Magnetic source imaging guidance of gamma knife radiosurgery for the treatment of epilepsy

2000 ◽  
Vol 93 (supplement_3) ◽  
pp. 136-140 ◽  
Author(s):  
Joseph R. Smith ◽  
Don W. King ◽  
Yong D. Park ◽  
Mark R. Lee ◽  
Gregory P. Lee ◽  
...  
Keyword(s):  
Gamma Knife ◽  
Gamma Knife Radiosurgery ◽  
Imaging Data ◽  
Source Imaging ◽  
Magnetic Source Imaging ◽  
Content Type ◽  
Ms Imaging ◽  
Magnetic Source ◽  
Fine Print ◽  
Image Focus

Object. The purpose of this study was to determine if magnetic source (MS) imaging could provide useful information in the planning and performance of gamma knife radiosurgery (GKS) for epilepsy. Methods. Magnetic source imaging of interictal epileptiform dipoles was studied in 53 epilepsy surgery candidates. All patients underwent volumetric magnetic resonance (MR) imaging. Subsequently, magnetoencephalography (MEG) was performed using single or dual 37—channel units. The MR images and MEG recordings were then coregistered to produce the MS imaging data. Magnetic source imaging epileptiform data were reviewed in a blinded fashion and spatial distributions were classified as focal, regional, multiple, scattered, or none. Postresection operative photographs were compared with MS image results to determine whether extensive or partial/no resection of the MS image focus had been accomplished. Magnetoencephalography dipoles were identified in 47 patients (89%), in 46 of whom the lesions were resected. This included 20 (80%) of 25 anterior temporal lobe (ATL) cases, and 26 (93%) of 28 extratemporal lobe (ETL) cases. Of the six patients who underwent extensive ATL resections, three (50%) were seizure free. Of 14 patients who underwent partial/no resection of the ATL, seven (50%) were seizure free. There was no clear relation between MS image spatial distribution and surgery-related outcome. Of the seven ATL cases with hippocampal atrophy, five patients (71%) were seizure free. Of 12 ETL cases (three lesional), 10 patients (83%) were seizure free. Of 14 patients who underwent partial/no ETL resections (three lesional), two (14%) were seizure free. Of five nonlesional ETL cases with focal MS image dipoles, four patients (80%) were seizure free. Of five nonlesional ETL cases with regional dipoles, three patients (60%) were seizure free. Of eight ETL cases with multiple MS image dipoles, two patients (25%) were seizure free. Spatial agreement of MS imaging and electrographic data had no apparent effect on outcome of either ATL or ETL cases. Conclusions. Nonlesional ETL cases with focal (and in some cases multiple or regional) epileptiform MS image dipole distributions benefit significantly from inclusion of the MS image epileptiform focus in the resections. Nonlesional ETL cases suitable for GKS may similarly benefit from including the MS image focus in the irradiated area.

Magnetoencephalography-directed surgery in patients with neocortical epilepsy

2002 ◽  
Vol 97 (4) ◽  
pp. 865-873 ◽  
Author(s):  
Adam N. Mamelak ◽  
Nancy Lopez ◽  
Massoud Akhtari ◽  
W. William Sutherling
Keyword(s):  
Imaging Data ◽  
Interictal Spikes ◽  
Source Imaging ◽  
Magnetic Source Imaging ◽  
Content Type ◽  
Ms Imaging ◽  
Depth Electrodes ◽  
Magnetic Source ◽  
Neocortical Epilepsy ◽  
Fine Print

Object. Magnetoencephalography (MEG) and magnetic source (MS) imaging are techniques that have been increasingly used for preoperative localization of epileptic foci and areas of eloquent cortex. The use of MEG examinations must be carefully balanced against the high cost and technological investments required to perform these studies, particularly when less expensive alternative localization methods are available. To help elucidate the value of MEG, the authors have critically reviewed their experience with whole-head MEG in the case management of patients undergoing epilepsy surgery. Methods. The authors identified 23 patients with suspected focal epilepsy who underwent whole-head MEG and MS imaging at Huntington Memorial Hospital and, subsequently, underwent invasive intracranial electrode monitoring and electrocorticography (ECoG) to localize the zone of seizure origin for surgical resection. The results of the MS imaging were retrospectively stratified into three groups by the number of interictal spikes recorded during a 4-hour recording session: Class I (no spikes), Class II (≤ five spikes), and Class III (≥ six spikes). Class III was further subdivided according to the clustering density of the interictal spikes: Class IIIA represents a mean distance between interictal spikes of 4 mm or greater (that is, diffusely clustered) and Class IIIB represents a mean distance between interictal spikes of less than 4 mm (that is, densely clustered). The authors analyzed these groups to determine to what extent the results of MS imaging correlated with the ECoG-determined zone of seizure origin. In addition, they assessed whether the MS imaging study provided critical localization data and correlated with surgical outcome following resection. A statistical analysis of these correlations was also performed. Of the 40 patients studied, 23 underwent invasive monitoring, including 13 with neocortical epilepsy, four with mesial temporal lobe epilepsy, and six with suspected neocortical epilepsy that could not be clearly localized by ECoG. Depth electrodes were used in nine cases, subdural grids in nine cases, depth electrodes followed by subdural grids and strips in four cases, and intraoperative ECoG in one case. Electrocorticography was able to localize the zone of seizure origin in 16 (70%) of 23 cases. In 11 (69%) of the 16 cases in which ECoG was able to localize the zone of seizure origin, the interictal spikes on the MS images were classified as Class IIIB (densely clustered) and regionally correlated to the MS imaging—determined localization in all cases (that is, the same lobe). In contrast, no Class IIIB cases were identified when ECoG was unable to localize the zone of seizure origin. This difference showed a trend toward, but did not achieve, statistical significance (p < 0.23), presumably because of the relatively small number of cases available for analysis. In three cases (all Class IIIB), MS imaging was used to guide invasive electrodes to locations that otherwise would not have been targeted and provided unique localization data, not evident from other imaging modalities, that strongly influenced the surgical management of the patient. The classification of findings on MS images into subgroups and subsequent statistical analysis generated a model that predicted that Class IIIB MS imaging data are likely to provide reliable information to guide surgical placement of electrodes, but all other data groups do not provide localization information that is reliable enough to guide surgical decision making. Conclusions. Magnetic source imaging can provide unique localization information that is not available when other noninvasive methods are used. Magnetic source imaging appears most useful for cases of neocortical epilepsy. In particular, when an MS imaging study revealed six or more interictal spikes that were densely clustered in a single anatomical location, the MS image was highly correlated with the zone of seizure origin identified by ECoG. In these cases the MS imaging data may be useful to guide placement of intracranial electrodes.

Magnetic source imaging and brain surgery: presurgical and intraoperative planning in 26 patients

2000 ◽  
Vol 92 (1) ◽  
pp. 79-90 ◽  
Author(s):  
Cary D. Alberstone ◽  
Stephen L. Skirboll ◽  
Edward C. Benzel ◽  
John A. Sanders ◽  
Blaine L. Hart ◽  
...  
Keyword(s):  
Surgical Resection ◽  
Source Imaging ◽  
Magnetic Source Imaging ◽  
Content Type ◽  
Intracranial Mass ◽  
Ms Imaging ◽  
Magnetic Source ◽  
Neurosurgical Technique ◽  
Mass Lesions ◽  
Fine Print

Object. The availability of large-array biomagnetometers has led to advances in magnetoencephalography that permit scientists and clinicians to map selected brain functions onto magnetic resonance images. This merging of technologies is termed magnetic source (MS) imaging. The present study was undertaken to assess the role of MS imaging for the guidance of presurgical planning and intraoperative neurosurgical technique used in patients with intracranial mass lesions.Methods. Twenty-six patients with intracranial mass lesions underwent a medical evaluation consisting of MS imaging, a clinical history, a neurological examination, and assessment with the Karnofsky Performance Scale. Magnetic source imaging was used to locate the somatosensory cortex in 25 patients, the visual cortex in six, and the auditory cortex in four. The distance between the lesion and the functional cortex was determined for each patient.Twenty-one patients underwent a neurosurgical procedure. As a surgical adjunct, a frameless stereotactic navigational system was used in 17 cases and a standard stereotactic apparatus in four cases. Because of the results of their MS imaging examination, two patients were not offered surgery, four underwent a stereotactic biopsy procedure, 10 were treated with a subtotal surgical resection, and seven were treated with complete surgical resection. One patient deteriorated before a procedure could be scheduled and, therefore, was not offered surgery, and two patients were offered surgery but declined. Three patients experienced surgery-related complications.Conclusions. Magnetic source imaging is an important noninvasive neurodiagnostic tool that provides critical information regarding the spatial relationship of a brain lesion to functional cortex. By providing this information, MS imaging facilitates a minimum-risk management strategy and helps guide operative neurosurgical technique in patients with intracranial mass lesions.

Preoperative magnetic source imaging for brain tumor surgery: a quantitative comparison with intraoperative sensory and motor mapping

2002 ◽  
Vol 97 (6) ◽  
pp. 1333-1342 ◽  
Author(s):  
Hagen Schiffbauer ◽  
Mitchel S. Berger ◽  
Paul Ferrari ◽  
Dirk Freudenstein ◽  
Howard A. Rowley ◽  
...  
Keyword(s):  
Brain Tumors ◽  
Cortical Mapping ◽  
Volume Data ◽  
Source Imaging ◽  
Magnetic Source Imaging ◽  
Somatosensory Stimulation ◽  
Content Type ◽  
Ms Imaging ◽  
Magnetic Source ◽  
Fine Print

Object. The aim of this study was to compare quantitatively the methods of preoperative magnetic source (MS) imaging and intraoperative electrophysiological cortical mapping (ECM) in the localization of sensorimotor cortex in patients with intraaxial brain tumors. Methods. Preoperative magnetoencephalography (MEG) was performed while patients received painless tactile somatosensory stimulation of the lip, hand, and foot. The early somatosensory evoked field was modeled using a single equivalent current dipole approach to estimate the spatial source of the response. Three-dimensional magnetic resonance image volume data sets with fiducials were coregistered with the MEG recordings to form the MS image. These individualized functional brain maps were integrated into a neuronavigation system. Intraoperative mapping of somatosensory and/or motor cortex was performed and sites were compared. In two subgroups of patients we compared intraoperative somatosensory and motor stimulation sites with MS imaging—based somatosensory localizations. Mediolateral projection of the MS imaging source localizations to the cortical surface reduced systematic intermodality discrepancies. The distance between two corresponding points determined using MS imaging and ECM was 12.5 ± 1.3 mm for somatosensory—somatosensory and 19 ± 1.3 mm for somatosensory—motor comparisons. The observed 6.5 mm increase in site separation was systematically demonstrated in the anteroposterior direction, as expected from actual anatomy. In fact, intraoperative sites at which stimulation evoked the same patient response exhibited a spatial variation of 10.7 ± 0.7 mm. Conclusions. Preoperative MS imaging and intraoperative ECM show a favorable degree of quantitative correlation. Thus, MS imaging can be considered a valuable and accurate planning adjunct in the treatment of patients with intraaxial brain tumors.

Localization of language-specific cortex by using magnetic source imaging and electrical stimulation mapping

1999 ◽  
Vol 91 (5) ◽  
pp. 787-796 ◽  
Author(s):  
Panagiotis G. Simos ◽  
Andrew C. Papanicolaou ◽  
Joshua I. Breier ◽  
James W. Wheless ◽  
Jules E. C. Constantinou ◽  
...  
Keyword(s):  
Temporal Cortex ◽  
Receptive Language ◽  
Cortical Stimulation ◽  
Source Imaging ◽  
Magnetic Source Imaging ◽  
Content Type ◽  
Language Functions ◽  
Ms Imaging ◽  
Magnetic Source ◽  
Fine Print

Object. In this paper the authors demonstrate the concordance between magnetic source (MS) imaging and direct cortical stimulation for mapping receptive language cortex.Methods. In 13 consecutive surgical patients, cortex specialized for receptive language functions was identified noninvasively by obtaining activation maps aided by MS imaging in the context of visual and auditory word-recognition tasks. Surgery was then performed for treatment of medically intractable seizure disorder (eight patients), and for resection of tumor (four), or angioma (one). Mapping of language areas with cortical stimulation was performed intraoperatively in 10 patients and extraoperatively in three. Cortical stimulation mapping verified the accuracy of the MS imaging—based localization in all cases.Conclusions. Information provided by MS imaging can be especially helpful in cases of atypical language representation, including bihemispheric representation, and location of language in areas other than those expected within the dominant hemisphere, such as the anterior portion of the superior temporal gyrus, the posteroinferior portion of the middle temporal gyrus, the basal temporal cortex, and the lateral temporooccipital cortex.

Magnetic source imaging of late evoked field responses to vowels: toward an assessment of hemispheric dominance for language

2001 ◽  
Vol 94 (3) ◽  
pp. 445-453 ◽  
Author(s):  
Michael D. Szymanski ◽  
David W. Perry ◽  
Nicole M. Gage ◽  
Howard A. Rowley ◽  
John Walker ◽  
...  
Keyword(s):  
Right Hemisphere ◽  
Magnetic Resonance Images ◽  
Hemispheric Dominance ◽  
Speech Sounds ◽  
Source Imaging ◽  
Magnetic Source Imaging ◽  
Content Type ◽  
Language Dominance ◽  
Magnetic Source ◽  
Fine Print

Object. The goal of this study was to determine whether the late neuromagnetic field elicited by simple speech sounds, which is detected by magnetoencephalography, may be used to estimate hemispheric dominance for language and to guide or constrain the intraoperative search for essential language sites. If sufficiently robust, a noninvasive method for assessing hemispheric dominance for language could reduce the necessity for amobarbital testing and the extent of intraoperative cortical stimulation—based mapping, both of which carry the risk of morbidity. Methods. Fifteen patients undergoing surgery for tumors during which intraoperative language mapping would be performed and two additional patients in whom intracarotid amobarbital testing confirmed right-hemisphere language dominance participated. Following a primary auditory response sources of late neuromagnetic fields elicited by vowel stimuli were modeled and coregistered using magnetic resonance images to form magnetic source (MS) images. A laterality index (LI) was calculated by summing the number of equivalent current dipolar sources in the late fields detected from each hemisphere. In 14 right-handed patients, 10 displayed left asymmetric LIs (0.37 ± 0.16, mean ± standard error of the mean in 14 patients). For both right-hemisphere dominant patients in whom an LI was obtainable, the LI was rightward. Stimulation-mapped essential language sites were found in 7 of 15 patients. For six of these seven patients, the MS image—derived LI was leftward. Conclusions. Asymmetry in single equivalent dipole modeling of the late neuromagnetic field evoked by simple speech sounds correlates with hemispheric language dominance, although not to the degree necessary for individual clinical predictions. With further development, MS imaging of simple language tasks may be used preoperatively to predict language dominance and even to identify or constrain the intraoperative search for likely sites of essential language cortex.

Mapping of receptive language cortex in bilingual volunteers by using magnetic source imaging

2001 ◽  
Vol 95 (1) ◽  
pp. 76-81 ◽  
Author(s):  
Panagiotis G. Simos ◽  
Eduardo M. Castillo ◽  
Jack M. Fletcher ◽  
David J. Francis ◽  
Fernando Maestu ◽  
...  
Keyword(s):  
Functional Imaging ◽  
Receptive Language ◽  
Language Mapping ◽  
Source Imaging ◽  
Magnetic Source Imaging ◽  
Content Type ◽  
Magnetic Source ◽  
Practical Implications ◽  
Language Cortex ◽  
Fine Print

Object. There are conflicting claims in the functional imaging literature concerning whether different languages are represented by distinct brain mechanisms in individuals who are proficient in more than one language. This interesting theoretical issue has practical implications when functional imaging methods are used for presurgical language mapping. To address this issue the authors compared the location and extent of receptive language cortex specific to English and Spanish in neurologically intact bilingual volunteers by using magnetic source imaging. Methods. Areas of the cortex that were specialized for receptive language functions were identified separately for each language in 11 healthy adults who were bilingual in English and Spanish. The authors performed exactly the same procedures used routinely for presurgical receptive language mapping. In each bilingual individual, the receptive language—specific map always encompassed the posterior portion of the superior temporal gyrus. In every case, however, substantial differences in the receptive language maps were also observed for the two languages, regardless of whether each participant's first language was English or Spanish. Conclusions. Although the reasons for such differences and their ultimate significance in identifying the cerebral mechanisms of language are subject to continuing investigation, their presence is noteworthy and has practical implications for the surgical management of patients with lesions in the temporal and parietal regions of the dominant hemisphere.

Gamma knife radiosurgery as a single treatment modality for large cerebral arteriovenous malformations

2000 ◽  
Vol 93 (supplement_3) ◽  
pp. 113-119 ◽  
Author(s):  
D. Hung-Chi Pan ◽  
Wan-Yuo Guo ◽  
Wen-Yuh Chung ◽  
Cheng-Ying Shiau ◽  
Yue-Cune Chang ◽  
...  
Keyword(s):  
Gamma Knife ◽  
Arteriovenous Malformations ◽  
Radiation Treatment ◽  
Gamma Knife Radiosurgery ◽  
Consecutive Series ◽  
Content Type ◽  
Obliteration Rate ◽  
Complete Obliteration ◽  
Fine Print

Object. A consecutive series of 240 patients with arteriovenous malformations (AVMs) treated by gamma knife radiosurgery (GKS) between March 1993 and March 1999 was evaluated to assess the efficacy and safety of radiosurgery for cerebral AVMs larger than 10 cm3 in volume. Methods. Seventy-six patients (32%) had AVM nidus volumes of more than 10 cm3. During radiosurgery, targeting and delineation of AVM nidi were based on integrated stereotactic magnetic resonance (MR) imaging and x-ray angiography. The radiation treatment was performed using multiple small isocenters to improve conformity of the treatment volume. The mean dose inside the nidus was kept between 20 Gy and 24 Gy. The margin dose ranged between 15 to 18 Gy placed at the 55 to 60% isodose centers. Follow up ranged from 12 to 73 months. There was complete obliteration in 24 patients with an AVM volume of more than 10 cm3 and in 91 patients with an AVM volume of less than 10 cm3. The latency for complete obliteration in larger-volume AVMs was significantly longer. In Kaplan—Meier analysis, the complete obliteration rate in 40 months was 77% in AVMs with volumes between 10 to 15 cm3, as compared with 25% for AVMs with a volume of more than 15 cm3. In the latter, the obliteration rate had increased to 58% at 50 months. The follow-up MR images revealed that large-volume AVMs had higher incidences of postradiosurgical edema, petechiae, and hemorrhage. The bleeding rate before cure was 9.2% (seven of 76) for AVMs with a volume exceeding 10 cm3, and 1.8% (three of 164) for AVMs with a volume less than 10 cm3. Although focal edema was more frequently found in large AVMs, most of the cases were reversible. Permanent neurological complications were found in 3.9% (three of 76) of the patients with an AVM volume of more than 10 cm3, 3.8% (three of 80) of those with AVM volume of 3 to 10 cm3, and 2.4% (two of 84) of those with an AVM volume less than 3 cm3. These differences in complications rate were not significant. Conclusions. Recent improvement of radiosurgery in conjunction with stereotactic MR targeting and multiplanar dose planning has permitted the treatment of larger AVMs. It is suggested that gamma knife radiosurgery is effective for treating AVMs as large as 30 cm3 in volume with an acceptable risk.

Factors related to complete occlusion of arteriovenous malformations after gamma knife radiosurgery

2000 ◽  
Vol 93 (supplement_3) ◽  
pp. 96-101 ◽  
Author(s):  
Jong Hee Chang ◽  
Jin Woo Chang ◽  
Yong Gou Park ◽  
Sang Sup Chung
Keyword(s):  
Gamma Knife ◽  
Arteriovenous Malformations ◽  
Gamma Knife Radiosurgery ◽  
Maximum Diameter ◽  
Content Type ◽  
Complete Occlusion ◽  
Factors Associated ◽  
Martin Grade ◽  
Fine Print

Object. The authors sought to evaluate the effects of gamma knife radiosurgery (GKS) on cerebral arteriovenous malformations (AVMs) and the factors associated with complete occlusion. Methods. A total of 301 radiosurgical procedures for 277 cerebral AVMs were performed between December 1988 and December 1999. Two hundred seventy-eight lesions in 254 patients who were treated with GKS from May 1992 to December 1999 were analyzed. Several clinical and radiological parameters were evaluated. Conclusions. The total obliteration rate for the cases with an adequate radiological follow up of more than 2 years was 78.9%. In multivariate analysis, maximum diameter, angiographically delineated shape of the AVM nidus, and the number of draining veins significantly influenced the result of radiosurgery. In addition, margin radiation dose, Spetzler—Martin grade, and the flow pattern of the AVM nidus also had some influence on the outcome. In addition to the size, topography, and radiosurgical parameters of AVMs, it would seem to be necessary to consider the angioarchitectural and hemodynamic aspects to select proper candidates for radiosurgery.

Gamma knife radiosurgery in the management of cavernous sinus meningiomas

2000 ◽  
Vol 93 (supplement_3) ◽  
pp. 68-73 ◽  
Author(s):  
Pierre-Hugues Roche ◽  
Jean Régis ◽  
Henry Dufour ◽  
Henri-Dominique Fournier ◽  
Christine Delsanti ◽  
...  
Keyword(s):  
Mr Imaging ◽  
Tumor Growth ◽  
Gamma Knife ◽  
Cavernous Sinus ◽  
Gamma Knife Radiosurgery ◽  
Surgical Removal ◽  
Content Type ◽  
Cavernous Sinus Meningioma ◽  
The Mean ◽  
Fine Print

Object. The authors sought to assess the functional tolerance and tumor control rate of cavernous sinus meningiomas treated by gamma knife radiosurgery (GKS). Methods. Between July 1992 and October 1998, 92 patients harboring benign cavernous sinus meningiomas underwent GKS. The present study is concerned with the first 80 consecutive patients (63 women and 17 men). Gamma knife radiosurgery was performed as an alternative to surgical removal in 50 cases and as an adjuvant to microsurgery in 30 cases. The mean patient age was 49 years (range 6–71 years). The mean tumor volume was 5.8 cm3 (range 0.9–18.6 cm3). On magnetic resonance (MR) imaging the tumor was confined in 66 cases and extensive in 14 cases. The mean prescription dose was 28 Gy (range 12–50 Gy), delivered with an average of eight isocenters (range two–18). The median peripheral isodose was 50% (range 30–70%). Patients were evaluated at 6 months, and at 1, 2, 3, 5, and 7 years after GKS. The median follow-up period was 30.5 months (range 12–79 months). Tumor stabilization after GKS was noted in 51 patients, tumor shrinkage in 25 patients, and enlargement in four patients requiring surgical removal in two cases. The 5-year actuarial progression-free survival was 92.8%. No new oculomotor deficit was observed. Among the 54 patients with oculomotor nerve deficits, 15 improved, eight recovered, and one worsened. Among the 13 patients with trigeminal neuralgia, one worsened (contemporary of tumor growing), five remained unchanged, four improved, and three recovered. In a patient with a remnant surrounding the optic nerve and preoperative low vision (3/10) the decision was to treat the lesion and deliberately sacrifice the residual visual acuity. Only one transient unexpected optic neuropathy has been observed. One case of delayed intracavernous carotid artery occlusion occurred 3 months after GKS, without permanent deficit. Another patient presented with partial complex seizures 18 months after GKS. All cases of tumor growth and neurological deficits observed after GKS occurred before the use of GammaPlan. Since the initiation of systematic use of stereotactic MR imaging and computer-assisted modern dose planning, no more side effects or cases of tumor growth have occurred. Conclusions. Gamma knife radiosurgery was found to be an effective low morbidity—related tool for the treatment of cavernous sinus meningioma. In a significant number of patients, oculomotor functional restoration was observed. The treatment appears to be an alternative to surgical removal of confined enclosed cavernous sinus meningioma and should be proposed as an adjuvant to surgery in case of extensive meningiomas.

Gamma knife radiosurgery for craniopharyngiomas

2000 ◽  
Vol 93 (supplement_3) ◽  
pp. 47-56 ◽  
Author(s):  
Wen-Yuh Chung ◽  
David Hung-Chi Pan ◽  
Cheng-Ying Shiau ◽  
Wan-Yuo Guo ◽  
Ling-Wei Wang
Keyword(s):  
Clinical Outcome ◽  
Gamma Knife ◽  
Tumor Volume ◽  
Gamma Knife Radiosurgery ◽  
Tumor Control ◽  
Content Type ◽  
Stereotactic Aspiration ◽  
Cystic Component ◽  
The Mean ◽  
Fine Print

Object. The goal of this study was to elucidate the role of gamma knife radiosurgery (GKS) and adjuvant stereotactic procedures by assessing the outcome of 31 consecutive patients harboring craniopharyngiomas treated between March 1993 and December 1999. Methods. There were 31 consecutive patients with craniopharyngiomas: 18 were men and 13 were women. The mean age was 32 years (range 3–69 years). The mean tumor volume was 9 cm3 (range 0.3–28 cm3). The prescription dose to the tumor margin varied from 9.5 to 16 Gy. The visual pathways received 8 Gy or less. Three patients underwent stereotactic aspiration to decompress the cystic component before GKS. The tumor response was classified by percentage reduction of tumor volume as calculated based on magnetic resonance imaging studies. Clinical outcome was evaluated according to improvement and dependence on replacement therapy. An initial postoperative volume increase with enlargement of a cystic component was found in three patients. They were treated by adjuvant stereotactic aspiration and/or Ommaya reservoir implantation. Tumor control was achieved in 87% of patients and 84% had fair to excellent clinical outcome in an average follow-up period of 36 months. Treatment failure due to uncontrolled tumor progression was seen in four patients at 26, 33, 49, and 55 months, respectively, after GKS. Only one patient was found to have a mildly restricted visual field; no additional endocrinological impairment or neurological deterioration could be attributed to the treatment. There was no treatment-related mortality. Conclusions. Multimodality management of patients with craniopharyngiomas seemed to provide a better quality of patient survival and greater long-term tumor control. It is suggested that GKS accompanied by adjuvant stereotactic procedures should be used as an alternative in treating recurrent or residual craniopharyngiomas if further microsurgical excision cannot promise a cure.

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