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Sukumaran AK, Raghavan RK, Mathew BS, Bhasi S, Koshi SM, Krishna KJ. Comparison of imaging modalities for the accurate delineation of arteriovenous malformations (AVM) and evaluation of setup accuracy with reference to non-invasive LINAC-based stereotactic radiosurgery (SRS). J Cancer Res Ther 2024; 20:874-880. [PMID: 39023594 DOI: 10.4103/jcrt.jcrt_938_21] [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: 06/10/2021] [Accepted: 04/04/2023] [Indexed: 07/20/2024]
Abstract
AIMS To compare the accuracy of nidus delineation using magnetic resonance angiography (MRA) to digital subtraction angiography (DSA) and to evaluate setup accuracy of non-invasive frame SRS treatments. SETTINGS AND DESIGN A prospective observational study of 16 patients who underwent non-invasive frame LINAC-based SRS for brain AVMs. MATERIALS AND METHODS The nidus was separately delineated using DSA and MRA after co-registration onto CT simulation images and compared with respect to their volume and maximum diameters. During treatment, the setup errors observed in x-, y-, and z-directions were recorded. STATISTICAL ANALYSIS Paired t-test (to compare volume and maximum diameter). Wilcoxon signed-rank test (for setup accuracy). RESULTS The mean volume of nidus contoured in MRA was 4.16 cc compared to 3.11 cc in DSA (P 0.297). The mean maximum diameters using MRA and DSA, respectively, in antro-posterior, cranio- caudal, and transverse diameters were 21.97 cc vs. 19.46 cc (P 0.2380), 6.59 cc vs. 9.63 cc (P 0.161), and 18.87 cc vs. 16.81 cc (P 0.178). But these modalities can potentially misinterpret the nidus volume, warranting caution for use of either modality alone. The mean translational shift observed in the x-, y-, and z-directions were 0.06 mm, 0.13 mm, and 0.13 mm, respectively, when couch was brought to neutral position after clockwise couch rotation and 0.07, 0, and 0, respectively, after counterclockwise couch rotation. CONCLUSION This study could not demonstrate any statistically significant differences in nidus delineation between MRA and DSA. Setup accuracy achieved with non-invasive thermoplastic mask-based immobilization is within acceptable limits for SRS.
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Affiliation(s)
- Anju K Sukumaran
- Department of Radiation Oncology, Regional Cancer Centre, Trivandrum, Kerala, India
| | - Rajeev K Raghavan
- Department of Radiation Oncology, Regional Cancer Centre, Trivandrum, Kerala, India
| | - Beela S Mathew
- Department of Radiation Oncology, Regional Cancer Centre, Trivandrum, Kerala, India
| | - Saju Bhasi
- Department of Radiation Physisics, Regional Cancer Centre, Trivandrum, Kerala, India
| | - Sumod M Koshi
- Department of Imageology, Regional Cancer Centre, Trivandrum, Kerala, India
| | - Km Jagathnath Krishna
- Department of Cancer Epidemiology and Bio-Statistics, Regional Cancer Centre, Trivandrum, Kerala, India
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Kitajima M, Uetani H. Arterial Spin Labeling for Pediatric Central Nervous System Diseases: Techniques and Clinical Applications. Magn Reson Med Sci 2023; 22:27-43. [PMID: 35321984 PMCID: PMC9849418 DOI: 10.2463/mrms.rev.2021-0118] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 01/12/2022] [Indexed: 01/28/2023] Open
Abstract
Dynamic susceptibility contrast (DSC) and arterial spin labeling (ASL) are techniques used to evaluate brain perfusion using MRI. DSC requires dynamic image acquisition with a rapid administration of gadolinium-based contrast agent. In contrast, ASL obtains brain perfusion information using magnetically labeled blood water as an endogenous tracer. For the evaluation of brain perfusion in pediatric neurological diseases, ASL has a significant advantage compared to DSC, CT, and single-photon emission CT/positron emission tomography because of the lack of radiation exposure and contrast agent administration. However, in ASL, optimization of several parameters, including the type of labeling, image acquisition, background suppression, and postlabeling delay, is required, because they have a significant effect on the quantification of cerebral blood flow (CBF).In this article, we first review recent technical developments of ASL and age-dependent physiological characteristics in pediatric brain perfusion. We then review the clinical implementation of ASL in pediatric neurological diseases, including vascular diseases, brain tumors, acute encephalopathy with biphasic seizure and late reduced diffusion (AESD), and migraine. In moyamoya disease, ASL can be used for brain perfusion and vessel assessment in pre- and post-treatment. In arteriovenous malformations, ASL is sensitive to detect small degrees of shunt. Furthermore, in vascular diseases, the implementation of ASL-based time-resolved MR angiography is described. In neoplasms, ASL-derived CBF has a high diagnostic accuracy for differentiation between low- and high-grade pediatric brain tumors. In AESD and migraine, ASL may allow for accurate early diagnosis and provide pathophysiological information.
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Affiliation(s)
- Mika Kitajima
- Department of Medical Imaging Sciences, Faculty of Life Sciences, Kumamoto University, Kumamoto, Kumamoto, Japan
| | - Hiroyuki Uetani
- Diagnostic Radiology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Kumamoto, Japan
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Rojas-Villabona A, Sokolska M, Solbach T, Grieve J, Rega M, Torrealdea F, Pizzini FB, De Vita E, Suzuki Y, Van Osch MJP, Biondetti E, Shmueli K, Atkinson D, Murphy M, Paddick I, Golay X, Kitchen N, Jäger HR. Planning of gamma knife radiosurgery (GKR) for brain arteriovenous malformations using triple magnetic resonance angiography (triple-MRA). Br J Neurosurg 2022; 36:217-227. [PMID: 33645357 DOI: 10.1080/02688697.2021.1884649] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
PURPOSE Intra-arterial Digital Subtraction Angiography (DSA) is the gold standard technique for radiosurgery target delineation in brain Arterio-Venous Malformations (AVMs). This study aims to evaluate whether a combination of three Magnetic Resonance Angiography sequences (triple-MRA) could be used for delineation of brain AVMs for Gamma Knife Radiosurgery (GKR). METHODS Fifteen patients undergoing DSA for GKR targeting of brain AVMs also underwent triple-MRA: 4D Arterial Spin Labelling based angiography (ASL-MRA), Contrast-Enhanced Time-Resolved MRA (CE-MRA) and High Definition post-contrast Time-Of-Flight angiography (HD-TOF). The arterial phase of the AVM nidus was delineated on triple-MRA by an interventional neuroradiologist and a consultant neurosurgeon (triple-MRA volume). Triple-MRA volumes were compared to AVM targets delineated by the clinical team for delivery of GKR using the current planning paradigm, i.e., stereotactic DSA and volumetric MRI (DSA volume). Difference in size, degree of inclusion (DI) and concordance index (CcI) between DSA and triple-MRA volumes are reported. RESULTS AVM target volumes delineated on triple-MRA were on average 9.8% smaller than DSA volumes (95%CI:5.6-13.9%; SD:7.14%; p = .003). DI of DSA volume in triple-MRA volume was on average 73.5% (95%CI:71.2-76; range: 65-80%). The mean percentage of triple-MRA volume not included on DSA volume was 18% (95%CI:14.7-21.3; range: 7-30%). CONCLUSION The technical feasibility of using triple-MRA for visualisation and delineation of brain AVMs for GKR planning has been demonstrated. Tighter and more precise delineation of AVM target volumes could be achieved by using triple-MRA for radiosurgery targeting. However, further research is required to ascertain the impact this may have in obliteration rates and side effects.
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Affiliation(s)
- Alvaro Rojas-Villabona
- The Gamma Knife Centre at Queen Square, National Hospital for Neurology and Neurosurgery, London, UK
- Department of Neurosurgery, Royal Victoria Infirmary, Newcastle upon Tyne, UK
| | - Magdalena Sokolska
- Medical Physics and Biomedical Engineering, University College London Hospitals, London, UK
| | - Thomas Solbach
- The Lysholm Department of Neuroradiology, National Hospital for Neurology and Neurosurgery, London, UK
| | - Joan Grieve
- Department of Neurosurgery, National Hospital for Neurology and Neurosurgery, London, UK
| | - Marilena Rega
- Institute of Nuclear Medicine, University College London Hospitals, London, UK
| | | | | | - Enrico De Vita
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK
| | - Yuriko Suzuki
- C. J. Gorter Center for High Field MRI, Department of Radiology, Leiden University Medical Center, Leiden, Netherlands
| | - Matthias J P Van Osch
- C. J. Gorter Center for High Field MRI, Department of Radiology, Leiden University Medical Center, Leiden, Netherlands
| | - Emma Biondetti
- MRI Group, Department of Medical Physics and Biomedical Engineering, University College London, London, UK
| | - Karin Shmueli
- MRI Group, Department of Medical Physics and Biomedical Engineering, University College London, London, UK
| | - David Atkinson
- Centre for Medical Imaging, University College London, London, UK
| | - Mary Murphy
- Department of Neurosurgery, National Hospital for Neurology and Neurosurgery, London, UK
| | - Ian Paddick
- The Gamma Knife Centre at Queen Square, National Hospital for Neurology and Neurosurgery, London, UK
| | - Xavier Golay
- Academic Neuroradiological Unit, Department of Brain Repair and Rehabilitation, Institute of Neurology, University College London, London, UK
| | - Neil Kitchen
- Department of Neurosurgery, National Hospital for Neurology and Neurosurgery, London, UK
| | - Hans Rolf Jäger
- The Lysholm Department of Neuroradiology, National Hospital for Neurology and Neurosurgery, London, UK
- Academic Neuroradiological Unit, Department of Brain Repair and Rehabilitation, Institute of Neurology, University College London, London, UK
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Huang YJ, Hsu SW, Lee TF, Ho JT, Chen WF. Consistency between Targets Delineated by Angiography, Computed Tomography, and Magnetic Resonance Imaging in Stereotactic Radiosurgery for Arteriovenous Malformation. Stereotact Funct Neurosurg 2017; 95:236-242. [DOI: 10.1159/000469667] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Accepted: 03/07/2017] [Indexed: 11/19/2022]
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Ozyurt O, Dincer A, Erdem Yildiz M, Peker S, Yilmaz M, Sengoz M, Ozturk C. Integration of arterial spin labeling into stereotactic radiosurgery planning of cerebral arteriovenous malformations. J Magn Reson Imaging 2017; 46:1718-1727. [DOI: 10.1002/jmri.25690] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Accepted: 02/13/2017] [Indexed: 11/06/2022] Open
Affiliation(s)
- Onur Ozyurt
- Bogazici University; Institute of Biomedical Engineering; Istanbul Turkey
- Acibadem University; Neuroradiology Research Center; Istanbul Turkey
| | - Alp Dincer
- Acibadem University; Neuroradiology Research Center; Istanbul Turkey
- Acibadem University; Department of Radiology, School of Medicine; Istanbul Turkey
| | - Mehmet Erdem Yildiz
- Acibadem University; Neuroradiology Research Center; Istanbul Turkey
- Acibadem University; Department of Radiology, School of Medicine; Istanbul Turkey
| | - Selcuk Peker
- Acibadem University; Department of Neurosurgery, School of Medicine; Istanbul Turkey
| | - Meltem Yilmaz
- Acibadem Kozyatagi Hospital; Department of Radiation Oncology, School of Medicine; Istanbul Turkey
| | - Meric Sengoz
- Acibadem Kozyatagi Hospital; Department of Radiation Oncology, School of Medicine; Istanbul Turkey
| | - Cengizhan Ozturk
- Bogazici University; Institute of Biomedical Engineering; Istanbul Turkey
- Bogazici University; Center for Life Sciences and Technologies; Istanbul Turkey
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Abstract
The use of magnetic resonance imaging (MRI) in radiotherapy (RT) planning is rapidly expanding. We review the wide range of image contrast mechanisms available to MRI and the way they are exploited for RT planning. However a number of challenges are also considered: the requirements that MR images are acquired in the RT treatment position, that they are geometrically accurate, that effects of patient motion during the scan are minimized, that tissue markers are clearly demonstrated, that an estimate of electron density can be obtained. These issues are discussed in detail, prior to the consideration of a number of specific clinical applications. This is followed by a brief discussion on the development of real-time MRI-guided RT.
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Affiliation(s)
- Maria A Schmidt
- Cancer Research UK Cancer Imaging Centre, Royal Marsden Hospital and the Institute of Cancer Research, Downs Road, Sutton, Surrey, SM2 5PT, UK
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Lee CC, Reardon MA, Ball BZ, Chen CJ, Yen CP, Xu Z, Wintermark M, Sheehan J. The predictive value of magnetic resonance imaging in evaluating intracranial arteriovenous malformation obliteration after stereotactic radiosurgery. J Neurosurg 2015; 123:136-44. [DOI: 10.3171/2014.10.jns141565] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT
The current gold standard for diagnosing arteriovenous malformation (AVM) and assessing its obliteration after stereotactic radiosurgery (SRS) is digital subtraction angiography (DSA). Recently, MRI and MR angiography (MRA) have become increasingly popular imaging modalities for the follow-up of patients with an AVM because of their convenient setup and noninvasiveness. In this study, the authors assessed the sensitivity and specificity of MRI/MRA in evaluating AVM nidus obliteration as assessed by DSA.
METHODS
The authors study a consecutive series of 136 patients who underwent SRS between January 2000 and December 2012 and who underwent regular clinical examinations, several MRI studies, and at least 1 post-SRS DSA follow- up evaluation at the University of Virginia. The average follow-up time was 47.3 months (range 10.1–165.2 months). Two blinded observers were enrolled to interpret the results of MRI/MRA compared with those of DSA. The sensitivity, specificity, positive predictive value, and negative predictive value for the obliteration of AVM were reported.
RESULTS
On the basis of DSA, 73 patients (53.7%) achieved final angiographic obliteration in a median of 28.8 months. The sensitivity (the probability of finding obliteration on MRI/MRA among those for whom complete obliteration was shown on DSA) was 84.9% for one observer (Observer 1) and 76.7% for the other (Observer 2). The specificity was 88.9% and 95.2%, respectively. The false-negative interpretations were significantly related to the presence of draining veins, perinidal edema on T2-weighted images, and the interval between the MRI/MRA and DSA studies.
CONCLUSIONS
MRI/MRA predicted AVM obliteration after SRS in most patients and can be used in their follow-up. However, because the specificity of MRI/MRA is not perfect, DSA should still be performed to confirm AVM nidus obliteration after SRS.
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Affiliation(s)
- Cheng-Chia Lee
- Departments of 1Neurological Surgery,
- 4Department of Neurosurgery, Neurological Institute, Taipei Veterans General Hospital
- 5School of Medicine, National Yang-Ming University, Taipei, Taiwan, Republic of China; and
| | - Michael A. Reardon
- 3Radiology & Medical Imaging, Neuroradiology Division, University of Virginia Health System, Charlottesville, Virginia
| | | | | | | | | | - Max Wintermark
- 6Department of Radiology, Stanford University, Palo Alto, California
| | - Jason Sheehan
- Departments of 1Neurological Surgery,
- 2Radiation Oncology, and
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8
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Radiosurgery for unruptured cerebral arteriovenous malformations in pediatric patients. Acta Neurochir (Wien) 2015; 157:281-91. [PMID: 25514868 DOI: 10.1007/s00701-014-2305-4] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2014] [Accepted: 12/03/2014] [Indexed: 10/24/2022]
Abstract
BACKGROUND Unruptured cerebral arteriovenous malformations (AVMs) in pediatric patients (age <18 years) were excluded from A Randomized Trial of Unruptured AVMs (ARUBA). Therefore, the efficacy of radiosurgery for unruptured pediatric AVMs is poorly understood. The goal of this study is to determine the outcomes and define the predictors of obliteration following radiosurgery for unruptured AVMs in pediatric patients. METHODS We evaluated a prospective database, from 1989 to 2013, of AVM patients treated with radiosurgery at our institution. Patients with age less than 18 years at the time of radiosurgery, unruptured nidi, and at least 2 years of radiologic follow-up or AVM obliteration were selected for analysis. Statistical analyses were performed to determine actuarial obliteration rates and identify factors associated with obliteration. RESULTS In the 51 unruptured pediatric AVM patients included for analysis, the median age was 13 years, and the most common presentation was seizure in 53 %. The median nidus volume and radiosurgical margin dose were 3.2 cm(3) and 21.5 Gy, respectively. The median radiologic follow-up was 45 months. The actuarial AVM obliteration rates at 3, 5, and 10 years were 29 %, 54 %, and 72 %, respectively. In the multivariate Cox proportional hazards regression analysis, higher margin dose (P = 0.002), fewer draining veins (P = 0.038), and lower Virginia Radiosurgery AVM Scale (P = 0.003) were independent predictors of obliteration. Obliteration rates were significantly higher with a margin dose of at least 22 Gy (P = 0.003) and for nidi with 2 or fewer draining veins (P = 0.001). The incidences of radiologically evident, symptomatic, and permanent radiation-induced changes were 55 %, 16 %, and 2 %, respectively. The annual post-radiosurgery hemorrhage rate was 1.3 %, and the incidence of post-radiosurgery cyst formation was 2 %. CONCLUSION Radiosurgery affords a favorable risk to benefit profile for unruptured pediatric AVMs. Pediatric patients with unruptured AVMs merit further study to define an optimal management approach.
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Veeravagu A, Hansasuta A, Jiang B, Karim AS, Gibbs IC, Chang SD. Volumetric analysis of intracranial arteriovenous malformations contoured for CyberKnife radiosurgery with 3-dimensional rotational angiography vs computed tomography/magnetic resonance imaging. Neurosurgery 2013; 73:262-70. [PMID: 23615081 DOI: 10.1227/01.neu.0000430285.00928.30] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Accurate target delineation has significant impact on brain arteriovenous malformation (AVM) obliteration, treatment success, and potential complications of stereotactic radiosurgery. OBJECTIVE We compare the nidal contouring of AVMs using fused images of contrasted computed tomography (CT) and magnetic resonance imaging (MRI) with matched images of 3-dimensional (3-D) cerebral angiography for CyberKnife radiosurgery (CKRS) treatment planning. METHODS Between May 2009 and April 2012, 3-D cerebral angiography was integrated into CKRS target planning for 30 consecutive patients. The AVM nidal target volumes were delineated using fused CT and MRI scans vs fused CT, MRI, and 3-D cerebral angiography for each patient. RESULTS The mean volume of the AVM nidus contoured with the addition of 3-D cerebral angiography to the CT/MRI fusion (9.09 cm(3), 95% confidence interval: 5.39 cm(3)-12.8 cm(3)) was statistically smaller than the mean volume contoured with CT/MRI fused scans alone (14.1 cm(3), 95% confidence interval: 9.16 cm(3)-19.1 cm(3)), with a mean volume difference of δ = 5.01 cm(3) (P = .001). Diffuse AVM nidus was associated with larger mean volume differences compared with a compact nidus (δ = 6.51 vs 2.11 cm(3), P = .02). The mean volume difference was not statistically associated with the patient's sex (male δ = 5.61, female δ = 5.06, P = .84), previous hemorrhage status (yes δ = 5.69, no δ = 5.23, P = .86), or previous embolization status (yes δ = 6.80, no δ = 5.95, P = .11). CONCLUSION For brain AVMs treated with CKRS, the addition of 3-D cerebral angiography to CT/MRI fusions for diagnostic accuracy results in a statistically significant reduction in contoured nidal volume compared with standard CT/MRI fusion-based contouring.
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Affiliation(s)
- Anand Veeravagu
- †Departments of Neurological Surgery, Stanford University School of Medicine, Stanford, California; ‡Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California; §Department of Surgery, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
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10
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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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11
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See AP, Raza S, Tamargo RJ, Lim M. Stereotactic radiosurgery of cranial arteriovenous malformations and dural arteriovenous fistulas. Neurosurg Clin N Am 2012; 23:133-46. [PMID: 22107864 DOI: 10.1016/j.nec.2011.09.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
Abstract
Cranial arteriovenous malformations (AVM) and cranial dural arteriovenous fistulas (AVF) carry a significant risk of morbidity and mortality when they hemorrhage. Current treatment options include surgery, embolization, radiosurgery, or a combination of these treatments. Radiosurgery is thought to reduce the risk hemorrhage in AVMs and AVFs by obliterating of the nidus of abnormal vasculature over the course of 2 to 3 years. Success in treating AVMs is variable depending on the volume of the lesion, the radiation dose, and the pattern of vascular supply and drainage. This article discusses the considerations for selecting radiosurgery as a treatment modality in patients who present with AVMs and AVFs.
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Affiliation(s)
- Alfred P See
- Department of Neurosurgery, The Johns Hopkins University, 600 North Wolfe Street, Baltimore, MD 21287, USA
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12
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Buis DR, Bot JCJ, Barkhof F, Knol DL, Lagerwaard FJ, Slotman BJ, Vandertop WP, van den Berg R. The predictive value of 3D time-of-flight MR angiography in assessment of brain arteriovenous malformation obliteration after radiosurgery. AJNR Am J Neuroradiol 2011; 33:232-8. [PMID: 22095967 DOI: 10.3174/ajnr.a2744] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE The purpose of radiosurgery of bAVMs is complete angiographic obliteration of its nidus. We assessed the diagnostic accuracy of 1.5T T2-weighted MR imaging and TOF-MRA images for detecting nidus obliteration after radiosurgery. MATERIALS AND METHODS The pre- and postradiosurgery MR images and DSA images from 120 patients who were radiosurgically treated for a bAVM were re-evaluated by 2 observers for patency of the nidus (preradiosurgery) and obliteration (postradiosurgery: final follow-up MR imaging), by using a 3-point scale of confidence. Consensus reading of the DSA after radiosurgery was considered the criterion standard for obliteration. Sensitivity, specificity, PPVs, and NPVs, and overall diagnostic performance by using ROC were determined. RESULTS Mean bAVM volume during radiosurgery was 3.4 mL (95% CI, 2.6-4.3 mL). Sixty-six patients (55%) had undergone previous endovascular embolization. The mean intervals between radiosurgery and follow-up MR imaging and for DSA, respectively, were 35.6 months (95% CI, 32.3-38.9 months) and 42.1 months (95% CI, 40.3-44.0 months). With ROC, an area under curve of 0.81-0.83 was found. PPVs of final follow-up MR-imaging for definitive obliteration varied between 0.89 [corrected] and 0.95. NPV was 0.52 [corrected] . An average false-positive rate, meaning overestimation of nidus obliteration of 0.10 [corrected] and an average false-negative rate, meaning underestimation of nidus obliteration of 0.42 [corrected] were found. CONCLUSIONS MRA is insufficient to diagnose obliteration in the follow-up of bAVMs after radiosurgery. A remaining nidus diameter <10 mm seems to be the major limiting factor for reliable assessment of obliteration. We highly recommend follow-up DSA for definitive diagnosis of complete obliteration.
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Affiliation(s)
- D R Buis
- Department of Neurosurgery, Neurosurgical Center Amsterdam, VU University Medical Center, Amsterdam, The Netherlands.
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Jameson MG, Holloway LC, Vial PJ, Vinod SK, Metcalfe PE. A review of methods of analysis in contouring studies for radiation oncology. J Med Imaging Radiat Oncol 2011; 54:401-10. [PMID: 20958937 DOI: 10.1111/j.1754-9485.2010.02192.x] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Inter-observer variability in anatomical contouring is the biggest contributor to uncertainty in radiation treatment planning. Contouring studies are frequently performed to investigate the differences between multiple contours on common datasets. There is, however, no widely accepted method for contour comparisons. The purpose of this study is to review the literature on contouring studies in the context of radiation oncology, with particular consideration of the contouring comparison methods they employ. A literature search, not limited by date, was conducted using Medline and Google Scholar with key words: contour, variation, delineation, inter/intra observer, uncertainty and trial dummy-run. This review includes a description of the contouring processes and contour comparison metrics used. The use of different processes and metrics according to tumour site and other factors were also investigated with limitations described. A total of 69 relevant studies were identified. The most common tumour sites were prostate (26), lung (10), head and neck cancers (8) and breast (7).The most common metric of comparison was volume used 59 times, followed by dimension and shape used 36 times, and centre of volume used 19 times. Of all 69 publications, 67 used a combination of metrics and two used only one metric for comparison. No clear relationships between tumour site or any other factors that may influence the contouring process and the metrics used to compare contours were observed from the literature. Further studies are needed to assess the advantages and disadvantages of each metric in various situations.
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Affiliation(s)
- Michael G Jameson
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, Australia.
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Oleaga L, Dalal S, Weigele J, Hurst R, Lee J, Voorhees A, Melhem E. The role of time-resolved 3D contrast-enhanced MR angiography in the assessment and grading of cerebral arteriovenous malformations. Eur J Radiol 2010; 74:e117-21. [DOI: 10.1016/j.ejrad.2009.04.063] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2008] [Accepted: 04/23/2009] [Indexed: 10/20/2022]
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Comparisons of DSA and MR angiography with digital subtraction angiography in 151 patients with subacute spontaneous intracerebral hemorrhage. J Clin Neurosci 2010; 17:601-5. [PMID: 20227278 DOI: 10.1016/j.jocn.2009.09.022] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2009] [Revised: 09/04/2009] [Accepted: 09/13/2009] [Indexed: 01/01/2023]
Abstract
To exclude underlying vascular abnormalities in patients with spontaneous intracerebral hemorrhage, the traditional paradigm requires investigation using digital subtraction angiography (DSA) in both the acute and subacute phases. We investigated whether MRI and magnetic resonance angiography (MRA), in the subacute stage of intracerebral hematoma, had high positive predictive values (PPV) and negative predictive values (NPV) in screening for vascular abnormality in the routine clinical setting. In a regional neurosurgical center in Hong Kong, we retrospectively reviewed 151 patients investigated with both MRI and DSA for underlying structural vascular abnormalities during the subacute phase. Sensitivity, specificity, and intermodality agreement were assessed. A total of 70/151 (46%) vascular lesions accountable for the hemorrhage were found. Patients with vascular abnormalities tended to be younger (mean age+/-standard deviation [SD], 33+/-15years), less likely to be hypertensive (6.3%), and the lesion was more likely to be accompanied by intraventricular hemorrhage (22%). In terms of cerebral arteriovenous malformation and dural arteriovenous fistulas, MRI/MRA had a PPV of 0.98 and a NPV of 1.00. We concluded that MRI/MRA was able to detect most structural vascular abnormalities in the subacute phase in most patients and, thus, its use is recommended as the screening test.
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Wowra B, Muacevic A, Tonn JC, Schoenberg SO, Reiser M, Herrmann KA. Obliteration dynamics in cerebral arteriovenous malformations after cyberknife radiosurgery: quantification with sequential nidus volumetry and 3-tesla 3-dimensional time-of-flight magnetic resonance angiography. Neurosurgery 2009; 64:A102-9. [PMID: 19165066 DOI: 10.1227/01.neu.0000339201.31176.c9] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVE 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. METHODS 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. RESULTS 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. CONCLUSION 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.
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Affiliation(s)
- Berndt Wowra
- European CyberKnife Center, Munich-Grosshadern, Munich, Germany.
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Zhang P, Wu L, Liu T, Kutcher GJ, Isaacson S. Incorporate imaging characteristics into an arteriovenous malformation radiosurgery plan evaluation model. Int J Radiat Oncol Biol Phys 2008; 70:1607-10. [PMID: 18374233 DOI: 10.1016/j.ijrobp.2007.12.022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2007] [Revised: 12/21/2007] [Accepted: 12/23/2007] [Indexed: 11/27/2022]
Abstract
PURPOSE To integrate imaging performance characteristics, specifically sensitivity and specificity, of magnetic resonance angiography (MRA) and digital subtraction angiography (DSA) into arteriovenous malformation (AVM) radiosurgery planning and evaluation. METHODS AND MATERIALS Images of 10 patients with AVMs located in critical brain areas were analyzed in this retrospective planning study. The image findings were first used to estimate the sensitivity and specificity of MRA and DSA. Instead of accepting the imaging observation as a binary (yes or no) mapping of AVM location, our alternative is to translate the image into an AVM probability distribution map by incorporating imagers' sensitivity and specificity, and to use this map as a basis for planning and evaluation. Three sets of radiosurgery plans, targeting the MRA and DSA positive overlap, MRA positive, and DSA positive were optimized for best conformality. The AVM obliteration rate (ORAVM) and brain complication rate served as endpoints for plan comparison. RESULTS In our 10-patient study, the specificities and sensitivities of MRA and DSA were estimated to be (0.95, 0.74) and (0.71, 0.95), respectively. The positive overlap of MRA and DSA accounted for 67.8% +/- 4.9% of the estimated true AVM volume. Compared with plans targeting MRA and DSA-positive overlap, plans targeting MRA-positive or DSA-positive improved ORAVM by 4.1% +/- 1.9% and 15.7% +/- 8.3%, while also increasing the complication rate by 1.0% +/- 0.8% and 4.4% +/- 2.3%, respectively. CONCLUSIONS The impact of imagers' quality should be quantified and incorporated in AVM radiosurgery planning and evaluation to facilitate clinical decision making.
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Affiliation(s)
- Pengpeng Zhang
- Department of Radiation Oncology, Columbia University, New York, NY 10021, USA.
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Geso M, Ackerly T, Brown S, Chua Z, He C, Wong CJ, Powell CE, Ho A, Qiao G, Solomon DH, Patterson W, Droege JM. Determination of dosimetric perturbations caused by aneurysm clip in stereotactic radiosurgery using gel phantoms and EBT-Gafchromic films. Med Phys 2008; 35:744-52. [DOI: 10.1118/1.2828200] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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