Dose fractionated gamma knife radiosurgery for large arteriovenous malformations on daily or alternate day schedule outside the linear quadratic model: Proof of concept and early results. A substitute to volume fractionation

2017 ◽  
Vol 65 (4) ◽  
pp. 826 ◽  
Author(s):  
KanchanKumar Mukherjee ◽  
Narendra Kumar ◽  
Manjul Tripathi ◽  
ArunS Oinam ◽  
ChiragK Ahuja ◽  
...  
Keyword(s):  
Gamma Knife ◽  
Arteriovenous Malformations ◽  
Gamma Knife Radiosurgery ◽  
Quadratic Model ◽  
Proof Of Concept ◽  
Linear Quadratic ◽  
Linear Quadratic Model ◽  
Early Results

scholarly journals Gamma Knife Radiosurgery: An Overview of Physics, Chemistry, Biology and Neuro-medicine

1970 ◽  
Vol 28 (2) ◽  
pp. 100-112
Author(s):  
KMN Uddin ◽  
JN Islam
Keyword(s):  
Gamma Knife ◽  
Vascular Malformations ◽  
Gamma Knife Radiosurgery ◽  
High Energy ◽  
Quadratic Model ◽  
High Dose ◽  
Linear Quadratic ◽  
Treatment Unit ◽  
Stereotactic Technique ◽  
Living Tissues

The gamma knife is a highly specialized treatment unit thatprovides an advanced sophisticated stereotactic approachto treatment of tumour and vascular malformations withinthe internal structure of the head. The gamma knife deliversa single high dose of radiation emanating from 201 cobalt-60 unit sources. All 201 beam simultaneously intersect atthe same time in a pre-defined location. The treatmentplanning system for gamma knife radiosurgery has beendeveloped using nonlinear programming techniques. Thesystem optimizes the shot sizes, location and weights forgamma knife treatments. Open stereotactic technique in the1990’s was essential for the treatment of a number offunctional conditions and cystic space occupying lesions.It has an important part to play in the investigation oftumours and can help to increase the number which areaccessible to treatment. It can be employed to guide notonly solid instruments but also ionizing irradiation to “masslesion– targets”. It is just this combination of stereotacticguidance and narrow beam, high energy radiation toprecisely defined target, is the basis of gamma kniferadiosurgery . The topic on radiological physics presents abroad field, which includes physics of radiation therapy,diagnosis and nuclear medicine. The emphasis is on thebasic physical principles which form a common foundationfor these areas. Consequently, the topic provides both basicradiation physics, physical aspects of treatment planningand use of radiation beams. Some knowledge of the effectof ionizing radiation on living tissues is necessary, for thosewho wish to understand the nature of any treatment usingradiation and who also wish to inform patients about suchtreatment. The topic relates to the effects of radiation onvisible structures, in other words, cells and tissues. Theradiobiological knowledge described here has beendeveloped in relation to standard radiotherapy. Moreover,the linear quadratic model of cell killing is also applicablefor single dose irradiation.DOI: 10.3329/jbcps.v28i2.5370J Bangladesh Coll Phys Surg 2010; 28: 100-112

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.

Factors related to complete occlusion of arteriovenous malformations after gamma knife radiosurgery

2000 ◽  
Vol 93 (supplement_3) ◽  
pp. 96-101 ◽  
Author(s):  
Jong Hee Chang ◽  
Jin Woo Chang ◽  
Yong Gou Park ◽  
Sang Sup Chung
Keyword(s):  
Gamma Knife ◽  
Arteriovenous Malformations ◽  
Gamma Knife Radiosurgery ◽  
Maximum Diameter ◽  
Content Type ◽  
Complete Occlusion ◽  
Factors Associated ◽  
Martin Grade ◽  
Fine Print

Object. The authors sought to evaluate the effects of gamma knife radiosurgery (GKS) on cerebral arteriovenous malformations (AVMs) and the factors associated with complete occlusion. Methods. A total of 301 radiosurgical procedures for 277 cerebral AVMs were performed between December 1988 and December 1999. Two hundred seventy-eight lesions in 254 patients who were treated with GKS from May 1992 to December 1999 were analyzed. Several clinical and radiological parameters were evaluated. Conclusions. The total obliteration rate for the cases with an adequate radiological follow up of more than 2 years was 78.9%. In multivariate analysis, maximum diameter, angiographically delineated shape of the AVM nidus, and the number of draining veins significantly influenced the result of radiosurgery. In addition, margin radiation dose, Spetzler—Martin grade, and the flow pattern of the AVM nidus also had some influence on the outcome. In addition to the size, topography, and radiosurgical parameters of AVMs, it would seem to be necessary to consider the angioarchitectural and hemodynamic aspects to select proper candidates for radiosurgery.

scholarly journals Simulating Radiotherapy Effect in High-Grade Glioma by Using Diffusive Modeling and Brain Atlases

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Alexandros Roniotis ◽  
Kostas Marias ◽  
Vangelis Sakkalis ◽  
Georgios C. Manikis ◽  
Michalis Zervakis
Keyword(s):  
High Grade Glioma ◽  
Quadratic Model ◽  
Normal Brain ◽  
Linear Quadratic ◽  
Linear Quadratic Model ◽  
Diffusive Model ◽  
Glioma Model ◽  
Modern Application ◽  
Diffusion Tensors ◽  
Brain Atlases

Applying diffusive models for simulating the spatiotemporal change of concentration of tumour cells is a modern application of predictive oncology. Diffusive models are used for modelling glioblastoma, the most aggressive type of glioma. This paper presents the results of applying a linear quadratic model for simulating the effects of radiotherapy on an advanced diffusive glioma model. This diffusive model takes into consideration the heterogeneous velocity of glioma in gray and white matter and the anisotropic migration of tumor cells, which is facilitated along white fibers. This work uses normal brain atlases for extracting the proportions of white and gray matter and the diffusion tensors used for anisotropy. The paper also presents the results of applying this glioma model on real clinical datasets.

scholarly journals Gamma Knife Radiosurgery in Medium-sized Arteriovenous Malformations: Preliminary Report

1996 ◽  
Vol 24 (6) ◽  
pp. 465-473 ◽  
Author(s):  
Masaaki YAMAMOTO ◽  
Mitsunobu IDE ◽  
Minoru JIMBO ◽  
Kintomo TAKAKURA ◽  
Tatsuo HIRAI ◽  
...  
Keyword(s):  
Gamma Knife ◽  
Arteriovenous Malformations ◽  
Preliminary Report ◽  
Gamma Knife Radiosurgery
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