Stereotactic radiosurgery of cavernous malformations

2000 ◽  
Vol 93 (6) ◽  
pp. 987-991 ◽  
Author(s):  
Bruce E. Pollock ◽  
Yolanda I. Garces ◽  
Scott L. Stafford ◽  
Robert L. Foote ◽  
Paula J. Schomberg ◽  
...  
Keyword(s):  
Radiation Dose ◽  
Mr Imaging ◽  
Stereotactic Radiosurgery ◽  
Lesion Size ◽  
Neurological Deficits ◽  
Morbidity Rate ◽  
Cavernous Malformations ◽  
Content Type ◽  
Latency Interval ◽  
Fine Print

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 arteriovenous malformations of the brain

1991 ◽  
Vol 75 (4) ◽  
pp. 512-524 ◽  
Author(s):  
L. Dade Lunsford ◽  
Douglas Kondziolka ◽  
John C. Flickinger ◽  
David J. Bissonette ◽  
Charles A. Jungreis ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Stereotactic Radiosurgery ◽  
Arteriovenous Malformations ◽  
Neurological Deficits ◽  
Content Type ◽  
Complete Obliteration ◽  
Latency Interval ◽  
Subtotal Removal ◽  
The Brain ◽  
Fine Print

✓ Stereotactic radiosurgery successfully obliterates carefully selected arteriovenous malformations (AVM's) of the brain. In an initial 3-year experience using the 201-source cobalt-60 gamma knife at the University of Pittsburgh, 227 patients with AVM's were treated. Symptoms at presentation included prior hemorrhage in 143 patients (63%), headache in 104 (46%), and seizures in 70 (31%). Neurological deficits were present in 102 patients (45%). Prior surgical resection (resulting in subtotal removal) had been performed in 36 patients (16%). In 47 selected patients (21%), embolization procedures were performed in an attempt to reduce the AVM size prior to radiosurgery. The lesions were classified according to the Spetzler grading system: 64 (28%) were Grade VI (inoperable), 22 (10%) were Grade IV, 90 (40%) were Grade III, 43 (19%) were Grade II, and eight (4%) were Grade I. With the aid of computer imaging-integrated isodose plans for single-treatment irradiation, total coverage of the AVM nidus was possible in 216 patients (95%). The location and volume of the AVM were the most important factors for the selection of radiation dose. Magnetic resonance (MR) imaging was performed at 6-month intervals in 161 patients. Seventeen patients who had MR evidence of complete obliteration underwent angiography within 3 months of imaging: in 14 (82%) complete obliteration was confirmed. Complete angiographic obliteration was confirmed in 37 (80%) of 46 patients at 2 years, the earliest confirmation being 4 months (mean 17 months) after radiosurgery. The 2-year obliteration rates according to volume were: all eight (100%) AVM's less than 1 cu cm; 22 (85%) of 26 AVM's of 1 to 4 cu cm; and seven (58%) of 12 AVM's greater than 4 cu cm. Magnetic resonance imaging revealed postirradiation changes in 38 (24%) of 161 patients at a mean interval of 10.2 months after radiosurgery; only 10 (26%) of those 38 patients were symptomatic. In the entire series, two patients developed permanent new neurological deficits believed to be treatment-related. Two patients died of repeat hemorrhage at 6 and 23 months after treatment during the latency interval prior to obliteration. Stereotactic radiosurgery is an important method to obliterate AVM's, especially those previously considered inoperable. Success and complication risks are related to the AVM location and the volume treated.

A fatal, chronically growing basilar artery: a new type of dissecting aneurysm

1996 ◽  
Vol 84 (6) ◽  
pp. 962-971 ◽  
Author(s):  
Tohru Mizutani
Keyword(s):  
Mr Imaging ◽  
Basilar Artery ◽  
Dissecting Aneurysm ◽  
Neurological Deficits ◽  
Vertebrobasilar Insufficiency ◽  
Content Type ◽  
Asymptomatic Patients ◽  
Basilar Arteries ◽  
Fine Print

✓ A long-term follow-up study (minimum duration 2 years) was made of 13 patients with tortuous dilated basilar arteries. Of these, five patients had symptoms related to the presence of such arteries. Symptoms present at a very early stage included vertebrobasilar insufficiency in two patients, brainstem infarction in two patients, and left hemifacial spasm in one patient. Initial magnetic resonance (MR) imaging in serial slices of basilar arteries obtained from the five symptomatic patients showed an intimal flap or a subadventitial hematoma, both of which are characteristic of a dissecting aneurysm. In contrast, the basilar arteries in the eight asymptomatic patients did not show particular findings and they remained clinically and radiologically silent during the follow-up period. All of the lesions in the five symptomatic patients gradually grew to fantastic sizes, with progressive deterioration of the related clinical symptoms. Dilation of the basilar artery was consistent with hemorrhage into the “pseudolumen” within the laminated thrombus, which was confirmed by MR imaging studies. Of the five symptomatic patients studied, two died of fatal subarachnoid hemorrhage (SAH) and two of brainstem compression; the fifth patient remains alive without neurological deficits. In the three patients who underwent autopsy, a definite macroscopic double lumen was observed in both the proximal and distal ends of the aneurysms within the layer of the thickening intima. Microscopically, multiple mural dissections, fragmentation of internal elastic lamina (IEL), and degeneration of media were diffusely observed in the remarkably extended wall of the aneurysms. The substantial mechanism of pathogenesis and enlargement in the symptomatic, highly tortuous dilated artery might initially be macroscopic dissection within a thickening intima and subsequent repetitive hemorrhaging within a laminated thrombus in the pseudolumen combined with microscopic multiple mural dissections on the basis of a weakened IEL. The authors note and caution that symptomatic, tortuous dilated basilar arteries cannot be overlooked because they include a group of malignant arteries that may grow rapidly, resulting in a fatal course.

Gamma knife thalamotomy for movement disorders: evaluation of the thalamic lesion and clinical results

2005 ◽  
Vol 102 ◽  
pp. 234-240 ◽  
Author(s):  
Chihiro Ohye ◽  
Tohru Shibazaki ◽  
Sumito Sato
Keyword(s):  
Mr Imaging ◽  
Gamma Knife ◽  
Clinical Results ◽  
Lesion Size ◽  
Lesion Volume ◽  
Thalamic Lesion ◽  
Content Type ◽  
Before And After ◽  
Single Isocenter ◽  
Fine Print

Object.The authors studied the effects of gamma knife thalamotomy (GKT) on Parkinson disease-related tremor and essential tremor before and after reloading of radioactive cobalt.Methods.Based on experience in stereotactic thalamotomy aided by depth microrecording, the target was located at the lateral border of the thalamic ventralis intermedius nucleus (VIM). For more precise targeting, the percentage representation of the thalamic VIM in relation to the entire thalamic length is useful. The location of the target was determined on magnetic resonance (MR) imaging and computerized tomography scanning. A maximum dose of 130 Gy was delivered to the target by using a single isocenter with the 4-mm collimator. In more recent cases, a systematic follow-up examination was performed at 3, 6, 12, 18, and 24 months after GKT.Since 1993, the authors have treated 70 patients with PD. Throughout the series the same dosimetric technique has been used. The course after GKT was compared between the 25 cases with PD treated before reloading and the 35 cases treated after reloading. In the majority (80–85%) treated after reloading, tremor and rigidity were reduced around 6 months after GKT. In the cases treated before reloading this effect took approximately 1 year. The thalamic reaction on MR imaging showed the same two lesion types in both series: a restricted and a diffuse. After reloading the restricted lesion was more frequent and the lesion volume was smaller.Conclusions.The shorter delay in clinical improvement and smaller lesion size may be related to an increased radiation dose.

Intramedullary ependymoma of the spinal cord

1990 ◽  
Vol 72 (4) ◽  
pp. 523-532 ◽  
Author(s):  
Paul C. McCormick ◽  
Roland Torres ◽  
Kalmon D. Post ◽  
Bennett M. Stein
Keyword(s):  
Spinal Cord ◽  
Mr Imaging ◽  
Tumor Recurrence ◽  
Neurological Deficits ◽  
Functional Improvement ◽  
Consecutive Series ◽  
Intramedullary Spinal Cord ◽  
Content Type ◽  
Fine Print

✓ A consecutive series of 23 patients underwent operative removal of an intramedullary spinal cord ependymoma between January, 1976, and September, 1988. Thirteen women and 10 men between the age of 19 and 70 years experienced symptoms for a mean of 34 months preceding initial diagnosis. Eight patients had undergone treatment prior to tumor recurrence and referral. Mild neurological deficits were present in 22 patients on initial examination. The location of the tumors was predominantly cervical or cervicothoracic. Radiological evaluation revealed a wide spinal cord in all cases. Magnetic resonance (MR) imaging was the single most important radiological procedure. At operation, a complete removal was achieved in all patients. No patient received postoperative radiation therapy. Histological examination revealed a benign ependymoma in all cases. The follow-up period ranged from 6 to 159 months (mean 62 months) with seven patients followed for a minimum of 10 years after surgery. Fourteen patients underwent postoperative MR imaging at intervals ranging from 8 months to 10 years postoperatively. No patient has been lost to follow-up review and there were no deaths. No patient showed definite clinical or radiological evidence of tumor recurrence during the follow-up period. Recent neurological evaluation revealed functional improvement from initial preoperative clinical status in eight patients, no significant change in 12 patients, and deterioration in three patients. The data support the belief that long-term disease-free control of intramedullary spinal ependymomas with acceptable morbidity may be achieved utilizing microsurgical removal alone.

Risk of early closed reduction in cervical spine subluxation injuries

1999 ◽  
Vol 90 (1) ◽  
pp. 13-18 ◽  
Author(s):  
Gerald A. Grant ◽  
Sohail K. Mirza ◽  
Jens R. Chapman ◽  
H. Richard Winn ◽  
David W. Newell ◽  
...  
Keyword(s):  
Cervical Spine ◽  
Mr Imaging ◽  
Disc Herniation ◽  
Closed Reduction ◽  
Spinal Cord Injuries ◽  
Spinal Injury ◽  
Neurological Deterioration ◽  
Neurological Deficits ◽  
Content Type ◽  
Fine Print

Object. The authors retrospectively reviewed 121 patients with traumatic cervical spine injuries to determine the risk of neurological deterioration following early closed reduction. Methods. After excluding minor fractures and injuries without subluxation, the medical records and imaging studies (computerized tomography and magnetic resonance [MR] images) of 82 patients with bilateral and unilateral locked facet dislocations, burst fractures, extension injuries, or miscellaneous cervical fractures with subluxation were reviewed. Disc injury was defined on MR imaging as the presence of herniation or disruption: a herniation was described as deforming the thecal sac or nerve roots, and a disruption was defined as a disc with high T2-weighted signal characteristics in a widened disc space. Fifty-eight percent of patients presented with complete or incomplete spinal cord injuries. Thirteen percent of patients presented with a cervical radiculopathy, 22% were intact, and 9% had only transient neurological deficits in the field. Early, rapid closed reduction, using serial plain radiographs or fluoroscopy and Gardner—Wells craniocervical traction, was achieved in 97.6% of patients. In two patients (2.4%) closed reduction failed and they underwent emergency open surgical reduction. The average time to achieve closed reduction was 2.1 ± 0.24 hours (standard error of the mean). The incidence of disc herniation and disruption in the 80 patients who underwent postreduction MR imaging was 22% and 24%, respectively. However, the presence of disc herniation or disruption did not affect the degree of neurological recovery, as measured by American Spinal Injury Association motor score and the Frankel scale following early closed reduction. Only one (1.3%) of 80 patients deteriorated, but that occurred more than 6 hours following closed reduction. Conclusions. Although disc herniation and disruption can occur following all types of traumatic cervical fracture subluxations, the incidence of neurological deterioration following closed reduction in these patients is rare. The authors recommend early closed reduction in patients presenting with significant motor deficits without prior MR imaging.

Stereotactic radiosurgery for residual neurocytoma

2001 ◽  
Vol 95 (5) ◽  
pp. 879-882 ◽  
Author(s):  
Elizabeth Tyler-Kabara ◽  
Douglas Kondziolka ◽  
John C. Flickinger ◽  
L. Dade Lunsford
Keyword(s):  
Stereotactic Radiosurgery ◽  
Tumor Volume ◽  
Neurological Deficits ◽  
Response To Treatment ◽  
Imaging Studies ◽  
Content Type ◽  
Adjacent Structures ◽  
Initial Resection ◽  
Fine Print

✓ The purpose of this report was to review the results of stereotactic radiosurgery in the management of patients with residual neurocytomas after initial resection or biopsy procedures. Four patients underwent stereotactic radiosurgery for histologically proven neurocytoma. Clinical and imaging studies were performed to evaluate the response to treatment. Radiosurgery was performed to deliver doses to the tumor margin of 14, 15, 16, and 20 Gy, depending on tumor volume and proximity to critical adjacent structures. More than 3 years later, imaging studies revealed significant reductions in tumor size. No new neurological deficits were identified at 53, 50, 42, and 38 months of follow up. The authors' initial experience shows that stereotactic radiosurgery appears to be an effective treatment for neurocytoma.

Reduction of hemorrhage risk after stereotactic radiosurgery for cavernous malformations

1995 ◽  
Vol 83 (5) ◽  
pp. 825-831 ◽  
Author(s):  
Douglas Kondziolka ◽  
L. Dade Lunsford ◽  
John C. Flickinger ◽  
John R. W. Kestle
Keyword(s):  
Parietal Lobe ◽  
Vascular Lesion ◽  
Annual Rate ◽  
Surgical Removal ◽  
Cavernous Malformations ◽  
Content Type ◽  
History Of ◽  
The Mean ◽  
Latency Interval ◽  
Fine Print

✓ The benefits of radiosurgery for cavernous malformations are difficult to assess because of the unclear natural history of this vascular lesion, the inability to image malformation vessels, and the lack of an imaging technique that defines “cure.” The authors selected for radiosurgery 47 patients who harbored a hemorrhagic malformation in a critical intraparenchymal location remote from a pial or ependymal surface. Of these, 44 patients had experienced at least two hemorrhages before radiosurgery. The mean patient age was 39 years; six patients had previously undergone attempted surgical removal. The malformation was located in the pons/midbrain in 24 cases, the medulla in three, the thalamus in nine, the basal ganglia in three, deep in a parietal lobe in four, and deep in a temporal lobe in four. Patients had sustained initial hemorrhages from 0.5 to 12 years prior to radiosurgery (mean 4.12 years). In these patients, who were not typical of the majority of patients with cavernous malformations, there were 109 bleeds before radiosurgery in 193 prior observation-years, for a 56.5% annual hemorrhage rate (including the first hemorrhage), or an annual rate of 32% subsequent to the first hemorrhage. The mean follow-up period after radiosurgery was 3.6 years (range 0.33–6.4 years). The proportion of patients with hemorrhage after radiosurgery was significantly reduced (p < 0.0001), as was the mean number of hemorrhages per patient (p = 0.00004). In the first 2 years after radiosurgery, there were seven bleeds in 80 observation-years (8.8% annual hemorrhage rate). In the 2- to 6-year interval after radiosurgery, the annual rate decreased to 1.1% (one bleed). After radiosurgery, 12 patients (26%) sustained neurological worsening that correlated with imaging changes. In eight patients these deficits were temporary; two underwent surgical resection and died. Two patients had new permanent deficits (4%). A significant reduction was observed in the hemorrhage rate after radiosurgery in patients who had deep hemorrhagic cavernous malformations, especially after a 2-year latency interval. This evidence provides further support to the belief that radiosurgery is an effective strategy for cavernous malformations, especially when located within the parenchyma of the brainstem or diencephalon.

The natural history of familial cavernous malformations: results of an ongoing study

1994 ◽  
Vol 80 (3) ◽  
pp. 422-432 ◽  
Author(s):  
Joseph M. Zabramski ◽  
Thomas M. Wascher ◽  
Robert F. Spetzler ◽  
Blake Johnson ◽  
John Golfinos ◽  
...  
Keyword(s):  
Natural History ◽  
Mr Imaging ◽  
Ongoing Study ◽  
Mr Images ◽  
Cavernous Malformations ◽  
Content Type ◽  
Imaging Characteristics ◽  
Familial Form ◽  
Fine Print

✓ Cavernous malformations are congenital abnormalities of the cerebral vessels that affect 0.5% to 0.7% of the population. They occur in two forms: a sporadic form characterized by isolated lesions, and a familial form characterized by multiple lesions with an autosomal dominant mode of inheritance. The management of patients with cavernous malformations, particularly those with the familial form of the disease, remains a challenge because little is known regarding the natural history. The authors report the results of an ongoing study in which six families afflicted by familial cavernous malformations have been prospectively followed with serial interviews, physical examinations, and magnetic resonance (MR) imaging at 6- to 12-month intervals. A total of 59 members of these six families were screened for protocol enrollment; 31 (53%) had MR evidence of familial cavernous malformations. Nineteen (61%) of these 31 patients were symptomatic, with seizures in 12 (39%), recurrent headaches in 16 (52%), focal sensory/motor deficits in three (10%), and visual field deficits in two (6%). Twenty-one of these 31 patients underwent at least two serial clinical and MR imaging examinations. A total of 128 individual cavernous malformations (mean 6.5 ± 3.8 lesions/patient) were identified and followed radiographically. During a mean follow-up period of 2.2 years (range 1 to 5.5 years), serial MR images demonstrated 17 new lesions in six (29%) of the 21 patients; 13 lesions (10%) showed changes in signal characteristics, and five lesions (3.9%) changed significantly in size. The incidence of symptomatic hemorrhage was 1.1% per lesion per year. The results of this study demonstrate that the familial form of cavernous malformations is a dynamic disease; serial MR images revealed changes in the number, size, and imaging characteristics of lesions consistent with acute or resolving hemorrhage. It is believed that the de novo development of new lesions in this disease has not been previously reported. These findings suggest that patients with familial cavernous malformations require careful follow-up monitoring, and that significant changes in neurological symptoms warrant repeat MR imaging. Surgery should be considered only for lesions that produce repetitive or progressive symptoms. Prophylactic resection of asymptomatic lesions does not appear to be indicated.

Gamma knife thalamotomy for movement disorders: evaluation of the thalamic lesion and clinical results

2005 ◽  
Vol 102 (Special_Supplement) ◽  
pp. 234-240 ◽  
Author(s):  
Chihiro Ohye ◽  
Tohru Shibazaki ◽  
Sumito Sato
Keyword(s):  
Mr Imaging ◽  
Gamma Knife ◽  
Clinical Results ◽  
Lesion Size ◽  
Lesion Volume ◽  
Thalamic Lesion ◽  
Content Type ◽  
Before And After ◽  
Single Isocenter ◽  
Fine Print

Object. The authors studied the effects of gamma knife thalamotomy (GKT) on Parkinson disease-related tremor and essential tremor before and after reloading of radioactive cobalt. Methods. Based on experience in stereotactic thalamotomy aided by depth microrecording, the target was located at the lateral border of the thalamic ventralis intermedius nucleus (VIM). For more precise targeting, the percentage representation of the thalamic VIM in relation to the entire thalamic length is useful. The location of the target was determined on magnetic resonance (MR) imaging and computerized tomography scanning. A maximum dose of 130 Gy was delivered to the target by using a single isocenter with the 4-mm collimator. In more recent cases, a systematic follow-up examination was performed at 3, 6, 12, 18, and 24 months after GKT. Since 1993, the authors have treated 70 patients with PD. Throughout the series the same dosimetric technique has been used. The course after GKT was compared between the 25 cases with PD treated before reloading and the 35 cases treated after reloading. In the majority (80–85%) treated after reloading, tremor and rigidity were reduced around 6 months after GKT. In the cases treated before reloading this effect took approximately 1 year. The thalamic reaction on MR imaging showed the same two lesion types in both series: a restricted and a diffuse. After reloading the restricted lesion was more frequent and the lesion volume was smaller. Conclusions. The shorter delay in clinical improvement and smaller lesion size may be related to an increased radiation dose.

Stereotactic radiosurgery for symptomatic solitary cerebral cavernous malformations considered high risk for resection

2010 ◽  
Vol 113 (1) ◽  
pp. 23-29 ◽  
Author(s):  
L. Dade Lunsford ◽  
Aftab A. Khan ◽  
Ajay Niranjan ◽  
Hideyuki Kano ◽  
John C. Flickinger ◽  
...  
Keyword(s):  
Mr Imaging ◽  
Stereotactic Radiosurgery ◽  
Radiation Effects ◽  
Brain Structures ◽  
Neurological Deficits ◽  
Surgical Removal ◽  
Cerebral Cavernous Malformations ◽  
Safe Procedure ◽  
Cavernous Malformations ◽  
Risk Of Hemorrhage

Object A retrospective study was conducted to reassess the benefit and safety of stereotactic radiosurgery (SRS) in patients with solitary cerebral cavernous malformations (CCMs) that bleed repeatedly and are poor candidates for surgical removal. Methods Between 1988 and 2005 at the University of Pittsburgh, the authors performed SRS in 103 evaluable patients (57 males and 46 females) with solitary symptomatic CCMs. The mean patient age was 39.3 years. Ninety-eight percent of these patients had experienced 2 or more hemorrhages associated with new neurological deficits. Seventeen patients (16.5%) had undergone attempted resection before radiosurgery. Ninety-three CCMs were located in deep brain structures and 10 were in subcortical lobar areas of functional brain importance. The median malformation volume was 1.31 ml, and the median tumor margin dose was 16 Gy. Results The follow-up ranged from 2 to 20 years. The annual hemorrhage rate—that is, a new neurological deficit associated with imaging evidence of a new hemorrhage—before SRS was 32.5%. After SRS 22 hemorrhages were observed within 2 years (10.8% annual hemorrhage rate) and 4 hemorrhages were observed after 2 years (1.06% annual hemorrhage rate). The risk of hemorrhage from a CCM was significantly reduced after radiosurgery (p < 0.0001). Overall, new neurological deficits due to adverse radiation effects following SRS developed in 14 patients (13.5%), with most occurring early in our experience. Modifications in technique (treatment volume within the T2-weighted MR imaging–defined margin, use of MR imaging, and dose reduction for CCM in critical brainstem locations) further reduced risks after SRS. Conclusions Data in this study provide further evidence that SRS is a relatively safe procedure that reduces the rebleeding rate for CCMs located in high-surgical-risk areas of the brain.

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