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Putz F, Bock M, Schmitt D, Bert C, Blanck O, Ruge MI, Hattingen E, Karger CP, Fietkau R, Grigo J, Schmidt MA, Bäuerle T, Wittig A. Quality requirements for MRI simulation in cranial stereotactic radiotherapy: a guideline from the German Taskforce "Imaging in Stereotactic Radiotherapy". Strahlenther Onkol 2024; 200:1-18. [PMID: 38163834 PMCID: PMC10784363 DOI: 10.1007/s00066-023-02183-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Accepted: 11/06/2023] [Indexed: 01/03/2024]
Abstract
Accurate Magnetic Resonance Imaging (MRI) simulation is fundamental for high-precision stereotactic radiosurgery and fractionated stereotactic radiotherapy, collectively referred to as stereotactic radiotherapy (SRT), to deliver doses of high biological effectiveness to well-defined cranial targets. Multiple MRI hardware related factors as well as scanner configuration and sequence protocol parameters can affect the imaging accuracy and need to be optimized for the special purpose of radiotherapy treatment planning. MRI simulation for SRT is possible for different organizational environments including patient referral for imaging as well as dedicated MRI simulation in the radiotherapy department but require radiotherapy-optimized MRI protocols and defined quality standards to ensure geometrically accurate images that form an impeccable foundation for treatment planning. For this guideline, an interdisciplinary panel including experts from the working group for radiosurgery and stereotactic radiotherapy of the German Society for Radiation Oncology (DEGRO), the working group for physics and technology in stereotactic radiotherapy of the German Society for Medical Physics (DGMP), the German Society of Neurosurgery (DGNC), the German Society of Neuroradiology (DGNR) and the German Chapter of the International Society for Magnetic Resonance in Medicine (DS-ISMRM) have defined minimum MRI quality requirements as well as advanced MRI simulation options for cranial SRT.
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Affiliation(s)
- Florian Putz
- Strahlenklinik, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany.
| | - Michael Bock
- Klinik für Radiologie-Medizinphysik, Universitätsklinikum Freiburg, Freiburg, Germany
| | - Daniela Schmitt
- Klinik für Strahlentherapie und Radioonkologie, Universitätsmedizin Göttingen, Göttingen, Germany
| | - Christoph Bert
- Strahlenklinik, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Oliver Blanck
- Klinik für Strahlentherapie, Universitätsklinikum Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Maximilian I Ruge
- Klinik für Stereotaxie und funktionelle Neurochirurgie, Zentrum für Neurochirurgie, Universitätsklinikum Köln, Cologne, Germany
| | - Elke Hattingen
- Institut für Neuroradiologie, Universitätsklinikum Frankfurt, Frankfurt am Main, Germany
| | - Christian P Karger
- Abteilung Medizinische Physik in der Strahlentherapie, Deutsches Krebsforschungszentrum (DKFZ), Heidelberg, Germany
- Nationales Zentrum für Strahlenforschung in der Onkologie (NCRO), Heidelberger Institut für Radioonkologie (HIRO), Heidelberg, Germany
| | - Rainer Fietkau
- Strahlenklinik, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Johanna Grigo
- Strahlenklinik, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Manuel A Schmidt
- Neuroradiologisches Institut, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Tobias Bäuerle
- Radiologisches Institut, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Andrea Wittig
- Klinik und Poliklinik für Strahlentherapie und Radioonkologie, Universitätsklinikum Würzburg, Würzburg, Germany
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Yuan J, Law SCK, Wong KK, Lo GG, Kam MKM, Kwan WH, Xue C, Wong OL, Yu SK, Cheung KY. 3D T1-weighted turbo spin echo contrast-enhanced MRI at 1.5 T for frameless brain metastases radiotherapy. J Cancer Res Clin Oncol 2021; 148:1749-1759. [PMID: 34363123 DOI: 10.1007/s00432-021-03755-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Accepted: 07/31/2021] [Indexed: 11/27/2022]
Abstract
PURPOSE Performance of 3D-T1W-TSE has been proven superior to 3D-MP-GRE at 3 T on brain metastases (BM) contrast-enhanced (CE) MRI. However, its performance at 1.5 T is largely unknown and sparsely reported. This study aims to assess image quality, lesion detectability and conspicuity of 1.5 T 3D-T1W-TSE on planning MRI of frameless BM radiotherapy. METHODS 94 BM patients to be treated by frameless brain radiotherapy were scanned using 3D-T1W-TSE with immobilization on multi-vendor 1.5 T MRI-simulators. BMs were jointly diagnosed by 4 reviewers. Enhanced lesion conspicuity was quantitatively assessed by calculating contrast ratio (CR) and contrast-to-noise ratio (CNR). Signal-to-noise ratio (SNR) reduction of white matter due to the use of flexible coil was assessed. Lesion detectability and conspicuity were compared between 1.5 T planning MRI and 3 T diagnostic MRI by an oncologist and a radiologist in 10 patients. RESULTS 497 BMs were jointly diagnosed. The CR and CNR were 75.2 ± 39.9% and 14.2 ± 8.1, respectively. SNR reduced considerably from 31.7 ± 8.3 to 21.9 ± 5.4 with the longer distance to coils. 3 T diagnostic MRI and 1.5 T planning MRI yielded exactly the same detection of 84 BMs. Qualitatively, lesion conspicuity at 1.5 T was not inferior to that at 3 T. Quantitatively, lower brain SNR and lesion CNR were found at 1.5 T, while lesion CR at 1.5 T was highly comparable to that at 3 T. CONCLUSION 1.5 T 3D-T1W-TSE planning MRI of frameless BM radiotherapy was comprehensively assessed. Highly comparable BM detectability and conspicuity were achieved by 1.5 T planning MRI compared to 3 T diagnostic MRI. 1.5 T 3D-T1W-TSE should be valuable for frameless brain radiotherapy planning.
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Affiliation(s)
- Jing Yuan
- Medical Physics and Research Department, Hong Kong Sanatorium and Hospital, 8/F, Li Shu Fan Block, 2 Village Road, Happy Valley, Hong Kong SAR, China.
| | - Stephen C K Law
- Comprehensive Oncology Centre, Hong Kong Sanatorium and Hospital, Happy Valley, Hong Kong SAR, China
| | - Ka Kin Wong
- Department of Diagnostic and Interventional Radiology, Hong Kong Sanatorium and Hospital, Happy Valley, Hong Kong SAR, China
| | - Gladys G Lo
- Department of Diagnostic and Interventional Radiology, Hong Kong Sanatorium and Hospital, Happy Valley, Hong Kong SAR, China
| | - Michael K M Kam
- Comprehensive Oncology Centre, Hong Kong Sanatorium and Hospital, Happy Valley, Hong Kong SAR, China
| | - Wing Hong Kwan
- Comprehensive Oncology Centre, Hong Kong Sanatorium and Hospital, Happy Valley, Hong Kong SAR, China
| | - Cindy Xue
- Medical Physics and Research Department, Hong Kong Sanatorium and Hospital, 8/F, Li Shu Fan Block, 2 Village Road, Happy Valley, Hong Kong SAR, China
| | - Oi Lei Wong
- Medical Physics and Research Department, Hong Kong Sanatorium and Hospital, 8/F, Li Shu Fan Block, 2 Village Road, Happy Valley, Hong Kong SAR, China
| | - Siu Ki Yu
- Medical Physics and Research Department, Hong Kong Sanatorium and Hospital, 8/F, Li Shu Fan Block, 2 Village Road, Happy Valley, Hong Kong SAR, China
| | - Kin Yin Cheung
- Medical Physics and Research Department, Hong Kong Sanatorium and Hospital, 8/F, Li Shu Fan Block, 2 Village Road, Happy Valley, Hong Kong SAR, China
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Calusi S, Arilli C, Mussi E, Puggelli L, Farnesi D, Casati M, Compagnucci A, Marrazzo L, Talamonti C, Zani M, Pallotta S. In phantom evaluation of targeting accuracy in MRI-based brain radiosurgery. Phys Med 2021; 85:158-164. [PMID: 34015617 DOI: 10.1016/j.ejmp.2021.05.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 04/06/2021] [Accepted: 05/08/2021] [Indexed: 01/21/2023] Open
Abstract
PURPOSE To determine the targeting accuracy of brain radiosurgery when planning procedures employing different MRI and MRI + CT combinations are adopted. MATERIALS AND METHOD A new phantom, the BrainTool, has been designed and realized to test image co-registration and targeting accuracy in a realistic anatomical situation. The phantom was created with a 3D printer and materials that mimic realistic brain MRI and CT contrast using a model extracted from a synthetic MRI study of a human brain. Eight markers distributed within the BrainTool provide for assessment of the accuracy of image registrations while two cavities that host an ionization chamber are used to perform targeting accuracy measurements with an iterative cross-scan method. Two procedures employing 1.5 T MRI-only or a combination of MRI (taken with 1.5 T or 3 T scanners) and CT to carry out Gamma Knife treatments were investigated. As distortions can impact targeting accuracy, MR images were preliminary evaluated to assess image deformation extent using GammaTool phantom. RESULTS MR images taken with both scanners showed average and maximum distortion of 0.3 mm and 1 mm respectively. The marker distances in co-registered images resulted below 0.5 mm for both MRI scans. The targeting mismatches obtained were 0.8 mm, 1.0 mm and 1.2 mm for MRI-only and MRI + CT (1,5T and 3 T), respectively. CONCLUSIONS Procedures using a combination of MR and CT images provide targeting accuracies comparable to those of MRI-only procedures. The BrainTool proved to be a suitable tool for carrying out co-registration and targeting accuracy of Gamma Knife brain radiosurgery treatments.
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Affiliation(s)
- S Calusi
- Department of Biomedical, Experimental and Clinical Sciences "Mario Serio", University of Florence, Italy; National Institute of Nuclear Physics, Florence, Italy.
| | - C Arilli
- Medical Physics Unit, AOU Careggi, Florence, Italy
| | - E Mussi
- Department of Industrial Engineering, University of Florence, Italy
| | - L Puggelli
- Department of Industrial Engineering, University of Florence, Italy
| | - D Farnesi
- CNR-IFAC, Institute of Applied Physics "N. Carrara", Florence, Italy
| | - M Casati
- Medical Physics Unit, AOU Careggi, Florence, Italy
| | | | - L Marrazzo
- Medical Physics Unit, AOU Careggi, Florence, Italy
| | - C Talamonti
- Department of Biomedical, Experimental and Clinical Sciences "Mario Serio", University of Florence, Italy; National Institute of Nuclear Physics, Florence, Italy; Medical Physics Unit, AOU Careggi, Florence, Italy
| | - M Zani
- Medical Physics Unit, AOU Careggi, Florence, Italy
| | - S Pallotta
- Department of Biomedical, Experimental and Clinical Sciences "Mario Serio", University of Florence, Italy; National Institute of Nuclear Physics, Florence, Italy; Medical Physics Unit, AOU Careggi, Florence, Italy
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Magnetic resonance imaging for brain stereotactic radiotherapy : A review of requirements and pitfalls. Strahlenther Onkol 2020; 196:444-456. [PMID: 32206842 PMCID: PMC7182639 DOI: 10.1007/s00066-020-01604-0] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Accepted: 03/03/2020] [Indexed: 12/29/2022]
Abstract
Due to its superior soft tissue contrast, magnetic resonance imaging (MRI) is essential for many radiotherapy treatment indications. This is especially true for treatment planning in intracranial tumors, where MRI has a long-standing history for target delineation in clinical practice. Despite its routine use, care has to be taken when selecting and acquiring MRI studies for the purpose of radiotherapy treatment planning. Requirements on MRI are particularly demanding for intracranial stereotactic radiotherapy, where accurate imaging has a critical role in treatment success. However, MR images acquired for routine radiological assessment are frequently unsuitable for high-precision stereotactic radiotherapy as the requirements for imaging are significantly different for radiotherapy planning and diagnostic radiology. To assure that optimal imaging is used for treatment planning, the radiation oncologist needs proper knowledge of the most important requirements concerning the use of MRI in brain stereotactic radiotherapy. In the present review, we summarize and discuss the most relevant issues when using MR images for target volume delineation in intracranial stereotactic radiotherapy.
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Park SC, Lee JK, Kim SM, Choi EJ, Lee CS. Systematic Stereotactic Error Reduction Using a Calibration Technique in Single-Brain-Pass and Multitrack Deep Brain Stimulations. Oper Neurosurg (Hagerstown) 2017; 15:72-80. [DOI: 10.1093/ons/opx183] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Accepted: 07/14/2017] [Indexed: 01/16/2023] Open
Affiliation(s)
| | - Jung Kyo Lee
- Department of Neurosurgery, Asan Medical Center, Seoul, Korea
- College of Medicine, University of Ulsan, Seoul, Korea, Seoul, Korea
| | - Seok Min Kim
- Department of Neurology, Asan Medical Center, Seoul, Korea
| | - Eu Jene Choi
- Department of Neurology, Asan Medical Center, Seoul, Korea
| | - Chong Sik Lee
- Department of Neurology, Asan Medical Center, Seoul, Korea
- College of Medicine, University of Ulsan, Seoul, Korea, Seoul, Korea
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Park SC, Lee CS, Kim SM, Choi EJ, Lee JK. Comparison of the Stereotactic Accuracies of Function-Guided Deep Brain Stimulation, Calculated Using Multitrack Target Locations Geometrically Inferred from Three-Dimensional Trajectory Rotations, and of Magnetic Resonance Imaging-Guided Deep Brain Stimulation and Outcomes. World Neurosurg 2017; 98:734-749.e7. [DOI: 10.1016/j.wneu.2016.11.046] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2016] [Revised: 11/08/2016] [Accepted: 11/10/2016] [Indexed: 12/26/2022]
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Park SC, Lee JK, Kim CH, Hong JP, Lee DH. Gamma-knife subcaudate tractotomy for treatment-resistant depression and target characteristics: a case report and review. Acta Neurochir (Wien) 2017; 159:113-120. [PMID: 27900544 DOI: 10.1007/s00701-016-3001-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2016] [Accepted: 10/18/2016] [Indexed: 01/01/2023]
Abstract
Stereotactic subcaudate tractotomy has previously been suggested to be an effective treatment for depression. This is the first study to report the use of gamma-knife subcaudate tractotomy for treatment-resistant depression. A 49-year-old woman with major depressive disorder had been treated for 30 years, with nine suicide attempts during that time. The right and left target maximum diameter was 11 mm within 50 % isodose lines. The target was located more posteriorly and inferiorly than the subgenual cingulate target typically used for deep-brain stimulation. The maximum radiation dose was 130 Gy. During the 4 months after surgery, the patient improved gradually from 23 to 4 according to the Hamilton Rating Scale for Depression and antidepressant medication was discontinued. Target-sized focal lesions were identified and no edema was seen postoperatively. No aggravation or neurologic deficit occurred during the 2.5 years of follow-up. Gamma-knife subcaudate tractotomy for depression is a minimally invasive technique. Investigations of the effectiveness and safety profile in a larger group are warranted.
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Affiliation(s)
- Seong-Cheol Park
- Department of Neurosurgery, Asan Medical Center, 88, Olympic Ro 43-Gil, Songpa-Gu, Seoul, 138-736, Korea
| | - Jung Kyo Lee
- Department of Neurosurgery, Asan Medical Center, 88, Olympic Ro 43-Gil, Songpa-Gu, Seoul, 138-736, Korea.
- College of Medicine, University of Ulsan, 88, Olympic Ro 43-Gil, Songpa-Gu, Seoul, 138-736, Korea.
| | - Chan-Hyung Kim
- Department of Psychiatry, Severance Hospital, Yonsei University, Seoul, Korea
| | - Jin Pyo Hong
- College of Medicine, University of Ulsan, 88, Olympic Ro 43-Gil, Songpa-Gu, Seoul, 138-736, Korea
- Department of Psychiatry, Asan Medical Center, Seoul, Korea
| | - Do Hee Lee
- Department of Neurosurgery, Asan Medical Center, 88, Olympic Ro 43-Gil, Songpa-Gu, Seoul, 138-736, Korea
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Hughes A, Huang Y, Pulkkinen A, Schwartz ML, Lozano AM, Hynynen K. A numerical study on the oblique focus in MR-guided transcranial focused ultrasound. Phys Med Biol 2016; 61:8025-8043. [PMID: 27779134 PMCID: PMC5102068 DOI: 10.1088/0031-9155/61/22/8025] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Recent clinical data showing thermal lesions from treatments of essential tremor using MR-guided transcranial focused ultrasound shows that in many cases the focus is oblique to the main axis of the phased array. The potential for this obliquity to extend the focus into lateral regions of the brain has led to speculation as to the cause of the oblique focus, and whether it is possible to realign the focus. Numerical simulations were performed on clinical export data to analyze the causes of the oblique focus and determine methods for its correction. It was found that the focal obliquity could be replicated with the numerical simulations to within [Formula: see text] of the clinical cases. It was then found that a major cause of the focal obliquity was the presence of sidelobes, caused by an unequal deposition of power from the different transducer elements in the array at the focus. In addition, it was found that a 65% reduction in focal obliquity was possible using phase and amplitude corrections. Potential drawbacks include the higher levels of skull heating required when modifying the distribution of power among the transducer elements, and the difficulty at present in obtaining ideal phase corrections from CT information alone. These techniques for the reduction of focal obliquity can be applied to other applications of transcranial focused ultrasound involving lower total energy deposition, such as blood-brain barrier opening, where the issue of skull heating is minimal.
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Affiliation(s)
- Alec Hughes
- Department of Medical Biophysics, University of Toronto, Toronto, Canada
- Physical Sciences Platform, Sunnybrook Research Institute, Toronto, Canada
| | - Yuexi Huang
- Physical Sciences Platform, Sunnybrook Research Institute, Toronto, Canada
| | - Aki Pulkkinen
- Department of Applied Physics, University of Eastern Finland, Kuopio, Finland
| | - Michael L Schwartz
- Division of Neurosurgery, Department of Surgery, Sunnybrook Health Sciences Centre, Toronto, Canada
| | - Andres M Lozano
- Division of Neurosurgery, Department of Surgery, Krembil Neuroscience Centre, Toronto Western Hospital, Toronto, Canada
| | - Kullervo Hynynen
- Department of Medical Biophysics, University of Toronto, Toronto, Canada
- Physical Sciences Platform, Sunnybrook Research Institute, Toronto, Canada
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Sammartino F, Krishna V, King NKK, Bruno V, Kalia S, Hodaie M, Marras C, Lozano AM, Fasano A. Sequence of electrode implantation and outcome of deep brain stimulation for Parkinson's disease. J Neurol Neurosurg Psychiatry 2016; 87:859-63. [PMID: 26354942 DOI: 10.1136/jnnp-2015-311426] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Accepted: 08/17/2015] [Indexed: 11/03/2022]
Abstract
INTRODUCTION The effect of the variability of electrode placement on outcomes after bilateral deep brain stimulation of subthalamic nucleus has not been sufficiently studied, especially with respect to the sequence of hemisphere implantation. METHODOLOGY We retrospectively analysed the clinical and radiographic data of all the consecutive patients with Parkinson's disease who underwent surgery at our centre and completed at least 1 year follow-up. The dispersion in electrode location was calculated by the square of deviation from population mean, and the direction of deviation was analysed by comparing the intended and final implantation coordinates. Linear regression analysis was performed to analyse the predictors of postoperative improvement of the motor condition, also controlling for the sequence of implanted hemisphere. RESULTS 76 patients (mean age 58±7.2 years) were studied. Compared with the first side, the second side electrode tip had significantly higher dispersion as an overall effect (5.6±21.6 vs 2.2±4.9 mm(2), p=0.04), or along the X-axis (4.1±15.6 vs 1.4±2.4 mm(2), p=0.03) and Z-axis (4.9±11.5 vs 2.9±3.6 mm(2), p=0.02); the second side stimulation was also associated with a lower threshold for side effects (contact 0, p<0.001 and contact 3, p=0.004). In the linear regression analysis, the significant predictors of outcome were baseline activities of daily living (p=0.010) and dispersion of electrode on the second side (p=0.005). CONCLUSIONS We observed a higher dispersion for the electrode on the second implanted side, which also resulted to be a significant predictor of motor outcome at 1 year.
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Affiliation(s)
- Francesco Sammartino
- Division of Neurosurgery, University of Toronto, Toronto Western Hospital, Toronto, Ontario, Canada
| | - Vibhor Krishna
- Division of Neurosurgery, University of Toronto, Toronto Western Hospital, Toronto, Ontario, Canada
| | - Nicolas Kon Kam King
- Division of Neurosurgery, University of Toronto, Toronto Western Hospital, Toronto, Ontario, Canada
| | - Veronica Bruno
- Morton and Gloria Shulman Movement Disorders Clinic and the Edmond J. Safra Program in Parkinson's Disease, Toronto Western Hospital - UHN, Division of Neurology, University of Toronto, Toronto, Ontario, Canada
| | - Suneil Kalia
- Division of Neurosurgery, University of Toronto, Toronto Western Hospital, Toronto, Ontario, Canada
| | - Mojgan Hodaie
- Division of Neurosurgery, University of Toronto, Toronto Western Hospital, Toronto, Ontario, Canada
| | - Connie Marras
- Morton and Gloria Shulman Movement Disorders Clinic and the Edmond J. Safra Program in Parkinson's Disease, Toronto Western Hospital - UHN, Division of Neurology, University of Toronto, Toronto, Ontario, Canada
| | - Andres M Lozano
- Division of Neurosurgery, University of Toronto, Toronto Western Hospital, Toronto, Ontario, Canada
| | - Alfonso Fasano
- Morton and Gloria Shulman Movement Disorders Clinic and the Edmond J. Safra Program in Parkinson's Disease, Toronto Western Hospital - UHN, Division of Neurology, University of Toronto, Toronto, Ontario, Canada
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Higuchi Y, Matsuda S, Serizawa T. Gamma knife radiosurgery in movement disorders: Indications and limitations. Mov Disord 2016; 32:28-35. [DOI: 10.1002/mds.26625] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Revised: 02/29/2016] [Accepted: 03/02/2016] [Indexed: 11/09/2022] Open
Affiliation(s)
- Yoshinori Higuchi
- Department of Neurological Surgery; Chiba University Graduate School of Medicine; Chiba Japan
| | - Shinji Matsuda
- Department of Neurology and Strokology; Chiba Central Medical Center; Chiba Japan
| | - Toru Serizawa
- Tokyo Gamma Unit Center; Tsukiji Neurological Clinic; Tokyo Japan
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Huang KC, Cao Y, Baharom U, Balter JM. Phantom-based characterization of distortion on a magnetic resonance imaging simulator for radiation oncology. Phys Med Biol 2016; 61:774-90. [PMID: 26732744 DOI: 10.1088/0031-9155/61/2/774] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
One of the major issues potentially limiting treatment planning with solely MR images is the possibility of geometric distortion inherent in MR images. We designed a large distortion phantom containing a 3D array of spheres and proposed a three-dimensional (3D) approach to determine the distortion of MR image volume. The approach to overcome partially filled spheres is also presented. The phantom was assembled with a 3D array of spheres filled with contrast and was scanned with a 3T MRI simulator. A 3D whole-sphere or half-sphere template is used to match the image pattern. The half-sphere template is used when the normalized cross-correlation value for the whole-sphere template is below a predetermined threshold. Procrustes method was applied to remove the shift induced by rotation and translation of the phantom. Then the distortion map was generated. Accuracy of the method was verified using CT images of a small phantom of the same design. The analysis of the small phantom showed that the method is accurate with an average offset of estimated sphere center 0.12 ± 0.04 mm. The Procrustes analysis estimated the rotation angle to be 1.95° and 0.01°, respectively, when the phantom was placed at 2° and 0° from the ceiling laser. The analysis showed that on the central plane through the magnet center, the average displacement is less than 1 mm for all radii. At distal planes, when the radius is less than 18 cm, the average displacement is less than 1 mm. However, the average displacement is over 1 mm but still less than 1.5 mm for larger radii. A large distortion phantom was assembled and analysis software was developed to characterize distortions in MRI scans. The use of two templates helps reduce the potential impact of residual air bubbles in some of the spheres.
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Affiliation(s)
- Ke Colin Huang
- Department of Radiation Oncology, University of Michigan Hospital, Ann Arbor, MI 48105, USA. Department of Radiation Oncology, Georgia Regents University, Augusta, GA 30912, USA
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Torrens M, Chung C, Chung HT, Hanssens P, Jaffray D, Kemeny A, Larson D, Levivier M, Lindquist C, Lippitz B, Novotny J, Paddick I, Prasad D, Yu CP. Standardization of terminology in stereotactic radiosurgery: Report from the Standardization Committee of the International Leksell Gamma Knife Society. J Neurosurg 2014; 121 Suppl:2-15. [DOI: 10.3171/2014.7.gks141199] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
ObjectThis report has been prepared to ensure more uniform reporting of Gamma Knife radiosurgery treatment parameters by identifying areas of controversy, confusion, or imprecision in terminology and recommending standards.MethodsSeveral working group discussions supplemented by clarification via email allowed the elaboration of a series of provisional recommendations. These were also discussed in open session at the 16th International Leksell Gamma Knife Society Meeting in Sydney, Australia, in March 2012 and approved subject to certain revisions and the performance of an Internet vote for approval from the whole Society. This ballot was undertaken in September 2012.ResultsThe recommendations in relation to volumes are that Gross Target Volume (GTV) should replace Target Volume (TV); Prescription Isodose Volume (PIV) should generally be used; the term Treated Target Volume (TTV) should replace TVPIV, GTV in PIV, and so forth; and the Volume of Accepted Tolerance Dose (VATD) should be used in place of irradiated volume. For dose prescription and measurement, the prescription dose should be supplemented by the Absorbed Dose, or DV% (for example, D95%), the maximum and minimum dose should be related to a specific tissue volume (for example, D2% or preferably D1 mm3), and the median dose (D50%) should be recorded routinely. The Integral Dose becomes the Total Absorbed Energy (TAE). In the assessment of planning quality, the use of the Target Coverage Ratio (TTV/ GTV), Paddick Conformity Index (PCI = TTV2/[GTV · PIV]), New Conformity Index (NCI = [GTV · PIV]/TTV2), Selectivity Index (TTV/PIV), Homogeneity Index (HI = [D2% –D98%]/D50%), and Gradient Index (GI = PIV0.5/PIV) are reemphasized. In relation to the dose to Organs at Risk (OARs), the emphasis is on dose volume recording of the VATD or the dose/volume limit (for example, V10) in most cases, with the additional use of a Maximum Dose to a small volume (such as 1 mm3) and/or a Point Dose and Mean Point Dose in certain circumstances, particularly when referring to serial organs. The recommendations were accepted by the International Leksell Gamma Knife Society by a vote of 92% to 8%.ConclusionsAn agreed-upon and uniform terminology and subsequent standardization of certain methods and procedures will advance the clinical science of stereotactic radiosurgery.
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Affiliation(s)
- Michael Torrens
- 1Department of Neurosurgery, Hygeia Hospital, Athens, Greece
| | - Caroline Chung
- 2Department of Radiation Oncology, University of Toronto, Ontario, Canada
| | - Hyun-Tai Chung
- 3Department of Neurosurgery, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Patrick Hanssens
- 4Gamma Knife Centre, St. Elizabeth Hospital, Tilburg, The Netherlands
| | - David Jaffray
- 2Department of Radiation Oncology, University of Toronto, Ontario, Canada
| | - Andras Kemeny
- 5National Centre for Stereotactic Radiosurgery, Royal Hallamshire Hospital, Sheffield, United Kingdom
| | - David Larson
- 6Department of Radiation Oncology, University of California, San Francisco, California
| | - Marc Levivier
- 7Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
| | | | - Bodo Lippitz
- 8Gamma Knife Department, Cromwell Hospital, London, United Kingdom
| | - Josef Novotny
- 9Department of Medical Physics, Na Homolce Hospital, Prague, Czech Republic
| | - Ian Paddick
- 8Gamma Knife Department, Cromwell Hospital, London, United Kingdom
| | - Dheerendra Prasad
- 10Departments of Radiation Medicine and Neurosurgery, Roswell Park Cancer Institute, Buffalo, New York; and
| | - Chung Ping Yu
- 11Gamma Knife, Canossa Hospital, Hong Kong, People's Republic of China
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13
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Moutsatsos A, Karaiskos P, Petrokokkinos L, Sakelliou L, Pantelis E, Georgiou E, Torrens M, Seimenis I. Assessment and characterization of the total geometric uncertainty in Gamma Knife radiosurgery using polymer gels. Med Phys 2013; 40:031704. [PMID: 23464299 DOI: 10.1118/1.4789922] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE This work proposes and implements an experimental methodology, based on polymer gels, for assessing the total geometric uncertainty and characterizing its contributors in Gamma Knife (GK) radiosurgery. METHODS A treatment plan consisting of 26, 4-mm GK single shot dose distributions, covering an extended region of the Leksell stereotactic space, was prepared and delivered to a polymer gel filled polymethyl methacrylate (PMMA) head phantom (16 cm diameter) used to accurately reproduce every link in the GK treatment chain. The center of each shot served as a "control point" in the assessment of the GK total geometric uncertainty, which depends on (a) the spatial dose delivery uncertainty of the PERFEXION GK unit used in this work, (b) the spatial distortions inherent in MR images commonly used for target delineation, and (c) the geometric uncertainty contributor associated with the image registration procedure performed by the Leksell GammaPlan (LGP) treatment planning system (TPS), in the case that registration is directly based on the apparent fiducial locations depicted in each MR image by the N-shaped rods on the Leksell localization box. The irradiated phantom was MR imaged at 1.5 T employing a T2-weighted pulse sequence. Four image series were acquired by alternating the frequency encoding axis and reversing the read gradient polarity, thus allowing the characterization of the MR-related spatial distortions. RESULTS MR spatial distortions stemming from main field (B0) inhomogeneity as well as from susceptibility and chemical shift phenomena (also known as sequence dependent distortions) were found to be of the order of 0.5 mm, while those owing to gradient nonlinearities (also known as sequence independent distortions) were found to increase with distance from the MR scanner isocenter extending up to 0.47 mm at an Euclidean distance of 69.6 mm. Regarding the LGP image registration procedure, the corresponding average contribution to the total geometric uncertainty ranged from 0.34 to 0.80 mm. The average total geometric uncertainty, which also includes the GK spatial dose delivery uncertainty, was found equal to (0.88 ± 0.16), (0.88 ± 0.26), (1.02 ± 0.09), and (1.15 ± 0.24) mm for the MR image series acquired with the read gradient polarity (direction) set toward right, left, posterior, and anterior, respectively. CONCLUSIONS The implemented methodology seems capable of assessing the total geometric uncertainty, as well as of characterizing its contributors, ascribed to the entire GK treatment delivery (i.e., from MR imaging to GK dose delivery) for an extended region of the Leksell stereotactic space. Results obtained indicate that the selection of both the frequency encoding axis and the read gradient polarity during MRI acquisition may affect the magnitude as well as the spatial components of the total geometric uncertainty.
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Affiliation(s)
- A Moutsatsos
- Medical Physics Laboratory, Medical School, University of Athens, Athens, Greece
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14
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Takemura A, Sasamoto K, Nakamura K, Kuroda T, Shoji S, Matsuura Y, Matsushita T. [Comparison of image distortion between three magnetic resonance imaging systems of different magnetic field strengths for use in stereotactic irradiation of brain]. Nihon Hoshasen Gijutsu Gakkai Zasshi 2013; 69:641-647. [PMID: 23782776 DOI: 10.6009/jjrt.2013_jsrt_69.6.641] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
In this study, we evaluated the image distortion of three magnetic resonance imaging (MRI) systems with magnetic field strengths of 0.4 T, 1.5 T and 3 T, during stereotactic irradiation of the brain. A quality assurance phantom for MRI image distortion in radiosurgery was used for these measurements of image distortion. Images were obtained from a 0.4-T MRI (APERTO Eterna, HITACHI), a 1.5-T MRI (Signa HDxt, GE Healthcare) and a 3-T MRI (Signa HDx 3.0 T, GE Healthcare) system. Imaging sequences for the 0.4-T and 3-T MRI were based on the 1.5-T MRI sequence used for stereotactic irradiation in the clinical setting. The same phantom was scanned using a computed tomography (CT) system (Aquilion L/B, Toshiba) as the standard. The results showed mean errors in the Z direction to be the least satisfactory of all the directions in all results. The mean error in the Z direction for 1.5-T MRI at -110 mm in the axial plane showed the largest error of 4.0 mm. The maximum errors for the 0.4-T and 3-T MRI were 1.7 mm and 2.8 mm, respectively. The errors in the plane were not uniform and did not show linearity, suggesting that simple distortion correction using outside markers is unlikely to be effective. The 0.4-T MRI showed the lowest image distortion of the three. However, other items, such as image noise, contrast and study duration need to be evaluated in MRI systems when applying frameless stereotactic irradiation.
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Affiliation(s)
- Akihiro Takemura
- Faculty of Health Sciences, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University
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15
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Lotterie JA, Duthil P, Januel AC, Redon A, Menegalli D, Blond S, Latorzeff I. [Stereotactic and diagnostic imaging in radiosurgery]. Cancer Radiother 2012; 16 Suppl:S10-25. [PMID: 22592146 DOI: 10.1016/j.canrad.2011.09.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2011] [Revised: 09/09/2011] [Accepted: 09/29/2011] [Indexed: 10/28/2022]
Abstract
Constant progress in medical imaging and particularly magnetic resonance imaging has profound impact in planning for stereotactic radiosurgery and radiotherapy. The purpose of this paper is to discuss the integration of medical imaging modalities in the planning process. Principles of generic algorithms to calculate stereotactic coordinates are treated for tomographic imaging and digital substraction angiography, and their accuracies are analyzed in a review of the literature. The algorithmic foundations and performance of automatic intermodality co-registration methods are developed. Finally, the MRI sequences useful in planning and follow-up are discussed and the role of MR angiographic sequences compared to conventional X-ray angiography in the particular case of the arteriovenous malformation planning.
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Affiliation(s)
- J-A Lotterie
- Centre régional de radiochirurgie, hôpital Rangueil, CHU de Toulouse, 1 avenue du Professeur-Jean-Poulhès,Toulouse, France .
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16
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Bardinet E, Belaid H, Grabli D, Welter ML, Vidal SF, Galanaud D, Derrey S, Dormont D, Cornu P, Yelnik J, Karachi C. Thalamic stimulation for tremor: Can target determination be improved? Mov Disord 2010; 26:307-12. [DOI: 10.1002/mds.23448] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2010] [Revised: 07/21/2010] [Accepted: 08/25/2010] [Indexed: 11/08/2022] Open
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Abstract
Functional neurosurgery involves precise surgical targeting of anatomic structures to modulate neurologic function. From its conception, advances in the surgical treatment of movement disorders have been intertwined with developments in medical imaging, culminating in the use of stereotactic magnetic resonance imaging (MRI). Meticulous attention to detail during image acquisition, direct anatomic localization, and planning of the initial surgical trajectory allows the surgeon to reach the desired anatomic and functional target with the initial trajectory in most cases, thus reducing the need for multiple passes through the brain, and the associated risk of hemorrhage and functional deficit. This philosophy is of paramount importance in a procedure that is primarily aimed at improving quality of life. Documentation of electrode contact location by means of stereotactic imaging is essential to audit surgical targeting accuracy and to further the knowledge of structure-to-function relationships within the human brain.
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18
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Clinical evaluation of stereotactic target localization using 3-Tesla MRI for radiosurgery planning. Int J Radiat Oncol Biol Phys 2009; 76:1472-9. [PMID: 19515512 DOI: 10.1016/j.ijrobp.2009.03.020] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2008] [Revised: 02/11/2009] [Accepted: 03/19/2009] [Indexed: 11/24/2022]
Abstract
PURPOSE Increasing the magnetic resonance imaging (MRI) field strength can improve image resolution and quality, but concerns remain regarding the influence on geometric fidelity. The objectives of the present study were to spatially investigate the effect of 3-Tesla (3T) MRI on clinical target localization for stereotactic radiosurgery. METHODS AND MATERIALS A total of 39 patients were enrolled in a research ethics board-approved prospective clinical trial. Imaging (1.5T and 3T MRI and computed tomography) was performed after stereotactic frame placement. Stereotactic target localization at 1.5T vs. 3T was retrospectively analyzed in a representative cohort of patients with tumor (n = 4) and functional (n = 5) radiosurgical targets. The spatial congruency of the tumor gross target volumes was determined by the mean discrepancy between the average gross target volume surfaces at 1.5T and 3T. Reproducibility was assessed by the displacement from an averaged surface and volume congruency. Spatial congruency and the reproducibility of functional radiosurgical targets was determined by comparing the mean and standard deviation of the isocenter coordinates. RESULTS Overall, the mean absolute discrepancy across all patients was 0.67 mm (95% confidence interval, 0.51-0.83), significantly <1 mm (p < .010). No differences were found in the overall interuser target volume congruence (mean, 84% for 1.5T vs. 84% for 3T, p > .4), and the gross target volume surface mean displacements were similar within and between users. The overall average isocenter coordinate discrepancy for the functional targets at 1.5T and 3T was 0.33 mm (95% confidence interval, 0.20-0.48), with no patient-specific differences between the mean values (p >.2) or standard deviations (p >.1). CONCLUSION Our results have provided clinically relevant evidence supporting the spatial validity of 3T MRI for use in stereotactic radiosurgery under the imaging conditions used.
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19
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Techavipoo U, Lackey J, Shi J, Leist T, Lai S. Phase labeling using sensitivity encoding (PLUS): Data acquisition and image reconstruction for geometric distortion correction in EPI. Magn Reson Med 2008; 61:650-8. [DOI: 10.1002/mrm.21871] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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20
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Whalen C, Maclin EL, Fabiani M, Gratton G. Validation of a method for coregistering scalp recording locations with 3D structural MR images. Hum Brain Mapp 2008; 29:1288-301. [PMID: 17894391 PMCID: PMC6871211 DOI: 10.1002/hbm.20465] [Citation(s) in RCA: 109] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2007] [Revised: 05/11/2007] [Accepted: 07/12/2007] [Indexed: 11/09/2022] Open
Abstract
A common problem in brain imaging is how to most appropriately coregister anatomical and functional data sets into a common space. For surface-based recordings such as the event related optical signal (EROS), near-infrared spectroscopy (NIRS), event-related potentials (ERPs), and magnetoencephalography (MEG), alignment is typically done using either (1) a landmark-based method involving placement of surface markers that can be detected in both modalities; or (2) surface-fitting alignment that samples many points on the surface of the head in the functional space and aligns those points to the surface of the anatomical image. Here we compare these two approaches and advocate a combination of the two in order to optimize coregistration of EROS and NIRS data with structural magnetic resonance images (sMRI). Digitized 3D sensor locations obtained with a Polhemus digitizer can be effectively coregistered with sMRI using fiducial alignment as an initial guess followed by a Marquardt-Levenberg least-squares rigid-body transform (df = 6) to match the surfaces. Additional scaling parameters (df = 3) and point-by-point surface constraints can also be employed to further improve fitting. These alignment procedures place the lower-bound residual error at 1.3 +/- 0.1 mm (micro +/- s) and the upper-bound target registration error at 4.4 +/- 0.6 mm (micro +/- s). The dependence of such errors on scalp segmentation, number of registration points, and initial guess is also investigated. By optimizing alignment techniques, anatomical localization of surface recordings can be improved in individual subjects.
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Affiliation(s)
- Christopher Whalen
- Beckman Institute, University of Illinois at Urbana‐Champaign, Urbana, Illinois
| | - Edward L. Maclin
- Beckman Institute, University of Illinois at Urbana‐Champaign, Urbana, Illinois
| | - Monica Fabiani
- Beckman Institute, University of Illinois at Urbana‐Champaign, Urbana, Illinois
- Psychology Department, University of Illinois at Urbana‐Champaign, Urbana, Illinois
| | - Gabriele Gratton
- Beckman Institute, University of Illinois at Urbana‐Champaign, Urbana, Illinois
- Psychology Department, University of Illinois at Urbana‐Champaign, Urbana, Illinois
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21
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Feygelman V, Walker L, Chinnaiyan P, Forster K. Simulation of intrafraction motion and overall geometrical accuracy of a frameless intracranial radiosurgery process. J Appl Clin Med Phys 2008; 9:68-86. [PMID: 19020489 PMCID: PMC5722363 DOI: 10.1120/jacmp.v9i4.2828] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2008] [Revised: 06/09/2008] [Accepted: 06/17/2008] [Indexed: 12/25/2022] Open
Abstract
We conducted a comprehensive evaluation of the clinical accuracy of an image-guided frameless intracranial radiosurgery system. All links in the process chain were tested. Using healthy volunteers, we evaluated a novel method to prospectively quantify the range of target motion for optimal determination of the planning target volume (PTV) margin. The overall system isocentric accuracy was tested using a rigid anthropomorphic phantom containing a hidden target. Intrafraction motion was simulated in 5 healthy volunteers. Reinforced head-and-shoulders thermoplastic masks were used for immobilization. The subjects were placed in a treatment position for 15 minutes (the maximum expected time between repeated isocenter localizations) and the six-degrees-of-freedom target displacements were recorded with high frequency by tracking infrared markers. The markers were placed on a customized piece of thermoplastic secured to the head independently of the immobilization mask. Additional data were collected with the subjects holding their breath, talking, and deliberately moving. As compared with fiducial matching, the automatic registration algorithm did not introduce clinically significant errors (<0.3 mm difference). The hidden target test confirmed overall system isocentric accuracy of < or =1 mm (total three-dimensional displacement). The subjects exhibited various patterns and ranges of head motion during the mock treatment. The total displacement vector encompassing 95% of the positional points varied from 0.4 mm to 2.9 mm. Pre-planning motion simulation with optical tracking was tested on volunteers and appears promising for determination of patient-specific PTV margins. Further patient study is necessary and is planned. In the meantime, system accuracy is sufficient for confident clinical use with 3 mm PTV margins.
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Affiliation(s)
- Vladimir Feygelman
- H. Lee Moffitt Cancer Center and Research InstituteDivision of Radiation OncologyTampaFloridaU.S.A.
| | - Luke Walker
- H. Lee Moffitt Cancer Center and Research InstituteDivision of Radiation OncologyTampaFloridaU.S.A.
| | - Prakash Chinnaiyan
- H. Lee Moffitt Cancer Center and Research InstituteDivision of Radiation OncologyTampaFloridaU.S.A.
| | - Kenneth Forster
- H. Lee Moffitt Cancer Center and Research InstituteDivision of Radiation OncologyTampaFloridaU.S.A.
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22
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Massager N, Abeloos L, Devriendt D, Op de Beeck M, Levivier M. Clinical Evaluation of Targeting Accuracy of Gamma Knife Radiosurgery in Trigeminal Neuralgia. Int J Radiat Oncol Biol Phys 2007; 69:1514-20. [PMID: 17689881 DOI: 10.1016/j.ijrobp.2007.05.013] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2006] [Revised: 05/07/2007] [Accepted: 05/07/2007] [Indexed: 11/27/2022]
Abstract
PURPOSE The efficiency of radiosurgery is related to its highly precise targeting. We assessed clinically the targeting accuracy of radiosurgical treatment with the Leksell Gamma Knife for trigeminal neuralgia. We also studied the applied radiation dose within the area of focal contrast enhancement on the trigeminal nerve root following radiosurgery. METHODS AND MATERIALS From an initial group of 78 patients with trigeminal neuralgia treated with gamma knife radiosurgery using a 90-Gy dose, we analyzed a subgroup of 65 patients for whom 6-month follow-up MRI showed focal contrast enhancement of the trigeminal nerve. Follow-up MRI was spatially coregistered to the radiosurgical planning MRI. Target accuracy was assessed from deviation of the coordinates of the intended target compared with the center of enhancement on postoperative MRI. Radiation dose delivered at the borders of contrast enhancement was evaluated. RESULTS The median deviation of the coordinates between the intended target and the center of contrast enhancement was 0.91 mm in Euclidean space. The radiation doses fitting within the borders of the contrast enhancement of the trigeminal nerve root ranged from 49 to 85 Gy (median value, 77 +/- 8.7 Gy). CONCLUSIONS The median deviation found in clinical assessment of gamma knife treatment for trigeminal neuralgia is low and compatible with its high rate of efficiency. Focal enhancement of the trigeminal nerve after radiosurgery occurred in 83% of our patients and was not associated with clinical outcome. Focal enhancement borders along the nerve root fit with a median dose of 77 +/- 8.7 Gy.
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Affiliation(s)
- Nicolas Massager
- Gamma Knife Center and Department of Neurosurgery, University Hospital Erasme, Université Libre de Bruxelles, Brussels, Belgium.
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23
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Stieber V, Robbins M, Balamucki C, deGuzman A, Tatter S, Ekstrand K, McMullen K, Branch C, Shaw E, Bourland JD, Lovato J, Munley M, Ellis T. Determination of a clinical value for the repair half-time (T1/2) of the trigeminal nerve based on outcome data from gamma knife radiosurgery for facial pain. Radiat Res 2007; 168:143-8. [PMID: 17638402 DOI: 10.1667/rr0620.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2006] [Accepted: 03/15/2007] [Indexed: 11/03/2022]
Abstract
Stereotactic radiosurgery (GKRS) using the Leksell Gamma Knife is a treatment option for patients with trigeminal pain. We analyzed a database of 326 GKRS procedures performed over 4.6 years at three discrete dose levels commonly described in the published literature. Logistic regression was used to model the logit of response as a function of treatment time. The resulting coefficient was converted to an estimated probability of response for the shortest and longest treatment times in clinical practice. The two estimated probabilities were then compared to yield the estimated difference in the biologically effective dose (BED) between the two doses, using a modified linear-quadratic model for stereotactic radiosurgery. This difference was used to back-calculate a clinical value for T(1/2), resulting in a range of 1.28-1.77 h for T(1/2). The biological model appeared to accurately predict that, given the doses and treatment times used in general clinical practice, there would be no significant difference in clinical outcome.
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Affiliation(s)
- Volker Stieber
- Radiation Oncology, Wake Forest University School of Medicine, Winston-Salem, NC 27157-1030, USA.
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24
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Atlas computarizado para la planificación de neurocirugías estereotácticas funcionales guiadas por imágenes. Neurocirugia (Astur) 2007. [DOI: 10.1016/s1130-1473(07)70254-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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25
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Allison RR, Gay HA, Mota HC, Sibata CH. Image-guided radiation therapy: current and future directions. Future Oncol 2006; 2:477-92. [PMID: 16922615 DOI: 10.2217/14796694.2.4.477] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Since its discovery, ionizing radiation has been a cornerstone of cancer treatment. In step with technological advances, radiation therapy has strived to increase its therapeutic ratio. With the advent of 3D and cross-sectional imaging, and the ability to modulate the radiation beam, the current age of radiation oncology was initiated, promising better tumor control rates with fewer side effects. However, these ever more precise and conformal treatments have also revealed the importance of accounting for organ and tumor motion. Efforts to understand and compensate for the uncertainties caused by movement are required to ensure accurate conformal radiation therapy. This review will explore the current and future directions of image-guided radiation therapy, whose goal is to increase the accuracy of radiotherapy.
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Affiliation(s)
- Ron R Allison
- The Brody School of Medicine at East Carolina University, Department of Radiation Oncology, 600 Moye Blvd, Greenville, NC 27858-4354, USA.
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26
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Cernica G, Wang Z, Malhotra H, de Boer S, Podgorsak MB. Investigation of gamma knife image registration errors resulting from misalignment between the patient and the imaging axis. Med Phys 2006; 33:941-3. [PMID: 16696470 DOI: 10.1118/1.2179751] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
The ability of Leksell GammaPlan to perform stereotactic space localizations with image sets where there is misalignment of the patient's head (stereotactic frame and fiducial apparatus) relative to the computed tomography (CT) scanner coordinate system was studied. Misalignment is sometimes necessary for patient comfort. Results equally apply to magnetic resonance imaging. Seven 0.5 mm diameter CT-visible spheres were rigidly mounted to a string tied tightly at each end to diagonally opposite posts attached to a Leksell stereotactic frame. A standard CT fiducial box was applied to the frame in the usual clinical manner. A baseline CT scan (1 mm slice thickness) was obtained with the fiducial box perfectly aligned with the scanner axis. After localization of the image set, the (x,y,z) coordinate of the center of each sphere was recorded. Repeat CT scans with varying fiducial box misalignments with the imaging axis were subsequently obtained. The mean difference between the base line and the respective coordinates in misaligned geometries was approximately 0.2 mm (sigma=0.2 mm), well within the accuracy of the image sets and the delivery of radiosurgery with the Gamma Knife.
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Affiliation(s)
- George Cernica
- Department of Physics, State University of New York, Buffalo, New York 14260, USA
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27
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Lightstone AW, Benedict SH, Bova FJ, Solberg TD, Stern RL. Intracranial stereotactic positioning systems: Report of the American Association of Physicists in Medicine Radiation Therapy Committee Task Group No. 68. Med Phys 2005; 32:2380-2398. [PMID: 16121596 DOI: 10.1118/1.1945347] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2005] [Revised: 04/14/2005] [Accepted: 05/11/2005] [Indexed: 11/07/2022] Open
Abstract
Intracranial stereotactic positioning systems (ISPSs) are used to position patients prior to precise radiation treatment of localized lesions of the brain. Often, the lesion is located in close proximity to critical anatomic features whose functions should be maintained. Many types of ISPSs have been described in the literature and are commercially available. These are briefly reviewed. ISPS systems provide two critical functions. The first is to establish a coordinate system upon which a guided therapy can be applied. The second is to provide a method to reapply the coordinate system to the patient such that the coordinates assigned to the patient's anatomy are identical from application to application. Without limiting this study to any particular approach to ISPSs, this report introduces nomenclature and suggests performance tests to quantify both the stability of the ISPS to map diagnostic data to a coordinate system, as well as the ISPS's ability to be realigned to the patient's anatomy. For users who desire to develop a new ISPS system, it may be necessary for the clinical team to establish the accuracy and precision of each of these functions. For commercially available systems that have demonstrated an acceptable level of accuracy and precision, the clinical team may need to demonstrate local ability to apply the system in a manner consistent with that employed during the published testing. The level of accuracy and precision required of an individual ISPS system is dependent upon the clinical protocol (e.g., fractionation, margin, pathology, etc.). Each clinical team should provide routine quality assurance procedures that are sufficient to support the assumptions of accuracy and precision used during the planning process. The testing of ISPS systems can be grouped into two broad categories, type testing, which occurs prior to general commercialization, and site testing, performed when a commercial system is installed at a clinic. Guidelines to help select the appropriate tests as well as recommendations to help establish the required frequency of testing are provided. Because of the broad scope of different systems, it is important that both the manufacturer and user rigorously critique the system and set QA tests appropriate to the particular device and its possible weaknesses. Major recommendations of the Task Group include: introduction of a new nomenclature for reporting repositioning accuracy; comprehensive analysis of patient characteristics that might adversely affect positioning accuracy; performance of testing immediately before each treatment to establish that there are no gross positioning errors; a general request to the Medical Physics community for improved QA tools; implementation of weekly portal imaging (perhaps cone beam CT in the future) as a method of tracking fractionated patients (as per TG 40); and periodic routine reviews of positioning accuracy.
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Affiliation(s)
- A W Lightstone
- Department of Medical Physics, Toronto-Sunnybrook Regional Cancer Centre, Toronto, Ontario M4N 3M5, Canada.
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28
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Doran SJ, Charles-Edwards L, Reinsberg SA, Leach MO. A complete distortion correction for MR images: I. Gradient warp correction. Phys Med Biol 2005; 50:1343-61. [PMID: 15798328 DOI: 10.1088/0031-9155/50/7/001] [Citation(s) in RCA: 170] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
MR images are known to be distorted because of both gradient nonlinearity and imperfections in the B0 field, the latter caused either by an imperfect shim or sample-induced distortions. This paper describes in detail a method for correcting the gradient warp distortion, based on a direct field mapping using a custom-built phantom with three orthogonal grids of fluid-filled rods. The key advance of the current work over previous contributions is the large volume of the mapping phantom and the large distortions (>25 mm) corrected, making the method suitable for use with large field of view, extra-cranial images. Experimental measurements on the Siemens AS25 gradient set, as installed on a Siemens Vision scanner, are compared with a theoretical description of the gradient set, based on the manufacturer's spherical harmonic coefficients. It was found that over a volume of 320x200x340 mm3 distortions can be successfully mapped to within the voxel resolution of the raw imaging data, whilst outside this volume, correction is still good but some systematic errors are present. The phenomenon of through-plane distortion (also known as 'slice warp') is examined in detail, and the perturbation it causes to the measurements is quantified and corrected. At the very edges of the region of support provided by the phantom, through-plane distortion is extreme and only partially corrected by the present method. Solutions to this problem are discussed. Both phantom and patient data demonstrate the efficacy of the gradient warp correction.
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Affiliation(s)
- Simon J Doran
- Department of Physics, University of Surrey, Guildford, Surrey, GU2 7XH, UK.
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29
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Mack A, Wolff R, Scheib S, Rieker M, Weltz D, Mack G, Kreiner HJ, Pilatus U, Zanella FE, Böttcher HD, Seifert V. Analyzing 3-tesla magnetic resonance imaging units for implementation in radiosurgery. J Neurosurg 2005; 102 Suppl:158-64. [PMID: 15662802 DOI: 10.3171/jns.2005.102.s_supplement.0158] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT The limiting factor affecting accuracy during gamma knife surgery is image quality. The new generation of magnetic resonance (MR) imaging units with field strength up to 3 teslas promise superior image quality for anatomical resolution and contrast. There are, however, questions about chemical shifts or susceptibility effects, which are the subject of this paper. METHODS The 3-tesla MR imaging unit (Siemens Trio) was analyzed and compared with a 1-tesla unit (Siemens Magnetom Expert) and to a 1.5-tesla unit (Philips Gyroscan). Evaluation of the magnitude of error was performed within transverse slices in two orientations (axial/coronal) by using a cylindrical phantom with an embedded grid. Deviations were determined for 21 targets in a slab phantom with known geometrical positions within the stereotactic frame. Distortions caused by chemical shift and/or susceptibility effects were analyzed in a head phantom. Inhouse software was used for data analyses. The mean deviation was less than 0.3 mm in axial and less than 0.4 mm in coronal orientations. For the known targets the maximum deviation was 1.16 mm. By optimizing these parameters in the protocol these inaccuracies could be reduced to less than 1.1 mm. Due to inhomogeneities a shift in the z direction of up to 1.5 mm was observed for a dataset, which was shown to be compressed by 1.2 mm. CONCLUSIONS The 3-tesla imaging unit showed superior anatomical contrast and resolution in comparison with the established 1-tesla and 1.5-tesla units; however, due to the high field strength the field within the head coil is very sensitive to inhomogeneities and therefore 3-tesla imaging data will have be handled with care.
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Mack A, Wolff R, Scheib S, Rieker M, Weltz D, Mack G, Kreiner HJ, Pilatus U, Zanella FE, Böttcher HD, Seifert V. Analyzing 3-tesla magnetic resonance imaging units for implementation in radiosurgery. J Neurosurg 2005. [DOI: 10.3171/sup.2005.102.s_supplement.0158] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Object. The limiting factor affecting accuracy during gamma knife surgery is image quality. The new generation of magnetic resonance (MR) imaging units with field strength up to 3 teslas promise superior image quality for anatomical resolution and contrast. There are, however, questions about chemical shifts or susceptibility effects, which are the subject of this paper.
Methods. The 3-tesla MR imaging unit (Siemens Trio) was analyzed and compared with a 1-tesla unit (Siemens Magnetom Expert) and to a 1.5-tesla unit (Philips Gyroscan). Evaluation of the magnitude of error was performed within transverse slices in two orientations (axial/coronal) by using a cylindrical phantom with an embedded grid. Deviations were determined for 21 targets in a slab phantom with known geometrical positions within the stereotactic frame. Distortions caused by chemical shift and/or susceptibility effects were analyzed in a head phantom. Inhouse software was used for data analyses.
The mean deviation was less than 0.3 mm in axial and less than 0.4 mm in coronal orientations. For the known targets the maximum deviation was 1.16 mm. By optimizing these parameters in the protocol these inaccuracies could be reduced to less than 1.1 mm. Due to inhomogeneities a shift in the z direction of up to 1.5 mm was observed for a dataset, which was shown to be compressed by 1.2 mm.
Conclusions. The 3-tesla imaging unit showed superior anatomical contrast and resolution in comparison with the established 1-tesla and 1.5-tesla units; however, due to the high field strength the field within the head coil is very sensitive to inhomogeneities and therefore 3-tesla imaging data will have be handled with care.
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Rohlfing T, Maurer CR, Dean D, Maciunas RJ. Effect of changing patient position from supine to prone on the accuracy of a Brown-Roberts-Wells stereotactic head frame system. Neurosurgery 2003; 52:610-8; discussion 617-8. [PMID: 12590686 DOI: 10.1227/01.neu.0000048727.65969.36] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2002] [Accepted: 09/22/2002] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVE Despite the growing popularity of frameless image-guided surgery systems, stereotactic frame systems are widely accepted by neurosurgeons and are commonly used to perform biopsies, functional procedures, and stereotactic radiosurgery. We investigated the accuracy of the Brown-Roberts-Wells stereotactic frame system when the mechanical load on the frame changes between preoperative imaging and the intervention because of different patient position: supine during imaging, prone during intervention. METHODS We analyzed computed tomographic images acquired from 14 patients who underwent stereotactic biopsy, deep brain stimulator implantation, or radiosurgery. Two images were acquired for each patient, one with the patient in the supine position and one in the prone position. The prone images were registered to the respective supine images by use of an intensity-based registration algorithm, once using only the frame and once using only the head. The difference between the transformations produced by these two registrations describes the movement of the patient's head with respect to the frame. RESULTS The maximum frame-based registration error between the supine and prone positions was 2.8 mm; it was more than 2 mm in two patients and more than 1.5 mm in six patients. Anteroposterior translation is the dominant component of the difference transformation for most patients. In general, the magnitude of the movement increased with brain volume, which is an index of head weight. CONCLUSION To minimize frame-based registration error caused by a change in the mechanical load on the frame, stereotactic procedures should be performed with the patient in the identical position during imaging and intervention.
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Affiliation(s)
- Torsten Rohlfing
- Department of Neurosurgery, Stanford University, Stanford, California 94305-5327, USA
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Castilla JM, Martín V, Fernández-Arconada O, Delgado P, Rodríguez-Salazar A. Primeros pasos en neuronavegación. Neurocirugia (Astur) 2003; 14:398-408. [PMID: 14603387 DOI: 10.1016/s1130-1473(03)70519-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
INTRODUCTION We try to evaluate the introduction of a neuronavigation system widely used in a neurosurgical department. MATERIAL AND METHODS We analyze the surgical procedures performed since the introduction of a neuronavigator in our hospital, the advantages and the problems related with its use. RESULTS From 21/12/00 to 31/12/01, 64 cranial and 5 spinal procedures were performed in our centre with the aid of the BrainLAB neuronavigation system. They were 19.37% of the elective surgeries: 45.7% of cranial and 2.8% of spinal procedures. The accuracy of registration was 1.6 mm; the number of trials for registration was 2.8 on average, although in 3 cases it was not possible; there were disarrangements during 9 surgical procedures (two of them after the lesions were reached). Magnetic resonance imaging (MRI) was used in 54 instances, computerized tomography (CT) in 5, fluoroscopy (Rx) in 1, CT plus MRI in 8, CT plus Rx in 1. Since Z-Touch localization system and software was available, it was used exclusively, disregarding the use of external fiducials. DISCUSSION AND CONCLUSIONS In our experience, neuronavigation needs extra time, but it helps in the election of the best position for the surgical approach, reduces the time required for scalp incision and craniotomy planning, and is useful for the opening of the dura and the corticectomy. As the operation proceeds, we found it less truhstworthy and necessary. The Z-touch system frees the imaging from the surgery. Its use in spinal operation is scarce and with limited results in our practice. We found the neuronavigation useful, and we employ it on a regular basis in every cranial procedure whenever it is possible.
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Affiliation(s)
- J M Castilla
- Servicio de Neurocirugía. Hospital General Yague. Burgos, Spain
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Keep MF, Mastrofrancesco L, Erdman D, Murphy B, Ashby LS. Gamma knife subthalamotomy for Parkinson disease: the subthalamic nucleus as a new radiosurgical target. J Neurosurg 2002. [DOI: 10.3171/jns.2002.97.supplement_5.0592] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
✓ The authors present the neuroimaging, treatment planning, and radiosurgical technique for the first reported case of unilateral radiosurgical subthalamotomy, which was performed to control motor symptoms associated with advanced Parkinson disease (PD) in a patient who had undergone previous contralateral radiofrequency (RF) pallidotomy.
A 73-year-old woman with end-stage PD had undergone RF pallidotomy of the right globus pallidus with resolution of symptoms. Two years following this procedure, due to the natural progression of her disease, she suffered recurrent motor fluctuations, dyskinesia, and worsening bradykinesia of the right side. Her Parkinson's Disease Disability Rating (PDDR) score was 28. Computerized tomography and magnetic resonance (MR) imaging were used to localize the left subthalamic nucleus (STN). The patient underwent gamma knife radiosurgery—a single shot of 120 Gy was administered using the 4-mm collimator helmet.
The patient was evaluated up to 42 months after the procedure. The dyskinesia became minimal. Right-sided motor control improved as did her balance. At 3 months after treatment MR imaging demonstrated the radiosurgical lesion in the left STN. At 3.5 years postradiosurgery, she experienced minimal focal (oral) dyskinesia, no bradykinesia or rigidity, and her PDDR score was 11.
Radiosurgery of the STN in this case was safe and effective. The STN is a readily localized anatomical target with neuroimaging. Radiosurgery avoids the risks of open procedures.
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St. George EJ, Butler P, Plowman PN. Can magnetic resonance imaging alone accurately define the arteriovenous nidus for gamma knife radiosurgery? J Neurosurg 2002. [DOI: 10.3171/jns.2002.97.supplement_5.0464] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Object. Current radiosurgical treatment of arteriovenous malformations (AVMs) relies on planning protocols that integrate data from both magnetic resonance (MR) imaging and stereotactic angiography studies. Angiography, however, is invasive and associated with a small but well-defined risk of neurological and systemic complications. Magnetic resonance imaging, on the other hand, is noninvasive with multiplanar capability, demonstrates good anatomical detail, and has been shown to be superior to angiography in the delineation of selected AVMs.
Methods. In this study, MR imaging—related accuracy of defining the AVM nidus in gamma knife radiosurgery is investigated using only T1- and T2-weighted sequences.
Conclusions. Little interobserver variability was observed and AVM nidi, as demonstrated on T1- and T2-weighted MR images, were well correlated in terms of size. The displacement of the new target, however, from the original nidus, was not predictable and occasionally was significant, thus precluding safe radiosurgical planning.
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Andrews DW, Suarez O, Goldman HW, Downes MB, Bednarz G, Corn BW, Werner-Wasik M, Rosenstock J, Curran WJ. Stereotactic radiosurgery and fractionated stereotactic radiotherapy for the treatment of acoustic schwannomas: comparative observations of 125 patients treated at one institution. Int J Radiat Oncol Biol Phys 2001; 50:1265-78. [PMID: 11483338 DOI: 10.1016/s0360-3016(01)01559-0] [Citation(s) in RCA: 268] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
BACKGROUND Stereotactic radiosurgery (SRS) and, more recently, fractionated stereotactic radiotherapy (SRT) have been recognized as noninvasive alternatives to surgery for the treatment of acoustic schwannomas. We review our experience of acoustic tumor treatments at one institution using a gamma knife for SRS and the first commercial world installation of a dedicated linac for SRT. METHODS Patients were treated with SRS on the gamma knife or SRT on the linac from October 1994 through August 2000. Gamma knife technique involved a fixed-frame multiple shot/high conformality single treatment, whereas linac technique involved daily conventional fraction treatments involving a relocatable frame, fewer isocenters, and high conformality established by noncoplanar arc beam shaping and differential beam weighting. RESULTS Sixty-nine patients were treated on the gamma knife, and 56 patients were treated on the linac, with 1 NF-2 patient common to both units. Three patients were lost to follow-up, and in the remaining 122 patients, mean follow-up was 119 +/- 67 weeks for SRS patients and 115 +/- 96 weeks for SRT patients. Tumor control rates were high (> or =97%) for sporadic tumors in both groups but lower for NF-2 tumors in the SRT group. Cranial nerve morbidities were comparably low in both groups, with the exception of functional hearing preservation, which was 2.5-fold higher in patients who received conventional fraction SRT. CONCLUSION SRS and SRT represent comparable noninvasive treatments for acoustic schwannomas in both sporadic and NF-2 patient groups. At 1-year follow-up, a significantly higher rate of serviceable hearing preservation was achieved in SRT sporadic tumor patients and may therefore be preferable to alternatives including surgery, SRS, or possibly observation in patients with serviceable hearing.
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Affiliation(s)
- D W Andrews
- Department of Neurosurgery, Thomas Jefferson University Hospital-Wills Neurosensory Institute, Philadelphia, PA 19107, USA
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Yu C, Petrovich Z, Apuzzo MLJ, Luxton G. An image fusion study of the geometric accuracy of magnetic resonance imaging with the Leksell stereotactic localization system. J Appl Clin Med Phys 2001; 2:42-50. [PMID: 11674837 PMCID: PMC5726018 DOI: 10.1120/jacmp.v2i1.2627] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2000] [Accepted: 10/04/2000] [Indexed: 11/23/2022] Open
Abstract
A special acrylic phantom designed for both magnetic resonance imaging (MRI) and computed tomography (CT) was used to assess the geometric accuracy of MRI-based stereotactic localization with the Leksell stereotactic head frame and localizer system. The acrylic phantom was constructed in the shape of a cube, 164 mm in each dimension, with three perpendicular arrays of solid acrylic rods, 5 mm in diameter and spaced 30 mm apart within the phantom. Images from two MR scanners and a CT scanner were obtained with the same Leksell head frame placement. Using image fusion provided by the Leksell GammaPlan (LGP) software, the coordinates of the intraphantom rod positions from two MRI scanners were compared to that of CT imaging. The geometric accuracy of MR images from the Siemens scanner was greatly improved after the implementation of a special software patch provided by the manufacturer. In general, much better accuracy was achieved in the transverse plane where images were acquired. Most distortion was found around the periphery while least distortion was present in the middle and most other parts of the phantom. For most intracranial lesions undergoing stereotactic radiosurgery, accuracy of target localization can be achieved within size of a voxel, especially with the Siemens scanner. However, extra caution should be taken for imaging of peripheral lesions where the distortion is the greatest.
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Affiliation(s)
- Cheng Yu
- Department of Radiation Oncology (CY, ZP), Department of Neurosurgery (MLJA)University of Southern California, Keck School of Medicine1441 Eastlake AvenueLos AngelesCalifornia90033
| | - Zbigniew Petrovich
- Department of Radiation Oncology (CY, ZP), Department of Neurosurgery (MLJA)University of Southern California, Keck School of Medicine1441 Eastlake AvenueLos AngelesCalifornia90033
| | - Michael L. J. Apuzzo
- Department of Radiation Oncology (CY, ZP), Department of Neurosurgery (MLJA)University of Southern California, Keck School of Medicine1441 Eastlake AvenueLos AngelesCalifornia90033
| | - Gary Luxton
- Department of Radiation OncologyStanford University School of MedicineStanfordCalifornia94305
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Vayssiere N, Hemm S, Zanca M, Picot MC, Bonafe A, Cif L, Frerebeau P, Coubes P. Magnetic resonance imaging stereotactic target localization for deep brain stimulation in dystonic children. J Neurosurg 2000; 93:784-90. [PMID: 11059658 DOI: 10.3171/jns.2000.93.5.0784] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT The actual distortion present in a given series of magnetic resonance (MR) images is difficult to establish. The purpose of this study was to validate an MR imaging-based methodology for stereotactic targeting of the internal globus pallidus during electrode implantation in children in whom general anesthesia had been induced. METHODS Twelve children (mean follow up 1 year) suffering from generalized dystonia were treated with deep brain stimulation by using a head frame and MR imaging. To analyze the influence of distortions at every step of the procedure, the geometrical characteristics of the frame were first controlled using the localizer as a phantom. Then pre- and postoperative coordinates of fixed anatomical landmarks and electrode positions, both determined with the head frame in place, were statistically compared. No significant difference was observed between theoretical and measured dimensions of the localizer (Student's t-test, ¿t¿ > 2.2 for 12 patients) in the x, y, and z directions. No significant differences were observed (Wilcoxon paired-sample test) between the following: 1) pre- and postoperative coordinates of the anterior commissure (AC) (deltax = 0.3+/-0.29 mm and deltay = 0.34+/-0.32 mm) and posterior commissure (PC) (deltax = 0.15+/-0.18 mm and deltay = 0.34+/-0.25 mm); 2) pre- and postoperative AC-PC distance (deltaL = 0.33+/-0.22 mm); and 3) preoperative target and final electrode position coordinates (deltax = 0.24+/-0.22 mm; deltay = 0.19+/-0.16 mm). CONCLUSIONS In the authors' center, MR imaging distortions did not induce detectable errors during stereotactic surgery in dystonic children. Target localization and electrode implantation could be achieved using MR imaging alone after induction of general anesthesia. The remarkable postoperative improvement in these patients confirmed the accuracy of the procedure (Burke-Marsden-Fahn Dystonia Rating Scale score delta = -83.8%).
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Affiliation(s)
- N Vayssiere
- Department of Pediatric Neurosurgery, University Hospital, Montpellier, France
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Bednarz G, Downes B, Werner-Wasik M, Rosenwasser RH. Combining stereotactic angiography and 3D time-of-flight magnetic resonance angiography in treatment planning for arteriovenous malformation radiosurgery. Int J Radiat Oncol Biol Phys 2000; 46:1149-54. [PMID: 10725625 DOI: 10.1016/s0360-3016(99)00530-1] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
PURPOSE This study was initiated to evaluate the advantages of using three-dimensional time-of-flight magnetic resonance angiography (3D TOF MRA), as an adjuvant to conventional stereotactic angiography, in obtaining three-dimensional information about an arteriovenous malformation (AVM) nidus and in optimizing radiosurgical treatment plans. METHODS AND MATERIALS Following angiography, contrast-enhanced MRI and MRA studies were obtained in 22 consecutive patients undergoing Gamma Knife radiosurgery for AVM. A treatment plan was designed, based on the angiograms and modified as necessary, using the information provided by MRA. The quantitative analysis involved calculation of the ratio of the treated volume to the MRA nidus volume (the tissue volume ratio [TVR]) for the initial and final treatment plans. RESULTS In 12 cases (55%), the initial treatment plans were modified after including the MRA information in the treatment planning process. The mean TVR for the angiogram-based plans was 1.63 (range 1.17-2.17). The mean coverage of the MRA nidus by the angiogram-based plans was 93% (range 73-99%). The mean MRA nidus volume was 2.4 cc (range 0. 6-5.3 cc). The MRA-based modifications resulted in increased conformity with the mean TVR of 1.46 (range 1.20-1.74). These modifications were caused by MRA revealing irregular nidi and/or vascular components superimposed on the angiographic projections of the nidi. In a number of cases, the information from MRA was essential in defining the nidus when the projections of the angiographic outlines showed different superior and/or inferior extent of the nidus. In two cases, MRA revealed irregular nidi, correlating well with the angiograms and showed that the angiographically acceptable plans undertreated 27% of the MRA nidus in one case and 18% of the nidus in the other case. In the remaining 10 cases (45%), both MRI and MRA failed to detect the nidus due to surgical clip artifacts and the presence of embolizing glue. CONCLUSIONS The 3D TOF MRA provided information on irregular AVM shape, which was not visualized by angiography alone, and it was superior to MRI for defining the AVM nidus. However, when imaging artifacts obscured the AVM nidus on MRI and MRA, angiography permitted detection of AVM. Utilizing MRA as a complementary imaging modality to angiography increased accuracy of the AVM radiosurgery and allowed for optimal dose planning.
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Affiliation(s)
- G Bednarz
- Department of Radiation Oncology, Kimmel Cancer Center of the Jefferson Medical College, Thomas Jefferson University, Philadelphia, PA, USA.
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