Krefeld, Germany
Krefeld, Germany

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MacK A.,Gamma Knife Center | Von Briel C.,Klinik Hirslanden | Curschmann J.,Klinik Hirslanden | Gruber G.,Klinik Hirslanden | And 6 more authors.
Radiosurgery | Year: 2010

Background: Given the high mechanical accuracy of the Leksell Gamma Knife®, the most sensitive technical factor having an influence on the overall precision of radiosurgery is still imaging (mainly MRI). The new generation of MRI scanners, with field strengths up to 3.0 T, deliver promising image quality with regard to anatomical resolution and contrast, but critical features are the sensitivity to susceptibility and chemical shift effects which both create artifacts. Changes in the magnetic properties of the ferromagnetic plates can cause additional problems in the z direction. Methods: All sequences from all scanners to be investigated were defined automatically and manually (upper, middle and lower block) in light-guided plates. After the procedure of definition the geometric imaging quality of the 3.0-T MRI-Scanner (Siemens 'Trio') was analyzed and compared to a Siemens Magnetom 'Expert' 1.0 T and to a Philips 'Gyroscan' 1.5 T. The analyses were performed in three steps: (1) the evaluation of the magnitude of error was performed within transversal slices in two orientations (axial/coronal) using a cylindrical phantom with an embedded grid; (2) the deviations were determined for 21 targets in a slab phantom with known geometrical positions within the stereotactic frame, and (3) distortions caused by chemical shift and/or susceptibility effects were analyzed in a head-phantom. In-house developed software was used for data analyses. Results: For all scanners tested, the 3D-volume scan is the most sensitive to a z shift. For scan times > 10 min the shift can increase to several millimeters in the z direction. SE sequences are rather insensitive but show up with a small shift in the y direction. The 3.0-T MRI-Scanner was analyzed using sequences in axial and coronal orientations. The mean deviation was < 0.3 mm in the axial and < 0.4 mm in the coronal orientation. For the known targets the maximum deviation came up to 1.18 mm (far from the center). Due to inhomogeneities an additional shift in the z direction up to 1.5 mm was observed for a dataset which was shown compressed by 1.2 mm. By optimizing the parameters in the protocol these inaccuracies could be reduced to < 1.1 mm. Conclusions: The 3.0-T scanner showed sophisticated anatomical contrast and resolution in comparison to the established 1.0- and 1.5-T scanners. However, due to the high field strength the field within the head coil is very sensitive to inhomogeneities and therefore 3.0-T imaging data still have to be handled with care. Long scan times especially for the 3D-volume sequences lead to a warming up and to a change in the magnetic properties of the ferromagnetic plates which cause an additional effect on the main-field B0 thus disturbing the z gradient. © 2010 S. Karger AG.


Tuleasca C.,Gamma Knife center | Tuleasca C.,Medical image analysis laboratory MIAL | Tuleasca C.,Ecole Polytechnique Federale de Lausanne | Tuleasca C.,University of Lausanne | And 10 more authors.
Neurochirurgie | Year: 2015

Biphasic response (shrinkage-regrowth-shrinkage) of tumors has never previously been reported in the postoperative course, neither after microsurgery, nor after Gamma Knife surgery (GKS). We present the case of an adult with dorsal midbrain syndrome resulting from a pilocytic astrocytoma centered on the mesencephalic tectum. The tumor extended to the third ventricle and the thalamus. Initially, due to tumor growth, a biopsy was performed and histology established. Later, a ventriculocisternostomy for obstructive hydrocephalus was performed. Finally, GKS was performed, as the tumor continued to grow. After GKS, the lesion exhibited a biphasic response, with a major shrinkage at 3 months, regrowth within the target volume at 6 and 9 months and a second phase of important shrinkage at 12 months, which persisted for the next two years. The possible mechanisms for this particular response pattern are discussed. © 2015 Elsevier Masson SAS.


PubMed | University of Pennsylvania, New York University, Cleveland Clinic, Gamma Knife Center and 4 more.
Type: Journal Article | Journal: Journal of neurosurgery | Year: 2016

OBJECTIVE In this multicenter study, the authors reviewed the results following Gamma Knife radiosurgery (GKRS) of cerebral arteriovenous malformations (AVMs), determined predictors of outcome, and assessed predictive value of commonly used grading scales based upon this large cohort with long-term follow-up. METHODS Data from a cohort of 2236 patients undergoing GKRS for cerebral AVMs were compiled from the International Gamma Knife Research Foundation. Favorable outcome was defined as AVM obliteration and no posttreatment hemorrhage or permanent symptomatic radiation-induced complications. Patient and AVM characteristics were assessed to determine predictors of outcome, and commonly used grading scales were assessed. RESULTS The mean maximum AVM diameter was 2.3 cm, with a mean volume of 4.3 cm


PubMed | Shinsuma Hospital, Komaki City Hospital, Kyoto Prefectural University of Medicine, Southern Research Institute and 18 more.
Type: Journal Article | Journal: Journal of neurosurgery | Year: 2016

OBJECTIVE In 1999, the World Health Organization categorized large cell neuroendocrine carcinoma (LCNEC) of the lung as a variant of large cell carcinoma, and LCNEC now accounts for 3% of all lung cancers. Although LCNEC is categorized among the non-small cell lung cancers, its biological behavior has recently been suggested to be very similar to that of a small cell pulmonary malignancy. The clinical outcome for patients with LCNEC is generally poor, and the optimal treatment for this malignancy has not yet been established. Little information is available regarding management of LCNEC patients with brain metastases (METs). This study aimed to evaluate the efficacy of Gamma Knife radiosurgery (GKRS) for patients with brain METs from LCNEC. METHODS The Japanese Leksell Gamma Knife Society planned this retrospective study in which 21 Gamma Knife centers in Japan participated. Data from 101 patients were reviewed for this study. Most of the patients with LCNEC were men (80%), and the mean age was 67 years (range 39-84 years). Primary lung tumors were reported as well controlled in one-third of the patients. More than half of the patients had extracranial METs. Brain metastasis and lung cancer had been detected simultaneously in 25% of the patients. Before GKRS, brain METs had manifested with neurological symptoms in 37 patients. Additionally, prior to GKRS, resection was performed in 17 patients and radiation therapy in 10. A small cell lung carcinoma-based chemotherapy regimen was chosen for 48 patients. The median lesion number was 3 (range 1-33). The median cumulative tumor volume was 3.5 cm


Biewald E.,University of Duisburg - Essen | Lautner H.,University of Duisburg - Essen | Gok M.,University of Duisburg - Essen | Horstmann G.A.,Gamma Knife Center | And 3 more authors.
British Journal of Ophthalmology | Year: 2016

Background To report eye salvaging rate, visual acuity (VA), local recurrences, complications and the potential benefit of adjuvant brachytherapy after endoresection of large uveal melanomas. Methods 200 patients were included in this retrospective study. They were treated from March 1999 to December 2010 with preoperative stereotactic gamma knife radiosurgery followed by endoresection and adjuvant brachytherapy in most cases. Results A total of 200 patients were included in this study (113 male, 87 female). Mean tumour height was 9.4 mm and the largest basal diameter ranged from 6.3 to 20 mm. The median follow-up time was 32.3 months. In 13.4% the eye was retained with a VA of 20/50 or better, in 33.6% VA was ranging from 20/400 to 20/50 and 53% had a VA of less than 20/400. In almost 90% of the cases the eye was preserved at the final visit. In 15.5% additional major surgery was required. In terms of survival 15.5% of our patients developed liver metastases during follow-up and died. Local tumour recurrence was observed in 10 out of 200 patients (5%) and was mainly treated with enucleation. The use of an adjuvant ruthenium-106 plaque did not lower the recurrence or enucleation rate significantly. Conclusions Eyes with a large uveal melanoma can be preserved by stereotactic radiotherapy followed by endoresection with the chance to obtain useful vision in approximately half of the cases. Adjuvant brachytherapy has no beneficial effect except a reduction of the frequency for major revision surgery. © 2016 by the BMJ Publishing Group Ltd.


PubMed | Gamma Knife Center and University of Duisburg - Essen
Type: | Journal: The British journal of ophthalmology | Year: 2016

To report eye salvaging rate, visual acuity (VA), local recurrences, complications and the potential benefit of adjuvant brachytherapy after endoresection of large uveal melanomas.200 patients were included in this retrospective study. They were treated from March 1999 to December 2010 with preoperative stereotactic gamma knife radiosurgery followed by endoresection and adjuvant brachytherapy in most cases.A total of 200 patients were included in this study (113 male, 87 female). Mean tumour height was 9.4mm and the largest basal diameter ranged from 6.3 to 20mm. The median follow-up time was 32.3months. In 13.4% the eye was retained with a VA of 20/50 or better, in 33.6% VA was ranging from 20/400 to 20/50 and 53% had a VA of less than 20/400. In almost 90% of the cases the eye was preserved at the final visit. In 15.5% additional major surgery was required. In terms of survival 15.5% of our patients developed liver metastases during follow-up and died. Local tumour recurrence was observed in 10 out of 200 patients (5%) and was mainly treated with enucleation. The use of an adjuvant ruthenium-106 plaque did not lower the recurrence or enucleation rate significantly.Eyes with a large uveal melanoma can be preserved by stereotactic radiotherapy followed by endoresection with the chance to obtain useful vision in approximately half of the cases. Adjuvant brachytherapy has no beneficial effect except a reduction of the frequency for major revision surgery.


Kliesch S.,University of Greifswald | Vogelgesang S.,University of Greifswald | Benecke R.,University of Rostock | Horstmann G.A.,Gamma Knife Center | Schroeder H.W.S.,University of Greifswald
Zentralblatt fur Neurochirurgie | Year: 2010

Case Report: We present a patient with an unusual malignant brain oedema occurring after gamma knife radiosurgery of a medium-sized vestibular schwannoma. Clinical presentation: A 62-year-old female with a large vestibular schwannoma underwent partial microsurgical resection; 6 months later she underwent a second intervention with gamma knife radiosurgery for a medium-sized tumour remnant. With a latency period of 6 months after radiosurgery, she presented with progressive neurological deterioration. Serial magnetic resonance imaging revealed progression of the tumour and of the perifocal oedema which finally extended up to the ipsilateral internal capsule. The patient became comatose. Intervention: The tumour was nearly completely removed via a standard retrosigmoid craniotomy. Histopathological examination demonstrated increased mitotic activity compared to the initial histology. The patient became conscious 10 days after surgery and recovered slowly. Surprisingly, the brain oedema resolved rapidly. The CT scan obtained 11 days after surgery showed almost complete disappearance of the oedema. Conclusion: Although rare, radiosurgery of medium-sized vestibular schwannomas causing brainstem compression may lead to life-threatening tumour progression and malignant brain oedema. Therefore, microsurgical gross total resection should be the preferred treatment option in vestibular schwannomas causing significant brainstem compression.


Golanov A.V.,Burdenko Neurosurgical Institute | Banov S.M.,Gamma Knife Center | Il'yalov S.R.,Gamma Knife Center | Trunin Y.Y.,Burdenko Neurosurgical Institute | And 6 more authors.
Zhurnal voprosy neĭrokhirurgii imeni N. N. Burdenko | Year: 2016

UNLABELLED: The study purpose was to evaluate the impact of gamma knife radiosurgery (GKRS) alone on the overall survival and rate of intracranial recurrences in brain metastasis patients.MATERIAL AND METHODS: Treatment outcomes in 502 patients (211 males and 291 females with 2782 brain metastases (BMs)) were retrospectively reviewed. Most patients (n=142; 28.2%) were diagnosed with breast cancer. Multiple BMs were detected in 259 patients (51.6%). The median of the total tumor volume and ВM number was 5.9 cm3 (0.09-44.5 cm3) and 4 (1-36), respectively. The mean marginal radiation dose was 21 Gy (15-24 Gy). The mean follow-up period was 10.6 months (0.2-47.2 months).RESULTS: The overall survival rate for 12 and 24 months was 37.6 and 19.1%, respectively. The median overall survival after GKRS was 8.6 months (95% confidence interval (CI) 7.0-10.0). Local control of metastatic lesions was achieved in 78.8% of patients. The median local recurrence-free survival was 6.8 months after radiosurgery. The development of new (distant) metastases was observed in 49.5% of patients. The median distant metastasis-free time was 8.8 months. The Karnofsky performance score (KPS) of ≥80 (HR 0.3935, 95% CI 0.2429-0.6376; p=0.0002), BM number of <3 (HR 0.6138, 95% CI 0.3993-0.9943; p=0.0269), and BMs of breast and lung cancers (HR 0.5442, 95% CI 0.3642-0.8071; p=0.0027) are predictors of better survival. In the case of intracranial metastasis recurrence, repeated radiosurgery provides the median overall survival of 19.6 months versus 9.6 months in patients without radiosurgery (HR 0.4026, 95% CI 0.2381-0.6809).CONCLUSION: Radiosurgical treatment of patients with multiple BMs provides the median overall survival of 8.6 months. A good functional status, non-extensive metastasis of the brain, and radiosensitive morphology of the primary tumor are the predictors of better survival. Repeated radiosurgical treatment for intracranial recurrences provides longer overall survival compared to that in patients without repeated radiosurgical treatment.Abstract available from the publisher.


PubMed | Gamma Knife Center and Burdenko Neurosurgical Institute
Type: Journal Article | Journal: Zhurnal voprosy neirokhirurgii imeni N. N. Burdenko | Year: 2016

The study purpose was to evaluate the impact of gamma knife radiosurgery (GKRS) alone on the overall survival and rate of intracranial recurrences in brain metastasis patients.Treatment outcomes in 502 patients (211 males and 291 females with 2782 brain metastases (BMs)) were retrospectively reviewed. Most patients (n=142; 28.2%) were diagnosed with breast cancer. Multiple BMs were detected in 259 patients (51.6%). The median of the total tumor volume and M number was 5.9 cm3 (0.09-44.5 cm3) and 4 (1-36), respectively. The mean marginal radiation dose was 21 Gy (15-24 Gy). The mean follow-up period was 10.6 months (0.2-47.2 months).The overall survival rate for 12 and 24 months was 37.6 and 19.1%, respectively. The median overall survival after GKRS was 8.6 months (95% confidence interval (CI) 7.0-10.0). Local control of metastatic lesions was achieved in 78.8% of patients. The median local recurrence-free survival was 6.8 months after radiosurgery. The development of new (distant) metastases was observed in 49.5% of patients. The median distant metastasis-free time was 8.8 months. The Karnofsky performance score (KPS) of 80 (HR 0.3935, 95% CI 0.2429-0.6376; p=0.0002), BM number of <3 (HR 0.6138, 95% CI 0.3993-0.9943; p=0.0269), and BMs of breast and lung cancers (HR 0.5442, 95% CI 0.3642-0.8071; p=0.0027) are predictors of better survival. In the case of intracranial metastasis recurrence, repeated radiosurgery provides the median overall survival of 19.6 months versus 9.6 months in patients without radiosurgery (HR 0.4026, 95% CI 0.2381-0.6809).Radiosurgical treatment of patients with multiple BMs provides the median overall survival of 8.6 months. A good functional status, non-extensive metastasis of the brain, and radiosensitive morphology of the primary tumor are the predictors of better survival. Repeated radiosurgical treatment for intracranial recurrences provides longer overall survival compared to that in patients without repeated radiosurgical treatment.


PubMed | Gamma Knife Center and Institute Jules Bordet
Type: | Journal: Surgical neurology international | Year: 2015

Gamma Knife (GK) surgery is a recognized treatment option for the management of small to medium-sized vestibular schwannoma (VS) associated with high-tumor control and low morbidity. When a radiosurgical treatment fails to stop tumor growth, repeat GK surgery can be proposed in selected cases.A series of 27 GK retreatments was performed in 25 patients with VS; 2 patients underwent three procedures. The median time interval between GK treatments was 45 months. The median margin dose used for the first, second, and third GK treatments was 12 Gy, 12 Gy, and 14 Gy, respectively. Six patients (4 patients for the second irradiation and 2 patients for the third irradiation) with partial tumor regrowth were treated only on the growing part of the tumor using a median margin dose of 13 Gy. The median tumor volume was 0.9, 2.3, and 0.7 cc for the first, second, and third treatments, respectively. Stereotactic positron emission tomography (PET) guidance was used for dose planning in 6 cases.Mean follow-up duration was 46 months (range 24-110). At the last follow-up, 85% of schwannomas were controlled. The tumor volume decreased, remained unchanged, or increased after retreatment in 15, 8, and 4 cases, respectively. Four patients had PET during follow-up, and all showed a significant metabolic decrease of the tumor. Hearing was not preserved after retreatment in any patients. New facial or trigeminal palsy did not occur after retreatment.Our results support the long-term efficacy and low morbidity of repeat GK treatment for selected patients with tumor growth after initial treatment.

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