery boost (three cases). Fractionated radiosurgery is optimal where the target volume is small, but abuts critically sensitive nervous system. There have been no progressions of disease at relatively early follow-up. It is argued that subtotal excision followed by appropriate dose radiation therapy is often a strong competitor to attempted radical excision given the attendant morbidity of this latter operation for meningiomas at this site. Patients referred for radiation therapy are best served by a department with both radiosurgery and conventional radiation therapy facilities.     

Stereotactic radiosurgery of meningiomas

Stereotactic radiosurgery has an expanding role in the management of selected intracranial tumors. In an initial 30-month experience using the 201-source cobalt-60 gamma knife at the University of Pittsburgh, 50 patients with meningiomas were treated. The most frequent site of origin was the skull base. Previously, 36 patients (72%) had undergone at least one craniotomy and four patients (8%) had received fractionated external beam radiation therapy. Stereotactic radiosurgery was the primary treatment modality in 16 patients (32%) with symptomatic tumors demonstrated by neuroimaging. Computer imaging-generated isodose plans (with one to five irradiation isocenters) for single-treatment irradiation gave optimal (greater than or equal to 50% isodose line) coverage in 44 patients (88%). The proximity of cranial nerves or vascular, pituitary, and brain-stem structures to the often convoluted tumor mass was crucial to dose selection. Serial imaging studies were evaluated in all 50 patients. Twenty-four patients were examined between 12 and 36 months after treatment; 13 (54%) showed a reduction in tumor volume while nine (38%) showed no change. Of 26 patients evaluated between 6 and 12 months after treatment, four showed a decrease in tumor size while 22 showed no change. Two patients (both with large tumors that received suboptimal irradiation) had delayed tumor growth outside the radiosurgical treatment volume. The actuarial 2-year tumor growth control rate was 96%. Between 3 and 12 months after radiosurgery, three patients developed delayed neurological deficits that gradually improved, compatible with delayed radiation injury. Although extended follow-up monitoring over many years will be necessary to fully evaluate treatment, to date stereotactic radiosurgery has proved to be a relatively safe and effective therapy for selected patients with symptomatic meningiomas, including those who failed surgical resection. Radiosurgery was an effective primary treatment alternative for those patients whose advanced age, medical condition, or high-risk tumor location mitigated against surgical resection.     

Stereotactic radiosurgery for meningiomas

The indications for and results after meningioma radiosurgery results are discussed. Particular emphasis is placed on longer-term results, the evolution of technique, complications, and recommendations regarding the role of radiosurgery together with other management strategies.     

Gamma knife radiosurgery for the treatment of cavernous sinus meningiomas

OBJECTIVE: We report on the efficacy of gamma knife radiosurgery for cavernous sinus meningiomas. METHODS: Between January 1994 and December 1999, we used gamma knife radiosurgery for the treatment of 43 patients with cavernous sinus meningiomas. Forty-two patients were followed up for a mean of 49.4 months (range, 18-84 mo). The patients' average age was 55 years (range, 18-81 yr). Twenty-two patients (52%) underwent operations before radiosurgery, and 20 patients (48%) underwent radiosurgery after the diagnosis was made by magnetic resonance imaging. The tumor volumes ranged from 1.2 to 101.5 cm(3) (mean, 14.7 cm(3)). The tumors either compressed or were attached to the optic apparatus in 17 patients (40.5%). The marginal radiation dose was 8 to 15 Gy (mean, 11 Gy), and the optic apparatus was irradiated with 2 to 12 Gy (mean, 6.2 Gy). Three patients with a mean tumor diameter greater than 4 cm were treated by two-stage radiosurgery. RESULTS: Thirty-eight patients (90.5%) demonstrated tumor growth control during the follow-up period after radiosurgery. Tumor regression was observed in 25 patients (59.5%), and growth was unchanged in 13 patients (31%). Regrowth or recurrence occurred in four patients (9.5%). The actual tumor growth control rate at 5 years was 92%. Only one patient (2.4%) experienced regrowth within the treatment field; in other patients, regrowth occurred at sites peripheral to or outside the treatment field. Twelve patients (28.6%) had improved clinically by the time of the follow-up examination. None of the patients experienced optic neuropathy caused by radiation injury or any new neurological deficits after radiosurgery. CONCLUSION: Gamma knife radiosurgery may be a useful option for the treatment of cavernous sinus meningiomas not only as an adjuvant to surgery but also as an alternative to surgical removal. We have shown it to be safe and effective even in tumors that adhere to or are in close proximity to the optic apparatus.     

Analysis of treatment outcome after stereotactic radiosurgery for cavernous sinus meningiomas

OBJECT: The long-term outcome of stereotactic radiosurgery for cavernous sinus (CS) meningiomas is not fully understood. The authors retrospectively reviewed their experience with 40 CS meningiomas treated with gamma knife radiosurgery. METHODS: Follow-up periods for the 40 patients ranged from 12 to 123 months (median 42 months), and the overall tumor control rates were 86.4% at 3 years and 82.3% at 10 years. Factors associated with tumor recurrence in univariate analysis were histological malignancy (p < 0.0001), partial treatment (p < 0.0001), suprasellar tumor extension (p = 0.0201), or extension in more than three directions outside the CS (p = 0.0345). When the tumor was completely covered with a dose to the margin that was higher than 14 Gy (Group A, 22 patients), no patient showed recurrence within the median follow-up period of 37 months. On the other hand, when a part of the tumor was treated with 10 to 12 Gy (Group B, 15 patients) or did not receive radiation therapy (Group C, three patients), the recurrence rates were 20% and 100%, respectively. Neurological deterioration was seen in nine patients, but all symptoms were transient or very mild. CONCLUSIONS: The data indicate that stereotactic radiosurgery can control tumor growth if the whole mass can be irradiated by dosages of more than 14 Gy. When optimal radiosurgical planning is not feasible because of a tumor's large size, irregular shape, or proximity to visual pathways, use of limited surgical resection before radiosurgery is the best option and should provide sufficient long-term tumor control with minimal complications.     

Linear accelerator radiosurgery for meningiomas in and around the cavernous sinus

OBJECTIVE: A retrospective study to evaluate the efficacy and side effects of linear accelerator radiosurgery in the treatment of cavernous sinus meningiomas. METHODS: Between 1993 and 2001, 42 patients with meningiomas involving the cavernous sinus underwent linear accelerator radiosurgery at our institution. A mean radiation dose of 14 Gy was delivered to the tumor margin. The median tumor volume was 8.2 cm3 (mean, 8.4 cm3). Median follow-up was 36 months (mean, 38 mo). RESULTS: Control of tumor growth was achieved in 97.5% of the patients. There was no mortality or permanent extraocular motor or pituitary dysfunction. Treatment-related complications included new trigeminal neuropathy in 4.7% and a new visual field defect in 2.8%. Two patients required shunt placement after developing hydrocephalus. One patient with symptomatic temporal lobe edema underwent partial excision of the tumor. Improvement of existing cranial neuropathies was noted in 29% of affected trigeminal nerves, in 22% of oculomotor nerves, and in 13% of Cranial Nerves IV and VI. CONCLUSION: This study indicates that linear accelerator radiosurgery can achieve a high control rate of meningiomas involving the cavernous sinus with no mortality and a low incidence of morbidity.     

Stereotactic radiosurgery for cavernous malformations

OBJECT: The use of stereotactic radiosurgery to treat cerebral cavernous malformations (CMs) is controversial. To evaluate the efficacy and safety of CM radiosurgery, the authors reviewed the experience at the Mayo Clinic during the past 10 years. METHODS: Seventeen patients underwent radiosurgery for high-surgical-risk CMs in the following sites: thalamus/basal ganglia (four patients), brainstem (12 patients), and corpus callosum (one patient). All patients had experienced at least two documented hemorrhages before undergoing radiosurgery. Stereotactic magnetic resonance (MR) imaging was used for target localization in all cases. The median margin radiation dose was 18 Gy and the median maximum dose was 32 Gy. The median length of follow-up review following radiosurgery was 51 months. The annual hemorrhage rate during the 51 months preceding radiosurgery was 40.1%, compared with 8.8% in the first 2 years following radiosurgery and 2.9% thereafter. In 10 patients (59%) new neurological deficits developed that were associated with regions of increased signal on long-repetition time MR imaging performed a median of 8 months (range 5-16 months) after radiosurgery. Three patients recovered, giving the group a permanent radiation-related morbidity rate of 41%. Compared with 31 patients harboring arteriovenous malformations (AVMs) of sizes and in locations similar to those of the aforementioned CMs, who underwent radiosurgery during the same time period, the patients with CMs were more likely to experience radiation-related complications (any complication, 59% compared with 10%; p < 0.001; permanent complication, 41% compared with 10%; p = 0.02). CONCLUSIONS: It is impossible to conclude that radiosurgery protects patients with CMs against future hemorrhage risk based on the available data, although it appears that some reduction in the bleeding rate occurs after a latency interval of several years. The risk of radiation-related complications after radiosurgery to treat CMs is greater than that found after radiosurgery in AVMs, even when adjusting for lesion size and location and for radiation dose.     

Stereotactic radiosurgery for anterior foramen magnum meningiomas

BACKGROUND: Total microsurgical resection is the procedure of choice for growing and symptomatic foramen magnum meningiomas. We hypothesized that for patients with advanced age, complicating medical conditions, or residual or recurrent meningiomas at the foramen magnum, stereotactic radiosurgery would be a useful adjunctive (n = 2) or alternative (n = 3) treatment. METHODS: We report our experience in five elderly patients (73-84 years) who underwent gamma knife radiosurgery. The median tumor volume was 10.5 ml and the tumor margin dose varied from 10 to 16 Gy. Because of the irregular tumor volumes along the inferior clivus, multiple isocenters of irradiation were required (range, 2-8; mean 4.4). RESULTS: During the follow-up interval of 1-5 years (median, 3 years), one patient died of an intercurrent illness, and all remaining patients were stable without any further deterioration in their clinical condition. Follow-up imaging studies revealed a reduction in tumor volume in one patient and no further growth in the remaining four. CONCLUSION: We believe that stereotactic radiosurgery provides safe and effective management for patients who are poor candidates for resection of their foramen magnum meningiomas.     

Two-staged gamma knife radiosurgery for the treatment of large petroclival and cavernous sinus meningiomas.

BACKGROUND: In this study, we report on the effectiveness and usefulness of two-staged gamma knife radiosurgery (GKS) for large petroclival and cavernous sinus meningiomas that have a high rate of surgical morbidity. METHODS: We have treated 7 patients suffering from large petroclival and cavernous sinus meningiomas using two-staged radiosurgery since March 1995. The tumors were located in the petroclival region in 4 patients, the cavernous sinus region in 2 patients, and in the petrocavernous region in the remaining patient. Three of the patients had been surgically treated and 4 patients (57%) were only followed with MR imaging. The volume of the tumors ranged between 34.5 to 101 cm(3) (mean 53.5 cm(3)). The treatment volume was between 6.8 to 29.6 cm(3) (mean 18.6 cm(3)). The treatment interval between the first GKS and second GKS was 6 months. The marginal doses for the tumors were 8 to 12 Gy (mean, 9 Gy). RESULTS: Six patients demonstrated tumor growth control during the follow-up period after the first radiosurgery (mean 39 months). Tumor regression was observed in 3 patients (43%). Three patients (43%) had improved clinically by the time of the follow-up examinations. No patient suffered from symptomatic radiation injury. CONCLUSION: Although we have treated only 7 patients using two-staged GKS, we believe this treatment may be a very useful option for large petroclival and cavernous sinus meningiomas in selected patients.     

Stereotactic radiosurgery without radiation therapy providing high local tumor control of multiple brain metastases from renal cell carcinoma.

The aim of this study was to analyse treatment effects after stereotactic radiosurgery (SRS) without whole brain radiation therapy (WBRT) as primary treatment for patients harboring brain metastases of renal cell carcinoma (RCC). During an 8-year period, 85 patients with 376 brain metastases from RCC underwent 134 outpatient SRS procedures. 65 % of all patients had multiple brain metastases. The median tumor volume was 1.2 cm (3) (range: 0.1 - 14.2 cm (3)). Mean prescribed tumor dose was 21.2 (+/- 3.2) Gy. Local/distant tumor recurrences were treated by additional SRS in cases of stable systemic disease. Overall median survival was 11.1 months after SRS. The local tumor control rate after SRS was 94 %. Most patients (78 %) died because of systemically progressing cancer. A KPS > 70 and RTOG class I were related to prolonged survival time. Patients of the RTOG groups I, II and III survived for 24.2 months, 9.2 months and 7.5 months, respectively. There was no permanent morbidity after SRS. 11 patients (12.9 %) showed transient radiogenic complications and 3 patients (3.5 %) died because of intratumoral bleedings after SRS. Stereotactic radiosurgery alone achieves excellent local tumor control rates for patients with small brain metastases from renal cell carcinoma.     

Imaging for the management of cavernous sinus meningiomas

The treatment of cavernous sinus meningiomas remains controversial. However, at present, the general consensus is that only tumors with extracavernous extensions should be operated on and that resection is performed only on the extracavernous portions. Since these tumors are deep-seated and in the vicinity of vital and highly functional neurovascular structures, surgery remains difficult and dangerous. To achieve the gross total removal of the extracavernous extensions with minimal sequelae, the operative strategy must take into account the location of the tumor extension, not only in the basal cisterns but also into the skull base structures, the vascularization of the tumor with its feeders, as well as the venous drainage pathways. These anatomical and surgical data are collected from preoperative imaging, which includes CT-scan with bony windows and consecutive fine sections, MRI, angio-MR, and DSA angiography performed with selective arteriography including late venous phases. The operative plan must define the type of craniotomy and complementary osteotomy, the usefulness of an anterior clinoidectomy with skeletonization of the optic nerve, and determine whether extensive exposure of the cerebral middle fossa is necessary to ensure substantial devascularization of the tumor and proximal control of the internal carotid artery at its intrapetrosal portion. In addition, the possible need for an extra-intracranial bypass prior to tumor removal should be evaluated. The high number of neuroimaging investigations is the guarantee of surgical accuracy and safety.     

Stereotactic radiosurgery and the risk of haemorrhage from cavernous malformations

Eighteen patients with cerebral cavernous malformations were treated with single dose of cobalt 60 source stereotactic radiosurgery. All had suffered at least one haemorrhage prior to treatment with six suffering 2, four suffering 3 and one suffering 4. Mean follow-up was 4.5 years. A total of 36 pretreatment haemorrhages occurred in 139 patient years. The first haemorrhage each patient suffered was taken as the start of observation and not included in the rehaemorrhage rate calculation. Three posttreatment haemorrhages occurred in 81 patient years of observation. The annual haemorrhage rate thus fell from 13% before to 3.7% after treatment. The odds ratio was thus 0.29 with a 95% confidence interval of (0.08-0.97), but this must be interpreted with caution because of the prereferral selection of this group of patients. Three patients developed complications of radiosurgery, two of them recovered fully.     

Stereotactic radiosurgery for management of deep brain cavernous malformations.

The indications for stereotactic radiosurgery for patients with cavernous malformations of the brain are discussed. Specific reference is made to technique and dose selection and to the results and potential complications of this approach. Radiosurgery is an alternative to microsurgical resection for some patients with malformations in high-risk brain locations.