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.

Stereotactic radiosurgery for pilocytic astrocytomas when multimodality therapy is necessary

2002 ◽  
Vol 97 (1) ◽  
pp. 56-64 ◽  
Author(s):  
Constantinos G. Hadjipanayis ◽  
Douglas Kondziolka ◽  
Paul Gardner ◽  
Ajay Niranjan ◽  
Shekhar Dagam ◽  
...  
Keyword(s):  
Tumor Progression ◽  
Stereotactic Radiosurgery ◽  
Multimodal Treatment ◽  
Tumor Volume ◽  
Parietal Lobe ◽  
Optic Tract ◽  
Content Type ◽  
Pilocytic Astrocytomas ◽  
Fine Print

Object. The goal of this study was to examine the role of stereotactic radiosurgery in the treatment of patients with recurrent or unresectable pilocytic astrocytomas. Methods. During a 13-year interval, 37 patients (median age 14 years) required multimodal treatment of recurrent or unresectable pilocytic astrocytomas. Tumors involved the brainstem in 18 patients, cerebellum in three, thalamus in five, temporal lobe in four, and parietal lobe in two, as well as the hypothalamus, optic tract, corpus callosum, insular cortex, and third ventricle in one patient each. Diagnosis was confirmed with the aid of stereotactic biopsy in 12 patients, open biopsy in five, partial resection in eight, and near-total resection in 12. Multimodal treatment included fractionated radiation therapy in 10 patients, stereotactic intracavitary irradiation of tumor in four, chemotherapy in two, cyst drainage in six, ventriculoperitoneal shunt placement in three, and additional cytoreductive surgery in four. Tumor volumes varied from 0.42 to 25 cm3. The median radiosurgical dose to the tumor margin was 15 Gy (range 9.6–22.5 Gy). After radiosurgery, serial imaging demonstrated complete tumor resolution in 10 patients, reduced tumor volume in eight, stable tumor volume in seven, and delayed tumor progression in 12. No procedure-related death was encountered. Thirty-three (89%) of 37 patients are alive at a median follow-up period of 28 months after radiosurgery and 59 months after diagnosis. Eight patients participated in follow-up review for more than 60 months. Three patients died of local tumor progression. Conclusions. Stereotactic radiosurgery is a valuable adjunctive strategy in the management of recurrent or unresectable pilocytic astrocytomas. Despite the favorable histological characteristics and prognosis usually associated with this neoplasm, an adverse location, recurrence, or progression of this disease requires alternative therapeutic approaches such as radiosurgery.

Gamma knife surgery for vestibular schwannoma: 10-year experience of 195 cases

2005 ◽  
Vol 102 (Special_Supplement) ◽  
pp. 87-97 ◽  
Author(s):  
Wen-Yuh Chung ◽  
Kang-Du Liu ◽  
Cheng-Ying Shiau ◽  
Hsiu-Mei Wu ◽  
Ling-Wei Wang ◽  
...  
Keyword(s):  
Mr Imaging ◽  
Gamma Knife ◽  
Vestibular Schwannoma ◽  
Tumor Volume ◽  
Radiation Effect ◽  
Gamma Knife Surgery ◽  
Homogeneous Distribution ◽  
Content Type ◽  
Fine Print

Object. The authors conducted a study to determine the optimal radiation dose for vestibular schwannoma (VS) and to examine the histopathology in cases of treatment failure for better understanding of the effects of irradiation. Methods. A retrospective study was performed of 195 patients with VS; there were 113 female and 82 male patients whose mean age was 51 years (range 11–82 years). Seventy-two patients (37%) had undergone partial or total excision of their tumor prior to gamma knife surgery (GKS). The mean tumor volume was 4.1 cm3 (range 0.04–23.1 cm3). Multiisocenter dose planning placed a prescription dose of 11 to 18.2 Gy on the 50 to 94% isodose located at the tumor margin. Clinical and magnetic resonance (MR) imaging follow-up evaluations were performed every 6 months. A loss of central enhancement was demonstrated on MR imaging in 69.5% of the patients. At the latest MR imaging assessment decreased or stable tumor volume was demonstrated in 93.6% of the patients. During a median follow-up period of 31 months resection was avoided in 96.8% of cases. Uncontrolled tumor swelling was noted in five patients at 3.5, 17, 24, 33, and 62 months after GKS, respectively. Twelve of 20 patients retained serviceable hearing. Two patients experienced a temporary facial palsy. Two patients developed a new trigeminal neuralgia. There was no treatment-related death. Histopathological examination of specimens in three cases (one at 62 months after GKS) revealed a long-lasting radiation effect on vessels inside the tumor. Conclusions. Radiosurgery had a long-term radiation effect on VSs for up to 5 years. A margin 12-Gy dose with homogeneous distribution is effective in preventing tumor progression, while posing no serious threat to normal cranial nerve function.

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.

Preliminary results of linear accelerator radiosurgery for acoustic schwannomas

1996 ◽  
Vol 85 (6) ◽  
pp. 1013-1019 ◽  
Author(s):  
William M. Mendenhall ◽  
William A. Friedman ◽  
John M. Buatti ◽  
Francis J. Bova
Keyword(s):  
Stereotactic Radiosurgery ◽  
Local Control ◽  
Linear Accelerator ◽  
Local Control Rate ◽  
Magnetic Resonance Images ◽  
High Rate ◽  
Content Type ◽  
Treatment Volume ◽  
Fine Print

✓ In this paper the authors evaluate the results of linear accelerator (LINAC)—based stereotactic radiosurgery for acoustic schwannomas. Fifty-six patients underwent LINAC-based stereotactic radiosurgery for acoustic schwannomas at the University of Florida between July 1988 and November 1994. Each patient was followed for a minimum of 1 year or until death; no patient was lost to follow up. One or more follow-up magnetic resonance images or computerized tomography scans were obtained in 52 of the 56 patients. Doses ranged between 10 and 22.5 Gy with 69.6% of patients receiving 12.5 to 15 Gy. Thirty-eight patients (68%) were treated with one isocenter and the dose was specified to the 80% isodose line in 71% of patients. Fifty-five patients (98%) achieved local control after treatment. The 5-year actuarial local control rate was 95%. At the time of analysis, 48 patients were alive and free of disease, seven had died of intercurrent disease, and one was alive with disease. Complications developed in 13 patients (23%). The likelihood of complications was related to the dose and treatment volume: 10 to 12.5 Gy to all volumes, three (13%) of 23 patients; 15 to 17.5 Gy to 5.5 cm3 or less, two (9%) of 23 patients; 15 to 17.5 Gy to more than 5.5 cm3, five (71%) of seven patients; and 20 to 22.5 Gy to all volumes, three (100%) of three patients. Linear accelerator—based stereotactic radiosurgery results in a high rate of local control at 5 years. The risk of complications is related to the dose and treatment volume.

Dose—response tolerance of the visual pathways and cranial nerves of the cavernous sinus to stereotactic radiosurgery

1998 ◽  
Vol 88 (1) ◽  
pp. 43-50 ◽  
Author(s):  
Klaus A. Leber ◽  
Jutta Berglöff ◽  
Gerhard Pendl
Keyword(s):  
Stereotactic Radiosurgery ◽  
Cavernous Sinus ◽  
Dose Response ◽  
Cranial Nerves ◽  
Visual Pathways ◽  
Content Type ◽  
Number Of Patients ◽  
Response Tolerance ◽  
Fine Print

As the number of patients treated with stereotactic radiosurgery increases, it becomes particularly important to define with precision adverse effects on distinct structures of the nervous system. Object. This study was designed to assess the dose—response tolerance of the visual pathways and cranial nerves after exposure of the cavernous sinus to radiation. Methods. A total of 66 sites in the visual system and 210 cranial nerves of the middle cranial fossa were investigated in 50 patients who had undergone gamma knife treatment for benign skull base tumors. The mean follow-up period was 40 months (range 24–60 months). Follow-up examinations consisted of neurological, neuroradiological, and neuroophthalmological evaluations. The actuarial incidence of optic neuropathy was zero for patients who received a radiation dose of less than 10 Gy, 26.7% for patients receiving a dose in the range of 10 to less than 15 Gy, and 77.8% for those who received doses of 15 Gy or more (p < 0.0001). Previously impaired vision improved in 25.8% and was unchanged in 51.5% of patients. No sign of neuropathy was seen in patients whose cranial nerves of the cavernous sinus received radiation doses of between 5 and 30 Gy. Because tumor control appeared to have been achieved in 98% of the patients, the deterioration in visual function cannot be attributed to tumor progression. Conclusions. The structures of the visual pathways (the optic nerve, chiasm, and tract) exhibit a much higher sensitivity to single-fraction radiation than other cranial nerves, and their particular dose—response characteristics can be defined. In contrast, the oculomotor and trigeminal nerves have a much higher dose tolerance.

Results of combined stereotactic radiosurgery and transarterial embolization for dural arteriovenous fistulas of the transverse and sigmoid sinuses

2001 ◽  
Vol 94 (6) ◽  
pp. 886-891 ◽  
Author(s):  
Jonathan A. Friedman ◽  
Bruce E. Pollock ◽  
Douglas A. Nichols ◽  
Deborah A. Gorman ◽  
Robert L. Foote ◽  
...  
Keyword(s):  
Stereotactic Radiosurgery ◽  
Transarterial Embolization ◽  
Symptom Relief ◽  
Related Complication ◽  
Content Type ◽  
Arteriovenous Fistulas ◽  
Dural Arteriovenous Fistulas ◽  
Lost To Follow Up ◽  
Fine Print

Object. Most dural arteriovenous fistulas (DAVFs) of the transverse and sigmoid sinuses do not have angiographically demonstrated features associated with intracranial hemorrhage and, therefore, may be treated nonsurgically. The authors report their experience using a staged combination of radiosurgery and transarterial embolization for treating DAVFs involving the transverse and sigmoid sinuses. Methods. Between 1991 and 1998, 25 patients with DAVFs of the transverse and/or sigmoid sinuses were treated using stereotactic radiosurgery; 22 of these patients also underwent transarterial embolization. Two patients were lost to follow-up review. Clinical data, angiographic findings, and follow-up records for the remaining 23 patients were collected prospectively. The mean duration of clinical follow up after radiosurgery was 50 months (range 20–99 months). The 18 women and five men included in this series had a mean age of 57 years (range 33–79 years). Twenty-two (96%) of 23 patients presented with pulsatile tinnitus as the primary symptom; two patients had experienced an earlier intracerebral hemorrhage (ICH). Cognard classifications of the DAVFs included the following: I in 12 patients (52%), IIa in seven patients (30%), and III in four patients (17%). After treatment, symptoms resolved (20 patients) or improved significantly (two patients) in 96% of patients. One patient was clinically unchanged. No patient sustained an ICH or irradiation-related complication during the follow-up period. Seventeen patients underwent follow-up angiographic studies at a mean of 21 months after radiosurgery (range 11–38 months). Total or near-total obliteration (> 90%) was seen in 11 patients (65%), and more than a 50% reduction in six patients (35%). Two patients experienced recurrent tinnitus and underwent repeated radiosurgery and embolization at 21 and 38 months, respectively, after the first procedure. Conclusions. A staged combination of radiosurgery and transarterial embolization provides excellent symptom relief and a good angiographically verified cure rate for patients harboring low-risk DAVFs of the transverse and sigmoid sinuses. This combined approach is a safe and effective treatment strategy for patients without angiographically determined risk factors for hemorrhage and for elderly patients with significant comorbidities.

Graft subsidence after instrument-assisted anterior cervical fusion

2002 ◽  
Vol 97 (2) ◽  
pp. 186-192 ◽  
Author(s):  
Gary W. Tye ◽  
R. Scott Graham ◽  
William C. Broaddus ◽  
Harold F. Young
Keyword(s):  
Smoking Status ◽  
Reoperation Rate ◽  
Anterior Cervical Fusion ◽  
Neurological Deficits ◽  
Cervical Fusion ◽  
Content Type ◽  
Plate Length ◽  
Graft Subsidence ◽  
Fine Print

Object. Bone grafts used in anterior cervical fusion (ACF) may subside postoperatively. The authors reviewed a recent series in which instrument-assisted ACF was performed to determine the degree of subsidence with respect to fusion length, use of segmental screws, and patient smoking status, age, and sex. Methods. Charts and implant records were reviewed for all 70 patients who underwent instrument-assisted ACF during a 2-year period. The procedures, grafting materials, plate types/lengths, and patient smoking status were recorded. The immediate postoperative and follow-up lateral radiographs were analyzed. The plate lengths and lengths of the fused segments were measured in a standardized fashion. The mean intraoperative and follow-up fusion segment lengths were 54.3 and 51.9 mm, respectively. Greater subsidence occurred in multilevel fusions than in single-level fusions. There were noticeable changes in the position of plates or screws on 14 of 70 follow-up x-ray films. No new neurological deficits related to graft subsidence occurred, and the reoperation rate was 3%. There was no statistical relation between subsidence and the following variables: segmental fixation, smoking status, sex, age, or dowel size when corrected for length of the plate. Hardware migration correlated significantly with plate length in cases of two- and three-level fusions. Conclusions. The length of a fusion segment decreases in the immediate weeks following instrument-assisted ACF. Construct length is the most important determinant of subsidence. When designing multilevel cervical constructs, consideration of the effects of graft subsidence may help to avoid hardware-related complications.

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.

Characterization of perioperative seizures and epilepsy following aneurysmal subarachnoid hemorrhage

2003 ◽  
Vol 99 (6) ◽  
pp. 978-985 ◽  
Author(s):  
Chih-Lung Lin ◽  
Aaron S. Dumont ◽  
Ann-Shung Lieu ◽  
Chen-Po Yen ◽  
Shiuh-Lin Hwang ◽  
...  
Keyword(s):  
Subarachnoid Hemorrhage ◽  
Predictive Factors ◽  
Aneurysmal Subarachnoid Hemorrhage ◽  
Neurological Deficits ◽  
Loss Of Consciousness ◽  
Content Type ◽  
Fisher Grade ◽  
The Mean ◽  
Fine Print

Object. The reported incidence, timing, and predictive factors of perioperative seizures and epilepsy after subarachnoid hemorrhage (SAH) have differed considerably because of a lack of uniform definitions and variable follow-up periods. In this study the authors evaluate the incidence, temporal course, and predictive factors of perioperative seizures and epilepsy during long-term follow up of patients with SAH who underwent surgical treatment. Methods. Two hundred seventeen patients who survived more than 2 years after surgery for ruptured intracranial aneurysms were enrolled and retrospectively studied. Episodes were categorized into onset seizures (≤ 12 hours of initial hemorrhage), preoperative seizures, postoperative seizures, and late epilepsy, according to their timing. The mean follow-up time was 78.7 months (range 24–157 months). Forty-six patients (21.2%) had at least one seizure post-SAH. Seventeen patients (7.8%) had onset seizures, five (2.3%) had preoperative seizures, four (1.8%) had postoperative seizures, 21 (9.7%) had at least one seizure episode after the 1st week postoperatively, and late epilepsy developed in 15 (6.9%). One (3.8%) of 26 patients with perioperative seizures (onset, preoperative, or postoperative seizure) had late epilepsy at follow up. The mean latency between the operation and the onset of late epilepsy was 8.3 months (range 0.3–19 months). Younger age (< 40 years old), loss of consciousness of more than 1 hour at ictus, and Fisher Grade 3 or greater on computerized tomography scans proved to be significantly related to onset seizures. Onset seizure was also a significant predictor of persistent neurological deficits (Glasgow Outcome Scale Scores 2–4) at follow up. Factors associated with the development of late epilepsy were loss of consciousness of more than 1 hour at ictus and persistent postoperative neurological deficit. Conclusions. Although up to one fifth of patients experienced seizure(s) after SAH, more than half had seizure(s) during the perioperative period. The frequency of late epilepsy in patients with perioperative seizures (7.8%) was not significantly higher than those without such seizures (6.8%). Perioperative seizures did not recur frequently and were not a significant predictor for late epilepsy.

CyberKnife frameless single-fraction stereotactic radiosurgery for benign tumors of the spine

2003 ◽  
Vol 14 (5) ◽  
pp. 1-5 ◽  
Author(s):  
Peter C. Gerszten ◽  
Cihat Ozhasoglu ◽  
Steven A. Burton ◽  
William J. Vogel ◽  
Barbara A. Atkins ◽  
...  
Keyword(s):  
Stereotactic Radiosurgery ◽  
Tumor Volume ◽  
Surgical Techniques ◽  
Outpatient Setting ◽  
Neurological Deficits ◽  
Benign Tumors ◽  
Minimal Risk ◽  
Single Fraction ◽  
Spinal Lesions

Object The role of stereotactic radiosurgery in the treatment of benign intracranial lesions is well established. Its role in the treatment of benign spinal lesions is more limited. Benign spinal lesions should be amenable to radiosurgical treatment similar to their intracranial counterparts. In this study the authors evaluated the effectiveness of the CyberKnife for benign spinal lesions involving a single-fraction radiosurgical technique. Methods The CyberKnife is a frameless radiosurgery system in which an orthogonal pair of x-ray cameras is coupled to a dynamically manipulated robot-mounted linear accelerator possessing six degrees of freedom, whereby the therapy beam is guided to the intended target without the use of frame-based fixation. Cervical spine lesions were located and tracked relative to skull osseous landmarks; lower spinal lesions were tracked relative to percutaneously placed fiducial bone markers. Fifteen patients underwent single-fraction radiosurgery (12 cervical, one thoracic, and two lumbar). Histological types included neurofibroma (five cases), paraganglioma (three cases), schwannoma (two cases), meningioma (two cases), spinal chordoma (two cases), and hemangioma (one case). Radiation dose plans were calculated based on computerized tomography scans acquired using 1.25-mm slices. Planning treatment volume was defined as the radiographic tumor volume with no margin. The tumor dose was maintained at 12 to 20 Gy to the 80% isodose line (mean 16 Gy). Tumor volume ranged from 0.3 to 29.3 ml (mean 6.4 ml). Spinal canal volume receiving more than 8 Gy ranged from 0.0 to 0.9 ml (mean 0.2 ml). All patients tolerated the procedure in an outpatient setting. No acute radiation-induced toxicity or new neurological deficits occurred during the follow-up period. Pain improved in all patients who were symptomatic prior to treatment. No tumor progression has been documented on follow-up imaging (mean 12 months). Conclusions Spinal stereotactic radiosurgery was found to be feasible, safe, and effective for the treatment of benign spinal lesions. Its major potential benefits are the relatively short treatment time in an outpatient setting and the minimal risk of side effects. This new technique offers an alternative therapeutic modality for the treatment of a variety of benign spinal neoplasms in cases in which surgery cannot be performed, in cases with previously irradiated sites, and in cases involving lesions not amenable to open surgical techniques or as an adjunct to surgery.

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