Stereotactic radiation treatment planning and follow-up studies involving fused multimodality imaging

2004 ◽  
Vol 101 (Supplement3) ◽  
pp. 326-333 ◽  
Author(s):  
Klaus D. Hamm ◽  
Gunnar Surber ◽  
Michael Schmücking ◽  
Reinhard E. Wurm ◽  
Rene Aschenbach ◽  
...  
Keyword(s):  
Image Fusion ◽  
Treatment Planning ◽  
Radiation Treatment ◽  
Data Sets ◽  
Slice Thickness ◽  
Radiation Treatment Planning ◽  
Content Type ◽  
Follow Up Studies ◽  
Fine Print

Object. Innovative new software solutions may enable image fusion to produce the desired data superposition for precise target definition and follow-up studies in radiosurgery/stereotactic radiotherapy in patients with intracranial lesions. The aim is to integrate the anatomical and functional information completely into the radiation treatment planning and to achieve an exact comparison for follow-up examinations. Special conditions and advantages of BrainLAB's fully automatic image fusion system are evaluated and described for this purpose. Methods. In 458 patients, the radiation treatment planning and some follow-up studies were performed using an automatic image fusion technique involving the use of different imaging modalities. Each fusion was visually checked and corrected as necessary. The computerized tomography (CT) scans for radiation treatment planning (slice thickness 1.25 mm), as well as stereotactic angiography for arteriovenous malformations, were acquired using head fixation with stereotactic arc or, in the case of stereotactic radiotherapy, with a relocatable stereotactic mask. Different magnetic resonance (MR) imaging sequences (T1, T2, and fluid-attenuated inversion-recovery images) and positron emission tomography (PET) scans were obtained without head fixation. Fusion results and the effects on radiation treatment planning and follow-up studies were analyzed. The precision level of the results of the automatic fusion depended primarily on the image quality, especially the slice thickness and the field homogeneity when using MR images, as well as on patient movement during data acquisition. Fully automated image fusion of different MR, CT, and PET studies was performed for each patient. Only in a few cases was it necessary to correct the fusion manually after visual evaluation. These corrections were minor and did not materially affect treatment planning. High-quality fusion of thin slices of a region of interest with a complete head data set could be performed easily. The target volume for radiation treatment planning could be accurately delineated using multimodal information provided by CT, MR, angiography, and PET studies. The fusion of follow-up image data sets yielded results that could be successfully compared and quantitatively evaluated. Conclusions. Depending on the quality of the originally acquired image, automated image fusion can be a very valuable tool, allowing for fast (∼ 1–2 minute) and precise fusion of all relevant data sets. Fused multimodality imaging improves the target volume definition for radiation treatment planning. High-quality follow-up image data sets should be acquired for image fusion to provide exactly comparable slices and volumetric results that will contribute to quality contol.

Stereotactic radiation treatment planning and follow-up studies involving fused multimodality imaging

2004 ◽  
pp. 326-333 ◽  
Author(s):  
Klaus D. Hamm ◽  
Gunnar Surber ◽  
Michael Schmücking ◽  
Reinhard E. Wurm ◽  
Rene Aschenbach ◽  
...  
Keyword(s):  
Image Fusion ◽  
Treatment Planning ◽  
Radiation Treatment ◽  
Data Sets ◽  
Slice Thickness ◽  
Radiation Treatment Planning ◽  
Content Type ◽  
Follow Up Studies ◽  
Fine Print

Object. Innovative new software solutions may enable image fusion to produce the desired data superposition for precise target definition and follow-up studies in radiosurgery/stereotactic radiotherapy in patients with intracranial lesions. The aim is to integrate the anatomical and functional information completely into the radiation treatment planning and to achieve an exact comparison for follow-up examinations. Special conditions and advantages of BrainLAB's fully automatic image fusion system are evaluated and described for this purpose. Methods. In 458 patients, the radiation treatment planning and some follow-up studies were performed using an automatic image fusion technique involving the use of different imaging modalities. Each fusion was visually checked and corrected as necessary. The computerized tomography (CT) scans for radiation treatment planning (slice thickness 1.25 mm), as well as stereotactic angiography for arteriovenous malformations, were acquired using head fixation with stereotactic arc or, in the case of stereotactic radiotherapy, with a relocatable stereotactic mask. Different magnetic resonance (MR) imaging sequences (T1, T2, and fluid-attenuated inversion-recovery images) and positron emission tomography (PET) scans were obtained without head fixation. Fusion results and the effects on radiation treatment planning and follow-up studies were analyzed. The precision level of the results of the automatic fusion depended primarily on the image quality, especially the slice thickness and the field homogeneity when using MR images, as well as on patient movement during data acquisition. Fully automated image fusion of different MR, CT, and PET studies was performed for each patient. Only in a few cases was it necessary to correct the fusion manually after visual evaluation. These corrections were minor and did not materially affect treatment planning. High-quality fusion of thin slices of a region of interest with a complete head data set could be performed easily. The target volume for radiation treatment planning could be accurately delineated using multimodal information provided by CT, MR, angiography, and PET studies. The fusion of follow-up image data sets yielded results that could be successfully compared and quantitatively evaluated. Conclusions. Depending on the quality of the originally acquired image, automated image fusion can be a very valuable tool, allowing for fast (∼ 1–2 minute) and precise fusion of all relevant data sets. Fused multimodality imaging improves the target volume definition for radiation treatment planning. High-quality follow-up image data sets should be acquired for image fusion to provide exactly comparable slices and volumetric results that will contribute to quality contol.

SPECIAL ASPECTS OF DIAGNOSTIC IMAGING FOR RADIOSURGERY OF ARTERIOVENOUS MALFORMATIONS

Neurosurgery ◽  
2008 ◽  
Vol 62 (suppl_5) ◽  
pp. A44-A52 ◽  
Author(s):  
Klaus D. Hamm ◽  
Joachim Klisch ◽  
Gunnar Surber ◽  
Gabriele Kleinert ◽  
Cornelia Eger ◽  
...  
Keyword(s):  
Image Fusion ◽  
Treatment Planning ◽  
Arteriovenous Malformations ◽  
Target Volume ◽  
Quantitative Comparison ◽  
Wilcoxon Test ◽  
Data Sets ◽  
Fusion Algorithm ◽  
Follow Up Studies

ABSTRACT OBJECTIVE Radiosurgery can be considered a well-established option for the treatment of arteriovenous malformations (AVMs). The exact application of the therapeutic dose is based on the availability of imaging data sets with superior image quality that can be superimposed using an image fusion algorithm. For follow-up studies, the quantitative comparison of the respective image data sets also plays an important role. Until now, digital subtraction angiography (DSA) has been a mandatory tool for treatment planning and follow-up procedures. The aim of this study was to investigate whether a suitable computed tomographic (CT) and/or magnetic resonance (MR) angiography procedure can replace DSA and, if so, in which cases. METHODS For 34 AVM patients, various MR data sets were used together with the stereotactically localized CT and DSA data sets for treatment planning. To define the AVM nidus precisely, all available MR data sets were fused onto the CT data set by the use of an automatic image fusion algorithm. The nidus was outlined in both localized DSA projections, resulting in the DSA target volume. Subsequently, the DSA target volume was adapted by inclusion of the available CT/MR data sets (localized and/or fused, slice by slice), resulting in the final target volume. Finally, both volumes were compared and analyzed. For precise comparison purposes, all available digital follow-up studies were fused. RESULTS In all cases, the thin-slice MR data sets (1-mm slice width) that included T1-weighted series and time of flight angiographies have been precisely fused onto the stereotactically localized treatment planning CT. The final target volume was compared with the DSA target volume as follows. In 19 cases, the final target volume was larger than the DSA target volume; in six cases, it was smaller; and in five cases, it was approximately equal. The difference was significant (Wilcoxon test, difference <0.0001; t test, t = 3.01; P > 0.005). In four cases, outlining the AVM was not possible without DSA. In five patients, a two- or three-vessel DSA was needed because there were different AVM compartments. In cases in which a previous partial embolization had been undergone by the patient, the use of superimposed CT sets with and without contrast medium was important to define the completely embolized partial volumes that were not subject to treatment. The inclusion of the DSA images enabled a better identification of those arterialized veins that did not belong to the nidus. In six cases, the follow-up MR studies showed contrast enhancements overlapping the AVM nidus as a result of brain-blood barrier disturbances (T1-weighted series with contrast). In seven cases, perifocal reactions were primarily observed (T2-weighted series) 12 months after treatment with rather low clinical relevance. CONCLUSION By integrating all available imaging modalities, the exact three-dimensional definition of the AVM nidus was safely realized for all patients. Stereotactic DSA data acquisition remains a crucial tool for safe nidus definition in radiosurgery treatment planning and cannot, therefore, be discarded at present. It is recommended that a quantitative comparison of all MR follow-up studies be established.

Gamma knife radiosurgery as a single treatment modality for large cerebral arteriovenous malformations

2000 ◽  
Vol 93 (supplement_3) ◽  
pp. 113-119 ◽  
Author(s):  
D. Hung-Chi Pan ◽  
Wan-Yuo Guo ◽  
Wen-Yuh Chung ◽  
Cheng-Ying Shiau ◽  
Yue-Cune Chang ◽  
...  
Keyword(s):  
Gamma Knife ◽  
Arteriovenous Malformations ◽  
Radiation Treatment ◽  
Gamma Knife Radiosurgery ◽  
Consecutive Series ◽  
Content Type ◽  
Obliteration Rate ◽  
Complete Obliteration ◽  
Fine Print

Object. A consecutive series of 240 patients with arteriovenous malformations (AVMs) treated by gamma knife radiosurgery (GKS) between March 1993 and March 1999 was evaluated to assess the efficacy and safety of radiosurgery for cerebral AVMs larger than 10 cm3 in volume. Methods. Seventy-six patients (32%) had AVM nidus volumes of more than 10 cm3. During radiosurgery, targeting and delineation of AVM nidi were based on integrated stereotactic magnetic resonance (MR) imaging and x-ray angiography. The radiation treatment was performed using multiple small isocenters to improve conformity of the treatment volume. The mean dose inside the nidus was kept between 20 Gy and 24 Gy. The margin dose ranged between 15 to 18 Gy placed at the 55 to 60% isodose centers. Follow up ranged from 12 to 73 months. There was complete obliteration in 24 patients with an AVM volume of more than 10 cm3 and in 91 patients with an AVM volume of less than 10 cm3. The latency for complete obliteration in larger-volume AVMs was significantly longer. In Kaplan—Meier analysis, the complete obliteration rate in 40 months was 77% in AVMs with volumes between 10 to 15 cm3, as compared with 25% for AVMs with a volume of more than 15 cm3. In the latter, the obliteration rate had increased to 58% at 50 months. The follow-up MR images revealed that large-volume AVMs had higher incidences of postradiosurgical edema, petechiae, and hemorrhage. The bleeding rate before cure was 9.2% (seven of 76) for AVMs with a volume exceeding 10 cm3, and 1.8% (three of 164) for AVMs with a volume less than 10 cm3. Although focal edema was more frequently found in large AVMs, most of the cases were reversible. Permanent neurological complications were found in 3.9% (three of 76) of the patients with an AVM volume of more than 10 cm3, 3.8% (three of 80) of those with AVM volume of 3 to 10 cm3, and 2.4% (two of 84) of those with an AVM volume less than 3 cm3. These differences in complications rate were not significant. Conclusions. Recent improvement of radiosurgery in conjunction with stereotactic MR targeting and multiplanar dose planning has permitted the treatment of larger AVMs. It is suggested that gamma knife radiosurgery is effective for treating AVMs as large as 30 cm3 in volume with an acceptable risk.

Natural history of postoperative aneurysm rests

1987 ◽  
Vol 66 (1) ◽  
pp. 30-34 ◽  
Author(s):  
Isaac Feuerberg ◽  
Christer Lindquist ◽  
Melker Lindqvist ◽  
Ladislau Steiner
Keyword(s):  
Natural History ◽  
Content Type ◽  
Follow Up Studies ◽  
History Of ◽  
Microsurgical Techniques ◽  
Fine Print ◽  
Saccular Aneurysms

✓ In a series of 715 patients operated on by microsurgical techniques for intracranial saccular aneurysms between 1970 and 1980, part of the aneurysmal sac was not obliterated in 28 aneurysms in 27 patients (3.8% of 715 cases). Clinical follow-up evaluation for 8 years (range 4 to 13 years) and angiographic follow-up studies for 6 years (range 2 to 10 years) in these 27 cases revealed that one aneurysm rest increased in size and bled twice, five were spontaneously obliterated, two decreased in size, 13 remained unchanged, and in seven cases no late follow-up angiography was performed. The incidence of rebleeding from an aneurysm rest was 3.7% of the 27 in whom the sac was not obliterated and 0.14% of all 715 patients who were operated on.

Polytetrafluoroethylene interposition grafts in vertebral tocarotid artery transposition

1989 ◽  
Vol 70 (2) ◽  
pp. 212-215 ◽  
Author(s):  
David A. Cavanaugh ◽  
Jim L. Story ◽  
Willis E. Brown ◽  
Lee V. Ansell ◽  
Holger E. I. Skerhut
Keyword(s):  
Myocardial Infarction ◽  
The Other ◽  
Anterior Myocardial Infarction ◽  
Content Type ◽  
Graft Placement ◽  
Follow Up Studies ◽  
Direct Anastomosis ◽  
Cerebrovascular Surgery ◽  
Fine Print

✓ Eight patients undergoing an end-to-side vertebral artery (VA) to common carotid artery transposition between August, 1979, and July, 1982, had a polytetrafluoroethylene (PTFE) interposition graft placed when a direct anastomosis was believed not to be satisfactory. Five of these patients are living; clinical and radiographic follow-up studies over periods ranging between 54 and 82 months show that their transpositions are patent. Two patients died perioperatively, one from an acute anterior myocardial infarction and the other from acute VA occlusion with a propagating thrombus. A third patient died of myocardial infarction 20 months after graft placement; the anastomosis had been found patent at 12 months. This report gives the clinical and radiographic follow-up results in a previously reported group of patients with PTFE interposition grafts. Some of these patients have been followed for over 6 years after surgery: the average radiographic follow-up period in the five survivors is 60 months, and all grafts are patent without evidence of progressive stenosis. Expanded PTFE appears to be an acceptable material for short interposition grafts in operations involving the VA; however, direct artery-to-artery anastomosis is preferred. The results of longer PTFE grafts in reconstructive cerebrovascular surgery have not been adequately studied.

scholarly journals Fundus image fusion in EYEPLAN software: An evaluation of a novel technique for ocular melanoma radiation treatment planning

2010 ◽  
Vol 37 (10) ◽  
pp. 5199-5207 ◽  
Author(s):  
Inder K. Daftari ◽  
Kavita K. Mishra ◽  
Joan M. O'Brien ◽  
Tony Tsai ◽  
Susanna S. Park ◽  
...  
Keyword(s):  
Image Fusion ◽  
Treatment Planning ◽  
Radiation Treatment ◽  
Ocular Melanoma ◽  
Fundus Image ◽  
Radiation Treatment Planning ◽  
Novel Technique

Dynamic and three dimensional transcranial ultrasonography of an arachnoid cyst in the cerebral convexity

2001 ◽  
Vol 94 (4) ◽  
pp. 655-659 ◽  
Author(s):  
Felix Schlachetzki ◽  
Thilo Hoelscher ◽  
Odo-Winfried Ullrich ◽  
Berthold Schalke ◽  
Ulrich Bogdahn
Keyword(s):  
High Resolution ◽  
Arachnoid Cyst ◽  
Three Dimensional ◽  
Reconstruction Algorithm ◽  
Diagnostic Procedures ◽  
Data Sets ◽  
Content Type ◽  
Tension Type Headaches ◽  
Fine Print

✓ Structural imaging of the brain, such as cerebral computerized tomography (CT) and magnetic resonance (MR) imaging, is state-of-the-art. Dynamic transcranial (dTC) ultrasonography and three-dimensional (3D) transcranial color-coded duplex (TCC) ultrasonography are complementary, noninvasive procedures with the capacity for real-time imaging, which may aid in the temporary management of space-occupying lesions. A 16-year-old woman presented with recurrent tension-type headaches. A space-occupying arachnoid cyst in the cerebral convexity was demonstrated on MR images. The patient underwent an examination for raised intracranial pressure, which was performed using a standard color-coded duplex ultrasonography system attached to a personal computer—based system for 3D data acquisition. Transcranial ultrasonography was used to identify the outer arachnoid membrane of the cyst, which undulated freely in response to rotation of the patient's head (headshake maneuver). Three-dimensional data sets were acquired and, using a multiplanar reformatting reconstruction algorithm, the authors obtained high-resolution images that corresponded to the initial MR image and a follow-up cranial CT scan. No detectable differences were observed on dTC or 3D TC ultrasonograms obtained at follow-up examinations performed 9 and 28 months later. Three-dimensional TCC and dTC ultrasonography may complement conventional diagnostic procedures such as MR and CT imaging. This report represents evidence of the high resolution and good reproducibility of 3D TC methods. Ultrasonography is a mobile and inexpensive tool and may be used to improve management and therapeutic strategies for patients with space-occupying brain lesions in selected cases.

Treatment of fractures of the atlas and axis by wiring without fusion

1972 ◽  
Vol 36 (6) ◽  
pp. 773-780 ◽  
Author(s):  
Robert L. McLaurin ◽  
Raul Vernal ◽  
James H. Salmon
Keyword(s):  
Internal Fixation ◽  
Operative Procedure ◽  
Neurological Sequelae ◽  
Content Type ◽  
Bone Fusion ◽  
Follow Up Studies ◽  
Atlas And Axis ◽  
Fine Print

✓ Fractures and dislocations involving C-1 and C-2 vertebrae have usually been treated by prolonged external immobilization or by internal fixation and fusion. This is a report of 12 patients treated by internal fixation by wiring only. Follow-up studies, up to 4 years, demonstrated healing of the bone and no late neurological sequelae. The advantage of internal fixation in reducing hospitalization and immobilization is accepted. The authors believe that in most instances the addition of bone fusion to the operative procedure is not essential and may increase morbidity.

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