Integration of three-dimensional corticospinal tractography into treatment planning for gamma knife surgery

2005 ◽  
Vol 102 (4) ◽  
pp. 673-677 ◽  
Author(s):  
Keisuke Maruyama ◽  
Kyousuke Kamada ◽  
Masahiro Shin ◽  
Daisuke Itoh ◽  
Shigeki Aoki ◽  
...  
Keyword(s):  
Treatment Planning ◽  
Gamma Knife ◽  
Diffusion Tensor ◽  
Three Dimensional ◽  
Spatial Relationship ◽  
Gamma Knife Surgery ◽  
Univariate Logistic Regression Analysis ◽  
Content Type ◽  
Combined Images ◽  
Fine Print

Object. In the radiosurgical treatment of critically located lesions, the effort to minimize the risk of complication is essential. In this study the integration of diffusion-tensor (DT) imaging—based tractography was clinically applied to treatment planning for gamma knife surgery (GKS). Methods. Seven patients with cerebral arteriovenous malformations located adjacent to the corticospinal tract (CST) underwent this technique. Data provided by DT imaging were acquired before the frame was affixed to the patient's head and the CST of the DT tractography was created using our original software. Stereotactic three-dimensional imaging studies were obtained after frame fixation and then coregistered with the data from DT tractography. After image fusion of the two studies, the combined images were transported to a GKS treatment-planning workstation. The spatial relationship between the dose distribution and the CST was clearly demonstrated within the 2 hours it took to complete the entire imaging process. The univariate logistic regression analysis of transient or permanent motor complications revealed a significant independent correlation with the volume of the CST that received 25 Gy or more and with a maximum dose to the CST (p < 0.05). Conclusions. The integration of DT tractography into the GKS treatment planning was highly useful in confirming the dose to the CST during treatment planning.

Stereotactic radiosurgery versus stereotactic radiotherapy for patients with vestibular schwannoma: a Leksell Gamma Knife Society 2000 debate

2000 ◽  
Vol 93 (supplement_3) ◽  
pp. 90-92 ◽  
Author(s):  
Mark E. Linskey
Keyword(s):  
Gamma Knife ◽  
Stereotactic Radiotherapy ◽  
Three Dimensional ◽  
Late Recurrence ◽  
Vestibular Schwannomas ◽  
Tumor Control ◽  
Complication Rates ◽  
Content Type ◽  
Single Fraction ◽  
Fine Print

✓ By definition, the term “radiosurgery” refers to the delivery of a therapeutic radiation dose in a single fraction, not simply the use of stereotaxy. Multiple-fraction delivery is better termed “stereotactic radiotherapy.” There are compelling radiobiological principles supporting the biological superiority of single-fraction radiation for achieving an optimal therapeutic response for the slowly proliferating, late-responding, tissue of a schwannoma. It is axiomatic that complication avoidance requires precise three-dimensional conformality between treatment and tumor volumes. This degree of conformality can only be achieved through complex multiisocenter planning. Alternative radiosurgery devices are generally limited to delivering one to four isocenters in a single treatment session. Although they can reproduce dose plans similar in conformality to early gamma knife dose plans by using a similar number of isocenters, they cannot reproduce the conformality of modern gamma knife plans based on magnetic resonance image—targeted localization and five to 30 isocenters. A disturbing trend is developing in which institutions without nongamma knife radiosurgery (GKS) centers are championing and/or shifting to hypofractionated stereotactic radiotherapy for vestibular schwannomas. This trend appears to be driven by a desire to reduce complication rates to compete with modern GKS results by using complex multiisocenter planning. Aggressive advertising and marketing from some of these centers even paradoxically suggests biological superiority of hypofractionation approaches over single-dose radiosurgery for vestibular schwannomas. At the same time these centers continue to use the term radiosurgery to describe their hypofractionated radiotherapy approach in an apparent effort to benefit from a GKS “halo effect.” It must be reemphasized that as neurosurgeons our primary duty is to achieve permanent tumor control for our patients and not to eliminate complications at the expense of potential late recurrence. The answer to minimizing complications while maintaining maximum tumor control is improved conformality of radiosurgery dose planning and not resorting to homeopathic radiosurgery doses or hypofractionation radiotherapy schemes.

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.

Gamma knife surgery of the pituitary: new treatment for thalamic pain syndrome

2005 ◽  
Vol 102 (Special_Supplement) ◽  
pp. 38-41 ◽  
Author(s):  
Motohiro Hayashi ◽  
Takaomi Taira ◽  
Taku Ochiai ◽  
Mikhail Chernov ◽  
Yuichi Takasu ◽  
...  
Keyword(s):  
Pituitary Gland ◽  
Diabetes Insipidus ◽  
Gamma Knife ◽  
Pain Syndrome ◽  
Pain Reduction ◽  
Gamma Knife Surgery ◽  
Content Type ◽  
Thalamic Pain Syndrome ◽  
Thalamic Pain ◽  
Fine Print

Object. Although reports in the literature indicate that thalamic pain syndrome can be controlled with chemical hypophysectomy, this procedure is associated with transient diabetes insipidus. It was considered reasonable to attempt gamma knife surgery (GKS) to the pituitary gland to control thalamic pain. Methods. Inclusion criteria in this study were poststroke thalamic pain, failure of all other treatments, intolerance to general anesthetic, and the main complaint of pain and not numbness. Seventeen patients met these criteria and were treated with GKS to the pituitary. The target was the pituitary gland together with the border between the pituitary stalk and the gland. The maximum dose was 140 to 180 Gy. All patients were followed for more than 3 months. Conclusions. An initial significant pain reduction was observed in 13 (76.5%) of 17 patients. Some patients experienced pain reduction within 48 hours of treatment. Persistent pain relief for more than 1 year was observed in five (38.5%) of 13 patients. Rapid recurrence of pain in fewer than 3 months was observed in four (30.8%) of 13 patients. The only complication was transient diabetes insipidus in one patient. It would seem that GKS of the pituitary might have a role to play in thalamic pain arising after a stroke.

Tumor recurrence and survival following gamma knife surgery for brain metastases

2005 ◽  
Vol 102 (Special_Supplement) ◽  
pp. 287-288 ◽  
Author(s):  
Thomas Mindermann
Keyword(s):  
Brain Metastasis ◽  
Brain Metastases ◽  
Gamma Knife ◽  
Tumor Recurrence ◽  
Patient Survival ◽  
Gamma Knife Surgery ◽  
Recurrence Rates ◽  
Term Survival ◽  
Content Type ◽  
Fine Print

Object. The authors evaluated prognostic factors for tumor recurrence and patient survival following gamma knife surgery (GKS) for brain metastasis. Methods. A retrospective review of 101 patient charts was undertaken for those patients treated with GKS for brain metastases from 1994 to 2001. Recurrence rates of brain metastasis following GKS depended on the duration of patient survival. Long-term survival was associated with a higher risk of tumor recurrence and shorter-term survival was associated with a lower risk. The duration of survival following GKS for brain metastases seems to be characteristic of the primary disease rather than the cerebral disease. Conclusions. Recurrence rates of brain metastasis following GKS are related to duration of survival, which is in turn mostly dependent on the nature and course of the primary tumor.

Prolonged survival in a subgroup of patients with brain metastases treated by gamma knife surgery

2005 ◽  
Vol 102 (Special_Supplement) ◽  
pp. 262-265
Author(s):  
C. P. Yu ◽  
Joel Y. C. Cheung ◽  
Josie F. K. Chan ◽  
Samuel C. L. Leung ◽  
Robert T. K. Ho
Keyword(s):  
Brain Metastases ◽  
Gamma Knife ◽  
Patient Survival ◽  
Gamma Knife Surgery ◽  
Prolonged Survival ◽  
Organ Involvement ◽  
Lesion Volume ◽  
Content Type ◽  
The Mean ◽  
Fine Print

Object. The authors analyzed the factors involved in determining prolonged survival (≥ 24 months) in patients with brain metastases treated by gamma knife surgery (GKS). Methods. Between 1995 and 2003, a total of 116 patients underwent 167 GKS procedures for brain metastases. There was no special case selection. Smaller and larger lesions were treated with different protocols. The mean patient age was 56.9 years, the mean number of initial lesions was 3.15, and the mean lesion volume was 10.45 cm.3 The mean follow-up time was 9.2 months. The median patient survival was 8.68 months. One-, 2-, 3-, 4-, and 5-year actuarial survival rates were 31.8%, 19.8%, 14.6%, 7.7%, and 6.9%, respectively. Patient age, number of lesions at presentation, and lesion volume had no influence on patient survival. Twenty-three (19.8%) patients survived for 24 months or more. Certain factors were associated with increased survival time. These were stable primary disease (21 of 23 patients), a long latency between diagnosis of the primary tumor and the occurrence of brain metastases (mean 28.4 months, median 16 months), absence of third-organ involvement, and repeated local procedures. Ten patients underwent repeated GKS (mean 3.4 per patient). Seven patients required open surgery for local treatment failures (recurrence or radiation necrosis). Two patients had both. Fifteen patients underwent repeated procedures. Conclusions. Aggressive local therapy with GKS, repeated GKS, and GKS plus surgery can achieve increased survival in a subgroup of patients with stable primary disease, no third-organ involvement, and long primary-brain secondary intervals.

Gamma knife surgery of brain cavernous hemangiomas

2005 ◽  
Vol 102 (Special_Supplement) ◽  
pp. 207-213 ◽  
Author(s):  
Roman Liscák ◽  
Vilibald Vladyka ◽  
Gabriela Simonová ◽  
Josef Vymazal ◽  
Josef Novotny
Keyword(s):  
Gamma Knife ◽  
Gamma Knife Surgery ◽  
Morbidity Rate ◽  
Lesion Volume ◽  
Lower Margin ◽  
Aged Patients ◽  
Content Type ◽  
Cavernous Hemangiomas ◽  
Prescription Dose ◽  
Fine Print

Object. The authors conducted a study to record more detailed information about the natural course and factors predictive of outcome following gamma knife surgery (GKS) for cavernous hemangiomas. Methods. One hundred twelve patients with brain cavernous hemangiomas underwent GKS between 1993 and 2000. The median prescription dose was 16 Gy. One hundred seven patients were followed for a median of 48 months (range 6–114 months). The rebleeding rate was 1.6%, which is not significantly different with that prior to radiosurgery (2%). An increase in volume was observed in 1.8% of cases and a decrease in 45%. Perilesional edema was detected in 27% of patients, which, together with the rebleeding, caused a transient morbidity rate of 20.5% and permanent morbidity rate of 4.5%. Before radiosurgery 39% of patients suffered from epilepsy and this improved in 45% of them. Two patients with brainstem cavernous hemangiomas died due to rebleeding. Rebleeding was more frequent in female middle-aged patients with a history of bleeding, a larger lesion volume, and a prescription dose below 13 Gy. Edema after GKS occurred more frequently in patients who had surgery, a larger lesion volume, and in those in whom the prescription dose was more than 13 Gy. Conclusions. Gamma knife surgery of cavernous hemangiomas can produce an acceptable rate of morbidity, which can be reduced by using a lower margin dose. Lesion regression was observed in many patients. Radiosurgery seems to remain a suitable treatment modality in carefully selected patients.

Gamma knife surgery for trigeminal neuralgia: improved initial response with two isocenters and increasing dose

2005 ◽  
Vol 102 (Special_Supplement) ◽  
pp. 185-188 ◽  
Author(s):  
Tracy E. Alpert ◽  
Chung T. Chung ◽  
Lisa T. Mitchell ◽  
Charles J. Hodge ◽  
Craig T. Montgomery ◽  
...  
Keyword(s):  
Radiation Dose ◽  
Trigeminal Neuralgia ◽  
Gamma Knife ◽  
Linear Regression Analysis ◽  
Initial Response ◽  
Gamma Knife Surgery ◽  
Invasive Treatment ◽  
Content Type ◽  
Improvement Score ◽  
Fine Print

Object. The authors sought to evaluate the initial response of trigeminal neuralgia (TN) to gamma knife surgery (GKS) based on the number of shots delivered and radiation dose. Methods. Between September 1998 and September 2003, some 63 patients with TN refractory to medical or surgical management underwent GKS at Upstate Medical University. Ten patients had multiple sclerosis and 25 patients had undergone prior invasive treatment. Gamma knife surgery was delivered to the trigeminal nerve root entry zone in one shot in 27 patients or two shots in 36 patients. The radiation dose was escalated to less than or equal to 80 Gy in 20 patients, 85 Gy in 21 patients, and greater than or equal to 90 Gy in 22 patients. Pain before and after GKS was assessed using the Barrow Neurological Institute Pain Scale and the improvement score was analyzed as a function of dose grouping and number of shots. Sixty patients were available for evaluation, with an initial overall and complete response rate of 90% and 27%, respectively. There was a greater improvement score for patients who were treated with two shots compared with one shot, mean 2.83 compared with 1.72 (p < 0.001). There was an increased improvement in score at each dose escalation level: less than or equal to 80 Gy (p = 0.017), 85 Gy (p < 0.001), and greater than or equal to 90 Gy (p < 0.001). Linear regression analysis also indicated that there was a greater response with an increased dose (p = 0.021). Patients treated with two shots were more likely to receive a higher dose (p < 0.001). There were no severe complications. Five patients developed mild facial numbness. Conclusions. Gamma knife surgery is an effective therapy for TN. Initial response rates appear to correlate with the number of shots and dose.

Does gamma knife surgery stimulate cellular immune response to metastatic brain tumors? A histopathological and immunohistochemical study

2005 ◽  
Vol 102 (Special_Supplement) ◽  
pp. 180-184 ◽  
Author(s):  
György T. Szeifert ◽  
Isabelle Salmon ◽  
Sandrine Rorive ◽  
Nicolas Massager ◽  
Daniel Devriendt ◽  
...  
Keyword(s):  
Immune Response ◽  
Brain Tumors ◽  
Gamma Knife ◽  
Cellular Immune Response ◽  
Lymphocytic Infiltration ◽  
Gamma Knife Surgery ◽  
Metastatic Brain Tumors ◽  
Content Type ◽  
Cellular Immune ◽  
Fine Print

Object. The aim of this study was to analyze the cellular immune response and histopathological changes in secondary brain tumors after gamma knife surgery (GKS). Methods. Two hundred ten patients with cerebral metastases underwent GKS. Seven patients underwent subsequent craniotomy for tumor removal between 1 and 33 months after GKS. Four of these patients had one tumor, two patients had two tumors, and one patient had three. Histological and immunohistochemical investigations were performed. In addition to routine H & E and Mallory trichrome staining, immunohistochemical reactions were conducted to characterize the phenotypic nature of the cell population contributing to the tissue immune response to neoplastic deposits after radiosurgery. Light microscopy revealed an intensive lymphocytic infiltration in the parenchyma and stroma of tumor samples obtained in patients in whom surgery was performed over 6 months after GKS. Contrary to this, extensive areas of tissue necrosis with either an absent or scanty lymphoid population were observed in the poorly controlled neoplastic specimens obtained in cases in which surgery was undertaken in patients less than 6 months after GKS. Immunohistochemical characterization demonstrated the predominance of CD3-positive T cells in the lymphoid infiltration. Conclusions. Histopathological findings of the present study are consistent with a cellular immune response of natural killer cells against metastatic brain tumors, presumably stimulated by the ionizing energy of focused radiation.

Visual changes after gamma knife surgery for optic nerve tumors

2005 ◽  
Vol 102 (Special_Supplement) ◽  
pp. 143-146 ◽  
Author(s):  
Yang Kwon ◽  
Jun Seok Bae ◽  
Jae Myung Kim ◽  
Do Hee Lee ◽  
Soon Young Kim ◽  
...  
Keyword(s):  
Optic Nerve ◽  
Gamma Knife ◽  
Gamma Knife Surgery ◽  
Optic Glioma ◽  
Content Type ◽  
Nerve Sheath ◽  
Optic Nerve Sheath Meningioma ◽  
Optic Nerve Tumors ◽  
Visual Changes ◽  
Fine Print

✓ Tumors involving the optic nerve (optic glioma, optic nerve sheath meningioma) are benign but difficult to treat. Gamma knife surgery (GKS) may be a useful treatment. The authors present data obtained in three such cases and record the effects of GKS.

Optic radiation tractography integrated into simulated treatment planning for Gamma Knife surgery

2007 ◽  
Vol 107 (4) ◽  
pp. 721-726 ◽  
Author(s):  
Keisuke Maruyama ◽  
Kyousuke Kamada ◽  
Masahiro Shin ◽  
Daisuke Itoh ◽  
Yoshitaka Masutani ◽  
...  
Keyword(s):  
Visual Field ◽  
Treatment Planning ◽  
Gamma Knife ◽  
Diffusion Tensor ◽  
Maximum Dose ◽  
Gamma Knife Surgery ◽  
Optic Radiation ◽  
Imaging Studies ◽  
Visual Field Deficits ◽  
Neurological Change

Object No definitive method of preventing visual field deficits after stereotactic radiosurgery for lesions near the optic radiation (OR) has been available so far. The authors report the results of integrating OR tractography based on diffusion tensor (DT) magnetic resonance imaging into simulated treatment planning for Gamma Knife surgery (GKS). Methods Data from imaging studies performed in 10 patients who underwent GKS for treatment of arteriovenous malformations (AVMs) located adjacent to the OR were used for the simulated treatment planning. Diffusion tensor images performed without the patient's head being secured by a stereotactic frame were used for DT tractography, and the OR was visualized by means of software developed by the authors. Data from stereotactic 3D imaging studies performed after frame fixation were coregistered with the data from DT tractography. The combined images were transferred to a GKS treatment-planning workstation. Delivered doses and distances between the treated lesions and the OR were analyzed and correlated with posttreatment neurological changes. Results In patients presenting with migraine with visual aura or occipital lobe epilepsy, the OR was located within 11 mm from AVMs. In a patient who developed new quadrantanopia after GKS, the OR had received 32 Gy. A maximum dose to the OR of less than 12 Gy did not cause new visual field deficits. A maximum dose to the OR of 8 Gy or more was significantly related to neurological change (p < 0.05), including visual field deficits and development or improvement of migraine. Conclusions Integration of OR tractography into GKS represents a promising tool for preventing GKS-induced visual disturbances and headaches. Single-session irradiation at a dose of 8 Gy or more was associated with neurological change.

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