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ABSTRACT: Radiosurgery has become an accepted treatment option for vestibular schwannomas. Nevertheless, predictors of tumor control and treatment toxicity in current radiosurgery of vestibular schwannomas are not well understood. To generate new information on predictors of tumor control and cranial nerve toxicity of single-fraction radiosurgery of vestibular schwannomas, we conducted a single-institution long-term observational study of radiosurgery for sporadic vestibular schwannomas. Minimum follow-up was 3 years. Investigated as potential predictors of tumor control and cranial nerve toxicity were treatment technology; tumor resection preceding radiosurgery; tumor size; gender; patient age; history of cancer, vascular disease, or metabolic disease; tumor volume; radiosurgical prescription dose; and isodose line. Three hundred eighty-six patients met inclusion criteria. Treatment failure was observed in 27 patients. History of unrelated cancer (strongest predictor) and prescription dose significantly predicted tumor control. The cumulative incidence of treatment failure was 30% after 6.5 years in patients with unrelated malignancy and 10% after ≥15 years in patients without such cancer (P < .02). Tumor volume was the only predictor of trigeminal neuropathy (observed in 6 patients). No predictor of facial nerve toxicity was found. On the House and Brackmann scale, 1 patient had a permanent one-level drop and 7 a transient drop of 1 to 3 levels. Serviceable hearing was preserved in 75.1%. Tumor hearing before radiosurgery, recurrence, and prescription isodose predicted ototoxicity. Unrelated malignancy is a strong predictor of tumor control. Tumor recurrence predominantly predicts ototoxicity. These findings potentially will aid future clinical decision making in ambiguous cases.
Neuro-Oncology 05/2012; 14(7):902-9. · 5.72 Impact Factor
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ABSTRACT: PurposeThe development of the CyberKnife technology, a combination of image guidance and industrial robotics, led to a paradigm shift
in radiosurgery.
Materials and methodsThe CyberKnife Robotic Radiosurgery System consists of a 6-MV compact LINAC mounted on a computer-controlled robotic manipulator
capable of 6 degrees of freedom, with a dedicated image-guidance system which acquires X-ray images during treatment. Apart
from standard neurosurgical indications (i.e., acoustic neurinomas, meningiomas, brain metastases, etc.) radiosurgical applications
are currently evolving to include extracranial indications such as tumors of the spine, pancreas, lung, and liver. We reviewed
the indications and outcomes in the first 1,000 patients treated in the CyberKnife Center Munich. Single-dose treatment was
chosen because published clinical studies have demonstrated high efficacy and low morbidity for intracranial and spinal tumors.
A recent development in radiosurgery is breathing-triggered real-time correction for respiratory motion of tumors, which makes
it possible to apply radiosurgical doses to moving targets. CyberKnife treatment is designed to be delivered on an outpatient
basis, mostly consisting of a single treatment session lasting between 60 and 90min. High quality imaging is of utmost importance
for successful radiosurgical applications. For example, high-field MRI, multislice CT’s, PET and PET-CT imaging data must
be integrated in the planning phase for optimal target definition.
ResultsA total of 750 patients with brain tumors were treated at the CyberKnife Center Munich in cooperation with the Department
of Neurosurgery of the University Munich. A total of 285 patients with brain metastases received 339 treatments for 780 brain
metastases. The first 55 spinal tumor patients were analyzed and have a mean follow-up of 14months (out of 200 spinal tumor
patients treated at our facility). Efficacy was high and complications minimal for all patient groups.
ConclusionCyberKnife radiosurgery technology may be used as a primary treatment modality or in multidisciplinary cancer therapy. Patient
selection, high quality diagnostic imaging and consideration of alternative modes of therapy are key issues in optimizing
the benefits of CyberKnife treatment.
International Journal of Computer Assisted Radiology and Surgery 04/2012; 3(5):447-456. · 1.48 Impact Factor
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International journal of radiation oncology, biology, physics 03/2012; 82(4):1324. · 4.59 Impact Factor
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ABSTRACT: Classic radiosurgery is a neurosurgical treatment concept for single-fraction irradiation of cerebral lesions not amenable to open surgery. Until recently it has been realized mainly by frame-based technologies (Gamma Knife; stereotactic linear accelerators). The CyberKnife described in 1997 is an image-guided frameless robotic technology for whole-body radiosurgery. It can be used for classic single-fraction radiosurgery and for hypofractionated treatments. The CyberKnife treatment procedure is completely non-invasive and can be repeated throughout the body if necessary. Brain metastases are an important and frequently treated indication of modern radiosurgery. Data concerning radiosurgical treatment of brain metastases with the CyberKnife are reviewed. Scientific evidence shows that the full-body applicability of the CyberKnife is not at the expense of an inferior intracranial treatment quality when compared to standard frame-based technology. The clinical results of CyberKnife single-fraction radiosurgery are in line with the published literature. The attractive therapeutic profile of CyberKnife radiosurgery is reflected by a high tumor control and a low toxicity and the repeatability of the treatments for recurrent metastases. Although hypofractionated treatments (in 3-5 fractions) of brain metastases have been performed with the CyberKnife to treat large metastases, the clinical significance of this new radiosurgical concept is unclear and requires further study. A new approach is to treat the resection cavity with radiosurgery after surgical removal of brain metastases. In this concept radiosurgery replaces fractionated radiation therapy as an adjunct to surgery. The initial results are very promising. The CyberKnife has been established as a modern non-invasive technology for intra- and extracranial radiosurgery. It adds to the oncological armamentarium and confers upon radiosurgery a greater emphasis as an oncological treatment concept.
Progress in neurological surgery 01/2012; 25:201-9.
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ABSTRACT: Conventional external beam radiotherapy is a standard procedure for treatment of spinal metastases. In case of progression spinal cord tolerance limits further radiotherapy in pre-irradiated areas. Spinal stereotactic radiotherapy is a non-invasive option to re-treat pre-irradiated patients. Nevertheless, spinal radiosurgery results in relevant dose deposition within the myelon with potential toxicity. Aim of the study was to retrospectively analyse the efficacy and feasibility for salvage radiosurgery of spinal metastases.
During a period of 4 years (2005-2009) 70 lesions in 54 patients were treated in 60 radiosurgery sessions and retrospectively analysed. Clinical (pain, sensory and motor deficit) and radiological (CT/MRI) follow-up data were collected prospectively after radiosurgery. Pain - as main symptom - was classified by the Visual Analogue Scale (VAS) score. Every patient received single session radiosurgery after having been treated first-line with conventionally fractionated radiotherapy. Kaplan-Meier method and life tables were used to analyse freedom from local failure and overall survival.
At a median follow-up of 14.5 months the actuarial rates of freedom from local failure at 6/12/18 months were 93%, 88% and 85%, respectively. The median radiosurgery dose was 1 × 18 Gy (range 10-28 Gy) to the median 70% isodose. The VAS score of patients with pain (median 6) dropped significantly (median 4, p = 0.002). In 6 out of 7 patients worse sensory or motor deficit after SRS was caused by local or distant failures (diagnosed by CT/MRI). One patient with metastatic renal cell carcinoma developed a progressive complete paraparesis one year after the last treatment at lumbar level L3. Due to multiple surgery and radiosurgery treatments at the lumbar region and further local progression, the exact reason remained unclear. Apart from that, no CTC grade III or higher toxicity has been observed.
By applying spinal radiosurgery relevant radiation doses can be limited to small parts of the myelon. This prevents myelopathic side effects and makes it an effective and safe treatment option for well-suited patients. Especially for previously irradiated patients with local failure or pain salvage SRS represents a valuable treatment option with high local control rates, low toxicity and significant pain reduction.
Radiation Oncology 12/2011; 6:173. · 2.32 Impact Factor
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ABSTRACT: OBJECTIVE: To determine the safety and feasibility after image-guided single fraction robotic stereotactic radiosurgery (SRS) in patients with bone metastases of prostate cancer. MATERIALS: andmethods: Forty patients with 64 bone metastases of prostate cancer were prospectively enrolled in a single center study and underwent 54 consecutive outpatient single session SRS procedures during a 4-year period. F-18 choline PET/CT in addition to standard CT imaging was done prior to SRS in all patients. Nineteen patients were under anti-androgen therapy, 8 patients had undergone chemotherapy before SRS. Overall survival and freedom from local tumor recurrence was analyzed with the Kaplan-Meier method. RESULTS: Mean follow-up was 14 months (3-48 months). Seventy-five percent of patients had a single bone metastasis. The median tumor volume was 13 cc. The mean prescribed tumor dose was 20.2 Gy (16.5-22 Gy). Eight patients had died at the time point of the data analysis. The actuarial 6-months, 12-months, and 24-months local tumor control rate was 95.5% (95% CI: 83.0-98.8) as measured by MRI and PET CT imaging. The median initial PSA before SRS was 5.4 ng/dl (CI: 1.4-8.2) and dropped to 2.7 ng/dl (CI: 0.14-10) after 3 months. One case of progressive neurological deficits was documented. CONCLUSIONS: This first report on single session, image-guided robotic SRS documents a safe, feasible, and patient-friendly treatment option in selected patients with bone metastases of prostate cancer.
Urologic Oncology 04/2011; · 3.22 Impact Factor
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ABSTRACT: The image-guided CyberKnife radiosurgery system is apable of tracking spinal targets without fiducial implants. Recently, a new version of this fiducial-free image guidance modality ("enhanced Xsight spine tracking") has been introduced. We assessed the accuracy of this novel technique versus its precursor in a comparative phantom study. The CyberKnife consists of a 6 MV linac on a six-axis robot and a stereoscopic kV image guidance system. An anthropomorphic head-and-neck phantom with a cervical spine section was mounted on the linac nozzle. The robotic manipulator was used to precisely move the phantom to defined positions in the CyberKnife workspace. Multiple stereoscopic images were acquired at different translational and rotational positions. The enhanced Xsight spine tracking readouts were recorded and compared to the nominal phantom position. These tests were repeated with the original Xsight spine tracking version to analyze potential differences. Enhanced Xsight spine tracking correctly reported translational offsets with an RMS error of less than 0.4 mm. Yaw and roll rotations were detected with an accuracy of 0.2°, 0.25°. Pitch offsets were slightly underestimated, with up to 0.3° for an offset of ± 2°. Nominal X (left-right) translational offsets were partially misinterpreted as roll (0.2° at a 10 mm offset). Apart from this, no correlation between rotational and translational directions was found. In comparison, the original Xsight spine tracking showed identical results for translations, but larger systematic and statistical errors for rotations. Enhanced Xsight spine tracking measurably improves precision in fiducial-free spinal radiosurgery with the CyberKnife.
Journal of Applied Clinical Medical Physics 01/2011; 12(2):3446. · 1.29 Impact Factor
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ABSTRACT: Objectives: Patients with vestibular schwannoma (VS) frequently suffer from disabling vestibular symptoms. This prospective follow-up study evaluates vestibular and auditory function and impairment of quality of life due to vertigo, dizziness, and imbalance in patients with unilateral VS of different sizes before/after microsurgical or radiosurgical treatment. Methods: Thirty-eight patients with unilateral VS were included. Twenty-two received microsurgery, 16 CyberKnife radiosurgery. Two follow-ups took place after a median of 50 and 186.5 days. Patients received a standardized neuro-ophthalmological examination, electronystagmography with bithermal caloric testing, and pure-tone audiometry. Quality of life was evaluated with the Dizziness Handicap Inventory (DHI). Patient data was grouped and analyzed according to the size of the VS (group 1: <20 mm vs group 2: ≥20 mm). Results: In group 1, the median loss of vestibular function was +10.5% as calculated by Jongkees Formula (range -43 to +52; group 2: median +36%, range -56 to +90). The median change of DHI scores was -9 in group 1 (range -68 to 30) and +2 in group 2 (-54;+20). Median loss of hearing was 4 dB (-42; 93) in group 1 and 12 dB in group 2 (5; 42). Conclusion: Loss of vestibular function in VS clearly correlates with tumor size. However, loss of vestibular function was not strictly associated with a long-term deterioration of quality of life. This may be due to central compensation of vestibular deficits in long-standing large tumors. Loss of hearing before treatment was significantly influenced by the age of the patient but not by tumor size. At follow-up 1 and 2, hearing was significantly influenced by the size of the VS and the manner of treatment.
Frontiers in neurology. 01/2011; 2:55.
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ABSTRACT: • To analyse the safety and efficacy of simultaneous standard anti-angiogenic therapy and stereotactic radiosurgery (SRS) in patients with spinal and cerebral metastases from renal cell carcinoma.
• In all, 106 patients with spinal (n= 55) or cerebral (n= 51) metastatic lesions and an Eastern Cooperative Oncology Group status of 0 or 1 were treated with sorafenib or sunitinib and simultaneous SRS. • The primary endpoint was local control. • Secondary endpoints were toxicity and overall survival.
• Median follow up was 14.7 months (range 1-42 months). Forty-five patients were treated with sunitinb and 61 patients with sorafenib. Two patients had asymptomatic tumour haemorrhage after SRS. • No skin toxicity, neurotoxicity or myelopathy occurred after SRS, and SRS did not alter the adverse effects of anti-angiogenic therapy. • Local tumour control 15 months after SRS was 98% (95% confidence interval 89-99%). The median pain score before SRS was 5 (range 1-8) and was lowered to 0 (range 0-2, P < 0.01) after SRS. There were no treatment-related deaths or late complications after SRS. • Overall survival was 17.4 months in patients with spinal lesions and 11.1 month in patients with cerebral lesions (P= 0.038).
• Simultaneous systemic anti-angiogenic therapy and SRS for selected patients with renal cell carcinoma who have spinal and cerebral metastases is safe and effective. • Single-fraction delivery allows for efficacious integration of focal radiation treatment into oncological treatment concepts without additional toxicity. • Further studies are needed to determine the limits of SRS for renal cell carcinoma metastases outside the brain and spine.
BJU International 12/2010; 108(5):673-8. · 2.84 Impact Factor
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ABSTRACT: To evaluate clinical targeting precision and assess patient movement data during fiducial-free, single-fraction spinal radiosurgery with the Cyberknife (CK).
Image-guided spine tracking accuracy was tested using two phantoms. Movement patterns (three translations, roll, pitch and yaw) were obtained from log files of 260 patient treatments (47 cervical, 89 thoracic, 90 lumbar, and 34 pelvic/sacral). For two treatments (average and maximum motion scenario), we added offsets to all beams according to recorded patient movements and recalculated the delivered dose distribution to simulate the dosimetric impact of intrafraction motion.
Phantom spine position was registered with an accuracy of <0.2 mm for translational and <0.3° for rotational directions. Residual patient motion yielded mean targeting errors per beam of 0.28 ± 0.13 mm (X), 0.25 ± 0.15 mm (Y), 0.19 ± 0.11 mm (Z) and 0.40 ± 0.20° (roll), 0.20 ± 0.08° (pitch), and 0.19 ± 0.08° (yaw). Spine region had little influence on overall targeting error, which was <1 mm for more than 95% of treatments (median, 0.48 mm). In the maximum motion case, target coverage decreased by 1.7% (from 92.1% to 90.4%) for the 20-Gy prescription isodose. Spinal cord volume receiving more than 8 Gy increased slightly, from 2.41 to 2.46 cm(3).
Submillimeter targeting precision was obtained for fiducial-free spinal radiosurgery despite patient motion. Patient motion has little effect on the delivered dose distribution when image-guided correction of beam aiming is employed.
International journal of radiation oncology, biology, physics 11/2010; 78(3):937-45. · 4.59 Impact Factor
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ABSTRACT: We prospectively analyzed the safety and outcome of frameless image-guided robotic stereotactic radiosurgery (SRS) for treatment of brain metastases in patients that would have otherwise been treated with frame-based techniques. During a three-year period, 333 patients with 783 brain metastases of various histologies underwent 391 outpatient SRS procedures. Fifty-five percent of patients had multiple brain metastases. The median (mean) tumor volume was 1.0 cc (2.7 cc). The mean prescribed tumor dose was 18.5 Gy (+/-1.3 Gy). Local/distant tumor recurrences were treated by additional SRS for patients with stable systemic disease. Survival and freedom from local tumor recurrence was analyzed with the Kaplan-Meier method. Prognostic factors were obtained from the Cox proportional hazards model. System accuracy tests (end-to-end tests) were performed with a standard head phantom. Overall median survival was 12.2 months after SRS. The actuarial one-year local control rate was 95.2% (95% CI: 92.0-97.2); the distant brain tumor control rate was 67% (95% CI: 61.0-71.2). Most patients died from systemically progressing cancer (69%). A Karnofsky performance score (KPS) > 70 was related to prolonged survival in the univariate and multivariate analysis. Recursive partition analysis (RPA) classes I and II were related to prolonged survival in the univariate analysis. Twenty-one patients (6.3%) developed treatment-related neurotoxic effects; no patient died because of complications of SRS. Forty-five end-to-end tests documented a mean targeting accuracy of 0.48 +/- 0.22 mm. Single-session, frameless robotic SRS is feasible, accurate, and safe in selected patients with brain metastases of various primary tumors. There seems to be no difference in patient selection, adverse effects, treatment outcomes, or system accuracy compared with frame-based SRS.
Journal of Neuro-Oncology 10/2009; 97(2):267-74. · 3.21 Impact Factor
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ABSTRACT: Radiosurgery is a non-invasive treatment for many spinal tumors. Sacral radiosurgery, however, requires invasive fiducial marker insertion to target and track the tumor's position. We present preliminary clinical results and phantom accuracy measurements of sacral radiosurgery using fiducial-free alignment based on vertebral anatomy distant to tumor location.
Fifty-one lesions in 38 patients were treated using fiducial-free spinal tracking of the L5 vertebra. An anthropomorphic phantom was used for accuracy measurements of this approach. Dose planning was based on 1.0mm computer tomography slices using inverse treatment planning.
Tracked targets were up to 17cm from the treated tumor. Phantom tests produced an overall mean targeting error of 1.43mm (+/-0.47mm). Patient median follow-up was 12.7months. Local tumor control was 95%. Treatment doses were 12-25Gy with a median prescription isodose of 65% (40-70%) and tumor volumes between 1.3 and 152.8cc. No short-term adverse events were noted during the follow-up period.
Fiducial-free tracking of the lower lumbar vertebrae is a feasible, accurate, and reliable tool for radiosurgery of sacral and pelvic tumors. It is a valuable novel alternative to surgical procedures and conventional fractionated radiation therapy for these challenging cases.
Radiotherapy and Oncology 07/2009; 93(1):37-44. · 5.58 Impact Factor
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ABSTRACT: To investigate the time-dependent obliteration of cerebral arteriovenous malformations (cAVM) after CyberKnife radiosurgery (CKRS) (Accuray, Inc., Sunnyvale, CA) by means of sequential 3-T, 3-dimensional (3D), time-of-flight (TOF) magnetic resonance angiography (MRA), and volumetry of the arteriovenous malformation (AVM) nidus.
In this prospective study, 3D TOF MRA was performed on 20 patients with cAVMs treated by single-fraction CKRS. Three-dimensional TOF MRA was performed on a 3-T, 32-channel magnetic resonance scanner (Magnetom TIM Trio; Siemens Medical Solutions, Erlangen, Germany) with isotropic voxel size at a spatial resolution of 0.6 x 0.6 x 0.6 mm3. The time-dependent relative decay of the transnidal blood flow evidenced by 3D TOF MRA was referred to as "obliteration dynamics." Volumetry of the nidus size was performed with OsiriX imaging software (OsiriX Foundation, Geneva, Switzerland). All patients had 3 to 4 follow-up examinations at 3- to 6-month intervals over a minimum follow-up period of 9 months. Subtotal obliteration was determined if the residual nidus volume was 5% or less of the initial nidus volume. Stata/IC software (Version 10.0; Stata Corp., College Station, TX) was used for statistical analysis and to identify potential factors of AVM obliteration.
Regarding their clinical status, case history, and pretreatments, the participants of this study represent difficult-to-treat cAVM patients. The median nidus volume was 1.8 mL (range, 0.4-12.5 mL); the median minimum dose prescribed to the nidus was 22 Gy (range, 16-24 Gy) delivered to the 67% isodose line (range, 55-80%). CKRS was well tolerated, with complications in 2 patients. No further hemorrhages occurred after RS, except 1 small and clinically inapparent incident. The median follow-up period after RS was 25.0 months (range, 11.7-36.8 months). After RS, a statistically significant obliteration was observed in all patients. However, the obliteration dynamics of the cAVMs showed a pronounced variability, with 2 types of post-therapeutic behavior identified. cAVMs of Group A showed a faster reduction of transnidal blood flow than cAVMs in Group B. The median time to subtotal obliteration was 23.8 months for all patients, 11.6 months for patients in Group A, and 27.8 months for patients in Group B (P = 0.05). Logistic regression analysis revealed dose homogeneity and the circumscribed isodose to be the only variables (P < 0.01) associated with the obliteration dynamics in this study. The cumulative complete angiographic obliteration rate was 67% (95% confidence interval, 32-95%) 2 years after RS.
The use of sequential 3D TOF MRA at 3 T and nidus volumetry enables a noninvasive quantitative assessment of the dynamic obliteration process induced by CKRS in cAVMs. This method may be helpful to identify factors related to AVM obliteration after RS when larger patient cohorts become available.
Neurosurgery 03/2009; 64(2 Suppl):A102-9. · 2.79 Impact Factor
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ABSTRACT: Radiosurgery is a special treatment method that employs highly focused radiation to destroy tumors with high precision in a single session. A broad base of scientific evidence already exists for the radiosurgical treatment of brain metastases. Recent advances in medical technology now allow radiosurgery to be extended to the spine as well.
Selective literature review based on a PubMed search using the search terms stereotaxis, radiosurgery, stereotactic radiotherapy, accuracy, quality assurance, spine, spine metastasis, pain, Novalis, CyberKnife, Synergy, and robotics. We also present and analyze our own data as an illustration of the application of spinal radiosurgery.
The literature search identified 20 scientific original publications and one recent review. The data indicate that, within the specific constraints of the method, radiosurgery can arrest the growth of up to 96% of spinal metastases. Durable pain relief can be achieved in patients with tumor-associated pain syndromes. The morbidity of spinal radiosurgery is low, with a less than 1% risk of myelopathy.
Spinal radiosurgery is an independent, essentially noninvasive method of treatment. Different types of radiosurgical treatment apparatus are available. For properly selected patients, radiosurgery offers a good chance of therapeutic success with relatively rare complications.
03/2009; 106(7):106-12. · 2.92 Impact Factor
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ABSTRACT: A comparison of treatment parameters and quality of clinical outcome in patients with single brain metastases treated with two different technologies for radiosurgery (Gamma Knife and CyberKnife).
Treatment parameters were statistically analyzed. Clinical outcome was assessed by matched-pair analysis based on the treatment device, differences in dose prescription, and the date of the treatment. Patients were matched according to their tumor size, age, gender, primary cancer, and Radiation Therapy Oncology Group score. Survival post-radiosurgery, local and distant tumor control, and complications were analyzed. Predictive factors were investigated.
423 single brain metastases were treated with Gamma Knife and 73 with CyberKnife. Tumor volumes were similar. The parameters minimum tumor dose, maximum tumor dose, prescription isodose volume, conformality index, homogeneity index, volume of tissue receiving a dose of 10 Gy or more were significantly larger in Gamma Knife group. Sixty-three patients were good matches. These showed the same pattern in parameters. Concerning the outcome analysis, only overall survival differed significantly between groups, twice as long with CyberKnife (P < 0.03). According to pooled data, dose was predictive of local failure, whole brain radiation therapy and chemotherapy were predictive of toxicity, the Radiation Therapy Oncology Group score was predictive of survival after radiosurgery, and date of treatment was predictive of overall survival. No factor predicted new brain metastases, including whole brain radiation therapy.
The most important result of this study was the finding that the obvious differences in treatment-related parameters between Gamma Knife and CyberKnife had no impact on the quality of the clinical outcome after radiosurgery. Survival time increased chronologically, presumably due to an intensified anti-cancer therapy in the more recent era of the CyberKnife treatments.
Journal of Neuro-Oncology 02/2009; 94(1):69-77. · 3.21 Impact Factor
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ABSTRACT: A prospective interventional case-series study.
To provide clinical results of CyberKnife fiducial-free spinal radiosurgery. The study focused on patients with no more than 2 malignant spinal tumors.
Progress in frameless radiosurgical technology has enabled the application of radiosurgery to the spine. The CyberKnife System has been used extensively for spine radiosurgery. Until recently, the system required metallic fiducial implants for precise target tracking. Fiducial-free spinal radiosurgery with the CyberKnife has recently become possible, but until now clinical results obtained with this method had been limited.
From August 2005 until October 2007, a consecutive series of 102 patients with a total of 134 malignant spinal tumors were selected for single-fraction, fiducial-free CyberKnife radiosurgery (CKRS). The study was limited to patients with a maximum of 2 tumors. Malignant primaries included breast cancer in 23 (22.6%) patients, renal cancer in 20 (19.6%) patients, gastro-intestinal cancers in 12 (11.8%) patients, prostate cancer each in 12 (11.8%) patients, lung cancer in 9 (8.9%) patients, sarcomas in 7 (6.9%) patients. A variety of other malignant tumors were found in 19 (18.6%) patients. Patients with spinal cord compression or evidence of myelopathy were excluded. The sequential neurologic status was recorded. Tumor-associated spinal pain was prospectively scored according to the visual analogue scale (VAS).
Of 102 individuals, 22 (21.6%) died due to progression of their systemic disease. Mean survival after CKRS was 1.4 years (CI: 1.2-1.6). Karnofsky performance score was the only independent predictor of survival after radiosurgery on log-rank test (P < 0.0001), and on Cox regression analysis (hazard ratio, 0.864, P < 0.0001, CI: 0.809-0.922). Median survival after initial tumor diagnosis was 18.4 years (CI: 15.1-23.4). Two (2%) patients suffered complications after radiosurgery; a tumor hemorrhage occurred in one, and another developed spinal instability. These and 2 other patients were stabilized by kyphoplasty. Neurotoxicity or myelopathy was not observed. Local tumor control 15 months after CKRS was 98% (95% CI: 89-99%). Tumor-associated pain was observed in 52 (51%) patients. In these patients the median pretreatment pain score of VAS = 7 (95% CI: 6-7) was significantly reduced to VAS = 1 (95% CI: 4-6) (P < 0.001) within 1 week after CKRS. Analysis of variance identified the initial pain score as the only significant variable to predict pain reduction after CKRS (P < 0.03). Pain recurrence in correlation with tumor recurrence was observed for 3 (6%) patients.
Spinal radiosurgery with the CyberKnife technology is a nonivasive, safe, and effective treatment method for patients with 1 or 2 small spinal malignant tumors. The best benefit of the treatment can be expected in patients with good to excellent clinical condition and patients with severe tumor associated pain.
Spine 12/2008; 33(26):2929-34. · 2.08 Impact Factor
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ABSTRACT: Is Gamma Knife surgery alone as effective as surgery plus whole brain irradiation (WBRT) for patients with a single, small-sized brain metastasis?
Patients aged between 18 and 80 years harboring a single, resectable metastasis < or =3 cm in diameter, a Karnofsky performance score (KPS) > or =70, and a stable systemic disease were randomly assigned to microsurgery plus WBRT or Gamma Knife surgery alone. The primary end point was length of survival, secondary end points were recurrence of tumor in the brain, health related quality of life, and treatment related toxicity.
Due to poor patient accrual, the study was stopped prematurely. The final analysis was based on 33 patients in the surgery and 31 patients in the radiosurgery group. Treatment results did not differ in terms of survival (P = 0.8), neurological death rates (P = 0.3), and freedom from local recurrence (P = 0.06). Patients of the radiosurgery group experienced more often distant recurrences (P = 0.04); after adjustment for the effects of salvage radiosurgery this difference was lost (P = 0.4). Radiosurgery was associated with a shorter hospital stay, less frequent and shorter timed steroid application (P < or = 0.001), and lower frequency of grade 1/2 toxicities (according to the RTOG/EORTC CNS toxicity criteria, P < or = 0.01). Improved scores for role functioning and quality of life were seen 6 weeks after radiosurgery (P < 0.05); this difference was lost 6 months after treatment.
In patients harboring a single, small-sized metastasis, Gamma Knife surgery alone is less invasive; local tumor control seems to be as high as after surgery plus WBRT. Distant tumor control, however, is significantly less frequently achieved (after radiosurgery alone). The role of radiosurgical salvage therapy (alternatively to WBRT) for distant tumor control deserves further prospective evaluation.
Journal of Neuro-Oncology 06/2008; 87(3):299-307. · 3.21 Impact Factor
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Int. J. Computer Assisted Radiology and Surgery. 01/2008; 3:447-456.
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ABSTRACT: Optic nerve sheath meningiomas (ONSMs) are benign lesions originating from the dural sheath of the optic nerve. Progressive growth can lead to gradual loss of vision and exophthalmos. Loss of vision following microsurgical resection is not uncommon, and although stereotactic fractionated radiotherapy can be a safe alternative to control tumor growth and preserve vision, it may also lead to complications. Frame-based stereotactic radiosurgery has only been rarely used because single-fraction high-dose treatments of intrinsic optic nerve lesions may induce unacceptably high toxicity. New frameless radiosurgery devices such as the robotic CyberKnife, an image-guided radiosurgery system, can provide the extremely tight conformality and submillimetric accuracy of frame-based systems combined with the possibility of delivering radiation in several sessions. In the present report the authors review the clinical presentation and management of ONSMs and describe their preliminary experience using multisession radiosurgery to treat these lesions.
Neurosurgical FOCUS 02/2007; 23(6):E11. · 2.87 Impact Factor
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ABSTRACT: The authors describe the technical application of the Xsight Spine Tracking System, data pertaining to accuracy obtained during phantom testing, and the initial clinical feasibility of using this fiducial-free alignment system with the CyberKnife in spinal radiosurgery.
The Xsight integrates with the CyberKnife radiosurgery system to eliminate the need for implantation of radiographic markers or fiducials prior to spinal radiosurgery. It locates and tracks spinal lesions relative to spinal osseous landmarks. The authors performed 10 end-to-end tests of accuracy using an anthropomorphic head and cervical spine phantom. Xsight was also used in the treatment of 50 spinal lesions in 42 patients. Dose planning was based on 1.5-mm-thick computed tomography slices in which an inverse treatment planning technique was used. All lesions could be treated using the fiducial-free tracking procedure. Phantom tests produced an overall mean targeting error of 0.52 +/- 0.22 mm. The setup time for patient alignment averaged 6 minutes (range 2-45 minutes). The treatment doses varied from 12 to 25 Gy to the median prescription isodose of 65% (40 to 70%). The tumor volume ranged between 1.3 and 152.8 cm3. The mean spinal cord volume receiving greater than 8 Gy was 0.69 +/- 0.35 cm3. No short-term adverse events were noted during the 1- to 7-month follow-up period. Axial and radicular pain was relieved in 14 of 15 patients treated for pain.
Fiducial-free tracking is a feasible, accurate, and reliable tool for radiosurgery of the entire spine. By eliminating the need for fiducial implantation, the Xsight system offers patients noninvasive radiosurgical intervention for intra- and paraspinal tumors.
Journal of Neurosurgery Spine 11/2006; 5(4):303-12. · 1.53 Impact Factor
